EP1807015A2 - Methods and apparatuses for manufacturing dental aligners - Google Patents

Methods and apparatuses for manufacturing dental aligners

Info

Publication number
EP1807015A2
EP1807015A2 EP05825468A EP05825468A EP1807015A2 EP 1807015 A2 EP1807015 A2 EP 1807015A2 EP 05825468 A EP05825468 A EP 05825468A EP 05825468 A EP05825468 A EP 05825468A EP 1807015 A2 EP1807015 A2 EP 1807015A2
Authority
EP
European Patent Office
Prior art keywords
physical
tooth
model
base
arch
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP05825468A
Other languages
German (de)
French (fr)
Inventor
Huafeng Wen
Frank Zhenhuan Liu
Gang Liu
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Align Technology Inc
Original Assignee
Align Technology Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US10/979,824 external-priority patent/US20060093993A1/en
Priority claimed from US10/979,504 external-priority patent/US20060093987A1/en
Priority claimed from US10/979,497 external-priority patent/US20060093982A1/en
Priority claimed from US10/979,823 external-priority patent/US7384266B2/en
Priority claimed from US11/013,154 external-priority patent/US7309230B2/en
Priority claimed from US11/013,152 external-priority patent/US7922490B2/en
Priority claimed from US11/012,924 external-priority patent/US20060127850A1/en
Priority claimed from US11/013,159 external-priority patent/US20060127860A1/en
Priority claimed from US11/013,157 external-priority patent/US20060127858A1/en
Priority claimed from US11/013,155 external-priority patent/US7293988B2/en
Priority claimed from US11/013,145 external-priority patent/US8636513B2/en
Priority claimed from US11/013,160 external-priority patent/US7435084B2/en
Priority claimed from US11/013,158 external-priority patent/US20060127859A1/en
Priority claimed from US11/013,156 external-priority patent/US20060127857A1/en
Priority claimed from US11/050,126 external-priority patent/US7335024B2/en
Priority claimed from US11/074,299 external-priority patent/US20060199145A1/en
Priority claimed from US11/074,301 external-priority patent/US20060199142A1/en
Priority claimed from US11/258,465 external-priority patent/US20070092853A1/en
Application filed by Align Technology Inc filed Critical Align Technology Inc
Publication of EP1807015A2 publication Critical patent/EP1807015A2/en
Withdrawn legal-status Critical Current

Links

Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61C—DENTISTRY; APPARATUS OR METHODS FOR ORAL OR DENTAL HYGIENE
    • A61C9/00—Impression cups, i.e. impression trays; Impression methods
    • A61C9/002—Means or methods for correctly replacing a dental model, e.g. dowel pins; Dowel pin positioning means or methods
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61C—DENTISTRY; APPARATUS OR METHODS FOR ORAL OR DENTAL HYGIENE
    • A61C9/00—Impression cups, i.e. impression trays; Impression methods
    • A61C9/004—Means or methods for taking digitized impressions
    • A61C9/0046—Data acquisition means or methods
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61C—DENTISTRY; APPARATUS OR METHODS FOR ORAL OR DENTAL HYGIENE
    • A61C9/00—Impression cups, i.e. impression trays; Impression methods
    • A61C9/004—Means or methods for taking digitized impressions
    • A61C9/0046—Data acquisition means or methods
    • A61C9/008—Mechanical means or methods, e.g. a contact probe moving over the teeth

Definitions

  • Orthodontics is the practice of manipulating a patient's teeth to provide better function and appearance.
  • brackets are bonded to a patient's teeth and coupled together with an arched wire.
  • the combination of the brackets and wire provide a force on the teeth causing them to move.
  • the body adapts bone and the surrounding soft-tissue to maintain the teeth in the desired location.
  • a patient may be fitted with a retainer.
  • orthodontists utilize their expertise to first determine a three-dimensional mental image of the patient's physical orthodontic structure and a three-dimensional mental image of a desired physical orthodontic structure for the patient, which may be assisted through the use of X-rays and/or models. Based on these mental images, the orthodontist further relies on his/her expertise to place the brackets and/or bands on the teeth and to manually bend (i.e., shape) wire, such that a force is asserted on the teeth to reposition the teeth into the desired physical orthodontic structure.
  • the orthodontist makes continual judgments as to the progress of the treatment, plans next steps in the treatment (e.g., determine new bend in the wire, reposition or replace brackets, decide whether a head gear is required, etc.), and evaluates the success of the previous steps.
  • plans next steps in the treatment e.g., determine new bend in the wire, reposition or replace brackets, decide whether a head gear is required, etc.
  • evaluates the success of the previous steps e.g., the orthodontist makes manual adjustments to the wire and/or replaces or repositions brackets based on his or her expert opinion.
  • orthodontic treatment is an iterative process requiring multiple wire changes, with the process success and speed being very much dependent on the orthodontist's motor skills and diagnostic expertise. As a result of multiple wire changes, patient discomfort is increased as well as the cost. As one would expect, the quality of care varies greatly from orthodontist to orthodontist as does the amount of time required to treat a patient.
  • the practice of orthodontics and other dental treatments including preparation of a denture can benefit from a computer model that is representative of the position of the teeth in a tooth arch.
  • the computer model may be prepared based on an impression model taken from the patient.
  • the computer model may be utilized to assist the dentist in planning an orthodontic treatment regimen by providing visual feedback of possible treatment steps in particular treatment regimen.
  • the computer modeling tool may be useful in designing and manufacturing removable aligning appliances for orthodontic treatment.
  • an impression model of the dentition of the patient is obtained by the orthodontist and shipped to a remote appliance manufacturing center, where information regarding the patient's teeth is captured by a computer.
  • a computer model of the dentition in a target situation is generated at the appliance manufacturing center and made available for viewing to the orthodontist over the Internet.
  • the orthodontist indicates changes he or she wishes to make to individual tooth positions.
  • another virtual model may be provided over the Internet and the orthodontist reviews the revised model, and indicates any further changes. After one or more of such iterations, the target situation is agreed upon.
  • One or more of the removable aligning appliances e.g., devices, shells, etc
  • the appliances move the teeth toward the desired or target positions.
  • Repositioning is accomplished with a series of appliances configured to receive the teeth in a cavity and incrementally reposition individual teeth in a series of at least three successive steps, usually including at least four successive steps, often including at least ten steps, sometimes including at least twenty-five steps, and occasionally including forty or more steps. Most often, the methods and systems will reposition teeth in from ten to twenty-five successive treatment steps, although complex cases involving many of the patient's teeth may take forty or more steps.
  • the successive use of a number of such appliances permits each appliance to be configured to move individual teeth in small increments.
  • the movements provided by successive appliances will usually not be the same for any particular tooth. Thus, one point on a tooth may be moved by a particular distance as a result of the use of one appliance and thereafter moved by a different distance and/or in a different direction by a later appliance.
  • the individual appliances include a polymeric shell having the teeth- receiving cavity formed therein, typically by molding as described below.
  • Each individual appliance will be configured so that its tooth-receiving cavity has a geometry corresponding to an intermediate or end tooth arrangement intended for that appliance. That is, when an appliance is first worn by the patient, certain of the teeth will be misaligned relative to an undeformed geometry of the appliance cavity.
  • the appliance is sufficiently resilient to accommodate or conform to the misaligned teeth, and will apply sufficient resilient force against such misaligned teeth in order to reposition the teeth to the intermediate or end arrangement desired for that treatment step.
  • Aligners have been fabricated from molds created using a stereo lithography process.
  • the materials used by stereo lithography processes may be toxic and harmful to human health.
  • the stereo lithography process builds the aligner mold layer by layer and thus causes the resulting aligners to have a step-like spacing between the layers. Such spacing has a tendency to house germs and bacteria while it is worn by a patient.
  • the stereo lithography process requires creation of a different aligner mold at each stage of the treatment. The process can be costly and produces waste, which is environmental unfriendly.
  • individual physical tooth models are created and then arranged into a tooth arch to serve as the underlying template for fabricating a dental aligner.
  • a registration feature may be implemented on each of the physical tooth models to track the positions of the individual physical tooth models relative to the other tooth models in the tooth arch.
  • a computer can be utilized to determine and/or record a position of a registration feature for each of the teeth in a patient's tooth arch. These recorded positions of the registration features may be altered to represent a tooth arch having a modified teeth arrangement.
  • a physical tooth arch having the modified tooth arrangement can be built on the base. For example, this modified tooth arch may represent the target tooth arch at one stage of an orthodontic treatment process.
  • a polymeric sheet may then be formed over the physical tooth arch model to create a dental aligner.
  • positions for the registration features are determined based on either a negative impression or a positive model of a patient's tooth arch.
  • the positions of the registration features By tracking the positions of the registration features, the relative position between the teeth in a given tooth arch can be ascertained.
  • information regarding the registration features can be mapped from the digital space into the physical space and vice versa.
  • the positions of the registration features are mapped onto a base plate by creating receptacles that are organized according to the positions of the registration features.
  • the base plate can then be utilized to receive the individual physical tooth models, each of which has a corresponding registration mark, and form a physical tooth arch that reflects the arrangement of the teeth in the digital tooth arch model.
  • Various methods and/or apparatus that can be utilized within the process of building physical and/or digital dental models are also disclosed herein. These methods and apparatus include casting physical models, acquiring positions of physical tooth models in a tooth arch, creating a base for receiving physical tooth models, adjusting positions of tooth models on a base using adjustment jigs, digitizing tooth models, predicting and preventing interference between tooth models, constructing a physical dental arch model using CNC, and constructing a dental aligner using CNC.
  • FIG. 1 is a flow chart for producing a dental aligner in one variation.
  • FIG. 2 is a perspective view of a casting chamber that may be used to cast a dental arch in one variation.
  • FIG. 3 illustrates a base plate for a dental arch attached to a casting chamber lid according to one variation.
  • FIG. 4 illustrates the use of a position measurement device to measure the locations and/or orientations of features in a negative impression of a dental arch according to one variation.
  • FIG. 5 illustrates a base plate having sockets by which physical tooth models may be attached to form a dental arch according to one variation.
  • FIG. 6 illustrates sockets formed in a recess in a base plate according to one variation.
  • FIG. 7 illustrates a base plate attached to the lid of a casting chamber and placed over the casting chamber so that pins attached to the base plate are positioned within a negative impression of a tooth arch according to one variation.
  • FIG. 8 illustrates a positive mold of a patient's tooth arch according to one variation.
  • FIG. 9 illustrates individual physical tooth models separated from the positive mold of FIG. 8 according to one variation.
  • FlG. 1OA illustrates a scanning system used to digitize physical tooth models according to one variation.
  • FIG. 1 OB illustrates a top view of physical tooth models mounted to a scan plate in the scanning system of FIG. 1OA according to one variation.
  • FIG. 1OC illustrates a side view of physical tooth models mounted to a scan plate in the scanning system of FIG. 1OA according to one variation.
  • FIG. 11 illustrates a physical tooth model mounted to a scan plate in the scanning system of FIG. 1OA by inserting pins on the tooth model into sockets in the scan plate according to one variation.
  • FIG. 12 illustrates examples of graphic projections of the individual digital representations of physical tooth models according to one variation.
  • FIG. 13 illustrates a digital representation of a tooth arch generated from the digital representations of individual tooth models shown in FIG. 12 according to one variation.
  • FIG. 14 illustrates a digital scan of a complete tooth arch superimposed over a digital model of a tooth arch generated from combining digital representations of individual teeth according to one variation.
  • FIG. 15 illustrates a graphical projection of a digital arch tooth arch model into which simulated roots have been incorporated according to one variation.
  • FIG. 16 illustrates roots being created for individual digital tooth models according to one variation.
  • FIG. 17 illustrates generation of a digital tooth arch model from individual digital tooth models comprising crowns and roots according to one variation.
  • FIG. 18 illustrates a digital model of a tooth arch in which the position and/or orientation of one of the teeth (shaded for emphasis) has been modified according to one variation.
  • FIG. 19 illustrates a digital model of a removable alignment appliance created based on the digital model of a modified tooth arch of FIG. 18 according to one variation.
  • FIG. 20 illustrates a removable alignment appliance created based on the digital model of FIG. 19 according to one variation.
  • FIG. 21 illustrates a base plate configured to receive physical tooth models to form a physical tooth arch that corresponds to the digital model of a modified tooth arch of FIG. 18 according to one variation.
  • FIG. 22 illustrates a physical model of a modified tooth arch that corresponds to the digital model of a modified tooth arch of FIG. 18 according to one variation.
  • FIG. 23 illustrates a physical tooth model attached by pins to sockets in a recessed portion of a base plate according to one variation.
  • the pins, surface of the recess, and bottom surface of the tooth model are angled with respect to the surface of the base plate.
  • FIG. 24 illustrates a polymeric sheet being placed over a physical model of a modified tooth arch for heat and vacuum formation of a removable aligner according to one variation.
  • FIG. 25 illustrates a removable aligner formed from the set-up of FIG. 24 according to one variation.
  • FIG. 26 illustrates a removable after excess material has been trimmed away according to one variation.
  • FIG. 27 illustrates a base plate configured for receiving multiple sets of physical tooth models for forming four separate physical arch models according to one variation.
  • FIG. 28 illustrates the base plate of FIG. 17 with physical tooth models attached to form four separate physical arch models according to one variation.
  • FIG. 29A is a flow chart for producing a dental aligner in one variation.
  • FIG. 29B is a flow chart for producing a dental aligner in one variation.
  • FIG. 30 is a flow chart for producing a physical dental arch model in accordance with one variation.
  • FIG. 31 illustrates a tooth model and a base respectively comprising complimentary features for assembling the tooth model with the base according to one variation.
  • FIG. 32 illustrates fixing a stud to a tooth model comprising a female socket to produce a tooth model having a protruded stud according to one variation.
  • FIG. 33 illustrates a tooth model comprising two pins that allow the tooth model to be plugged into two corresponding holes in a base according to one variation.
  • FIG. 34 illustrates a tooth model comprising a protruded pin that allows the tooth model to be plugged into a hole in a base according to one variation.
  • FIG. 35 illustrates cone shaped studs protruded out of the bottom of a tooth model according to one variation.
  • FIG. 36 illustrates example shapes for the studs at the bottom of a tooth model according to one variation.
  • FIG. 37A illustrates an example of a base comprising a plurality of female sockets for receiving a plurality of tooth models for forming a physical dental arch model according to one variation.
  • FIG. 37B illustrates another example of a base comprising a plurality of female sockets for receiving a plurality of tooth models for forming a physical dental arch model according to one variation.
  • FIG. 38 illustrates a tooth model that can be assembled to the base in FIG.
  • FIG. 39 illustrates a laser cutting system for fabricating features in a base for receiving tooth models according to one variation.
  • FIG. 40 illustrates a base comprising multiple sets of sockets for receiving a plurality of dental arches in different configurations according to one variation.
  • FIG. 41 is a flow chart for producing a physical dental arch model in accordance with one variation.
  • FIG. 42 illustrates an example of a mechanical location device for acquiring the coordinates of the physical tooth models according to one variation.
  • FIG. 43 is a flow chart for producing a physical dental arch model in accordance with one variation.
  • FIG. 44 illustrates an example of an optical location device for acquiring the coordinates of the physical tooth models according to one variation.
  • FIG. 45 is a flow chart for producing a physical dental arch model in accordance with one variation.
  • FIGS. 46A - 46D illustrate adjustment jigs that are capable of providing different positional and rotational adjustment for tooth models according to one variation.
  • FIG. 47 illustrates another arrangement of adjustment jigs for rotational adjustment of tooth models according to one variation.
  • FIG. 48 illustrates adjustment jigs for different increments of translational adjustments according to one variation.
  • FIG. 49 shows a rotational adjustment jig mounted on top of a translational adjustment jig according to one variation.
  • FIG. 50 shows a jig having a universal joint mounted on a translation stage according to one variation.
  • FIG. 51 is a flow chart for producing a physical dental arch model in accordance with one variation.
  • FIG. 52 illustrates an example in which the pins at the bottom portions of two adjacent tooth models interfere with each other.
  • FIG. 53 illustrates an example in which two adjacent tooth models mounted on a base interfere with each other at the tooth portions of the tooth models.
  • FIG. 54 illustrates a tooth model having pin configurations that prevent the tooth models from interfering with each other according to one variation.
  • FIG. 55 A is a front view of two tooth models having pin configurations of
  • FIG. 54 according to one variation.
  • FIG. 55B is a perspective bottom view of two tooth models having pin configurations of FIG. 54 according to one variation.
  • FIG. 56 illustrates a mechanism for fixing tooth models to a base using removable pins according to one variation.
  • FIG. 57 illustrates a mechanism for fixing tooth models to a base using spring-loaded pins to prevent interference between tooth models according to one variation.
  • FIG. 58 illustrates a mechanism for fixing tooth models to a base using spring-loaded pins to prevent interference between tooth models according to one variation.
  • FIG. 59 illustrates a mechanism for fixing tooth models to a base using spring-loaded pins to prevent interference between tooth models according to one variation.
  • FIG. 60 illustrates an exemplary flow chart for producing a physical dental arch model.
  • FIG. 61 illustrates a tooth model and a base respectively comprising complimentary features for assembling the tooth model with the base.
  • FIG. 62 illustrates fixing a stud to a tooth model comprising a female socket to produce a tooth model having a protruded stud.
  • FIG. 63 illustrates a tooth model comprising two pins that allow the tooth model to be plugged into two corresponding holes in a base.
  • FIG. 64 illustrates a tooth model comprising a protruded pin that allows the tooth model to be plugged into a hole in a base.
  • FIG. 65 illustrates cone shaped studs protruded out of the bottom of a tooth model.
  • FIG. 66 illustrates exemplified shapes for the studs at the bottom of a tooth model.
  • FIG. 67A illustrates an example of a base comprising a plurality of female sockets for receiving a plurality of tooth models for forming a physical dental arch model.
  • FIG. 67B illustrates another example of a base comprising a plurality of female sockets for receiving a plurality of tooth models for forming a physical dental arch model.
  • FIG. 68 illustrates a tooth model that can be assembled to the base in FIG.
  • FIG. 69 illustrates an exploded top perspective view of a casting chamber, a chamber lid, and a base for casting a physical tooth model.
  • FIG. 70 illustrates an exploded bottom perspective view of a casting chamber, a chamber lid, and a base for casting a physical tooth model.
  • FIG. 71 is a cross-sectional view illustrating an example where the chamber lid is placed over the chamber and pins located on the base, which is attached to the chamber lid, are positioned in the cavity of the negative impression.
  • FIG. 72 illustrates the physical tooth models which are created from the casting chamber shown in FIG. 71. A full tooth arch is casted and then separated into individual tooth models.
  • FIG. 73 is a flow chart illustrating another example for casting a physical tooth arch.
  • a base layer simulating the gum portion is provided to isolate the cast of the tooth arch to the crown portion of the tooth arch.
  • FIG. 74 shows perspective views of a casting chamber, a dental impression that can be fixed in the casting chamber, and a lid for the chamber.
  • FIG. 75 shows the front view of a lid attached with solidified casting material on its underside after first molding in the casting chamber.
  • FIG. 76 shows a front view of a reference base attached to the chamber lid.
  • FIG. 77 illustrates the making a hole on the base portion, which includes a gum profile, of the casting material adhered to the underside of the lid.
  • FIG. 78 shows a tooth model similar to the model of FIG. 4 with additional pins.
  • FIG. 79 shows a cross-sectional view of one pin.
  • FIG. 80 illustrates the lid positioned over the chamber, aligning the gum profile of the base with the negative impression. As shown, the gum profile of the base is provided to displace cast material and therefore isolating the cast to the crown position.
  • FIG. 81 illustrates positive tooth models created from the casting chamber of
  • FIG. 80 The tooth models have a profile isolated to the crown position.
  • FIG. 82 illustrates a container for casting a dental base or base component that can receive physical tooth models.
  • FIG. 83 illustrates a plurality of base components molded by a plurality of containers.
  • FIG. 84 a base comprising multiple sets of sockets for receiving a plurality of dental arches in different configurations.
  • FIG. 85 is a flow chart illustrating an example for digitizing a patient's tooth arch.
  • FIG. 86 illustrates an exemplified mechanical location device for acquiring the coordinates of the physical tooth models.
  • FIG. 87 illustrates an arch model component having registration features.
  • FIG. 88 is a top view of a scan plate mounted with a plurality of arch model components.
  • FIG. 89 is a side view of a scanning system including a scan plate mounted with a plurality of arch model components.
  • FIG. 90 is a block diagram illustrating an exemplary system for digitizing the tooth arch model components from a patient's tooth arch model.
  • FIG. 91 is an example of a flow chart for producing a physical dental arch model.
  • FIG. 92 illustrates a tooth model and a base respectively comprising complimentary features for assembling the tooth model with the base.
  • FIG. 93 illustrates fixing a stud to a tooth model comprising a female socket to produce a tooth model having a protruded stud.
  • FIG. 94 illustrates a tooth model comprising two pins that allow the tooth model to be plugged into two corresponding holes in a base.
  • FIG. 95 illustrates a tooth model comprising a protruded pin that allows the tooth model to be plugged into a hole in a base.
  • FIG. 96 illustrates cone shaped studs protruded out of the bottom of a tooth model.
  • FIG. 97 illustrates exemplified shapes for the studs at the bottom of a tooth model.
  • FIG. 98A illustrates an example of a base comprising a plurality of female sockets for receiving a plurality of tooth models for forming a physical dental arch model.
  • FIG. 98B illustrates another example of a base comprising a plurality of female sockets for receiving a plurality of tooth models for forming a physical dental arch model.
  • FIG. 99 illustrates a tooth model that can be assembled to the base in FIGS.
  • FIG. 100 illustrates an example in which the pins at the bottom portions of two adjacent tooth models interfere with each other.
  • FIG. 101 illustrates an example in which two adjacent tooth models mounted on a base interfere with each other at the tooth portions of the tooth models.
  • FIG. 102 illustrates a tooth model having pin configurations that prevent the tooth models from interfering with each other.
  • FIG. 103 A is a front view of two tooth models having pin configurations of
  • FIG. 102
  • FIG. 103B is a perspective bottom view of two tooth models having pin configurations of FIG. 102.
  • FlG. 104 illustrates a mechanism for fixing tooth models to a base using removable pins.
  • FIG. 105 illustrates a mechanism for fixing tooth models to a base using spring-loaded pins to prevent interference between tooth models.
  • FIG. 106 illustrates a triangulated mesh that simulates the surfaces of a patient's tooth.
  • FIG. 107 illustrates the calculation of the interference depth.
  • FIG. 108 illustrates the set-up of an orthogonal bounding box for calculating the interference depth.
  • FIG. 109 shows the grid over a rectangular face of a bounding box for the digital tooth model.
  • FIG. 1 10 illustrates the calculation of the interference depth between two tooth models.
  • FIG. 1 1 1 illustrates two digital tooth models having aligned coordinate systems.
  • FIG. 1 12 illustrates the discrete digital model for an object.
  • FIG. 1 13 illustrates the interference depth between two digital tooth models along two directions.
  • FIG. 1 14 illustrates the optimized direction of the interference depth between two digital tooth models in a three dimensional system.
  • FIG. 1 15 illustrates the sum of the depths of interference between two digital tooth models over a multiple steps.
  • FIG. 1 16 is an example of a flow chart for producing a physical dental arch model.
  • FIG. 1 17 illustrates the smoothening of the digital dental arch model in preparation for a CNC based manufacturing of physical dental arch model.
  • FIG. 1 18A illustrates the segmentation of digital dental arch model into segmented components suitable for CNC based manufacturing in accordance with the present invention.
  • FIG. 118B illustrates the segmentation of digital aligner model into segmented components suitable for CNC based manufacturing in accordance with the present invention.
  • FIGS. 1 19A-D illustrates the segmentation of an inter-proximal region by removing a space around the inter-proximal region and replacing it by a wedge.
  • FIGS. 120A-D illustrates physical tooth components comprising features that allow them to be plugged or attached into a base.
  • FIG. 121 A illustrates how a tooth component fits into a base component.
  • FIG. 121B illustrates an aligner assembled from a plurality of aligner components each comprising features that assist the assembling.
  • FIG. 122 illustrates exemplified arrangements for fitting one or more physical tooth components into a base.
  • FIG. 123 illustrates a portion of an arch assembled by a plurality of physical tooth components each comprising features that assist the attachment to attach to each other to form a physical dental arch model without a base.
  • FIG. 124 illustrates one method of casting a multi-layer dental model, as described herein.
  • FIG. 125 illustrates a casting chamber for forming a dental model, as described herein.
  • FIG. 126A is a graph showing the temperature over time of different amounts of Epoxy during curing in an oven.
  • FIG. 126B is a graph showing the temperature of different amounts of
  • FIG. 127 illustrates an example of the formation of a dental model.
  • FIG. 128 illustrates another variation of forming a dental model.
  • FIG. 129A illustrates a model block of Epoxy.
  • FIG. 129B is a chart illustrating the presence of stabilizer decrease shrinkage of Epoxy. DETAILED DESCRIPTION OF THE INVENTION
  • a tooth is intended to mean a single tooth or a combination of teeth
  • a fluid is intended to mean one or more fluids, or a mixture thereof.
  • generating”, “creating”, and “formulating” a digital representation mean the process of utilizing computer calculation to create a numeric representation of one or more objects.
  • a digital representation may comprise a file saved on a computer, wherein the file includes numbers that represent a three-dimensional projection of a tooth arch.
  • a digital representation comprises a data set including parameters that can be utilized by a computer program to recreate a digital model of the desired objects.
  • This application discloses methods and apparatus that may be used, for example, for manufacturing dental aligners.
  • the term "dental aligner” may refer to any dental device for rendering corrective teeth movement or for correcting malocclusion.
  • One or more dental aligners can be worn on the subject's teeth so that a subject wearing the dental aligners will gradually have his or her teeth repositioned by the dental aligner "pushing" (or pulling) against the teeth and/or gums (gingiva). Additional uses for the disclosed methods and apparatuses other than manufacturing dental aligners are also contemplated.
  • FIG. 1 an exemplary process for fabricating a dental aligner is illustrated. Variations of the methods and apparatus may, but do not necessarily, include combinations of two or more of the steps illustrated in the flow chart of FIG. 1. Variations of the methods and apparatus need not include all of the steps shown in FIG. 1. Moreover, the steps shown in FIG. 1 need not be executed in the order depicted. Variations on the methods and apparatus may also include process steps and apparatus not shown in FIG. 1.
  • a negative impression of a patient's dental arch is made.
  • Suitable techniques for forming such negative impressions may include, but are not limited to, conventional processes known to one of ordinary skill in the art as well as processes disclosed in examples below.
  • physical models of the patient's teeth are produced.
  • the patient's pre-treatment arch is cast from a negative impression of the patient's arch made in step 100.
  • Suitable casting techniques may include, but are not limited to, conventional techniques known to one of ordinary skill in the art and improvements thereof.
  • the cast of the dental arch may be separated into physical models of individual teeth or groups of teeth that can be arranged on a base (e.g., base plate) to model the patient's tooth arch.
  • the tooth models may be arranged to form the pretreatment tooth arch, a projected tooth arrangement at one of manage treatment stages, or the intended post-treatment tooth arch.
  • a physical model of the patient's pre-treatment dental arch may be produced from the digital model of the dental arch.
  • physical models of individual teeth or groups of teeth may be manufactured from the digital model using, for example, computer numerical control (CNC) based manufacturing techniques. Suitable CNC manufacturing techniques include, but are not limited to, those disclosed in examples below.
  • CNC manufacturing techniques include, but are not limited to, those disclosed in examples below.
  • Such physical models of individual teeth or groups of teeth manufactured from a digital model can also be arranged on a base to model the patient's tooth arch at different stages during an orthodontic treatment.
  • positional information allowing assembly of tooth models to represent the pre-treatment arch may be collected if needed by, for example, characterizing the locations of features in the negative impression and/or characterizing the locations of features in or on a cast made from the negative impression prior to separating the cast into physical models of individual teeth or groups of teeth.
  • either a positive or a negative tooth arch model may be digitized (e.g., digitized through scanning), and position information of each of the individual teeth in the tooth arch is determined based on the digitized model of the tooth arch.
  • Such features used to determine and track the relative positions of physical tooth models within a tooth arch may be referred to herein as registration features, registration marks, reference features, or reference marks.
  • Registration features may include, but are not limited to, pins or other structures inserted into or formed on or in the tooth arch during or after casting as well as features of the teeth.
  • the relative positions of such registration features may also be derived from a previously generated digital model of the dental arch.
  • Suitable methods and apparatus for collecting positional information allowing the assembly of the tooth models into a physical dental arch model include, but are not limited to, those disclosed in examples below and variations/improvements thereof.
  • the tooth models may be attached to the base using, for example, pins or other features on the tooth models that mate with receptacles, such as holes, sockets or other receiving features, arranged on the base.
  • the locations, shapes, and dimensions of, for example, holes in the base and/or pins in the tooth models may be selected to prevent interference between pins or similar features during assembly of the physical arch model.
  • Suitable methods and apparatus for attaching physical tooth models to a base include, but are not limited to, those disclosed in examples below and variations thereof.
  • a digital model of the pre-treatment dental arch is produced in some variations of the disclosed methods and apparatus (step 1 10).
  • the digital model is acquired by scanning or otherwise digitizing a negative impression of the dental arch and/or a cast of the dental arch made from the negative impression. Suitable techniques for scanning or otherwise digitizing a negative impression or a cast made from the negative impression include, but are not limited to, those disclosed in examples below.
  • the digital model of the pre-treatment arch is acquired by scanning or otherwise digitizing physical models of individual teeth or groups of teeth to provide digital models of individual teeth or groups of teeth. Suitable methods and apparatus for scanning or otherwise digitizing physical models of individual teeth or groups of teeth include, but are not limited to, those disclosed in examples below. Digital models of individual teeth or groups of teeth may be assembled to form a digital model of the pre-treatment arch.
  • Positional information allowing assembly of digital models of teeth or groups of teeth into a digital model of the dental arch may be collected if needed by, for example, characterizing the locations of registration features in the negative impression and/or characterizing the locations of registration features in or on a cast (i.e., a positive model) made from the negative impression prior to separating the cast into physical models of individual teeth or groups of teeth.
  • Suitable methods and apparatus for collecting positional information allowing the assembly of digital models of teeth or groups of teeth into a digital model of the dental arch include, but are not limited to, those disclosed in examples below and variations thereof.
  • a digital model of a patient's pre-treatment arch includes digital models of the roots of the teeth. Suitable methods for modeling the roots include, but are not limited to, those disclosed in examples below and variations thereof.
  • a digital model of a target dental arch is produced (step
  • a target dental arch is a desired arrangement of a patient's teeth to be achieved, for example, by the use of dental aligners.
  • a target dental arch may be the desired final arrangement of the patient's teeth or an arrangement to be achieved at an intermediate stage between the pre-treatment dental arch and the desired final dental arch.
  • a target dental arch is produced by modifying the positions of teeth in a digital model of the arrangement of the patient's teeth at an earlier stage of treatment.
  • a digital model of a target arch may be produced by altering the positions of the teeth in a digital model of the pre-treatment arch.
  • a digital model of a target arch is produced by assembling digital models of individual teeth or groups of teeth.
  • Positional information allowing assembly of digital models of teeth or groups of teeth into a digital model of a target dental arch may be acquired if needed by, for example, characterizing the locations of physical models of individual teeth or groups of teeth in an existing digital model of the target arch.
  • Suitable methods and apparatus for producing digital models of target dental arches include, but are not limited to, those disclosed in examples below.
  • digital models of target arches may also include digital models of the roots of the teeth.
  • a physical model of a target dental arch is produced by arranging individual physical tooth models to form a target dental arch (step 120).
  • the physical model of the target dental arch may be produced by arranging physical models of teeth or groups of teeth on a base at positions selected in accordance with the digital model.
  • the digital model may also be used to predict and avoid interference between tooth roots, between tooth crowns, and/or between pins or other features on or associated with the teeth or the base used to attach the teeth to the base.
  • a dental aligner is fabricated based on the physical dental arch which comprises a plurality of physical tooth models (step 125).
  • a dental aligner can be fabricated by forming a sheet of suitable material over a physical model of the target dental arch.
  • a digital model of the dental aligner is produced based on either a digital or physical model of the target dental arch.
  • the physical dental aligner may be manufactured from the digital model of the dental aligner using, for example, CNC based manufacturing techniques. Suitable CNC manufacturing methods and apparatus include but are not limited to those disclosed in examples below.
  • a casting chamber 150 for casting a dental arch from a negative impression comprises a chamber body 155 and a lid 160.
  • Chamber body 155 includes a cavity 165 in which the negative impression of the dental arch may be placed.
  • Casting chamber body 155 and lid 160 also include pins and alignment holes, not shown, allowing lid 160 to be precisely and reproducibly placed on chamber body 155.
  • FIG. 3 shows the underside of lid 160 to which has been attached a base plate 170
  • Lid 160 and base plate 170 also optionally include alignment pins and alignment holes, not shown, allowing base plate 170 to be precisely and reproducibly placed with respect to lid 160 and thus chamber body 155.
  • Base plate 170 may serve as the reference for a physical model of a dental arch to be cast in casting chamber 150. Variations of casting chambers for casting dental arches are disclosed in U.S. Patent Application No. 1 1/013,160, entitled “SYSTEM AND METHODS FOR CASTING PHYSICAL TOOTH MODEL,” filed December 14, 2004.
  • the negative impression 180 of the patient's tooth arch is placed in casting chamber body 155 and coupled (e.g., glued, bonded, interlocked, etc.) to the bottom 185 of casting chamber cavity 165.
  • a three dimensional position input device e.g., a 3-D digitizer
  • position input device 190 includes a stylus 195 that may be positioned at points within negative impression 180.
  • Position input device 190 may measure, for example, the spatial orientation of stylus 195 and/or the position of its tip.
  • the position input device 190 is a mechanical location determination device such as, for example, a MicroScribe®, available from Immersion Corporation.
  • a mechanical location determination device such as, for example, a MicroScribe®, available from Immersion Corporation.
  • FIG. 4 for example, position input device 190 is depicted as such a mechanical location device.
  • An example of utilizing a mechanical location device to characterize the locations of features in a negative impression of a dental arch is disclosed in U.S. Patent Application No. 1 1/013,159, entitled "PRODUCING A BASE FOR ACCURATELY RECEIVING DENTAL TOOTH MODELS,” filed December 14, 2004.
  • position input device 190 may be, for example, an optical location device, optical scanner (e.g., laser scanner) imaging machines (e.g., CAT scanner, MRI scanner), ultrasound scanner, magnetic scanner.
  • optical and/or magnetic sensing techniques are utilized to measure the position of a stylus 195 or to otherwise determine the positions of features in negative impression 180. Examples of the use of such optical, imaging, or magnetic sensing techniques to characterize the locations of features in a negative impression of a dental arch are disclosed in U.S. Patent Application No. 1 1/013,157, entitled "PRODUCING ACCURATE BASE FOR A DENTAL ARCH MODEL," filed December 14, 2004.
  • position input device 190 and casting chamber body 155 may be fixed to a common platform 200.
  • a coordinate system based on casting chamber body 155 can then be established by manipulating stylus 195 to measure the locations of two points on the casting chamber body 155 to define the x axis.
  • the y axis may be established with a third reading.
  • the x-y plane may be defined on the surface that receives the negative impression.
  • the z axis can be determined by taking the cross product of the x and y axes.
  • the positions of features in negative impression 180 may then be measured with respect to the coordinate system on chamber body 155 by placing stylus 195 at points on or in the features.
  • stylus 195 can be inserted into the negative impression of a tooth to approximate the root position for that particular tooth.
  • stylus 195 is inserted into the cavity along the longitudinal orientation of the tooth, and, if desirable, further adjusted to a position that approximates the position of the root of the tooth.
  • a computer may then be used to record the position of stylus 195, which corresponds to the approximate root position.
  • the placement of stylus 195 is controlled by an operator.
  • an automated system having optical and/or tactile feedback is utilized to position stylus 195.
  • the approximate position of the root for each tooth may also be defined by one or more positionings/placements of stylus 195.
  • stylus 195 is used to define two positions or longitudinal axes which in combination approximate the position of a registration feature, which may correspond to the position of the root of the teeth. Pin-like objects placed on a positive tooth model may be utilized later to simulate the positions or axes defined by stylus 195, which in turn can represent the approximate position of the root.
  • stylus 195 is used to define four points within each of the tooth cavities within the negative impression 180 of the tooth arch. The four defined points are then utilized to define the position for the placement of two pins or of an asymmetric peg/interface which can simulate the position of the registration feature.
  • stylus 195 is used to sample a series of points that represent the profile of each of the tooth cavities within negative impression 180. For example, three or more points on the surface of a tooth cavity may be sampled to define an approximate surface profile of the tooth. The approximate surface profile may then be used to define an approximate root position. Two pin positions may be calculated to fit within the approximate surface profile along the longitudinal axis of the tooth.
  • a sectional plan is defined at the base of the tooth based on a sampling with stylus 195 of the negative impression representing the gingival tissue. A pair of pins, with a pre-set distance "d", is then positioned perpendicular to this sectional plan and centered within the tooth that is defined by the approximate surface profile determined by stylus 195.
  • base plates for receiving dental arch models and physical tooth models are manufactured to have complimentary features (e.g., receptacles) allowing the tooth models to be mounted on the base plate to form the dental arch model.
  • features such as, for example, pins, studs, and sockets may be provided on the tooth models, such that the tooth models can be mounted on base plates. Examples of mounting features are disclosed in U.S. Patent Application No. 10/979,824, entitled “PRODUCING A BASE FOR PHYSICAL DENTAL ARCH MODEL," filed November 2, 2004.
  • a base plate 170 is provided with sockets 205 into which can be inserted pins 175 to be attached to physical tooth models.
  • the pins or other features on the physical tooth models allowing attachment of the physical tooth models to base plate 170 may also serve as registration features allowing the relative positions and orientations of the physical tooth models to be tracked. In some variations such pins also approximate the position of roots, as described above.
  • the coordinate system in which position input device 190 (FIG. 4) characterized negative impression 180 can be properly transposed to the base plate 170.
  • the locations of the sockets 205 (i.e., receptacles) on the base plate 170 may be chosen based on the data collected with position input device 190 to correspond to the positions of the registration features determined based on the negative impression of the patient's tooth arch.
  • Sockets 205 may be formed in base plate 170, for example, by CNC based machining, by laser machining, or by printing or forming sockets in a soft material which is later cured or hardened.
  • Pin and socket positions chosen to correspond to teeth in a tooth arch might interfere in some circumstances. For example, tilted tooth orientations might result in pins on adjacent teeth colliding with each other when inserted into a base plate.
  • some or all adjacent pairs of teeth are examined for interference between pins. Where detected, such interference may be avoided, for example, by altering the configuration of the pins. For example, the position, orientation, or length of pins may be selected to avoid interference with pins on neighboring teeth.
  • removable, retractable and/or spring-loaded pins may also be used. Socket positions and configurations may then be selected to compliment the non- interfering pin configurations.
  • sockets are formed to receive pins for teeth oriented at an angle with respect to the surface of base plate 170.
  • a recess 210 having a flat surface 215 is formed in a base plate 170.
  • Flat surface 215 can be tilted to accommodate tilted pins 175, which mate with matching tilted sockets 205 formed in base plate 170.
  • Examples of sockets accommodating tilted teeth and pins are disclosed in U.S. Patent Application No. 11/013,156, entitled "PRODUCING NON-INTERFERING TOOTH MODELS ON A BASE,” filed December 14, 2004.
  • pins 175 are then inserted into sockets 205 and lid 160 is flipped over and placed on top of the chamber body 155 holding the negative impression 180 of the tooth arch.
  • each pair of pins corresponds to a tooth in the tooth arch represented by the negative impression.
  • the positions of pins 175 correspond to approximate root positions defined by position input device 190.
  • a casting material is injected into the cavity 220 of the negative impression 180, which is positioned within the casting chamber cavity 165.
  • suitable casting materials include, but are not limited to, polymers and plasters.
  • heat, infra-red light, or ultraviolet light, for example, may be applied to promote curing of the casting material. Examples of casting processes and casting materials are disclosed in U.S. Patent Application No. 1 1/013,160, entitled “SYSTEM AND METHODS FOR CASTING PHYSICAL TOOTH MODEL,” filed December 14, 2004, U.S. Patent Application No. 1 1/013,158, entitled “PRODUCING A PHYSICAL TOOTH MODEL COMPATIBLE WITH A PHYSICAL DENTAL ARCH MODEL,” filed December 14, 2004.
  • the casting material cures to form a positive arch 225 within the negative impression, with pins 175 bonded to the positive arch.
  • the user may then decouple the negative impression 180 from the positive arch 225, resulting in a positive tooth arch 225 of the patient with a plurality of pins 175 that, optionally, simulate the root positions.
  • positive arch 225 is cast by sequentially applying and curing multiple layers of casting material to form a layered model of the dental arch. Examples of multi-layer casting methods and devices are disclosed in U.S. Patent
  • a base plate is prepared with a base surface, which simulates the gum line, prior to and subsequently used in the casting of a positive arch 225 having the isolated crown portion without the gum portion.
  • a first positive dental arch including both crowns of the teeth and segments of the gum is cast from negative impression 180.
  • the crown portions are then cut away to leave a gum portion in which sockets or other features may be formed as described above.
  • This gum portion is them implemented on a base plate in casting the dental arch using, for example, another casting material that does not adhere to the solidified material of the base plate. Examples of methods and apparatus to cast a tooth arch isolated to the crown portions of the teeth are disclosed in U.S. Patent Application No. 1 1/013,158, entitled "PRODUCING A PHYSICAL TOOTH MODEL COMPATIBLE WITH A PHYSICAL DENTAL ARCH MODEL,” filed December 14, 2004.
  • the positive arch 225 resulting from the casting processes described above may be digitized to generate a three-dimensional digital representation of the dental arch.
  • This digital model of the dental arch may be utilized later, for example, to align or to aid in alignment of tooth models formed by separating the positive arch into individual teeth or groups of teeth.
  • the three dimensional digital representation may be constructed, for example, using conventional digitizing techniques such as laser 3-D scanning.
  • the teeth on the positive tooth arch 225 are separated to form physical models 230 of the individual teeth, as shown in FIG. 9. Separation may be achieved by, for example, sawing, laser cutting, or other techniques that are well known to one of ordinary skill in the art.
  • Individual physical tooth models 230 may be arranged to recreate positive tooth arch 225 or to represent a target dental arch by, for example, inserting their pins 175 into sockets appropriately arranged on a base plate.
  • the individual physical tooth models 230 are attached to adjustment jigs which are then attached to the base plate.
  • the adjustment jigs alter the position or orientation of the physical tooth models 230 compared to that obtained by attaching the physical tooth models 230 directly to a base plate.
  • the adjustment jigs enable the rotation of physical tooth models 230 around two axes. Examples illustrating the use of adjustment jigs with physical tooth models in a dental arch model are disclosed in U.S. Patent Application No. 10/979,504, entitled "PRODUCING AN ADJUSTABLE PHYSICAL DENTAL ARCH MODEL," filed November 2, 2004 and U.S. Patent Application No.
  • the relative positions of pins 175 can be known, for example, through the relative positions of sockets 205 formed in base plate 170 prior to the casting of tooth arch 225 onto pins 175 (FIGS. 3 and 7).
  • the relative positions of pins 175 can also be known, for example, by defining their positions with respect to negative impression 180 using a position input device as described above (FIG. 4).
  • either the positive arch 225 or the negative tooth arch impression 180 may be digitized by three-dimensional scanning using, for example, techniques such as laser scanning, optical scanning, destructive scanning, CT scanning, MRI scanning, and acoustic scanning.
  • the resulting digital model of the arch may be utilized alone or in combination with the registration feature information (e.g., pin information) to determine the relative positions of the teeth in the tooth arch.
  • the separated tooth models 230 are assembled to recreate positive arch 225 by geometry matching.
  • Positive arch 225 is first digitized to obtain a 3D digital arch model.
  • individual tooth models 230 are then scanned to obtain digital tooth models for individual teeth as described below, for example.
  • the digital tooth models can be matched to the digital arch model using rigid body transformations. Each tooth is sequentially matched to result in rigid body transformations corresponding to the tooth positions that can reconstruct an arch.
  • unique registration features are added to each pair of tooth models 230 before positive arch 225 is separated. Separated physical tooth models 230 can be assembled to recreate a positive arch 225 by matching physical tooth models having the same unique registration marks.
  • individual physical tooth models 230 are assembled and registered with the assistance of three dimensional point picking devices such as position input device 190 described above (FIG. 4).
  • the coordinates of registration features on the physical tooth models 230 are determined before separation of tooth arch 225. After separation, the coordinates of the registration features are use to arrange physical tooth models 230 to recreate tooth arch 225.
  • individual physical tooth models 230 may be digitized as described next, for example, to form digital models of the individual teeth. These individual digital tooth models may then be used, for example, to create digital models of dental arches. Examples of digitization of individual physical tooth models and construction of a digital dental arch from digital models of teeth are disclosed in U.S. Provisional Application No. 60/676,546, entitled "DIGITIZATION OF DENTAL ARCH MODEL,” filed April 29, 2005.
  • Scanning system 240 includes a scan plate 245 on which one or more physical tooth models 230 can be mounted.
  • Scan plate 245 can be rotated by a rotation mechanism 250 under the control of a computer 255.
  • the rotation mechanism 250 can include a motor and a gear transport mechanism that is coupled to the scan plate 245.
  • an image capture device 260 captures images of physical tooth models 230.
  • the coordinates of a plurality of surface points on the physical tooth models 230 can be computed, for example, by triangulation using the captured image data.
  • the surfaces of the physical tooth models 230 can be constructed by interpolating computed coordinates of the points on the surface.
  • Image capture device 260 can be, for example, a digital camera, digital video camera, laser scanner, or other optical scanner. Some variations utilize a plurality of image capture devices. The throughput and accuracy of the digitization process may increase with the number of image capture devices used.
  • the individual physical tooth models 230 are placed on scan plate 245 one at a time and scanned one at a time.
  • a plurality of individual physical tooth models 230 are place onto scan plate 245 and scanned together.
  • eight physical tooth models 230 are scanned at a time.
  • sixteen physical tooth models 230 are scanned at a time.
  • the scanning throughput is increased with increased packing density on scan plate 245.
  • higher packing density may decrease the distance between the physical tooth models 230, which may cause the adjacent physical tooth models 230 to block each other in image captures.
  • Various techniques that are well known to one of ordinary skill in the art may be utilized to determine the desired packing density and distribution pattern for placement of physical tooth models 230 on scan plate 245.
  • FIG. 1OB is a top view, illustrating one variation of a tooth model platform for scanning.
  • a plurality of physical tooth models 230 are mounted to a scan plate 245.
  • Physical tooth models 230 can have different sizes and shapes.
  • the small circles may be, for example, about 10 mm in diameter and represent small teeth (e.g., lower incisors, canine, etc.) or tooth components.
  • the large circles may be, for example, about 15mm in diameter and represent large teeth (e.g. upper central incisors, molars) or larger tooth components.
  • physical tooth models 230 are placed, for example, at least about 5 mm apart from each other and at almost equal height to avoid overlap.
  • Scan plate 245 may be about 150 mm in diameter, for example.
  • the packing efficiency of physical tooth models 230 can be determined by their sizes, heights, and shapes and by their distribution on scan plate 245. As one of ordinary skill in the art having the benefit of this disclosure would appreciate, other distributions of physical tooth models 230 on a scan plate 245 differing from that shown in FIG. 1OB may also be suitable.
  • FIG. 1 OC shows a side view of scan plate 245 in one variation.
  • Physical tooth models 230 are mounted on scan plate 245 in a substantially vertical orientation. Images of the physical tooth models are scanned or captured from a direction 265 oblique to the physical tooth models 230 such that their top and side surfaces can be captured at different angles as scan plate 245 is rotated.
  • the image capture direction 265 can be about 45 degree off vertical axis 270. Other relative orientations of the image capture direction 265 and the physical tooth models may also be suitable.
  • scan plate 245 can be mounted on goniometer and/or translation stages which can provide up to 6 axes for 6 degree of freedom movements.
  • pre-determined receptacles are prepared on a base plate 245, such that the scanned digital data of each tooth profile is associated with the position of its corresponding receptacle.
  • physical tooth models 230 are mounted on scan plate 245 by inserting pins 175 on physical tooth models 230 into receiving features 275 formed in scanning plate 245.
  • Receiving features 275 may be sockets or holes as described above with respect to the fabrication and use of base plates for dental arch models. The positions of receiving features 275 are precisely known.
  • the positions and orientations of pins 175 and physical tooth models 230 during the scanning process can be determined in relation to the receiving features.
  • the coordinates of the surface of that tooth are known with respect to the positions of the pins in that tooth. That is, the location of points on the surface of a digitized tooth and the location of the pins in that tooth can be translated into the same coordinate system. Consequently, if the positions of the pins are known or defined, then the positions of points on the surface of the tooth are also known.
  • FIG. 12 illustrates examples of graphic projections of the individual digital representations 280 of selected teeth, each of which comprises a crown portion of the corresponding tooth.
  • a section of the gingival tissue (not shown) is also digitized.
  • the digital representations 280 of individual teeth may then be utilized by a computer program to generate a digital representation of the complete tooth arch.
  • digital tooth models 280 are used to generate a digital representation 285 of the tooth arch, shown in FIG. 13. Since the relative positions of the pins for each of the teeth is known, and the digital tooth models can be referenced to the pins during scanning, a computer can recalculate and arrange the individual digital tooth models based on the pin information to form the patient's pre-treatment tooth arch. Digital models of the tooth roots may be later incorporated into digital model 285 of the tooth arch, if desired.
  • the computer uses the relative locations of pins 175 in positive arch 225 to calculate the relative positions of corresponding digital tooth models 280 required to align digital dental arch model 285 with positive arch model 225.
  • alignment of the digital tooth models 280 in digital arch model 285 may be accomplished or aided by reference to a three-dimensional digital model of the patient's complete tooth arch generated from scanning or otherwise digitizing either negative impression 180 or positive tooth arch 225.
  • a three- dimensional digital model 290 of the tooth arch generated from scanning a compete physical arch model may be superimposed on digital dental arch model 285, which was generated from combining digital tooth models 280.
  • the overlaid individual tooth sections allow an operator and/or software to match up individual teeth between the two digital tooth arches.
  • the position of each tooth within digital dental arch 285 may then be adjusted to match that of the corresponding tooth in the digital model 290 of the complete tooth arch.
  • the adjusted digital arch model 285 may then be utilized for computer modeling or preparation of a dental appliance, for example.
  • FIG. 15 illustrates a graphical projection of a digital arch model 285 comprising both crowns 280 and roots 295.
  • Digital simulation of tooth roots is disclosed, for example, in U.S. Provisional Application No. 60/676,546, entitled “DIGITIZATION OF DENTAL ARCH MODEL,” filed April 29, 2005.
  • a computer generates a digital model of the root portion for each of the crowns, based, for example, on the morphology, dimension, size, and/or shape of the crown.
  • an operator or a computer selects roots matching the crowns from a data library of predefined roots of different sizes and shapes.
  • the crowns in the dental arch and the roots in the data library are categorized as, for example, incisor, canine, premolar, or molar. Roots are then selected from the category matching that of the crown. Data from x-ray images may also be utilized in the root selection process.
  • the computer may further modify its size to provide a better match between the root and the crown.
  • a digital root is coupled to its digital crown to align an axis of the root with a primary axis of the crown.
  • the position and/or orientation of a digital root with respect to its digital crown are determined based on the morphology of the crown and/or x-ray information.
  • an operator may be presented with a visual representation of the complete digital tooth model (crown and root) and an opportunity to make manual adjustments to the position and/or orientation of the root. Such an adjustment may be based on x-ray or other clinical data, for example.
  • digital tooth models 300 comprising roots 305 and crowns 310 are generated based on digital tooth models 280 prior to generation of a digital model of the complete tooth arch.
  • FIG. 16 shows examples of the graphical projections of such individual tooth models 300.
  • Various methods for generating roots for corresponding crowns may be applied to create the root portion for each of the individual digital tooth models 300.
  • information regarding pin locations corresponding to approximate root positions may be applied to position/couple the root profile to the crown.
  • a computer program may utilize the pin location information to determine if the root portion is centered in relation to the crown portion. The direction of the pin and the amount of misalignment, if any, may also be calculated.
  • a computer may use the pin information to determine whether the primary axis of the root is tilted in relation to the primary axis of the crown, such that the simulated root can be tilted by the corresponding amount and in the matching orientation.
  • digital tooth models 300 comprising crowns 310 and roots 305 have been generated, they may be used by a computer program to generate a digital model 315 of the dental arch.
  • the relative positions of digital tooth models 300 in digital tooth arch model 315 may be determined, for example, by the methods described above with respect to the generation of digital tooth arch 285 (FIG. 13).
  • Digital arch model 315 may then be utilized for computer modeling or preparation of a dental appliance, for example.
  • FIG. 18 illustrates an example of a digital tooth arch 320 with the position/orientation of one of the teeth 325 within the tooth arch being modified.
  • An attempt to modify the position of a tooth in a physical or digital tooth arch model, or in a patient's actual tooth arch may result in interference between teeth.
  • an attempted modification might require the crowns or roots of neighboring teeth to make contact or to overlap.
  • a digital model of a tooth arch may be used to predict and prevent such interference between physical tooth models in a physical dental arch model and/or between a patient's actual teeth.
  • the position and/or orientation of a digital tooth model in a digital arch model is modified, and then the resulting overlap between digital tooth models in the digital arch model is calculated to predict and quantify the amount of interference that would result.
  • a modified digital tooth arch may be utilized to fabricate a removable aligning appliance for orthodontic treatment.
  • a digital representation of a shell 330 configured to serve as an aligner is generated by a computer based on the modified digital representation of the tooth arch 320, as shown in FIG. 19.
  • a physical shell 335 is then fabricated based on the digital representation of the shell 330.
  • Various fabrication techniques that are well known to one of ordinary skill in the art may be utilized to create a physical object based on its digital representation. For example, three- dimensional polymeric printing techniques may be utilized to create a polymeric aligner based on the digital representation of the shell.
  • FIG. 20 illustrates an example of a polymeric aligner 335 created based on the digital representation of the shell 330 shown in FIG. 19.
  • the modified digital representation of the tooth arch 320 is provided as a reference to modify the arrangements of a corresponding physical model of the tooth arch.
  • the desired aligner may then be fabricated using the modified physical model of the tooth arch.
  • a modification of the position or orientation of a digital tooth model in a digital arch model results in a corresponding modification of the positions and orientations of that tooth's pins with respect to the pins of the other teeth in the arch.
  • the digital representation of modified tooth arch 320 can be configured to retain all of the revised pin positions. These revised pin positions may then be utilized to modify the physical model of the tooth arch such that the physical model corresponds to the modified digital representation of the tooth arch.
  • the revised relative pin positions and orientations for the teeth in the digital arch model may be used to create a digital model of a base plate on which a corresponding physical model may be assembled.
  • the digital base plate model may include, for example, the relative positions and orientations in a physical base plate of sockets into which pins on physical tooth models may be inserted to form a physical arch model that corresponds to the modified digital tooth arch.
  • the digital base plate model may be used, for example, in CNC based manufacturing of a physical base plate.
  • the creation and use of digital base plate models is disclosed, for example, in U.S. Patent Application No. 11/013,145, entitled "FABRICATING A BASE COMPATIBLE WITH PHYSICAL TOOTH MODELS,” filed December 14, 2004.
  • sockets or holes 340 are drilled into a base plate 345 with CNC machinery, for example, so that the position and orientation of these holes 340 correspond to the revised pin position in the digital representation of the tooth arch 320.
  • Sockets 340 may also be formed, for example, by laser machining, or by printing or forming sockets in a soft material which is later cured or hardened. Examples of socket forming techniques are disclosed in U.S. Patent Application No. 10/979,824, entitled "PRODUCING A BASE FOR PHYSICAL DENTAL ARCH MODEL," filed November 2, 2004, U.S. Patent Application No.
  • sockets 340 are formed, physical models 230 of the patient's individual teeth, such as the ones shown in FIG. 9, can then be inserted onto the base plate 345 to form a tooth arch 350 that corresponds to the modified digital representation of the tooth arch 320, as shown in FIG. 22.
  • the operator may adjust the individual teeth (e.g., shaving, or rounding out sections of the tooth profile, etc.) to ensure that a proper fit between the teeth 230 on the tooth arch 350 can be achieved.
  • Pins and socket positions in a base plate chosen to correspond to teeth in a modified physical tooth arch model might interfere similarly to as described above with respect to the fabrication of base plate 170 (FIGS. 3 and 5). For example, tilted tooth orientations might result in pins on adjacent teeth colliding with each other when inserted into a base plate.
  • some or all adjacent pairs of teeth are examined for interference between pins. Where detected, such interference may be avoided by, for example, altering the configuration of the pins. For example, the position, orientation, or length of pins may be selected to avoid interference with pins on neighboring teeth.
  • removable, retractable and/or spring-loaded pins may also be used.
  • Socket positions and configurations may then be selected to compliment the non-interfering pin configurations.
  • Examples of methods and apparatuses for detection and avoidance of potential interference between pins are disclosed in U.S. Patent Application No. 1 1/013,156, entitled “PRODUCING NON-INTERFERING TOOTH MODELS ON A BASE,” filed December 14, 2004 and U.S. Patent Application No. 1 1/050,126, entitled “METHODS FOR PRODUCING NON-INTERFERING TOOTH MODELS, filed February 3, 2005.
  • the pins represent the roots of teeth
  • interference between the pins may be avoided by, for example, selecting a different modification of the tooth arch that does not result in interference.
  • sockets in a base plate for a modified tooth arch are formed to receive pins for teeth oriented at an angle with respect to the surface of the base plate.
  • a recess 355 having a flat surface 360 is formed in a base plate 345.
  • Flat surface 360 is tilted to accommodate a tilted tooth model 230.
  • Tilted pins 175 mate with matching tilted sockets 340 formed in base plate 345. Examples of sockets accommodating tilted teeth are disclosed in U.S. Patent Application No. 1 1/013, 156, entitled "PRODUCING NON-INTERFERING TOOTH MODELS ON A BASE,” filed December 14, 2004.
  • the desired aligner may be fabricated using modified physical tooth arch model 350 in a vacuum forming process.
  • a sheet of aligner material 365 may be placed over modified physical tooth arch model 350.
  • Sheet 365 may be heated and then vacuum formed around physical tooth arch model 350 by, for example, a vacuum pump that removes air at the bottom of base plate 345 to cause the softened aligner material 365 to fittingly form around physical dental arch model 350.
  • Suitable aligner materials include but are not limited to polymers.
  • the vacuum-formed sheet 370 of aligner material may be removed from physical tooth arch model 350, as shown in, FIG. 25. Excess materials on the vacuum-formed polymeric sheet 370 may then be trimmed off to form a polymeric shell 375 that can serve as a removable aligner, as shown in FIG. 26.
  • one or more copies of the digital representation of the tooth arch which represents the original condition of the patient's tooth arch, may be created.
  • Each of the duplicate digital tooth arches may be modified in varying degrees to represent the projected or intended position of the patient's teeth for a specific stage (i.e., treatment step) within a series of stages during the process of orthodontic treatment.
  • the modified digital tooth arches may then be implemented to fabricate a series of removable aligners that match the modified digital tooth arches.
  • a base plate is configured with multiple sets of holes, where each set of holes forms an arch configured for receiving a plurality of positive teeth models to form a tooth arch.
  • a base plate 380 comprises four sets of holes 385, 390, 395, and 400 representing four arches. The holes correspond to projected pin positions based on the digital representations of the four different arches.
  • Corresponding positive teeth models are then inserted into the holes on the base plate 380 to form four positive arch models 405, 410, 415, and 420 as shown in FIG. 28. These four positive arch models may then be utilized to form four separate dental aligners.
  • a sheet of aligner material such as a polymer sheet, may be placed over the four positive arches on the base plate and vacuum-formed to create the four dental aligners.
  • the four positive arch models represent tooth arrangement of four different treatment steps of an orthodontic treatment process.
  • the four positive arch models represent arches of four different patients; each may be at a different stage of the treatment process.
  • a process for manufacturing a dental aligner starts by determining a position of a registration feature for each of the teeth within a patient's tooth arch (step 500). This may comprise, for example, determining a position of a registration feature for each of the teeth based on a negative impression of the patient's tooth arch.
  • the positions of the registration features may be determined in some variations with a position determination device such as, for example, a microscribe. For example, determining a position of a registration feature may comprise scanning an inner surface of a negative mold of the patient's tooth arch.
  • Such scanning may comprise, for example, scanning the inner surface of the negative mold with a position determining device such as, for example, a mechanical scanning device or an optical scanning device.
  • Scanning an inner surface of a negative mold of the patient's tooth arch may comprise, for example, sampling locations on the inner surface profile of the negative mold and utilizing information of the inner surface profile to determine the position of the corresponding registration feature for each of the teeth within the patient's tooth arch.
  • the registration features may be pins, for example. In some variations, the positions of the registration features may also be determined based on a positive tooth arch model of the patient's tooth arch.
  • the next step is to construct individual tooth models of teeth in the patient's tooth arch comprising registration features corresponding to those of step 500.
  • Constructing individual tooth models may comprise, for example, fabricating a tooth arch model of a patient's tooth arch in which each of the teeth has its corresponding registration feature, and dividing the tooth arch model into individual tooth models.
  • Fabricating a tooth arch model of a patient's tooth arch may comprise, for example, positioning a corresponding registration feature in each tooth location within a negative mold of the patient's tooth arch, and filling the negative mold with a polymer to form the tooth arch model.
  • the next step is to prepare a base for receiving the individual tooth models.
  • This may comprise, for example, creating a receptacle on the base for each of the tooth models, such that when all the tooth models are coupled to the receptacles the tooth models form a tooth arch.
  • the receptacles may be configured, for example, to receive the registration feature of the corresponding tooth model.
  • each of the registration features comprises a pair of pins
  • each of the receptacles comprises a pair of holes configured to receive the pins.
  • the base is prepared to have receptacles for receiving the tooth models to form a modified teeth arrangement that differs from a teeth arrangement of the patient's tooth arch.
  • the modified tooth arrangement may be created utilizing a computer, for example.
  • the computer may have a visualization interface to create the modified teeth arrangement.
  • bases may be prepared utilizing a CNC machine.
  • step 515 the individual tooth arch models are attached to the base to form a tooth arch.
  • the tooth arch formed by the individual tooth models attached to the base may be, for example, a target tooth arch in an orthodontic treatment process.
  • a dental aligner may be fabricated. This may comprise fabricating the dental aligner on the tooth arch formed by the individual tooth models.
  • fabricating a dental aligner comprises placing a polymeric sheet over the tooth arch formed by the individual tooth models and heat forming the polymeric sheet over the tooth arch.
  • the tooth arch on which the dental aligner is fabricated may be, for example, a modified teeth arrangement that, for example, comprises a projected teeth arrangement of the patient's tooth arch in a stage of an orthodontic treatment process.
  • a process for manufacturing a dental aligner utilize a physical model of a tooth arch constructed from individual physical tooth models of teeth in a patient's tooth arch with reference to a digital model of the tooth arch.
  • Some of these variations start by generating a digital model for each of the individual physical tooth models (step 600).
  • generating a digital model of an individual physical tooth model comprises scanning the individual physical tooth model. This may comprise, for example, fabricating the individual physical tooth model and then scanning it to create the digital model of the physical tooth model.
  • fabricating an individual physical tooth model comprises acquiring a negative impression of a patient's tooth arch, casting a positive mold of the negative impression, and separating the positive mold to form at least one individual physical tooth model.
  • the next step (step 605) is to generate a digital model of the tooth arch from the digital models of the individual physical tooth models.
  • the teeth in the digital model of the tooth arch are arranged to have relative positions with respect to each other corresponding to the relative positions that the teeth in a patient's tooth arch have with respect to each other.
  • this comprises determining a position of a registration feature for each of a plurality of teeth within the patient's tooth arch, where each registration feature identifies a relative position of its tooth in relation to other teeth within the patient's tooth arch, representing the registration features in corresponding digital models of individual physical tooth models, and arranging the teeth in the digital model of the tooth arch such that the registration features in the digital model of the tooth arch have relative positions with respect to each other corresponding to the relative positions that the registration features determined for the teeth in the patient's tooth arch have with respect to each other.
  • step 615 the position of at least one of the teeth in the digital model of the tooth arch is modified compared to the position of the corresponding tooth in the patient's current tooth arch.
  • each of the individual physical tooth models includes a registration feature represented in the digital model of the tooth arch, and the individual physical tooth models are arranged such that their registration features have relative positions with respect to each other that correspond to the relative positions that the registration features in the modified digital model of the tooth arch have with respect to each other.
  • registration features included in the individual physical tooth models are configured to attach the individual physical tooth modes to a base to form a physical model of a tooth arch.
  • the registration features included in the physical tooth models comprise pins.
  • each of the individual physical tooth models includes a registration feature represented in the digital model of the tooth arch, and features on the base at which the registration features may be attached are formed at locations with relative positions with respect to each other corresponding to the relative positions that the registration features represented in the digital model of the tooth arch have with respect to each other.
  • the registration features included in the physical tooth models may comprise pins, for example.
  • the features on the base may comprise, for example, receptacles into which the registration features included in the individual physical tooth models may be inserted.
  • a dental aligner may be formed over the individual physical tooth models. In one example, this comprises placing a polymeric sheet over the tooth arch formed by the individual tooth models and heat forming the polymeric sheet over the tooth arch.
  • CNC manufacturing includes methods and apparatus known to one of ordinary skill in the art, and improvements thereof, for computer controlled manufacturing of physical models based on digital representations.
  • CNC manufacturing can include, for example, milling, stereolithography, laminated object manufacturing, selective laser sintering, fused deposition modeling, solid ground curing, 3D ink jet printing, laser machining, molding, and casting.
  • Bases may be fabricated from materials including, but not limited to, polymers, thermal elastic materials, urethane, epoxy, plastics, plaster, stone, clay, acrylic, latex, dental PVS, resin, metals, wax, wood, paper, ceramics, porcelain, glass, sand, ice, and concrete.
  • methods for producing a base for physical tooth models may comprise, for example, receiving digital tooth models representing the physical tooth models, generating a digital base model compatible with the digital tooth models, and producing a base using CNC manufacturing in accordance with the digital base model.
  • the methods may also comprise, for example, receiving position information for the physical tooth models on the physical base, and forming features on a base plate in accordance with the position information to produce the physical base.
  • the features formed on the base are configured to receive the physical tooth models.
  • the methods may also comprise, for example, receiving position information for the physical tooth models on the physical base, and forming features on a base plate in accordance with the position information to produce the physical base.
  • the features formed on the base plate complement features on the tooth models.
  • the methods may also comprise, for example, receiving positional information for sockets for receiving physical tooth models on the base, causing relative movement between a laser and a base plate, emitting a laser beam from the laser to the base plate, and producing a socket in the base plate with the emitted laser beam.
  • Physical tooth models having one or more pins, protrusions, or other pluggable features may be attached to the base to form a physical dental arch by inserting the pluggable features into sockets in the base.
  • the features in the physical tooth models may be shaped in accordance with the profile of the emitted laser beam that produces the sockets in the base plate.
  • the systems may comprise, for example, a computer device adapted to store digital tooth models representing the physical tooth models, a computer processor that is capable of generating a digital base model compatible with the digital tooth models, and an apparatus that can fabricate the base using CNC based manufacturing in accordance with the digital base model.
  • the systems may also comprise, for example, a computer configured to store position information for physical tooth models comprising features for attaching the tooth models to a base, and apparatus under the control of the computer configured to fabricate on a base plate features complementary to the features on the tooth models in response to the position information to thereby produce a physical base for receiving the physical tooth models.
  • the system may also comprise, for example, a computer adapted to store positional information for sockets to be formed on a base plate, a transport system configured to move the base under the control of the computer, and a laser configured to emit a laser beam onto the base plate to form a socket in the base plate after the base plate is moved to a position in accordance to the positional information stored in the computer.
  • a computer adapted to store positional information for sockets to be formed on a base plate
  • a transport system configured to move the base under the control of the computer
  • a laser configured to emit a laser beam onto the base plate to form a socket in the base plate after the base plate is moved to a position in accordance to the positional information stored in the computer.
  • bases for physical tooth models may comprise, for example, a base portion and a plurality of features adapted for receiving the physical tooth models.
  • the plurality of features may be fabricated by CNC based manufacturing, for example.
  • a base plate may comprise a plurality of pairs of sockets. Each pair of sockets may be adapted to receive two pins associated with a physical tooth model.
  • Implementations may include one or more of the following.
  • a method for producing a base for physical tooth models may include receiving digital tooth models representing the physical tooth models, generating a digital base model compatible with the digital tooth models, and producing a base capable of receiving the physical tooth models using CNC based manufacturing in accordance with the digital base model.
  • the base may comprise one or more features to assist the reception of the physical tooth models.
  • the physical tooth models may include features that are complementary to the features in the base. For example, the features in the base and the features in the physical tooth models may join together to attach the physical tooth models to the base.
  • Such features on the base and the physical tooth models may include, but are not limited to, one or more pins, registration slots, notches, protrusions, holes, interlocking mechanisms, jigs, and pluggable or attachable features.
  • the features may be arranged on the base to receive physical tooth models in arrangements corresponding to at least a portion of a tooth arch model.
  • a digital base model compatible with the physical tooth models is produced.
  • the coordinates of the physical tooth models may be accounted for in the digital base model.
  • Receiving features such as holes and sockets in the base may be specified in the digital base model.
  • the relative positions of the receiving features may be acquired, for example, by scanning and digitizing a patient's tooth arch to produce a digital model of the tooth arch.
  • the base may be fabricated in accordance with the digital base model. This may ensure the accurate assembly of the physical tooth models on the physical base.
  • the same physical tooth models may be attached to the base in two or more different configurations.
  • two or more bases are produced having features arranged in different configurations for receiving physical tooth models.
  • the physical tooth models may be labeled by a predetermined sequence that defines the positions of the physical tooth models on the base. The labels may include, but are not limited to, one or more of a barcode, a printed symbol, a hand ⁇ written symbol, and a Radio Frequency Identification (RFID).
  • RFID Radio Frequency Identification
  • the physical tooth models may be attached to each other to form a physical dental arch or part of a physical dental arch that can be attached to a base.
  • Physical tooth models may be fabricated in accordance with digital tooth models.
  • digital tooth models may be acquired by scanning and digitizing physical tooth models.
  • Implementations may also include one or more of the following.
  • a system for producing a base for physical tooth models may include a computer device adapted to store digital tooth models representing the physical tooth models, a computer processor that is capable of generating a digital base model compatible with the digital tooth models, and an apparatus that can fabricate the base to receive the physical tooth models using CNC based manufacturing in accordance with the digital base model.
  • the base can comprise one or more features to assist the reception of the physical tooth models.
  • the physical tooth models can comprise one or more features to assist the physical tooth models to be received by the base.
  • Implementations may also include one or more of the following.
  • a base for physical tooth models may include a base portion and a plurality of features fabricated by CNC manufacturing, for example, to receive the physical tooth models.
  • the plurality of features may be fabricated in accordance with a digital base model produced in response to the physical tooth models.
  • a base for physical tooth models includes a base plate having a plurality of pairs of sockets. Each pair of sockets is adapted to receive two pins associated with a physical tooth model.
  • the base can further include a plurality of tooth models each having two pins connected at its bottom portion.
  • Each pair of sockets can include a socket on the inside of the tooth arch model and a socket on the outside of the tooth arch model.
  • the physical tooth models include features to allow them to be attached, plugged or locked to a base.
  • the physical tooth models may be pre-fabricated having standard registration and attaching features for assembling.
  • the physical tooth models may be automatically assembled onto a base by a robotic arm under computer control.
  • the physical dental arch model obtained by the disclosed system and methods may be used for various dental applications such as dental crowns, dental bridges, aligner fabrication, biometrics, and teeth whitening.
  • the arch model may be assembled from segmented manufacturable components that can be individually manufactured by automated, precise numerical manufacturing techniques.
  • the same physical tooth models may be used to form different tooth arch models having different teeth configurations.
  • the tooth models may be reused as tooth positions are changed during a treatment process. Much of the cost of making multiple tooth arch models in orthodontic treatment may therefore be eliminated.
  • the same base can support different tooth arch models having different teeth configurations.
  • the base may include more than one set of receiving features that can receive tooth models at different positions.
  • the base may include a plurality of configurations of sockets, with each configurations adapted to receive physical tooth models to form a different arrangement of a tooth arch model. This may reduce cost in the dental treatment of teeth alignment.
  • the physical tooth models in a physical dental arch model may be easily separated, repaired or replaced, and reassembled without the replacement of the whole arch model.
  • a method for producing a physical dental arch model generally includes the steps illustrated in FIG. 30. In some variations the order of these steps is altered, some of these steps are not included, and/or additional steps are included.
  • an individual tooth model is created in step 2500.
  • An individual tooth model is a physical model that can be part of a physical tooth arch model. Physical tooth arch models can be used in various dental applications.
  • registration features are added to the individual tooth model to allow it to be attached to another individual tooth model or to a base.
  • steps 2500 and 2505 happen together, making a separate step 2505 optional.
  • a base is designed for receiving the tooth model. Step 2510 may precede steps 2500 and 2505 in some variations.
  • step 2515 the tooth model positions in a tooth arch model are determined. In some variations this step may precede steps 2500, 2505, and 2510.
  • a base including features for receiving the individual tooth models is fabricated in step 2520. The base may be fabricated in accordance with a digital model. Step 2520 may precede steps 2500 and 2505 in some variations.
  • step 2525 the tooth models are attached to the base.
  • tooth models can be obtained in step 2500 by a number of different methods.
  • the tooth models can be created by casting, for example.
  • a negative impression is first made from a patient's arch using for example PVS.
  • a positive of the patient's arch is next made by pouring a casting material into the negative impression. After the material is dried, the mold may then be taken out with the help of an impression knife. A positive of the arch is thus obtained.
  • the negative impression of the patient's arch is placed in a specially designed container.
  • a casting material is then poured into the container over the impression to create a model.
  • a lid is subsequently placed over the container. The container is opened and the mold can be removed after the specified time.
  • casting materials include, but are not limited to, auto polymerizing acrylic resin, thermoplastic resin, light-polymerized acrylic resins, polymerizing silicone, polyether, plaster, epoxies, or a mixture of materials.
  • the casting material may be selected based on the uses of the cast. For example, the material may be chosen to be easy to cut to obtain individual tooth models. The material may also be chosen to be strong enough for the tooth model to take the pressure in a pressure forming process subsequently used for producing a dental aligner.
  • features that can allow tooth models to be attached to a base can be added to the casting material in the casting process. Registration points or pins can be added to each tooth before the casting material is dried.
  • universal joints can be inserted at the top of the casting chamber using specially designed lids, which would hang the universal joints directly into the casting area for each tooth.
  • Individual tooth models may be cut from the positive arch.
  • the cutting may be done in such a manner that the individual tooth models can be joined again to form a tooth arch.
  • the separation of individual teeth from the mold can be achieved using a number of different cutting methods including, but not limited to, laser cutting and mechanical sawing.
  • Separating the positive mold of the arch into tooth models may result in the loss of the relative 3D coordinates of the individual tooth models in an arch. Several methods may be used for finding the relative positions and orientations of the tooth models in the arch. In one variation, unique registration features are added to each pair of tooth models before the positive arch mold is separated. The separated tooth models can be assembled to form a physical dental arch model by matching tooth models having the same unique registration marks.
  • the positive arch mold may be digitized by three- dimensional scanning using a technique such as, for example, laser scanning, optical scanning, destructive scanning, CT scanning and Sound Wave Scanning to obtain a digital arch model.
  • the digital arch model may track and store the positions and orientations of the individual tooth models in the arch.
  • the digital arch model may be smoothened and segmented and each segment may be physically fabricated by CNC based manufacturing to obtain individual tooth models. Unique registration marks may be added to the digital tooth models and made into physical features in the CNC based manufacturing.
  • the separated tooth models may be assembled by geometry matching.
  • the intact positive arch impression is first scanned to obtain a 3D digital arch model.
  • Individual teeth are then scanned to obtain digital tooth models for individual teeth.
  • the digital tooth models can be matched using rigid body transformations to the digital arch model. Inter-proximal areas, roots of the teeth, and the gingival areas may be ignored in the geometry match due to their complex shape.
  • features such as cusps, points, crevasses, front faces and back faces of the teeth are matched with high precision.
  • Each tooth may be sequentially matched to result in rigid body transformations corresponding to the tooth positions that can reconstruct the arch.
  • the separated tooth models are assembled and registered with the assistance of a 3D point picking device.
  • the coordinates of the tooth models are picked up by 3D point picking devices such as a stylus or microscribe device before separation.
  • Unique registration marks can be added on each tooth model in an arch before separation.
  • the tooth models and the registration marks can be labeled by unique IDs.
  • the tooth arch can later be assembled by identifying tooth models having the same registration marks as were picked from the jaw.
  • Such 3D point picking devices can be used to pick the same points again for each tooth model to confirm the tooth coordinates.
  • the base is designed to receive the tooth models.
  • the base and tooth models may include complimentary features to allow them to be assembled together.
  • the tooth model may have a protruding structure attached to it.
  • Such complimentary features may also include, but are not limited to, registration slots, notches, protrusions, holes, interlocking mechanisms, and jigs.
  • Protruding structures can be obtained, for example, during the casting process or be created after casting by using a CNC machine on each tooth.
  • the positions of the receiving features in the base may be determined, for example, by the initial positions of the teeth in an arch or the desired positions of the teeth during a treatment process (step 2515).
  • a digital model of a tooth arch may be used to select the positions of the receiving features in a base.
  • the digital arch model may represent a patient's existing tooth arch or desired positions of the teeth.
  • a digital model of the base may be constructed in accordance with the locations of the teeth in the digital arch model and with the locations and orientations on the corresponding individual physical tooth models of features such as pins, for example, with which the individual physical tooth models will be attached to the base.
  • the digital base model may specify the locations on the base of features such as sockets or holes, for example, that will receive features on the individual tooth models to attach the individual tooth models to the base.
  • the base may be fabricated in accordance with the digital base model by, for example, CNC manufacturing. After fabrication of the base, physical tooth models may be inserted into the receiving features in the base to form a physical dental arch model matching the digital model. Fabrication of the base from a digital model may ensure accurate assembly of the physical dental arch model.
  • step 2520 the base plate is taken through a CNC process, for example, to create female structures for each individual tooth before a positive arch is cast from the negative impression.
  • the base is then placed over a casting chamber containing the impression and the chamber is filled with epoxy.
  • the female structures fill with epoxy and the resulting mold has male studs present on each tooth model to be later separated from the positive arch.
  • FIG. 31 shows a tooth model 2530 with male stud 2535 after mold separation.
  • the base 2540 comprises a female feature 2545 that can receive the male stud 2535 when the tooth model 2530 is assembled to the base 2540.
  • a tooth model 2550 includes a female socket 2555 that can be drilled by CNC based machining, for example, after casting and separation.
  • a male stud 2560 that fits the female socket 2555 can be attached to the tooth model 2550 by for example, screwing or gluing.
  • the resulting tooth model 2565 includes male stud 2560 that allows it to be attached to the base.
  • tooth models are provided with male protrusion features allowing the tooth models to be attached to a base.
  • FIG. 33 shows a tooth model 2570 having two pins 2575 sticking out and a base 2580 having registration slots 2585 adapted to receive the two pins 2575 to allow the tooth model 2570 to be attached to the base 2580.
  • FIG. 34 shows a tooth model 2590 having one pin 2595 protruding out at an angle and a base 2600 having a hole 2605 adapted to receive pin 2595 to allow, the tooth model 2590 to be attached to the base 2600.
  • FIG. 35 shows a tooth model 2610 having cone shaped studs 2615.
  • the base will have a number of holes or receiving features complimentary to the number of male protrusions on the tooth models at the corresponding locations for each tooth model.
  • the studs can take different shapes such as, for example, oval, rectangle, square, triangle, circle, and semi-circle.
  • the shapes may be selected to correspond to slots on the base having identical shapes. Such slots can be drilled, for example, using CNC based machining.
  • studs that are asymmetrically shaped or protrude tilted at an angle to the tooth base can help to define a unique orientation for the tooth model on the base.
  • a base 2630 has a plurality of sockets 2635 and 2640 for receiving the studs of a plurality of tooth models.
  • the positions of the sockets 2635, 2640 may be determined, for example, by the initial positions of the teeth in a patient's arch or by tooth positions during an orthodontic treatment process.
  • Base 2630 may be in the form, for example, of a plate comprising a plurality of pairs of sockets 2635, 2640 as shown in FIG. 37A.
  • Each pair of sockets 2635, 2640 may be adapted to receive two pins associated with a physical tooth model.
  • Each pair of sockets may include a socket 2635 on the inside of the tooth arch model and a socket 2640 on the outside of the tooth arch model.
  • Sockets 2635, 2640 may be drilled or milled, for example, by machining in accordance with a digital base model. The positions of the sockets 2635, 2640 may be specifically defined in the digital base model. Simulations may be done before hand to examine the interaction between the digital base model and digital tooth models to ensure the dental arch is as specified by the orthodontic treatment.
  • FIG. 37B shows a base 2645 according to another variation.
  • a plurality of pairs of female sockets 2650, 2655 are provided in base 2645.
  • Each pair of the sockets 2650, 2655 may be formed in a surface 2660 and may be adapted to receive a physical tooth model 2665.
  • the bottom portion of physical tooth model 2665 includes a surface 2670. The surface 2670 makes contact with the surface 2660 when the physical tooth model 2665 is inserted into the base 2645, which assures the stability of the physical tooth model 2665 over the base 2645.
  • FIG. 38 shows one variation of a tooth model 2675 compatible with a base
  • Tooth model 2675 includes two pins 2680 connected to its bottom portion. The two pins 2680 can be plugged into a pair of sockets 2635 and 2640 on the base 2630. Thus each pair of sockets 2635 and 2640 may uniquely define the positions of a tooth model. The orientation of the tooth model may also be uniquely defined if the two pins are labeled as inside and outside, or the sockets and the pins are made asymmetric inside and outside.
  • Each tooth model may include one or a plurality of studs or pins that are to be plugged into a corresponding number of sockets in a base. In some variations, male studs and corresponding sockets may take different shapes as described above. In some variations, a tooth model sits on a small surface milled in the base and features such as pins or studs prevent the tooth model from rotating or shifting.
  • a physical tooth arch model may be obtained, for example, by assembling tooth models on a base such as base 2630 (step 2525).
  • base 2630 may comprise a plurality of configurations of female sockets 2635 and 2640.
  • each of the configurations may be adapted to receive the same physical tooth models to form a different arrangement of at least a portion of a tooth arch model.
  • bases such as base 2630 can be fabricated by a system that includes a computer device adapted to store digital tooth models representing the physical tooth models. As described above, the digital tooth models can be obtained by various scanning techniques. A computer processor may then generate a digital base model compatible with the digital tooth models. An apparatus fabricates the base using, for example, CNC based manufacturing in accordance with the digital base model. The base fabricated is adapted to receive the physical tooth models.
  • features for receiving tooth models such as sockets or holes, for example, are formed in a base using laser-based technologies.
  • a laser beam may be focused precisely at the locations of the receiving features.
  • the intensity and duration of the laser beam may then be controlled, for example, to heat, melt or vaporize the base material to form the receiving features.
  • the laser 2685 may be a carbon dioxide laser under CNC control.
  • the laser beam 2690 may be focused on a base plate 2695 by an optical system 2700 comprising a pressurized gas inlet 2705.
  • the cutting process may be automated by a computer 2710.
  • the base plate 2695 may be transported by a transport system 2715 such as a motorized X-Y stage under the control of computer 2710, for example.
  • the coordinates of female sockets 2720 may be input to the CNC machine.
  • the coordinate information may be derived from the digital dental arch model and/or digital base models as previously described.
  • the base plate 2695 may be moved into positions allowing the laser beam to be focused at the intended locations where the sockets are to be made.
  • a laser beam may be emitted under the control of the computer 2710 and focused at the intended locations.
  • the laser beam 2690 may heat the illuminated areas on the base plate to cause heating, melting, ablation, and/or evaporation of the base plate material.
  • the socket 2720 may be cut by the laser beam under the control of the computer 2710.
  • a microscope may be mounted for examining the result of the cutting for minor refinement.
  • the intensity and temporal duration of the emitted laser beam 2690 may be controlled according to the properties of the base plate 2695 so that the socket 2720 can be produced accurately in width, depth and shape.
  • the pins in the under side of physical tooth models may be shaped in accordance with the spatial profile of the emitted laser beam 2690. This may ensure that the pins affixed to the tooth models are compatible with and fit the sockets.
  • the emitted laser beam 2690 may produce a cone shaped socket in the base plate 2695 and the tooth model may include cone shaped studs such as studs 2615 on tooth model 2610 shown in FIG. 35.
  • a plurality of laser beams may be used to form the socket 2720.
  • Different laser beam may include different intensity, frequencies, spatial profiles, and directions of illumination. For example, one laser may be used to burn a large hole and another laser may be used to cut fine features to the final shape of the socket.
  • bases formed by laser fabrication technologies need no further finishing after the sockets are formed.
  • Laser fabrication may have the advantage, in some variations, of not requiring physical contact with the base.
  • the laser optics may include other arrangements.
  • a flying optics system may include mirrors that can scan the laser beam across a stationary base in two dimensions.
  • a fixed optics system may keep the laser and optics stationary while the work piece is moved in both X and Y axes, as shown in FIG. 39.
  • a hybrid system may move the laser and optics in one axis and the base in another axis.
  • physical tooth models may be labeled by a predetermined sequence that defines the positions of the physical tooth models on, for example, the base 2630.
  • labels may include, but are not limited to, a barcode, a printed symbol, a hand ⁇ written symbol, and a Radio Frequency Identification (RPID).
  • RPID Radio Frequency Identification
  • Female sockets such as sockets 2635, for example, may also be labeled by the parallel sequence for the physical tooth models.
  • physical tooth models can be removed from a base, repaired or replaced, and re-assembled without the replacement of the whole arch model.
  • Tooth models may be fabricated from materials including, but not limited to, polymers, urethane, epoxy, plastics, plaster, stone, clay, acrylic, metals, wood, paper, ceramics, and porcelain.
  • Bases may be fabricated from materials including, but not limited to, polymers, urethane, epoxy, plastics, plaster, stone, clay, acrylic, metals, wood, paper, ceramics, porcelain, glass, and concrete.
  • a physical dental arch model may be used in dental applications such as, for example, dental crowns, dental bridges, aligner fabrication, biometrics, and teeth whitening.
  • aligner fabrication for example, each stage of the teeth treatment may correspond to a unique physical dental arch model.
  • Aligners may be fabricated, for example, using different physical dental arch models one at a time as tooth movement progresses during the treatment. In one variation, at each stage of the treatment the desired tooth positions for the next stage are determined. A physical dental arch model having modified teeth positions is fabricated using the process described above. A new aligner may be made using the new physical dental arch model.
  • each physical arch model may use a separate base.
  • one base may be used for two or more physical arch models.
  • a base may include a plurality of sets of receiving features for physical tooth models, with each set corresponding to a different treatment stage.
  • a base 2725 may comprise multiple sets of sockets 2730, 2735, 2740, and 2745 each for receiving a dental arch in a different configuration.
  • each configuration may be adapted to receive the same physical tooth models to form a different arrangement of a tooth arch model.
  • the base may be assembled from a plurality of base components.
  • the base components may comprise features to assist the assembly of the base components to form the base for the dental arch model such as, for example, pins, registration slots, sockets, notches, protrusions, holes, interlocking mechanisms, jigs, and pluggable or attachable features.
  • the base components may be individually replaced to form a different base configuration without changing the base components that are not changed in the orthodontic steps.
  • positions of physical tooth models in a tooth arch model are described below.
  • the positions may be acquired using mechanical location devices.
  • the positions may be acquired, for example, using optical or magnetic location devices.
  • the position information may then be used in the production of the physical tooth arch model.
  • methods for producing a base configured to receive physical tooth models may comprise, for example, acquiring the coordinates of the physical tooth models in the physical dental arch model using a mechanical or an optical location device, determining the configurations of first features affixed to the physical tooth models, and determining the locations of second features in the base in accordance with the coordinates of the physical tooth models in the physical dental arch model and the configurations of the first features.
  • the second features may be configured to receive the first features affixed to the physical tooth models.
  • the first features may be, for example, pins or studs.
  • the second features may be, for example, sockets or holes adapted to receive pins or studs.
  • methods for producing a base configured to receive physical tooth models comprise acquiring the coordinates of the physical tooth models in the physical dental arch model from an impression of a patient's arch using a mechanical or an optical location device, and determining the locations of the physical tooth models in the base in accordance with the coordinates of the physical tooth models in the physical dental arch model.
  • methods for acquiring the coordinates of a patient's dental arch comprise obtaining an impression of the patient's arch, touching a point on the surface of the impression with a stylus connected to a plurality of rigidly connected marking objects, capturing an image of the plurality of rigidly connected marking objects, determining the coordinates of the marking objects, and using the coordinates of the marking objects to calculate the position of the stylus to obtain the coordinates of the point on the surface of the impression.
  • the physical dental arch models comprise one or more physical tooth models each including a tooth portion and two or more first features affixed to the bottom of the tooth portion, and a base including a plurality of second features configured to receive the first features affixed to the physical tooth models.
  • the locations of the second features may be determined by the coordinates acquired from the impression of a patient arch using a mechanical or an optical location device.
  • the first features may be, for example, pins or studs.
  • the second features may be, for example, sockets or holes adapted to receive pins or studs.
  • a method for producing a physical dental arch model generally includes the steps illustrated in FIG. 41. In some variations the order of these steps is altered, some of these steps are not included, and/or additional steps are included.
  • step 2800 the positions of physical tooth models in a tooth arch model are acquired using a mechanical location device.
  • An individual tooth model is created in step 2805.
  • An individual tooth model is a physical model that can be part of a physical tooth arch model.
  • registration features are added to the individual tooth model to allow it to be attached to another individual tooth model or to a base.
  • steps 2805 and 2810 happen together, making a separate step 2810 optional.
  • step 2815 the tooth model positions acquired in step 2800 are used to design a base having features such as sockets, for example, for receiving the tooth models.
  • Step 2815 may precede steps 2805 and 2810 in some variations.
  • the base is fabricated in step 2820.
  • step 2825 the tooth models are attached to the base.
  • steps 2805 - 2825 may be substantially similar to corresponding steps in the process of FIG. 30 discussed above. Consequently, only step 2800 is now described.
  • a dental impression 2830 of a patient's arch may be made using, for example, a pre-designed container 2835, as shown in FIG. 42.
  • the impression may be fixed in the container using an epoxy, for example.
  • the relative positions of the patient's teeth may be measured off the impression using a mechanical location device 2840.
  • An example of a mechanical location device is the Microscribe available from Immersion Corporation. Microscribe is a hand-held 3D digitizer that can develop a digital computer model for an existing 3D object. Other 3D digitizers that can be use to create three-dimensional digital representations of physical objects may also be suitable.
  • the mechanical location device 2840 may include mechanical arms 2845, 2850 having one or more mechanical joints 2855.
  • Mechanical joints 2855 may be equipped with precision bearings for smooth manipulation and internal digital optical sensors for decoding the motion and rotation of the mechanical arms 2845, 2850.
  • the end segment may be a stylus 2857 that can be manipulated to touch points on the dental impression 2830 held in the container 2835.
  • the mechanical location device 2840 may be fixed to a common platform with the container 2835.
  • accurate 3D positional and angular information of the points that the stylus touches may be decoded and output at an electronic output port 2860.
  • information about six degrees of freedom may be obtained by an additional decoder for self-rotation of the stylus.
  • Additional sensors may be placed at the tip of the stylus to measure the hardness of the surface of the object measured.
  • Immersion Corporation's MicroScribe uses a pointed stylus attached to a CMM-type device to produce an accuracy of .009 inches, for example.
  • a user selects points of interest at each tooth position in the impression and places the stylus at those points. Positional and angular information may be decoded and then transmitted to a computer. In this way, Cartesian XYZ coordinates may be acquired, for example, for each tooth or for each first feature (e.g., pin or stud) location and orientation.
  • first feature e.g., pin or stud
  • a user may establish a coordinate system based on the container or chamber in which the arch impression is held.
  • the user may establish this system by taking readings for two points on two sides of the container to define the x axis. Another reading on the plane establishes the x-y plane. An origin may then be determined on the x-y plane.
  • the z axis may be established by taking the cross product of the x and y axes.
  • a user selects a plurality of points on the surfaces of the arch impression corresponding to each tooth.
  • the 3D points measured from the impression surfaces may then be interpolated to create surfaces and solids integrated into an overall digital model.
  • the number of points defining the curves and the number of curves depends on the desired resolution in the model.
  • surfacing functions offered by the design application software may be used to create and blend the model surfaces.
  • the model may be shaded or rendered, defined as a solid or animated depending on the designer's intentions.
  • the teeth in the digital model may be labeled so that the order of the physical tooth models can be properly defined for the physical dental arch model.
  • readings acquired by the stylus can be rendered in real time to allow the user to visualize the digital tooth models.
  • the coordinate axes and points may be rendered in the software using different colored cylinders/spheres etc. so as to distinguish the different meanings of values.
  • the user will first take a reading that will establish the center of two pins on or to be attached to the tooth and their orientation vector. Then the user will take two more points that will give the direction to move from the center of the pins. The dimensions and positions of the two pins may be calculated using these values. The pins may then be visually rendered in the software. The user may fine tune these readings as required. After the readings for each pin have been acquired, their locations and orientations may be saved
  • a digital arch model including a plurality of digital tooth models is developed based on the locations and orientations of features such as, for example, pins or studs and/or on the coordinates of physical tooth models acquired by the mechanical location device.
  • the digital arch model may be used, for example, to control CNC based drilling or milling of features (e.g., holes or sockets) in a base to receive features such as, for example, pins or studs on physical tooth models in a physical dental arch model.
  • One example of a detailed process for defining pin locations is as follows: 1) establish a new coordinate system based on the arch impression-container chamber, a) take 3D coordinate readings for two points (on the left and right side of the container) that will establish the x axis, b) take a number of readings on the plane that will be the x-y plane, c) calculate the circumcenter of these two sets of points on each side, d) find the midpoint of the circumcenter and mark it as the origin, e) establish the y axis by taking the perpendicular bisector of this line segment, f) establish the z axis by taking the cross product of the x and y axes; 2) find the highest point inside the container chamber ,a) take readings for many points on the impression, b) use the max value of z as the highest point; 3) acquire the pin readings for each tooth in the arch impression, a) take a reading that will establish the center of the two pins, and their orientation
  • a method for producing a physical dental arch model generally includes the steps illustrated in FIG. 43. In some variations the order of these steps is altered, some of these steps are not included, and/or additional steps are included.
  • step 2865 the positions of physical tooth models in a tooth arch model are acquired using an optical location device.
  • An individual tooth model is created in step 2870.
  • step 2875 registration features are added to the individual tooth model to allow it to be attached to another individual tooth model or to a base.
  • steps 2870 and 2875 happen together, making a separate step 2875 optional.
  • the tooth model positions acquired in step 2865 are used to design a base having features such as sockets, for example, for receiving the tooth models.
  • Step 2880 may precede steps 2870 and 2875 in some variations.
  • the base is fabricated in step 2885.
  • step 2890 the tooth models are attached to the base.
  • steps 2870 - 2890 may be substantially similar to corresponding steps in the process of FIG. 41 discussed above. Consequently, only step 2865 is now described.
  • an impression 2895 of a patient's tooth arch is obtained and held in a container 2900, as shown in FIG. 44.
  • the relative positions of the patient's teeth may be measured off impression 2895 using an optical location system 2905 comprising, for example, a location device 2910 and a camera system 2915.
  • location device 2910 comprises, for example, three marking objects 2920, 2925, and 2930 that are connected by "T" shaped linking arms 2935. Marking objects 2920, 2925, 2930 may be shaped, for example, as spheres, boxes, or triangles and may be of different shapes and colors for ease of pattern recognition.
  • the marking objects may be balls of different colors such as, for example, red, green and black.
  • Location device 2910 also comprises a stylus 2940 that may be placed in contact with the surface of the impression 2895. The six degrees of freedom of the location device 2910 may be obtained by various techniques.
  • the tip of stylus 2940 is brought in contact with a point on the impression surface and camera system 2915 captures images of the location device 2910.
  • Camera system 2915 may include a plurality of cameras that point at location device 2910 from different viewing angles.
  • the positions and orientations of the "T" shaped linking arms 2935, and thus the location and orientation of stylus 2940 as well as the location of the point in impression 2895 it contacts, may be obtained by image analysis. For example, the center of each marking object 2920, 2925, 2930 may be determined and the coordinates of marking objects 2920, 2925, 2930 obtained using triangulation techniques.
  • the "T" shape of linking arms 2935 may be reconstructed. Distances may be derived by pattern recognition.
  • the tip of stylus 2940 may then be moved to a different point on the surface of impression 2895 and images of location device 2910 again captured and analyzed. In this way coordinates may be acquired, for example, for the surfaces of the teeth in impression 2895 and/or for each first feature (e.g., pin or stud).
  • first feature e.g., pin or stud
  • the image analysis and processing may include a search for a specific object in a binary image including objects of various shapes, positions, and orientations. Such a search is often referred to as "chamfer matching."
  • Chamfer matching uses an edge matching technique in which the edge points of one image are transformed by a set of parametric transformation equations to edge points of a similar image that is slightly different. For example, spherically shaped marking objects may be fit to pre ⁇ designed circles in the image. The positions of the marking objects 2920, 2925, 2930 may be obtained exactly using chamfer matching. These positions may be used to determine the position of the tip of the stylus 2940 on the surface of the dental impression 2895.
  • the captured images may contain noise in some variations.
  • the noise which may affect the accuracy of coordinate calculations, may be removed by several techniques such as, for example, transparent pen. Care should be taken to avoid producing artificial information with the noise removal process, as that may also affect the accuracy of calculations.
  • markers that reflect infra-red (IR) light may be attached to the marking objects 2920, 2925, 2930, and light emitting diodes (LEDs) that emit IR light may be mounted on or near one or more cameras to illuminate the marking objects.
  • the camera lenses may be shielded with IR pass filters. The light emitted from the LEDs is reflected by the markers and then captured by the cameras.
  • the centers of the marker images may be matched from the various camera views using triangulation to compute their frame-to-frame positions in 3D space.
  • the coordinates of the markers and hence of the stylus may then be calculated.
  • the marking objects 2920, 2925, 2930 may be marked by reflectors that reflect light in visible wavelengths.
  • the reflectors serve as reference points in the successive images to assist in tracking the movement of the marking objects.
  • a magnetic motion capture system is used to track the locations of the marking objects. Magnets and magnetic sensors may be attached to each of the marking objects 2920, 2925, 2930. The magnets and the sensors may be connected with cables to a magnetic motion tracking system. The sensors detect low- frequency magnetic fields generated by the magnets. The detected signals may be used to calculate the locations of the transmitting sources, that is, the magnets. Positional and rotational information about the balls can be obtained, stored, and displayed by a computer system, for example.
  • a magnetic motion tracking system includes six or more sensors per marking object.
  • a digital arch model including a plurality of digital tooth models may be developed based on the locations and orientations of features such as, for example, pins or studs and/or on the coordinates of physical tooth models acquired by the location device.
  • the digital arch model may then be used, for example, to control CNC based manufacturing of a base to receive physical tooth models in a physical dental arch model.
  • methods for producing a physical dental arch model having one or more physical tooth models are described.
  • the methods may comprise, for example, producing a digital base model compatible with the physical tooth models, producing a base having receiving features using CNC based manufacturing in accordance with the digital base model, producing adjustment jigs, and assembling the physical tooth models and adjustment jigs with the base at the receiving features to form the physical dental arch model.
  • methods for producing a physical dental arch model having one or more adjustable physical tooth models are described.
  • the methods may comprise, for example, providing a universal joint including an inner rotative joint member and an outer joint member housing the inner rotative joint member, attaching one of the inner rotative joint member and the outer joint member to a receiving feature on a base, attaching a physical tooth model to another one of the inner rotative joint member and the outer joint member of the universal joint; and rotating the physical tooth model relative to the base.
  • systems for producing a physical dental arch model may comprise, for example, a computer storage device adapted to store digital tooth models for the physical tooth models, a computer processor that is capable of generating a digital base model compatible with the digital tooth models, and an apparatus that can fabricate the base having receiving features using CNC based manufacturing in accordance with the digital base model.
  • the physical tooth models can be assembled with adjustment jigs at the receiving features of the base to form the physical dental arch model.
  • the physical dental arch models may comprise, for example, a base having receiving features, physical tooth models associated with the receiving features on the base, and adjustment jigs adapted to be assembled with the physical tooth models at the receiving features of the base.
  • the physical dental arch models may also comprise, for example, an adjustment jig configured to receive a physical tooth model and to enable rotations of the physical tooth model around at least two separate axes, and a base configured to receive the adjustment jig such that the physical tooth model can rotate relative to the base around at least the two separate axes.
  • the physical dental arch models may also comprise, for example, a universal joint including an inner rotative joint member and an outer joint member housing the inner rotative joint member, a base configured to receive one of the inner rotative joint member and the outer joint member, and a physical tooth model to be attached to another one of the inner rotative joint member and the outer joint member such that the physical tooth model can rotate relative to the base.
  • a universal joint including an inner rotative joint member and an outer joint member housing the inner rotative joint member, a base configured to receive one of the inner rotative joint member and the outer joint member, and a physical tooth model to be attached to another one of the inner rotative joint member and the outer joint member such that the physical tooth model can rotate relative to the base.
  • Implementations may include one or more of the following.
  • a method for producing a physical dental arch model having one or more physical tooth models may include producing a digital base model compatible with the physical tooth models, producing a base having receiving features using CNC based manufacturing in accordance with the digital base model, producing adjustment jigs, and assembling the physical tooth models and adjustment jigs with the base at the receiving features to form the physical dental arch model.
  • the adjustment jigs may be capable of adjusting one or more translational and/or rotational degrees of freedom of the physical tooth models.
  • an adjustment jig comprises a universal joint.
  • a physical tooth model may be associated with one or more jigs at a receiving feature of the base. Two jigs at a receiving feature of the base may adjust a combination of translational and/or rotational degrees of freedom of the physical tooth models. Rotational adjustment may be achieved in combination with translational adjustment to allow flexible adjustment of the physical tooth models in all six degrees of freedom.
  • the jigs may be labeled in accordance with the degrees of freedom and the extent of the adjustment they can make to the position or orientation of physical tooth models.
  • physical tooth models can be assembled in two or more different configurations on the same base by using sets of jigs corresponding to the different configurations.
  • the different tooth configurations may correspond, for example, to different stages of an orthodontic treatment process. This may reduce the cost of making tooth arch models for orthodontic treatments.
  • Implementations may also include one or more of the following.
  • a system for producing a physical dental arch model having one or more physical tooth models may comprise a computer storage device adapted to store digital tooth models for the physical tooth models, a computer processor that is capable of generating a digital base model compatible with the digital tooth models, and an apparatus that can fabricate the base having receiving features using CNC based manufacturing in accordance with the digital base model.
  • the physical tooth models may be assembled with adjustment jigs at the receiving features of the base to form the physical dental arch model.
  • the adjustment jigs may be capable of adjusting the translational or rotational degrees of freedom of the physical tooth models over the base.
  • the system may further comprise a device that is capable of fabricating the adjustment jigs to be assembled with the physical tooth models at the receiving features of the base.
  • a method for producing a physical dental arch model generally includes the steps illustrated in FIG. 45. In some variations the order of these steps is altered, some of these steps are not included, and/or additional steps are included.
  • an individual tooth model is created in step 3000.
  • registration features are added to the individual tooth model to allow it to be attached to another individual tooth model or to a base.
  • steps 3000 and 3005 happen together, making a separate step 3005 optional.
  • a base is designed for receiving the tooth model. Step 3010 may precede steps 3000 and 3005 in some variations.
  • step 3015 the tooth model positions in a tooth arch model are determined. In some variations this step may precede steps 3000, 3005, and 3010.
  • a base including features for receiving the individual tooth models is fabricated in step 3020.
  • Step 3020 may precede steps 3000 and 3005 in some variations.
  • adjustment jigs are fabricated in step 3025 .
  • step 3030 the orientations and micro-positions of the tooth models in the tooth arch model are determined so that appropriate jigs can be selected for each tooth model.
  • step 3035 the tooth models are attached to the base with adjustment jigs to form the tooth arch model.
  • steps 3000-3020 may be substantially similar to corresponding steps in the process of FIG. 30 discussed above. Consequently, only the fabrication and use of adjustment jigs is now described.
  • an adjustment jig is a device that includes a first feature that allows it to be attached or plugged to a base and a second feature that allows it to receive a physical tooth model.
  • Such attachment features may include, but are not limited to, pins, slots, notches, protrusions, holes, and interlocking mechanisms.
  • a physical tooth model attached to a base via such an adjustment jig may have a position and/or orientation altered compared to that which would result from attaching the physical tooth model directly to the base.
  • adjustment jigs may be fabricated using CNC based manufacturing. For example, once desired tooth positions and orientations are known they may be input into a digital arch model and used to drive CNC fabrication of the jigs. Each adjustment jig may be fabricated to provide a specific combination of positional and orientational adjustment.
  • Adjustment jigs may take various forms. Some example adjustment jigs, according to one variation, are shown in FIG. 46A-46D.
  • FIG. 46A shows an adjustment jig 3040 comprising a body portion 3045, two pins 3050 (first feature) connected to the bottom of the body portion 3045, and two pins 3055 (second feature) connected to the top of the body portion 3045.
  • the pins 3050 may be plugged, for example, into sockets 2635, 2640 on base 2630 shown in FIG. 37A discussed above.
  • Pins 3055 are adapted to be plugged, for example, into sockets made in the bottom of a physical tooth model.
  • Adjustment jig 3040 provides a physical tooth model an upward positional translation (i.e.
  • adjustment jig 3060 shown in FIG. 46B provides a tooth model a downward positional translation (i.e. intrusion), compared to an average height, without rotational adjustment.
  • Adjustment jig 3065 shown in FIG. 46C provides a tooth model a tipping rotation off the vertical axis.
  • Adjustment jig 3070 shown in FIG. 46D provides a tooth model a combination of a tipping rotation off the vertical axis and a torsional rotation around the vertical axis.
  • adjustment jigs may include studs 3080 as shown in
  • Rotational adjustment of tooth models may be achieved by studs 3080 that may be plugged into the sockets on a base 3085 at the low ends.
  • the upper ends of the studs 3080 may be plugged into sockets in physical tooth models to assemble the tooth models to the base with a desired rotational adjustment.
  • FIG. 48 illustrates adjustment jigs according to another variation.
  • adjustment jigs 3090, 3095, 3100 provide different increments of translational adjustments.
  • translational adjustments may be along one-dimension or two dimensions.
  • Adjustment jigs 3090, 3095, 3100 may be used in combination with adjustment jigs 3040, 3060, 3065, 3070, and studs 3080.
  • FIG. 49 shows a rotational adjustment jig 3105 according to another variation.
  • Rotational adjustment jig 3105 may be used, for example, alone or in combination with other adjustment jigs.
  • FIG. 49 shows rotational adjustment jig 3105 mounted on top of a translational adjustment jig 31 10.
  • a tooth arch model may be obtained, for example, by plugging adjustment jigs or combinations of adjustment jigs into sockets in a base, and then attaching physical tooth models to the adjustment jigs.
  • adjustment jigs may be shared by different tooth models in a tooth arch model and/or shared between different stages of an orthodontic treatment.
  • adjustment jigs may be labeled as to their degree of adjustment by, for example, a barcode, a printed symbol, a hand-written symbol, or a Radio Frequency Identification (RFID).
  • RFID Radio Frequency Identification
  • Corresponding sockets in a base may also be labeled by the parallel sequence for the physical tooth models.
  • a treatment plan specifies the exact positional and orientational adjustments for each tooth model.
  • Appropriate adjustment jigs may be used for each physical tooth model at each receiving location on the base to realize the specified positional and orientational adjustments. This capability may reduce the need for making different tooth arch model at each stage of the orthodontic treatment, and thus may reduce the cost of the treatment.
  • an adjustment jig 31 15 may include a universal joint 3120 mounted on a translation stage 3125.
  • Translation stage 3125 may be attached to a physical base comprising, for example, one or more receiving features configured to receive the adjustment jig.
  • the receiving features may include, but are not limited to, pins, slots, notches, protrusions, holes, interlocking mechanisms, and other pluggable or attachable feature.
  • the combination of the universal joint 3120 and the translation stage 3125 may enable the physical tooth model to be adjusted with six degrees of freedom relative to the base as well as relative to adjacent physical tooth models in the physical dental arch model.
  • the universal joint 3120 includes an inner rotative joint member 3130 and an outer joint member 3135 that houses the inner rotative joint member 3130.
  • the inner rotative joint member 3130 comprises a spherical outer surface.
  • the inner rotative joint member 3130 is affixed with a pin or handle 3140 that is adapted to be attached to a physical tooth model.
  • the physical tooth model may include features to assist the physical tooth model to be mounted on the adjustment jig.
  • the features may include, but are not limited to, pins, slots, notches, protrusions, holes, interlocking mechanisms, and other pluggable or attachable features.
  • the outer joint member 3135 may be a shell having a spherical inner surface that is adapted to make contact with the spherical outer surface of the inner rotative joint member 3130. This may allow flexible rotation of the inner rotative joint member 3130 and the associated tooth model attached to it.
  • the rotational adjustment may include polar rotations, azimuthal rotations, and self rotations around the pin or handle 3140. This allows orientational adjustment of the physical tooth model relative to the base.
  • the inner rotative joint member 3130 may be clamped to the outer joint member 3135 by clamp mechanism 3145 to stop their relative rotation.
  • the translational movement may be similarly stopped by, for example, set screws.
  • outer joint member 3135 may be attached to a physical tooth model and inner rotative joint member 3130 may be attached to the base or to the translation stage 3125.
  • the orientations of the physical tooth model may be adjusted relative to the base similarly to as described above.
  • the degree of orientational and positional adjustments of the physical tooth models may be measured and calibrated with precision position measurement devices such as, for example, the Microscribe available from Immersion Corporation. Adjustments may be made, for example, in accordance with a digital dental arch model that defines the rigid-body rotations and translations necessary for each physical tooth model at each step of the treatment. A digital dental arch model may also allow simulations of the adjustments and prevention of interference between adjacent tooth models.
  • the physical tooth models, their associated adjustment jigs, and the corresponding receiving features on the base may be labeled in accordance with a predetermined configuration of physical tooth models in the physical dental arch model. The receiving features on the base correspond to teeth in the patient's arch.
  • the receiving features may be defined by their positions on the base.
  • the adjustment jigs and the physical tooth models may be tagged, for example, by alphanumerical symbols, barcodes and/or Radio Frequency Identification (RFID) which define the correspondence of the jigs to the patient's teeth.
  • RFID Radio Frequency Identification
  • the physical tooth models and their associated adjustment jigs may later be assembled to the corresponding receiving features on the base in accordance with the predetermined configuration of physical tooth models in the physical dental arch model.
  • the adjustment jigs may also allow the physical models to be adjusted or reassembled in accordance with another configuration of physical tooth models in the physical dental arch model.
  • the fabrication of the physical tooth models may include the use of their associated adjustment jigs to ensure compatibility and precision in the assembling of the physical arch model.
  • a universal joint may be directly inserted into the casting material using specially designed lids for the casting chamber.
  • the physical tooth models, the adjustment jigs having the universal joint, and the base having the receiving features may all be included in a combined digital model. This may be accomplished, for example, using CAD software.
  • the model may be segmented into CNC manufacturable components. The compatibility between the segmented components may be simulated prior to their manufacture.
  • the physical dental arch model may then be obtained by assembling the fabricated components.
  • the methods may comprise, for example, determining the positions and orientations of two adjacent physical tooth models in the physical dental arch model, and selecting the configurations of pins to be affixed to the bottoms of the two adjacent physical tooth models such that the two adjacent physical tooth models do not interfere with each other when the two physical tooth models are mounted to a base by inserting the pins into corresponding sockets in the base.
  • the methods may also comprise, for example, determining the positions and orientations of a first physical tooth model, determining the positions and orientations of a second physical tooth model that is adjacent to the first physical tooth model, checking for interference between the first physical tooth model and the second physical tooth model, modifying the positions and orientations of at least one of the physical tooth models to prevent interference if interference is detected, and fabricating the first physical tooth model and the second physical tooth model in accordance with the modified positions and orientations of the first physical tooth model and/or the second physical tooth model.
  • the methods may also comprise, for example, producing a digital dental arch model that simulates the positions and orientations of a first physical tooth model and the positions and orientations of a second physical tooth model that is adjacent to the first physical tooth model, checking for interference between the first physical tooth model and the second physical tooth model, modifying the positions and orientations of at least one of the physical tooth models in the digital dental arch model to prevent interference if interference is detected, and fabricating the first physical tooth model and the second physical tooth model in accordance with the modified digital arch model.
  • the methods may also comprise, for example, producing a digital dental arch model that simulates the positions and orientations of a first physical tooth model and the positions and orientations of a second physical tooth model that is adjacent to the first physical tooth model, where the physical tooth models include mounting features allowing them to be mounted to a base, checking for interference between the physical tooth models, modifying the configurations of the mounting features of one or both of the physical tooth models to prevent interference if interference is detected, and fabricating the physical tooth models including the mounting features in accordance with the modified digital arch model.
  • the physical dental arch models may comprise, for example, a base comprising a plurality of sockets that are configured to receive physical tooth models, and two physical tooth models each comprising a tooth portion and two or more pins affixed to the bottom of the tooth portion. Pins of the two physical tooth models are configured to prevent interference between the two physical tooth models when they are inserted in the base.
  • the positions and the orientations of tooth models may be iteratively modified until all interference between adjacent tooth models in an arch model are removed before the physical tooth models are fabricated.
  • Some variations may enable adjacent physical tooth models in a physical dental arch model to be assembled without interference between the tooth models. This may result in the positions and orientations of the tooth models more accurately representing desired configurations in orthodontic treatments.
  • pin configurations on physical tooth models may be modified to prevent interference without otherwise changing the physical tooth models. This may allow physical tooth models to be reused as tooth positions are changed during a treatment process. Reuse of physical tooth models may reduce the cost of making physical tooth arch models in some variations.
  • receiving features in a base may be modified to receive tooth models having different pin configurations to avoid interference between adjacent tooth models in a tooth arch model and/or to avoid interference during insertion of the physical tooth models.
  • a method for producing a physical dental arch model generally includes the steps illustrated in FIG. 51. In some variations the order of these steps is altered, some of these steps are not included, and/or additional steps are included.
  • an individual tooth model is created in step 3200.
  • registration features such as pins, for example, are added to the individual tooth model to allow it to be attached to another individual tooth model or to a base.
  • steps 3200 and 3205 happen together, making a separate step 3205 optional.
  • a base is designed for receiving the tooth model. Step 3210 may precede steps 3200 and 3205 in some variations.
  • step 3215 the tooth model positions in a tooth arch model are determined.
  • this step may precede steps 3200, 3205, and 3210.
  • step 3220 some or all adjacent tooth models are checked to determine if they will interfere with each other during or after being mounted on a base to form a tooth arch. If no interference is detected, the process skips to step 3230. If interference is detected in step 3220, then in step 3225 the configurations of features on the physical tooth models such as pins, for example may be selected and/or modified to prevent the interference.
  • a base including features for receiving the individual tooth models is fabricated in step 3230.
  • step 3235 the tooth models are attached to the base.
  • steps 3200-3215 and 3230-3235 may be substantially similar to corresponding steps in the process of FIG. 30 described above. Consequently, only the detection and prevention of interference between physical tooth models is now described.
  • step 3220 some or all pairs of adjacent tooth models in a digital dental arch model are examined to detect or predict interference or collision between teeth in the arch.
  • interference or collision may occur, for example, between physical tooth models and/or between features such as pins, for example, affixed to the physical tooth models to allow attachment of the physical tooth models to a base to form the dental arch.
  • FIG. 52 shows two interfering physical tooth models 3240 and
  • Tooth models 3250 and 3265 may collide with each other when they are inserted into a base 3270 because of the required insertion angles.
  • step 3225 the configurations of the features used to attach the physical tooth models to the base may be selected and/or modified to avoid the interference. For example, the lengths, positions, orientations, and number of pins affixed to the tooth models may be adjusted to avoid interference. In some variations, adjustment of the configurations of features on the tooth models to avoid interference may be an iterative process.
  • the configurations of pins or other features used to attach physical tooth models to a base may be selected or modified by various methods to prevent interference between tooth models.
  • a digital dental arch model that represents the physical tooth model is first produced or received.
  • the digital dental arch model defines the positions and orientations of the tooth models in the physical dental arch model. These positions and orientations may be in accordance, for example, with the requirements of an orthodontic treatment.
  • the positions of the physical tooth models including the pins or similar features may be simulated to examine the interference between adjacent physical tooth models mounted on a base.
  • the pin configurations in the digital model may be adjusted to avoid any interference that might occur in the simulation.
  • physical tooth models having the selected pin configurations may be fabricated by Computer Numerical Control (CNC) based manufacturing in accordance with the digital dental arch model.
  • CNC Computer Numerical Control
  • FIG. 54 illustrates a tooth model 3275 having two pins 3280 and 3285 affixed to its bottom portion.
  • the pins 3280 and 3285 are designed to have different lengths.
  • FIG. 55A and FIG. 55B are two perspective views showing how the pin configuration shown in FIG. 54 may prevent interference between two tooth models.
  • FIG. 55A shows a front perspective view of tooth model 3290 including pins 3295 and tooth model 3300 including pins 3305. Pins 3295 and pins 3305 are configured to have different lengths so that they do not collide with each other when they are inserted into a base (not shown).
  • FIG. 55B is a bottom perspective view of the same pair of tooth models.
  • physical tooth models may include retractable or removable pins.
  • a tooth model 3310 is placed on a flat surface 3315 in a recess created in a base 3320.
  • Base 3320 includes through holes 3325 and 3330.
  • Tooth model 3310 includes in its bottom portion holes 3335 and 3340 that are in registration and alignment with through holes 3325 and 3330.
  • Pins 3345 may be inserted along directions 3350, 3355 into through holes 3325 and 3330 in the base and into holes 3335 and 3340 in the physical tooth model to affix the tooth model 3310 to the base 3320.
  • Using removable pins may avoid interference during or after installation of the tooth model on a base.
  • the features affixed to a physical tooth model to allow the physical tooth model to be attached to a base may include a spring loaded pin mechanism.
  • tooth model 3360 includes holes 3365 and spring-loaded mechanisms 3370.
  • Pins 3375 may be inserted into holes 3365 and spring load mechanisms 3370.
  • Pins 3375 are retractable with compressed springs to avoid interference during or after installation of the tooth model on a base. After the tooth models are properly mounted and fixed, the pins 3375 may extend to their normal positions to maximize position and angle control. The overall pin lengths may be cut to be compatible with the spring load mechanisms to prevent interference between tooth models.
  • the features affixed to a physical tooth model to allow the physical tooth model to be attached to a base may include spring loaded pin mechanisms having pins of different lengths.
  • tooth model 3380 includes retractable pins 3375 and 3385 of different lengths. Using pins of different lengths may avoid interference during or after installation of the tooth model on a base.
  • tooth model 3390 includes retractable pins 3395 inserted into holes 3400 and spring-loaded mechanisms 3405 at an angle relative to the bottom of the tooth model. Inserting pins 3395 at such an angle may avoid interference during or after installation of the tooth model on a base.
  • the ability to select or modify pin configurations to prevent interference between tooth models may allow the use of longer pins and result in a more stable physical tooth arch model.
  • modular sockets may be prepared on the undersides of physical tooth models. Pins of different lengths may be plugged into the sockets to prevent interference between adjacent tooth models.
  • the methods described above are also applicable to prevent tooth model interference in precision mount of tooth models in casting chambers.
  • the shape and the height of the tooth models may be modified to avoid interference of teeth during insertion or at the corresponding treatment positions.
  • the apparatus comprises: a chamber body having a cavity adapted to hold the negative impression of the patient's tooth and to receive a cast material; and a chamber lid configured to seal the cast material in the casting chamber to permit the casting material to solidify in the casting chamber thereby forming a physical tooth model representing the patient's tooth.
  • the apparatus further includes a plurality of registration features (e.g., pins) arranged to correspond to the tooth arch, wherein each of the teeth in the tooth arch has at least one corresponding registration feature.
  • a positive tooth arch i.e., a physical tooth model
  • the each of the registration features is associated (e.g., portion of the registration feature is embedded within the positive tooth arch) with a corresponding tooth in the positive tooth arch.
  • the casting chamber for casting a physical tooth model representing a patient's tooth comprises: a chamber body having a cavity adapted to hold the negative impression of the patient's tooth and to receive a cast material and chamber walls surrounding the cavity, wherein the negative impression and the chamber body are registered by a registration unit; and a chamber lid configured to seal the cast material in the casting chamber to permit the casting material to solidify in the casting chamber thereby forming a physical tooth model representing the patient's tooth.
  • a method for producing a physical tooth model comprises: holding a negative impression of a patient's tooth in a casting chamber by a registration unit; pouring a cast material over the negative impression of the patient's tooth; and solidifying the cast material to produce the physical tooth model.
  • the method for producing a physical tooth model comprises receiving a negative impression of a patient's tooth in a casting chamber; pouring a casting material over the negative impression of the patient's tooth; solidifying the casting material wherein the casting material is attached to the lid of the casting chamber; and cutting a tooth portion off the solidified casting material to produce a reference base portion of the casting material attached to the lid of the casting chamber, wherein the reference base is configured to mold the physical tooth model.
  • the method for producing a physical tooth model comprises receiving a negative impression of a patient's tooth in a casting chamber; pouring a casting material over the negative impression of the patient's tooth; solidifying the casting material wherein the casting material is attached to the lid of the casting chamber; cutting a tooth portion off the solidified casting material to produce a reference base attached to the lid of the casting chamber, and producing first features in the reference base to assist the molding of the physical tooth model having second features complimentary to the first features using the reference base.
  • a casting system for producing a physical tooth model comprises a casting chamber configured to hold a negative impression of a patient's tooth and to receive casting material that can subsequently solidify in the casting chamber; a chamber lid configured to hold the solidified casting material and to produce a reference base by cutting off the tooth portion, wherein the reference base is adapted to mold the physical tooth model.
  • Variations may include one or more of the following features.
  • the casting system is configured for molding a reference base (e.g., gum portion) and using the reference base to mold a physical tooth model.
  • the reference base can include features to allow the fabrication of features in the physical tooth model to allow the physical tooth model to be fixed to a base.
  • the reference base also serves as position reference for precisely locating the features on the physical tooth model as required by orthodontic treatment.
  • the same physical tooth models can be used to form different tooth arch model having different teeth configurations.
  • the tooth models can be reused as tooth positions are changed during a treatment process. Much of the cost of making multiple tooth arch models in orthodontic treatment is therefore eliminated
  • Variations may include one or more of the following features.
  • the apparatus and method allows physical tooth models be produced inexpensively and reliably in a simple system with minimal parts.
  • the physical tooth models are molded to the correct shape including features to allow them to be inserted, attached, or plugged to a dental base.
  • the physical tooth models can be pre-fabricated having standard registration and attaching features for assembling.
  • the physical tooth models can be automatically assembled onto a base by a robotic arm under computer control.
  • there is no need for complex and costly units such as micro-actuators for adjusting multiple degrees of freedom for each tooth model.
  • the physical dental arch model obtained through the disclosed apparatus and methods may be used for various dental applications such as dental crown, dental bridge, aligner fabrication, biometrics, and teeth whitening.
  • the arch model may be assembled from segmented manufacturable components that can be individually manufactured by automated, precise numerical manufacturing techniques.
  • the same base can support different tooth arch model having different teeth configurations.
  • the base can include more than one set of receiving features that can receive tooth models at different positions.
  • the reusable base further reduces cost in the dental treatment of teeth alignment.
  • Variations of the apparatus and methods may permit the physical tooth models in the physical dental arch model be easily separated, repaired or replaced, and reassembled after the assembly without the need to replace the complete arch model.
  • the manufacturable components can be attached to a base.
  • the assembled physical dental arch model specifically corresponds to the patient's arch. Therefore, complex and costly mechanisms such as micro-actuators for adjusting multiple degrees of freedom for each tooth model may not be needed.
  • the described methods and system may be simple to make and easy to use.
  • An exemplary process for producing a physical dental arch model is illustrated in FIG. 60.
  • the process includes the following steps. First, individual tooth models are created in step 51 10.
  • An individual tooth model is a physical model that can be part of a physical tooth arch model, which can be used in various dental applications. Registration features are next added to the individual tooth model to allow them to be attached to each other or a base in step 5120.
  • a base is designed for receiving the tooth model in step 5130.
  • the tooth model positions in a tooth arch model are next determined in step 5140.
  • a base is fabricated in step 5150.
  • the base includes features for receiving the individual tooth model.
  • the tooth models are then attached to the base at the predetermined positions using the pre-designed features in step 5160.
  • the tooth model can be created by casting.
  • a negative impression is first made from a patient's arch or a patient's tooth using for example PVS.
  • the negative impression of the patient's arch is placed in a specially designed chamber.
  • a casting material is then poured into the chamber over the impression to create a model.
  • a lid is subsequently placed over the chamber. The chamber is opened and the mold can be removed after the specified time.
  • casting materials include, but not limited to, auto polymerizing acrylic resin, thermoplastic resin, light-polymerized acrylic resins, polymerizing silicone, polyether, plaster, epoxies, or a mixture of materials.
  • the casting material can be selected based on the uses of the cast. In one variation , the material is selected for easy cutting to obtain individual tooth model. Additionally, the material selected is strong enough for the tooth model to take the pressure in pressure form for producing a dental aligner.
  • FIG. 69 and FIG. 70 respectively illustrate exploded top and bottom perspective views casting chamber 5701 including a chamber body 5710, a chamber lid 5702, and a chamber base 5703 for casting a physical tooth model.
  • Chamber body 5710 assembly includes a cavity 5720 and a mounting plate 5730 inside the chamber cavity 5720.
  • a negative impression of a patient's tooth or arch can be glued or fastened to the mounting plate 5730.
  • the mounting plate 5730 At the bottom surface of the impression mounting plate 5730, there are two precision alignment liners that mate with two precision locating pins on the chamber cavity 5720 bottom surface. The two precision locating pins and liners allow precise locating of the impression repetitively.
  • multiple through holes 5733 through the bottom of the cast chamber to the cavity 5720 provide access to the impression mount plate to assist the removal of the impression mounting plate 5730 from the cast chamber.
  • the chamber lid 5702 is mated precisely to the casting chamber body 5710 by two precision locating liners 5715 on the chamber lid 5702 and two precision alignment pins (not shown) which can be inserted into the aligners 5722 on the casting chamber assembly's top surface.
  • the two precision locating liners 5715 on the chamber lid 5702 and the aligners 5722 on the chamber body 5710 may also serve as position references for measurement and machining. These features allow repetitive cast of the teeth with precise locations of the teeth.
  • Chamber lid 5702 can include a variable spacer 5750 and a casting adaptor.
  • the thickness of the variable spacer is determined by measuring the height of the impression inside the casting chamber cavity 5720.
  • the maximum thickness of the spacer is used so that the distance of the casting adaptor and the impression is minimum when the lid 5702 is tightly placed on the casting chamber body 5710.
  • the adaptor can have a horse-shoe- shaped extrusion machined out of plastics or metal parts.
  • a plurality of pins 5755 i.e., registration features) are positioned on the variable spacer.
  • the casting adaptor is a machined part. Measurements of the specific teeth impression are used to calculate the required machine operations. There are multiple undersized holes on the adaptor to hold the metal pins tightly during the casting process. The locations and orientations of the pins are calculated from measurements of the impression inside the cavity 5720 of the chamber body 5710. In some cases, a horse-shoe-shaped extrusion step is also machined based on specific measurement.
  • the casting chamber lid 5702 includes multiple threaded through holes 5716 around the cavity 5720 of the casting chamber 5701. These holes serve as a lifting unit to overcome the large forces involved in de-molding. Metal bolts or screws are pushed through the threaded holes to lift the chamber lid 5702 and the cured mold out of the impression. [0392] A plurality of through holes on the casting chamber lid 5702 allows the fastening of the chamber lid 5702 to the Chamber body 5710 during the cast and cure process. The chamber lid 5702 is fixed tightly to the casting Chamber body 5710, maintaining the precision locations during processes such as vibrating, elevated temperature cure process as well as transportation during the cure process.
  • the casting chamber lid 5702 also has a slotted through window 5740.
  • This window acts a view port as well as an overflow reservoir for the plastics liquid.
  • the chamber lid 5702 also includes a handle 5728 for easy carrying and handling of the chamber lid 5702.
  • the window allows UV light irradiation through the window to assist the polymerization and solidification of the casting material in the casting chamber 5701.
  • the cast material can be solidified by cooling or heating, irradiation by UV or IR light, or by microwave radiation.
  • the cast material can comprise one or more crosslinking agents that can cause the polymerization and solidification of the cast material to produce the physical tooth model.
  • the window is placed on the side wall of the chamber 5710.
  • Chamber base 5703 is can be fixed to a platform using the multiple through holes 5736.
  • the platform can also host measurement devices.
  • the two precision locating pins on the chamber body 5710 mate with the two precision liners 5738 on the bottom of a chamber body 5710, thus produce repetitively precision mount of the casting chambers 5701 on to the chamber base 5703.
  • the casting system comprises precision locating pins and liners in a casting chamber 5701, a chamber lid 5702 and a chamber base.
  • Precision measurement and computer software can also be used to produce the positions of the receiving features of the physical tooth model.
  • the receiving features enable the physical tooth mode to be mounted or attached to a physical base.
  • the receiving features can include a pin, a registration slot, a socket, a notch, a protrusion, a hole, an interlocking mechanism, a jig, and a pluggable or attachable feature.
  • the physical base as shown in FIGS. 61-68 include complimentary second features for receiving the first features to enable the physical tooth models to be mounted to the physical base.
  • the positions of the first features may be used for determining the locations of the second features in the physical base in fabricating the base.
  • FIG. 71 a cross-sectional view of one variation of a casting chamber is shown.
  • the casting system 5762 comprises a chamber 5765 having a negative impression 5762 of a patient's tooth arch secured therein, a lid 5760 having a variable spacer 5764, and plurality of pins 5766 positioned on the variable spacer 5764. Each pair of pins 5764 is positioned to correspond to a tooth in the tooth arch of the negative impression 5766.
  • a positive tooth arch can then be cast within the negative impression 5767, resulting in a positive dental arch mold having pins 5766 extending from the base portion of each of the teeth in the positive dental arch mold.
  • the positive mold can ten be separated into individual tooth models 5770, as shown in FIG. 72.
  • each of the tooth models 5770 comprises a crown portion, a base portion and a pair of pins 5776 extending form the base portion.
  • the precision units in the casting chamber design can also be used in other manufacturing processes such as 2D scanning of the negative impression, base plate machining, and/or bite setting measurement.
  • 2D scanning as used in this example is a manufacturing process where an impression for a patient's teeth are measured for the positions and orientations of the simulated "roots" - the metal pins.
  • a measurement device such as a digitizer is mounted rigidly on a flat platform. Multiple pairs of precision locating pins on the platform can receive the mating precision liners on the bottom of the casting chamber 5701. The locating pins positions relative to the measurement device are precisely machined and measured, providing position references for the measurements.
  • the measurement device must have the capabilities of measuring 5-degree of freedoms at each reading in order to provide accurate and efficient measurements.
  • the chamber can be fixed or clamped down tightly with fasteners through the mounting holes on the casting chamber 5701.
  • the measurement device such as a digitizer is first calibrated against the particular chamber, by measuring the locations of two precision locating pins at the top of the surface. After calibration, the locations and orientations of each tooth are measured. Two or more points for each tooth are measured. In one implementation, the gingival shape/profile is also measured. Other measurements can include the height of the impression, etc.
  • bite setting positions of the upper teeth and lower teeth of a patient is also measured using references to the precision locating liners on the casting chamber lid. After both the lower teeth and the upper teeth of a patient are cast, and de- molded, the two chamber lids with the upper teeth and the lower teeth are set to their nature bite setting position. Springs and universal joints may be used to hold the upper and lower teeth with chamber lids in the bite setting position. A measurement device is then used to measure the relationships between the pair of the precision locating liners on both chamber lids. With the assistance of known positions of the teeth to each chamber lids that are measured and calculated during the machining of the base plate, the nature bite position of the upper and lower teeth are then calculated.
  • tooth models can be added to the casting material during the casting process.
  • registration points or pins are added to each tooth before the casting material has dried.
  • universal joints are inserted at the top of the casting chamber using specially designed lids, which would hang the universal joints directly into the casting area for each tooth.
  • step 5110 individual tooth models are next cut from the positive tooth arch.
  • the positive tooth arch is cut to obtain individual teeth in such a manner that they can be joined again to form a tooth arch.
  • the separation of individual teeth from the mold can be achieved using a number of different cutting methods including laser cutting and mechanical sawing.
  • Separating the positive mold of the arch into tooth models may result in the loss of the relative 3D coordinates of the individual tooth models in the arch.
  • Several methods may be implemented in step 5120 for finding relative position of the tooth models.
  • unique registration features are added to each pair of tooth models before the positive arch mold is separated.
  • the separated tooth models can be assembled to form a physical dental arch model by matching tooth models having the same unique registration marks.
  • the positive arch mold can also be digitized by a three-dimensional scanning using a variety of techniques, such as laser scanning, optical scanning, destructive scanning, CT scanning, and acoustic wave scanning.
  • a digital arch model can be obtained through the 3D scanning.
  • the physical digital arch model is subsequently smoothed and segmented. Each segment can be physically fabricated by CNC based manufacturing to obtain individual tooth models.
  • the physical digital arch model tracks and stores the positions of the individual tooth models. Unique registration marks can be added to the digital tooth models that can be made into a physical feature through CNC base manufacturing.
  • CNC based manufacturing examples include, but not limited to, CNC based milling, stereolithography, Laminated Object Manufacturing, Selective Laser Sintering, Fused Deposition Modeling, Solid Ground Curing, and 3D ink jet printing.
  • the separated tooth models are assembled by geometry matching.
  • the intact positive arch impression is first scanned to obtain a 3D physical digital arch model.
  • Individual teeth are then scanned to obtain digital tooth models for individual teeth.
  • the digital tooth models can be matched using rigid body transformations to match a physical digital arch model, due to complex shape of the arch, inter-proximal areas, root of the teeth and gingival areas may be ignored in the geometry match.
  • High precision may be desirable for matching features such as cusps, points, crevasses, the front faces and back faces of the teeth.
  • Each tooth is sequentially matched to result in rigid body transformations corresponding to the tooth positions, and a tooth arch is reconstructed therefrom.
  • the separated tooth models are assembled and registered with the assistance of a 3D point picking devices.
  • the coordinates of the tooth models are picked up by 3D point picking devices such as stylus or Microscribe devices before separation.
  • Unique registration marks can be added on each tooth model in an arch before separation.
  • the tooth models and the registration marks can be labeled by unique IDs.
  • the tooth arch can later be assembled by identifying tooth models having the same registration marks as were picked from the Jaw.
  • 3D point picking devices can be used to pick the same points again for each tooth model to confirm the tooth coordinates.
  • a base is made to receive the tooth models.
  • the base and tooth models include complementary features to allow them to be assembled together.
  • the tooth model has a protruding structure attached to it.
  • the features at the base and tooth models can also include one or more of following: a registration slot, a socket, a notch, a protrusion, a hole, an interlocking mechanism, and a jig.
  • the protruding structure can be obtained during the casting process or be created after casting by using a CNC machine on each tooth.
  • the positions of the receiving features in the base are determined by either the initial positions of the teeth in an arch or the desired teeth positions during a treatment process.
  • FIG. 61 shows a tooth model 5210 with male stud 5220 after mold separation.
  • the base 5230 comprises a female feature 5240 that can receive the male stud 5220 when the tooth model 5210 is assembled to the base 5230.
  • a tooth model 5310 includes a female socket 5315 that can be drilled by CNC based machining after casting and separation.
  • a male stud 5320 that fits the female socket 5315 can be attached to the tooth model 5310 by for example, screwing, glue application, etc.
  • the resulted tooth model 5330 includes male stud 5310 that allows it to be attached to the base.
  • FIG. 63 shows a tooth model 5410 having two pins 5415 protruding therefrom and a base 5420 having registration slots 5425 adapted to receive the two pins 5415 to allow the tooth model 5410 to be attached to the base 5420.
  • FIG. 64 shows a tooth model 5510 having one pin 5515 protruding out and a base 5520 having a hole 5525 adapted to receive the pin 5515 to allow the tooth model 5510 to be attached to the base 5520.
  • the tooth model can include two or more pins wherein the base will have a corresponding number of holes at the corresponding locations for each tooth model.
  • the tooth model 5530 can also include cone shaped studs 5535 as shown in FIG. 65. The studs can also take a combination of configurations described above.
  • the studs protruding from the tooth model 5540 can take different shapes 5545 such as oval, rectangle, square, triangle, circle, semi-circle, each of which correspond to slots on the base having matching shapes that can be drilled using the CNC based machining.
  • the asymmetrically shaped studs can help to define a unique orientation for the tooth model on the base.
  • FIG. 67A shows a base 5550 having a plurality of sockets 5555 and 5560 for receiving the studs of a plurality of tooth models.
  • the positions of the sockets 5555, 5560 are determined by either initial teeth positions in a patient's arch or the teeth positions during the orthodontic treatment process.
  • the base 5550 can be in the form of a plate as shown in FIG. 67A, including a plurality of pairs of sockets 5555,' 5560. Each pair of sockets 5555, 5560 is adapted to receive two pins associated with a physical tooth model.
  • Each pair of sockets includes a socket 5555 on the inside of the tooth arch model and a socket 5560 on the outside of the tooth arch model.
  • FIG. 67B Another variation of a base 5565 is shown in FIG. 67B.
  • a plurality of pairs of female sockets 5570, 5575 are provided in the base 5565.
  • Each pair of the sockets 5570, 5575 is formed in a surface 5580 and is adapted to receive a physical tooth model 5585.
  • the bottom portion of the physical tooth model 5585 includes a surface 5590.
  • the surface 5590 contacts the surface 880 when the physical tooth model 5585 is inserted into the base 5565, which assures the stability of the physical tooth model 5585 over the base 5565.
  • a tooth model 5595 compatible with the base 5550 is shown in FIG. 68.
  • the tooth model 5595 includes two pins 5600 connected to its bottom portion.
  • the two pins 5600 can be plugged into a pair of sockets 5555 and 5560 on the base 5550.
  • each pair of sockets 5555 and 5560 uniquely defines the positions of a tooth model.
  • the orientation of the tooth model is also uniquely defined if the two pins are labeled as inside and outside, or the sockets and the pins are made asymmetric inside and outside.
  • each tooth model may include correspond to one or a plurality of studs that are to be plugged into the corresponding number of sockets.
  • the male studs and the sockets may also take different shapes as described above.
  • a tooth arch model is obtained after the tooth models are assembled to the base 5550 (step 5160).
  • the base 5550 can have a plurality of configurations in the female sockets 5555. Each of the configurations is adapted to receive the same physical tooth models to form a different arrangement of at least a portion of a tooth arch model. In one variation, the different arrangement represents the projected tooth position in the various treatment steps for an orthodontic treatment process.
  • the base 5550 can be fabricated by a system that includes a computer device adapted to store digital tooth models representing the physical tooth models. As described above, the digital tooth model can be obtained by various scanning techniques. A computer processor can then generate a digital base model compatible with the digital tooth models. An apparatus fabricates the base using CNC based manufacturing in accordance with the digital base model. The fabricated base is adapted to receive the physical tooth models.
  • the physical tooth models can be identified or labeled by a predetermined sequence that define the positions of the physical tooth models on the base 5550.
  • the labels can include a barcode, a printed symbol, hand-written symbol, a Radio Frequency Identification (RFID).
  • RFID Radio Frequency Identification
  • the female sockets 5555 can also be labeled by the parallel sequence for the physical tooth models.
  • tooth models can be separated from the base for repair.
  • the tooth models can be removed, repaired or replaced, and re-assembled without the replacement of the whole arch model.
  • Materials for the tooth models can include polymers, urethane, epoxy, plastics, plaster, stone, clay, acrylic, metals, wood, paper, ceramics, and porcelain.
  • the base can comprise a material such as polymers, urethane, epoxy, plastics, plaster, stone, clay, acrylic, metals, wood, paper, ceramics, porcelain, glass, and concrete.
  • the arch model can be used in different dental applications such as dental crown, dental bridge, aligner fabrication, biometrics, and teeth whitening.
  • aligner fabrication for example, each stage of the teeth treatment may correspond a unique physical dental arch model.
  • Removable appliances such as aligners can be fabricated using different physical dental arch models one at a time as the teeth movement progresses during the treatment.
  • the desirable teeth positions for the next stage are calculated.
  • a physical dental arch model having modified teeth positions is fabricated using the process described above.
  • a new aligner is made using the new physical dental arch model.
  • each base is specific to an arch configuration. There is no need for complex and costly mechanisms such as micro-actuators for adjusting multiple degrees of freedom for each tooth model.
  • the described methods and system is simple to make and easy to use.
  • Different stages of the arch model can share the same tooth models.
  • the positions for the tooth models at each stage of the orthodontic treatment can be modeled using orthodontic treatment software.
  • Each stage of the arch model may use a separate base.
  • one base is used in a plurality stages of the arch models.
  • the base may include a plurality of sets of receptive positions for the tooth models. Each set corresponds to one treatment stage.
  • the tooth models can be reused through the treatment process. Therefore, much of the cost of making multiple tooth arch models in orthodontic treatment may be avoided.
  • an exemplary process, for producing a physical dental arch model is illustrated in FIG. 73.
  • the process includes the following steps. First a reference base is molded for an individual tooth model in step 5100. The individual tooth model is next molded with the assistance of the reference base in step 51 10.
  • An individual tooth model is a physical model that can be part of a physical tooth arch model, which can be used in various dental applications. Registration features are next added to the individual tooth model to allow them to be attached to each other or a base in step 5120.
  • a base is designed for receiving the tooth model in step 5130.
  • the tooth model positions in a tooth arch model are next determined in step 5140.
  • a base is fabricated in step 5150. The base includes features for receiving the individual tooth model.
  • the tooth models are finally attached to the base at the predetermined positions using the pre-designed features in step 5160.
  • the making of a physical tooth model can include two steps: first the molding of a reference base for the tooth model in step 5100, and second, casting the physical tooth model with the assistance of the reference base in step 51 10. Both steps can be implemented using the same casting chamber 5815, as shown in FIG. 74.
  • a horse-shoe shaped negative impression 5810 from a patient's upper or lower arch can be fixed into a mounting plate by pins in the specially designed casting chamber 5815.
  • a chamber lid 5805 can close the casting chamber 5815 while allowing casting materials to be poured into the casting chamber 5815 through holes 5806.
  • the casting material examples include but not limited to, resin, epoxy mixture, polymers, thermal elastic material, urethane, plaster, clay, acrylic, latex, dental PVS, metal, aluminum, ice, wax, and one or more crosslinking agents that can cause the polymerization.
  • the casting material is poured over the impression to first fill the teeth areas above the gum line in the impression.
  • the casting material is subsequently poured over the rest of the areas and then filled to the outer rim of the casting chamber 5815 to leave ample thickness for the base portion that can be used as the reference base, as described below.
  • Air bubbles can be removed from the casting material to reduce surface tension before curing. Air bubbles trapped in the epoxy may also distort the original anatomy of teeth and supporting structures.
  • the casting chamber 5815 having the closed chamber lid 5805 is placed in an industrial vibrator to remove air bubbles introduced during the mixing and pouring procedure. The casting chamber 5815 is closed and the sealed by the chamber lid 5805 after air bubble stops coming out of the casting material. The excess casting material coming out of the container is wiped out by a cleaning agent.
  • the solidification of the casting material may take hours.
  • the solidification casting process may be facilitated with the assistance of heating, cooling, UV or IR exposures through a window in the chamber lid.
  • Epoxy setting may require 4- 8 hours.
  • FIG. 75 shows the front view of a chamber lid having the solidified material 5820 that includes a tooth portion 5825, a base portion 5832 (also called the gingival portion), and the chamber lid 1040.
  • the tooth potion 5825 that is a positive replica of negative impression is cut off from the base portion 5832.
  • the cutting can be implemented along pre-defined horizontal lines approximately 10 mm below the lowest point of gum line.
  • the cutting can be applied for example using disc-type saw cutting equipment.
  • a reference base 5835 is formed in attachment to the chamber lid 5840.
  • the reference base 5855 e.g., a mold of the gum/base, portion of the tooth arch
  • the reference base is directly attached to the chamber lid.
  • the reference base 5835 is used to cast physical tooth models using another casting material that does not adhere to the solidified material of the reference base, as described in relation to step 51 10.
  • the physical tooth models include features that enable them to be attached to a physical base.
  • the features can include a registration slot, a socket, a notch, a protrusion, a hole, an interlocking mechanism, a pin, a protrusion etc. The positions of these features have to be accurately produced on the physical tooth models.
  • FIG. 77 a machine 5855 is used to drill or mill a hole in the reference base 5845 that is attached to the chamber lid 5855. The drilling and milling may be applied using CNC based manufacturing techniques.
  • FIG. 78 shows a top view of one such machined hole 5860 in the reference base 5865.
  • a pin 5875 can be inserted into the hole 5880 in the reference base 5870.
  • the pin 5875 can adhere to the casting material and fixed to the physical tooth model during the casting of the physical tooth model in step 5110.
  • the pin 5875 that is affixed to the physical tooth model can therefore enable the physical tooth model to be attached to a dental base.
  • features such as the holes 5860, 5880 are made on the reference base at precisely determined positions such that the physical tooth models can be mounted on to the base in accordance to the positional and orientational requirement of the orthodontic treatment.
  • the positions of the features such as the holes 5860, 5880 on the reference base 5845, 5865 can be referenced to the chamber lid 5850 because the reference base 5845, 5865 are solidly fixed to the chamber lid 5850.
  • a reference point such as the corner of the chamber lid is first picked on the chamber lid 5850.
  • a location measurement device such as a Microscribe device can be used to determine the exact locations of the hole to be made relative to the reference position on the chamber lid 5850.
  • the required location of the hole can be input from a digital arch model in which the positions and orientations of each tooth model are specified in accordance to the orthodontic treatment.
  • the reference base as well as the chamber lid therefore serve as reference for physical tooth models to be fabricated.
  • Individual tooth model can be obtained in step 51 10 in a number of different methods.
  • the tooth model can be created by casting.
  • a negative impression is first made from a patient's arch using, for example, PVS.
  • a positive of the patient's arch is next made by pouring a casting material into the negative impression. After the material is dried, the mould is then taken out with the help of the impression knife. A positive of the arch is thus obtained.
  • the negative impression of the patient's arch is placed in a specially designed container.
  • a casting material is then poured into the container over the impression to create a model.
  • a lid is subsequently placed over the container. The container is opened and the mould can be removed after the specified time.
  • FIG. 80 illustrates an example where a gum portion 5888 (i.e., reference base) of a tooth arch is attached to a variable spacer 5889 on the casting chamber lid 5885.
  • the negative impression 5892 of the patient's tooth arch is positioned inside the chamber 5890.
  • Corresponding pins 5898 i.e., registration features
  • the gum portion 5888 is aligned with the negative impression 5892 and may engage the negative impression.
  • the resulting void between the gum portion 5888 and the negative impression 5892 is a space for casting the crown portion of the tooth arch.
  • FIG. 81 illustrates a positive tooth dental arch mold 5895 fabricated from the casting system 5894 shown in FIG. 80.
  • the positive tooth arch is isolated to the crown portion 5896 of the tooth arch, with pins 5898 (i.e., registration features) extending directly from the crown portion 5896.
  • a Base For Receiving Physical Tooth Models [0439] Examples and variations of method for fabricating a base for receiving physical tooth models are described below. Various implementations of a base design are also discussed.
  • the method includes providing cast materials in a container; pressing the underside of the physical tooth models into the cast materials to produce impressions in the cast materials; and solidifying the cast materials having the impressions to produce the base that is adapted to receive the physical tooth models.
  • the method comprises: placing the physical tooth models in a container; pouring the cast materials over the underside of the physical tooth models in the container; and solidifying the cast materials having the impressions to produce the base that is adapted to receive the physical tooth models.
  • the method comprises: transferring a cast materials in a container; placing the underside of a physical tooth model in the container such that the underside of the physical tooth model produces an impression in the cast materials; solidifying the cast materials having the impressions to produce a base component; and assembling a plurality of base components to form the base configured to receive the dental arch model.
  • Implementations of a system for producing a base may include one or more of the following.
  • the method for producing a base for physical tooth models includes providing cast materials in a container, pressing the underside of the physical tooth models into the cast materials to produce impressions in the cast materials, and solidifying the cast materials having the impressions to produce the base that is adapted to receive the physical tooth models.
  • the casting a material can be selected from the group consisting of polymers, thermal elastic materials, urethane, epoxy, plaster, clay, acrylic, latex, dental PVS, resin, metal, aluminum, ice, wax, sand, and stone.
  • the method can further include labeling the physical tooth models in a predetermined sequence that define the positions of the physical tooth models on the base.
  • the method can further include defining the positions of the impressions on the base such that the physical tooth models received by the impressions form at least a portion of an arch.
  • the method can further include defining the positions of the impressions on the base in accordance with a digital arch models.
  • the digital arch model can be produced by scanning and digitizing a patient arch.
  • the method can further include cooling the cast materials to cause the solidification of the cast materials having the impressions.
  • the method can further include illuminating UV irradiation on the cast materials to cause the solidification of the cast materials having the impressions.
  • the method can further comprise applying crosslinking agents to the cast materials to cause the polymerization and solidification of the cast materials having the impressions.
  • the physical tooth models can include first features to assist the reception of the physical tooth models by the base.
  • the features can comprise one or more of a pin, a registration slot, a notch, a protrusion, a hole, an interlocking mechanism, a jig, and a pluggable or attachable feature.
  • the impressions in the base can comprise second features complimentary to the first features to assist the reception of the physical tooth models by the base.
  • the tooth models can comprise a material selected from the group consisting of polymers, urethane, epoxy, plastics, plaster, stone, clay, acrylic, metals, wood, paper, ceramics, and porcelain.
  • Implementations of the system may include one or more of the following.
  • the method for producing a base for physical tooth models includes placing the physical tooth models in a container, pouring the cast materials over the underside of the physical tooth models in the container, and solidifying the cast materials having the impressions to produce the base that is adapted to receive the physical tooth models.
  • the casting a material can be selected from the group consisting of polymers, thermal elastic materials, urethane, epoxy, plaster, clay, acrylic, latex, dental PVS, resin, metal, aluminum, ice, and wax.
  • the physical tooth models can comprise first features to assist the reception of the physical tooth models by the base.
  • Implementations of the system may include one or more of the following.
  • the base components can comprise features to assist the assembly of the base components to form the base for the dental arch model.
  • the features comprise one or more of a pin, a registration slot, a socket, a notch, a protrusion, a hole, an interlocking mechanism, a jig, and a pluggable or attachable feature.
  • Variations may include one or more of the following features.
  • the base for receiving dental tooth models can be produced with simple, inexpensive and reliable methods and system.
  • the casting chambers are can be used multiple times to reduce manufacturing cost.
  • the base can be molded in a plurality of components. Only a component of the base needs to be re-molded if the position of one physical tooth model is changed in an orthodontic treatment. This further reduces treatment cost.
  • the physical tooth models can include features to allow them to be attached, plugged or locked to a base.
  • the physical tooth models can be pre-fabricated having standard registration and attaching features for assembling.
  • the physical tooth models can be automatically assembled onto a base by a robotic arm under computer control.
  • the manufacturable components can be attached to a base.
  • the assembled physical dental arch model specifically corresponds to the patient's arch. There is no need for complex and costly mechanisms such as micro-actuators for adjusting multiple degrees of freedom for each tooth model.
  • the described methods and system is simple to make and easy to use.
  • FIG. 60 shows an exemplary process for producing a physical dental arch model.
  • First individual tooth model is created in step 51 10.
  • An individual tooth model can be a physical model that can be part of a physical tooth arch model, which can be used in various dental applications. Registration features are next added to the individual tooth model to allow them to be attached to each other or a base in step 5120.
  • a positive dental arch is produced in step 5130.
  • a cast container is prepared by forming a base in step 5140.
  • a base is fabricated by casting in step 5150. The base includes features for receiving the individual tooth model.
  • the tooth models are finally attached to the base at the predetermined positions using the pre-designed features in step 5160.
  • the tooth model can be created by casting.
  • a negative impression is first made from a patient's arch using for example PVS.
  • a mold or a positive of the patient's arch is next made by pouring a casting material into the negative impression and allowing the mold to dry to obtain a positive model of the arch with teeth mounted thereon.
  • a negative impression of the patient's arch is placed in a specially designed container. The undersides of the tooth models are placed upward. A casting material is then poured onto the underside of the container over the impression to create a model. A lid is subsequently placed over the container.
  • the container is opened and the mold can be removed after the specified time.
  • casting materials include auto polymerizing acrylic resin, thermoplastic resin, light-polymerized acrylic resins, polymerizing silicone, polyether, plaster, epoxies, or a mixture of materials.
  • the casting material for molding the tooth models can be selected based on the uses of the cast. The material should be easy for cutting to obtain individual tooth model. Additionally, the material needs to be strong enough for the tooth model to take the pressure in pressure form for producing a dental aligner.
  • step 5120 features that allow tooth models to be attached to a base (step 5120) can be added to the casting material in the casting process. Registration points or pins can be added to each tooth before the casting material has dried.
  • universal joints can be inserted at the top of the casting chamber using specially designed lids, which would hang the universal joints directly into the casting area for each tooth.
  • step 51 individual tooth models are next cut from the arch positive.
  • One requirement for cutting is to obtain individual teeth in such a manner that they can be joined again to form a tooth arch.
  • the separation of individual teeth from the mold can be achieved using a number of different cutting methods including laser cutting and mechanical sawing.
  • Separating the positive mold of the arch into tooth models may result in the loss of the relative 3D coordinates of the individual tooth models in an arch.
  • Several methods are provided in step 5120 for finding relative position of the tooth models.
  • unique registration features are added to each pair of tooth models before the positive arch mold is separated.
  • the separated tooth models can be assembled to form a physical dental arch model by matching tooth models having the same unique registration marks.
  • the positive arch mold can also be digitized by a three-dimensional scanning using techniques such as laser scanning, optical scanning, destructive scanning, CT scanning and Sound Wave Scanning.
  • a physical digital arch model is therefore obtained.
  • the physical digital arch model is subsequently smoothed and segmented. Each segment can be physically fabricated by CNC based manufacturing to obtain individual tooth models.
  • the physical digital arch model tracks and stores the positions of the individual tooth models. Unique registration marks can be added to the digital tooth models that can be made into a physical feature in CNC base manufacturing.
  • Examples of CNC based manufacturing include CNC based milling,
  • Stereolithography Laminated Object Manufacturing, Selective Laser Sintering, Fused Deposition Modeling, Solid Ground Curing, and 3D ink jet printing.
  • the separated tooth models are assembled by geometry matching.
  • the intact positive arch impression is first scanned to obtain a 3D physical digital arch model.
  • Individual teeth are then scanned to obtain digital tooth models for individual teeth.
  • the digital tooth models can be matched using rigid body transformations to match a physical digital arch model due to complex shape of the arch, inter-proximal areas, root of the teeth and gingival areas may be ignored in the geometry match. High precision is required for matching features such as cusps, points, crevasses, the front faces and back faces of the teeth.
  • Each tooth is sequentially matched to result in rigid body transformations corresponding to the tooth positions that can reconstruct an arch.
  • the separated tooth models are assembled and registered with the assistance of a 3D point picking devices.
  • the coordinates of the tooth models are picked up by 3D point picking devices such as stylus or Microscribe devices before separation.
  • Unique registration marks can be added on each tooth model in an arch before separation.
  • the tooth models and the registration marks can be labeled by unique IDs.
  • the tooth arch can later be assembled by identifying tooth models having the same registration marks as were picked from the Jaw.
  • 3D point picking devices can be used to pick the same points again for each tooth model to confirm the tooth coordinates.
  • positive dental arches are first produced together in 5130.
  • the positive dental arches can be made from a negative impression of the patient's arch by casting as described above. Separate positive arches are made for upper jaw and the lower jaw.
  • a base can be separated into a plurality of components, each of which can be molded as described below. The whole base can be assembled together by the components after they are separately molded.
  • a casting container 5900 is next prepared in step 5140 for casting a base or a base component 5910 to support a physical dental arch model, as shown in FIG. 82.
  • the base component 5910 can include features 5920 that allow a plurality of base components 5910 to be assembled to form a base.
  • Features 5920 can for examples include sockets, holes, pins, and protrusions that allow the base components 5910 to tightly join or interlock to each other.
  • the base component 5910 can include pins 5930 that can enable the mounting of one or more tooth models to the base component 5910.
  • a physical dental arch model can include a plurality of tooth models, which can represent a whole or portion of a patient's arch.
  • a casting material such as epoxy, plaster or a mixture of materials is poured into the contained.
  • the casting material can be a paste, a fluid, a thick mixture of polymeric, ceramic, or colloidal materials.
  • Examples of casting materials include auto polymerizing acrylic resin, thermoplastic resin, light- polymerized acrylic resins, polymerizing silicone, polyether, plaster, epoxies, or a mixture of materials.
  • the casting materials can include crosslinking agents to the cast materials to cause the polymerization and solidification of the cast materials having the impressions.
  • the casting material can be irradiated by UV light through a window opened on the casting container ion to cause the polymerization and the solidification of the cast materials having the impressions.
  • the undersides of a positive dental arch are then pressed into the casting material.
  • the casting material can then be solidified by heating or cooling.
  • the casting material can also be irradiated by UV light through a window opened on the casting container ion to cause the polymerization and the solidification of the cast materials having the impressions.
  • the container is opened and the mold can be removed.
  • a base as shown in FIGS. 61, 63, 64, 67A is obtained after the casting material is dried and solidified in step 5150.
  • the solidification of the casting materials can be accomplished by non ⁇ uniform treatment by heating, cooling, UV or IR illuminations, or microwave radiation.
  • heating wires can laid out in the casting container to specifically heat the fine features in the impressions for receiving the physical tooth models.
  • the casting material may also comprise non-uniform distribution of ingredients.
  • the concentration of the crosslinking agents may be higher near the fine features in the impressions for receiving the physical tooth models.
  • a base or base component for receiving dental tooth models can be produced with simple, inexpensive and reliable methods and system, as described herein.
  • the casting chambers are can be used multiple times to reduce manufacturing cost.
  • FIG. 83 illustrates a base 5962 comprising a plurality of base components
  • the system of FIG. 83 illustrates casting of a base for receiving the tooth models.
  • second features which determines first features (e.g., registration features on the tooth model) locations and orientations can be cast into the base plate for receiving the first features on the tooth models.
  • Each of the base components 5940, 5950, 5960 is configured to receive a physical tooth model and can molded by one of a plurality of casting containers 5935, 5945, 5955.
  • the base components 5940, 5950, 5960 are assembled to form a dental base 5962 for receiving physical tooth models.
  • the base components 5940, 5950, 5960 can include features to assist the assembly of the base components 5940, 5950, 5960 to form the base 5960 for the dental arch model.
  • the features comprise one or more of a pin, a registration slot, a socket, a notch, a protrusion, a hole, an interlocking mechanism, a jig, and a pluggable or attachable feature.
  • FIG. 83, 5935-5955 should have interconnect features, to allow one to connect to the other, or insert to a common base to form an arch, these features can be configured to be small enough to avoid interference.
  • the above features base may be pre-inserted to casting box, e.g, pins.
  • the base component 5940, 5950, 5960 can be individually replaced for a different base configuration without changing the base components that are not changed in the orthodontic steps.
  • the base can be molded in a plurality of base components 5940, 5950, 5960 that can be subsequently assembled to form the whole dental base.
  • only one base component 5910 of the base needs to be re-molded if the position of one physical tooth model is changed in an orthodontic treatment. This may further reduce treatment costs.
  • FIG. 84 shows a base 5965 having multiple sets of sockets 5970, 5975,
  • the base can include a plurality of configurations in the sockets for the tooth models. Each configuration is adapted to receive the same physical tooth models to form a different arrangement of a tooth arch model.
  • a positive impression is placed in a specially designed container as shown in FIG. 83. Casting material is then poured over the impression. A lid is subsequently placed top of the container for a specified period of time.
  • the casting material can be solidified by heating or cooling.
  • UV light irradiated through a window opened on the casting container ion causes the polymerization and the solidification of the cast materials having the impressions.
  • the container is opened and the mold can be removed.
  • a base as shown in FIGS. 61 , 63, 64, 67A is obtained.
  • Examples and variations of apparatus and methods for digitizing a patient's tooth arch comprises producing a physical arch model for the patient's tooth arch, separating the physical arch model into a plurality of arch model components, mounting the arch model components on a scan plate, capturing one or more images of the arch model components, and developing digital representations of the arch model components using the captured one or more images.
  • Another variation comprises producing a physical arch model for the patient's arch, separating the physical arch model into a plurality of arch model components, mounting the arch model components on a scan plate, capturing one or more images of the arch model components, developing digital representations of the arch model components using the captured one or more images, and combining the digital representations for the arch model components into a digital arch model.
  • a system for digitizing a patient's arch comprises a scan plate configured to be mounted with a plurality of arch model components that are separated from a physical arch model corresponding to the patient's arch, an image capturing device configured to capture at least one image of the arch model components, and a computer configured to develop digital representations of the arch model components using the captured one or more image.
  • Variations of the method and the system may include one or more of the following features.
  • the disclosed system and methods may support the digitization of a patient's tooth arch at high throughput.
  • a plurality of tooth arch model components i.e., individual tooth models
  • the system may be configured such that three dimensional scanning can be conducted on the arch model components at high throughput in parallel.
  • multiple scanning platforms may be setup next to each other to process a large number of tooth arches at the same time.
  • the multiple scanning platforms may be configured with network connections to allow each of the scanning platform to communicate with a central computer, such that data and/or images collected from scanning can be send to a central computer for processing.
  • Variations of the methods and systems for digitizing a patient's tooth arch may allow one to achieve improved accuracy in scanning of the individual tooth model.
  • the patient's tooth arch model is separated into components (e.g., individual tooth models) to allow three-dimensional scanning of the critical areas of the arch model components.
  • the components and the scanning system may be configured such that the surfaces of the arch model components can be scanned in a fashion as to avoid obstruction by different parts of the same arch model component or other components mounted on the rotate-able scan table.
  • registration marks such as locking pins, are implemented in the tooth arch model components. These registration marks may improve scanning and digital reconstruction accuracy.
  • the digital representations of the tooth arch model components are translated into the common coordinates for the tooth arch model, and then combined to form the digital models of the patient's tooth arch.
  • the digital arch models may be used as input or reference for various applications.
  • the digital tooth arch models may be utilized in CNC based manufacturing of dental arch models, dental arch base, and/or dental aligners for the patient.
  • the digital representation of the tooth arch model may be utilized with root modeling techniques and/or implemented with computer display system for various dental and orthodontic applications.
  • FIG. 85 illustrates the process for digitizing a patient's arch.
  • reference points and coordinates are determined for a patient's dental arch model in step 61 10.
  • a negative impression 6280 of a patient's arch can be first obtained.
  • the negative dental impression 6280 can be fixed in a container 6290 using an epoxy.
  • the container 6290 can be marked by one ore more reference marks 6295 that can define the coordinates of the impression 6280.
  • the relative positions of the patient teeth are measured off the impression using a mechanical location device 6200.
  • An example of a mechanical location device is a microscribe, available from Immersion and Phantom.
  • Other 3D digitizer that can be utilized to develop a digital computer model for an existing 3D object may also be implemented. As shown in FIG.
  • the mechanical location device 6200 includes mechanical arms 6210, 6220 having one or more mechanical joints 6230.
  • the mechanical joint 6230 is equipped with precision bearings for smooth manipulation and internal digital optical sensors for decoding the motion and rotation of the mechanical arms 6210, 6220.
  • the end segment is a stylus 6240 that can be manipulated to touch surfaces on the dental impression 6280 held in the container 6290.
  • the mechanical location device 6200 may be fixed to a common platform as the container 6290.
  • Accurate 3D positional and angular information of the points that the stylus touches can be decoded and output at the electronic output port 6270.
  • the positional and orientational information can be obtained by an additional decoder for self-rotation of the stylus.
  • Additional sensors may be placed at the tip of the stylus to measure the hardness of the surface of the measurement object.
  • Immersion Corp.'s MicroScribe® uses a pointed stylus attached to a CMM-type device to produce an accuracy of .009 inches.
  • the MicroScribe digitizer in measuring the teeth positions from the impression of the patient's teeth, can be mounted on a fixture fixed to a base plate.
  • the device can communicate with a host computer via USB, serial port, or other computer connections.
  • the user selects points of interest at each tooth positions in the impression and places the stylus at the point of interest.
  • Positional and angular information are decoded and then transmitted to the computer.
  • the coordinates (e.g., Cartesian XYZ, etc. )of the acquired points are then calculated and logged for each first feature location and orientation (or alternatively each tooth).
  • a user may establishe a new coordinate system based on the container chamber in which the arch impression is held.
  • the user establishes this system by taking readings for two points on two sides of the container to define the x-axis. Another reading on the plane establishes the x-y plane. An origin is then determined on the x-y plane.
  • the z-axis will be established by taking the cross product of the x-axis and y- axis.
  • the user next selects a plurality of points on the surfaces of the arch impression corresponding to each tooth.
  • the 3D points measured from the impression surfaces are then interpolated to create surfaces and solids integrated into an overall design.
  • the user will start reading the pin readings. For each tooth, the user will first take a reading that will establish the center of the two pins, and their orientation vector. Then the user will take two more points that will give us the direction to move from the center of the pins, and finally the dimensions and positions of two pins will be calculated using these values, and the pins will be visually rendered in the software. In one variation, the system allows the user may fine-tune these readings as required.
  • a digital dental arch model can include a plurality of digital tooth models.
  • the digital dental model can be developed based on the first feature locations and orientations or alternatively the coordinates of the physical tooth models acquired by the mechanical location device.
  • the exported data can be used to control CNC based drilling and milling.
  • the number of points defining the curves and number of curves depends on the desired resolution in the model. Surfacing functions offered by the design application are used to create and blend the model surfaces.
  • the model may be shaded or rendered, defined as a solid or animated depending on the designer's intentions.
  • the teeth may be labeled so the order of the physical tooth models are can properly be defined for the physical dental arch model. All the readings acquired by the stylus can be rendered in real time to allow the user to visualize the digital tooth models.
  • the coordinate axes and points can be rendered in the software using different colored cylinders/spheres etc. so as to distinguish the different meanings of values.
  • the negative impression 6280 in the container 6290 can be filled with malleable casting material, which after solidification forms a physical arch model of the patient's arch (step 6120).
  • the one ore more reference marks 6295 i.e., registration features
  • the physical dental arch model is then separated into a plurality arch model components 6300 in step 6130.
  • the arch model can include the upper arch, the lower arch (the jaw), a segment of an upper or lower arch comprising one or more teeth, or a fraction of a tooth.
  • the arch model components 6300 are cut vertically, such as that registration features 6310 in the base portion 320 can be vertically mounted to a scan plate 6520 as shown in FIG. 89.
  • the vertical mounting of the arch model components 6510 allows them to be scanned relatively uniformly around their longitudinal axis along the length of the tooth, which may be beneficial for constructing uniform surfaces in the digital representation of the arch model components.
  • the criteria for separating the arch model into arch model components are to ensure each arch model component can be easily scanned by one or more image capture devices as described below.
  • the arch model component is cut to a substantially convex shape such that the surfaces of the arch model component can be captured by an image capture device without being obstructed by another part of the same arch model component.
  • FIG. 87 shows an arch model component 6300 that is separated from the arch model.
  • the arch model component 6300 includes registration features 6310 that are adapted to be attached to the receiving features in the scan plate as described below.
  • the registration features 6310 can include pins, protrusions, slots, holes, etc., which are complimentary to the receiving features on the receiving features in the scan plate as described below.
  • the registration features 6310 can be produced in the arch model before the arch model is separated into arch model components 6300.
  • the arch model components are digitized by a scanning system 6600 as shown in FIG. 90.
  • the scanning system 6600 includes a scan table 6620 on which one or more arch model components 6610 can be mounted.
  • the scan table 6620 can be rotated by a rotation mechanism 6630 under the control of a computer 6640.
  • the rotation mechanism 6630 can include a motor and a gear transport mechanism that is coupled to the scan plate 6620.
  • an image capture device 6650 captures an image of the arch model components 6610.
  • the image capture device 6650 can be a digital camera, and a digital video camera, laser scanner, other optical scanners, etc. There can also be provided a plurality of image capture devices. The throughput and accuracy may increase with the number of the image capture devices.
  • the optical axis of the image capture device can be for example 45 degree off the vertical axis (or the top surface of the scan table).
  • the arch model components 6610 cut off the arch model are of elongated shapes that can be mounted vertically over the scan table. As the scan plate 6620 is rotated by the rotation mechanism 6630, the vertically mounted arch model components 6610 can be scanned (i.e. image captured) at relatively uniform angle.
  • the individual tooth arch model components 6610 are placed on the scan table one at a time, and scanned one at a time. In another variation, a plurality of individual tooth arch model components 6610 are place onto a single scan table and scanned together.
  • the user may planned the distribution of the arch model components 6610 on the scan plate prior to the placement of the arch model components on the scan plate (e.g., step 6150) to improve the accuracy image scanning and improve throughput of the system.
  • the scanning throughput is increased with increased packing density on the scan plate.
  • higher packing density may decreases the distance between the arch model components, which may cause the adjacent arch model components to block each other in image captures.
  • Various techniques which are well known to one of ordinary skill in the art, may be utilized to determine the desired packing density and distribution pattern for placement of the tooth arch components on the scan plate.
  • FIG. 88 illustrates the top view of arch model components 6410 over scan plate 6400.
  • the arch model components 6410 can have different sizes and shapes.
  • the small circles may be 10 mm in diameter and represent small teeth (, e.g. lower incisors, cannie, etc.) or tooth components.
  • Large circles may be 15mm in diameter, which may represent large teeth (e.g. upper central incisors, molars) or larger tooth components.
  • the arch components are placed at lease 5 mm apart from each other and almost equal height to avoid overlap.
  • the scan plate 400 may be 150 mm in diameter.
  • the scanning volume can be an extruded octane or a cylinder 20 mm in height.
  • FIG. 89 shows a side view of a scanning platform 6500.
  • the arch model components 6510 are substantially vertically mounted over the scan plate 6520.
  • the image scanning direction 6530 can be 45 degree off the vertical axis.
  • the scan plate 6520 can be mounted goniometer and translation stage, which can provide up to 6 axes for 6 degree of freedom movements.
  • each arch model component is projected along the image capture direction (e.g. 45 degrees of vertical axis of the scan plate 6400) around its axis to produce a shadow around the arch model component.
  • the arch model components can be distributed such that there are no overlaps between the shadow areas of the adjacent arch model components.
  • the distributions of the arch model components 6410 can be varied to ensure that there is no obstruction of views between adjacent arch model components. The distributions can be iterated to maximize the packing density.
  • a model is prepared to simulate the shadow cast by the objects on the plate when the objects are being scanned in the designated scanning directions.
  • One or more scanner may be implemented.
  • the projection of the scanner may be direction to same over lapping region.
  • the position of the object may then be adjusted, such that all the shadows are close to each other, but with no overlaps.
  • This configuration may then be utilized for scanning of the toot arch components.
  • This model for determining a desired scanning configuration may be performed with either a physical model or a computer model.
  • the image scanning direction can be optimized.
  • a patient's arch model is separated into 20 arch model components.
  • the position of the 20 arch model components can be first simulated on a scan plate.
  • the image scanning direction 6530 can be varied to optimize the quality of the image capture.
  • the operator creates each individual shadow projection based on one scanning direction.
  • the articles/objects on the scan plate are arranged to ensure all the shadows are close to each other with no overlaps. Then based on the plate design for all of the scanning directions, the final plate design is determined.
  • a computer may be implemented to calculate a configuration for distributing the objects on the plate for scanning, such that each of the individual tooth arch components can be scanned in the process.
  • Each scanning direction's shadow collision is calculated separately, and the final readjustment may be determined through several iterations of calculation to minimize interference.
  • the shadows of the adjacent arch model components are allowed to overlap to certain extent, which means that certain surface areas on the arch model components are blocked from image scanning at certain directions. It is configured such that the overlap does not block a significant angular span of each surface area of an arch model component. This assures that the surface area blocked at certain direction can be scanned at other similar directions.
  • individual shadow maps are projected based on two or more scanning directions. Shadows from each scan direction may be colored coded to determine which area the scanner is able to scan from a given scanning direction. The combined data for the shadow cast from all directions are mapped. The distribution of the objects on the scan plate can be adjusted to ensure that the combined shadow map shows the shadows close to each other with minimal or no overlaps. The color coded shadows may be utilized to associate problems with specific scanning direction. In one configuration, shadow maps are close to each other with no overlaps that show color loss, such that all the area can allow shadow overlaps, but there is no shadow color overlap. In another variation, the objects are positioned such that any area on the scan article is seen at least once by the scanner at a certain scan angle.
  • the arch model components 6510 are mounted on the scan plate 6520 in step 6160.
  • the images of the arch model components 6510 are captured or scanned at different directions in step 6170 as the scan plate is rotated.
  • the coordinates of a plurality of surface points on the arch model components are computed by triangulation using the captured image data.
  • the surfaces of the arch model components are constructed by interpolating computed coordinates of the points on the surface. Since the registration features of the arch component models and the receiving features of the scan plate are precisely known and inter-translate-able, the coordinates of the surfaces of the arch model components can be translated to the original coordinates of the reference marks in the container 6290 (casting chamber).
  • the 6520 can together define the relative positions of the arch model components 6300.
  • the positions of the registration features 6310 on each arch model component 6300 are precisely defined.
  • the receiving features are also produced at precise locations on the scan table 6520.
  • the captured image data can be interpreted to define the relative positions of the arch model components 6510 relative to the receiving features on the scan plate 6520.
  • the coordinates of the arch model components 6510 can be transformed into the original coordinates defined by the reference marks 6295 for the impression of the patient's arch.
  • the digital arch model obtained in the above example is used as input data to produce physical arch models using CNC based manufacturing, such as milling, stereo lithography, laser machining, molding, and casting. Additionally, digital arch model can be manipulated and modeled to simulate the teeth positions at each step of an orthodontic treatment of a patient's teeth. Furthermore, interference between adjacent tooth models can be prevented by simulation of teeth movement with a computer ahead of time.
  • the method comprises: acquiring the coordinates of a plurality of points on the surfaces of each of the two physical tooth models; digitally representing the surfaces of each of the two physical tooth models by a mesh of points in three dimensions using the acquired coordinates, wherein the meshes representing the surfaces of the two physical tooth models intersect at least at one point to form an overlapping portion; and calculating the depth of the overlapping portion between the two meshes to quantify the interference of the two physical tooth models.
  • the method comprises: acquiring the coordinates of a plurality of points on the surfaces of each of the two physical tooth models; digitally representing the surfaces of each of the two physical tooth models by a mesh of points in three dimensions using the acquired coordinates, wherein the meshes representing the surfaces of the two physical tooth models intersect at least at one point to form an overlapping portion; calculating the depth of the overlapping portion between the two meshes; and adjusting the positions or the orientations of at least one of the two physical tooth models in accordance with the depth of the overlapping portion between the two physical tooth models to prevent the interference between the physical tooth models.
  • the method comprises: acquiring the coordinates of a plurality of points on the surfaces of each of the two physical tooth models; digitally representing the surfaces of each of the two physical tooth models by a mesh of points in three dimensions using the acquired coordinates; interpolating each of the two meshes to produce one or more surfaces to represent the boundaries of one of the two physical tooth models, wherein the interpolated surfaces intersect at least at one point to form an overlapping portion; and calculating the depth of the overlapping portion between the two interpolated surfaces to quantify the interference of the two physical tooth models.
  • the method comprises: digitally representing the surfaces of each of the two physical tooth models by a mesh of points in three dimensions; interpolating the meshes of points to produce interpolated surfaces to represent the boundaries of the two physical tooth models, wherein the interpolated surfaces representing the boundaries of the two physical tooth models intersect at least at one point to form an overlapping portion; specifying a straight line running through the overlapping portion and intersecting the two interpolated surfaces representing the boundaries of the two physical tooth models; and calculating the length of the straight line in the overlapping portion to quantify the interference between the two physical tooth models.
  • the method comprises: digitally representing the surfaces of each of the two physical tooth models by a mesh of points in three dimensions; interpolating the meshes of points to produce interpolated surfaces to represent the boundaries of the two physical tooth models, wherein the interpolated surfaces representing the two physical tooth models intersect at least at one point to form an overlapping portion; developing aligned coordinate systems or a common coordinate system for the two interpolated surfaces representing the two physical tooth models; specifying a straight line running through the overlapping portion and intersecting the two interpolated surfaces representing the boundaries of the two physical tooth models; and calculating the length of the straight line in the overlapping portion to quantify the interference between the two physical tooth models.
  • the method comprises: digitally representing the surfaces of each of the two physical tooth models by a mesh of points in three dimensions; interpolating the meshes of points to produce interpolated surfaces to represent the boundaries of the two physical tooth models, wherein the interpolated surfaces representing the boundaries of two physical tooth models intersect at least at one point to form an overlapping portion; specifying three orthogonally oriented straight lines each running through the overlapping portion and intersecting the two interpolated surfaces representing the boundaries of the two physical tooth models; calculating the lengths of three orthogonally oriented straight lines in the overlapping portion; defining three vectors along the three orthogonally oriented straight lines, each of the vectors having a magnitude of the inverse of the corresponding length of the overlapping portion; calculating a vector sum of the three vectors to determine the direction and the distance required for the interpolated surfaces representing the boundaries of the two physical tooth models to move apart to avoid interference between the two physical tooth models; and moving apart the interpolated surfaces representing the boundaries of the two physical tooth models in accordance
  • adjacent physical tooth models in a physical dental arch model are simulated.
  • the interference between the two physical tooth models can be predicted before they are assembled to form a physical arch model.
  • the positions and the orientations of the tooth models can be adjusted/modified to prevent the interference.
  • the precision and effectiveness of the orthodontic treatments can be improved.
  • the physical tooth models can are used multiple times, each time they are utilized to form a different tooth arch pattern.
  • the configurations of the base plate receptacles for receiving the pins on the physical tooth models can be modified without modifying the tooth models themselves.
  • By monitoring interference between teeth in a digital environment one can move the teeth in a digital environment and created a tooth distribution pattern that is realistic and can be implemented with the physical tooth models.
  • by detecting interference one can prevent a tooth model being moved into a position that overlaps a tooth in an adjacent position.
  • the boundaries of the individual tooth are utilized to predict the movement of tooth during the treatment process.
  • the physical tooth models can be reused as tooth positions are changed during a treatment steps.
  • the physical tooth can be positioned on a first based in a first pattern representing the target tooth positions in step one of the treatment cycle.
  • An aligner is then fabricated utilizing this first tooth arch pattern.
  • a second based can then be made to receiving the same set of physical tooth model but configuring them to form a second pattern representing the target tooth positions in step two of the treatment process.
  • a second aligner is then fabricated utilizing this second tooth arch pattern. Therefore, much of the cost of making multiple tooth arch models in the orthodontic treatment process may then be eliminated.
  • the tooth models can be configured with pins or other registration features to assist with their assembly on a base.
  • the same base is configured to support different tooth arch models having different teeth configurations/patterns.
  • the base can include more than one sets of receiving features that can receive tooth models at different positions.
  • the reusable base may further reduce cost in the dental treatment of teeth alignment.
  • the receiving features/receptacles on the base can be modified to receive tooth models having different pin configurations to avoid interference between the adjacent tooth models in a tooth arch model.
  • the physical tooth models include features to allow them to be attached, plugged, locked, or otherwise attached to the base.
  • the physical tooth models can be pre ⁇ fabricated to include registration features which can be utilized to determine the position and/or orientation of the tooth.
  • the registration feature can further be configure to be used for assembly of the physical tooth models on a base plate.
  • the physical tooth models can be automatically assembled onto a base by a robotic arm under computer control.
  • the apparatus and methods disclosed herein may be used for various dental applications, such as dental crown, dental bridge, aligner fabrication, biometrics, teeth whitening, etc.
  • the arch model can be assembled from segmented manufacturable components that are individually manufactured by automated, precise numerical manufacturing techniques.
  • the physical tooth models in the physical dental arch model can be easily separated, repaired or replaced, and reassembled after the assembly without the replacement of the whole arch model.
  • the manufacturable components can be attached to a base.
  • the assembled physical dental arch model specifically corresponds to the patient's arch at the pretreatment configuration or at one of the targeted steps' configuration during the dental alignment treatment process.
  • FIG. 91 illustrates an example for producing a physical dental arch model.
  • the process includes the following steps.
  • First individual tooth model is created in step 71 10.
  • An individual tooth model is a physical model that can be part of a physical tooth arch model, which can be used in various dental applications.
  • Registration features are next added to the individual tooth model to allow them to be attached to each other or a base in step 7120.
  • steps 71 10 and 7120 are merged together, such that the registration features are created during the process of fabricating individual tooth models.
  • a base is designed for receiving the tooth model in step 7130.
  • the base for receiving the physical tooth models may be designed/prepared before the individual physical tooth models are fabricated.
  • the tooth model positions in a tooth arch model are next determined in step 7140.
  • the digital tooth models are developed in step 7150.
  • the interference between the physical tooth models is predicted in step 7160.
  • the pin configurations affixed to the tooth models are selected to prevent interference between adjacent tooth models when they are mounted on the base.
  • a base is fabricated in step 7180.
  • the base includes features/receptacles for receiving the individual tooth model having the selected pin configurations.
  • the tooth models are finally attached to the base at the predetermined positions using the pre-designed features in step 7190.
  • the individual tooth models can be obtained in step 7110 in a number of different methods.
  • the tooth model can be created by casting.
  • a negative impression is first made from a patient's arch using for example PVS.
  • a positive of the patient's arch is next made by pouring a casting material into the negative impression. After the material is dried, the mold is then taken out with the help of the impression knife. A positive of the arch is thus obtained.
  • the negative impression of the patient's arch is placed in a specially designed container.
  • a casting material is then poured into the container over the impression to create a model.
  • a lid is subsequently placed over the container. The container is opened and the mold can be removed after the specified time.
  • casting materials include, but not limited to, auto polymerizing acrylic resin, thermoplastic resin, light-polymerized acrylic resins, polymerizing silicone, polyether, plaster, epoxies, or a mixture of materials.
  • the casting material can be selected based on the uses of the cast. In one variation, the material is selected to allow for ease of cutting in obtaining individual tooth models. Additionally, the material may be selected to be strong enough for the tooth model to take the pressure in pressure form for producing a dental aligner.
  • step 7120 can be added to the casting material in the casting process.
  • registration points or pins can be added to each tooth before the casting material is dried.
  • universal joints can be inserted at the top of the casting chamber using specially designed lids, which would hang the universal joints directly into the casting area for each tooth.
  • step 7110 individual tooth models are next cut from the arch positive.
  • the teeth are cut obtain individual teeth in such a manner that they can be joined again to form a tooth arch.
  • the separation of individual teeth from the mold can be achieved using a number of different cutting methods including laser cutting and mechanical sawing.
  • step 7120 Separating the positive mold of the arch into tooth models may result in the loss of the relative 3D coordinates of the individual tooth models in an arch.
  • Various methods may be implemented in step 7120 for determining the relative positions of the physical tooth models.
  • unique registration features e.g., pins
  • the separated tooth models can be assembled to form a physical dental arch model by matching tooth models having the same unique registration marks (e.g., producing a base having features/receptacles for receiving the registration marks on the tooth models, such that when the tooth models are inserted on the base plate a tooth arch is formed).
  • the positive arch mold can also be digitized by a three-dimensional scanning using a technique such as laser scanning, optical scanning, destructive scanning, CT scanning and Sound Wave Scanning.
  • a digital dental arch model is therefore obtained.
  • the digital dental arch model is subsequently smoothened and segmented. Each segment can be physically fabricated by CNC based manufacturing to obtain individual tooth models.
  • the digital dental arch model tracks and stores the positions of the individual tooth models. Unique registration marks can be added to the digital tooth models that can be made into a physical feature in CNC base manufacturing.
  • CNC based manufacturing examples include, but not limited to, CNC based milling, Stereolithography, Laminated Object Manufacturing, Selective Laser Sintering, Fused Deposition Modeling, Solid Ground Curing, and 3D ink jet printing.
  • the separated tooth models are assembled by geometry matching.
  • the intact positive arch impression is first scanned to obtain a 3D digital dental arch model.
  • Individual teeth are then scanned to obtain digital tooth models for individual teeth.
  • the digital tooth models can be matched using rigid body transformations to match a digital dental arch model. Due to complex shape of the arch, inter-proximal areas, root of the teeth and gingival areas may be ignored in the geometry match.
  • high precision scanning is utilized to obtain high resolution digital objects for matching of features such as cusps, points, crevasses, the front and back faces of the teeth.
  • Each tooth is sequentially matched to result in rigid body transformations corresponding to the tooth positions that can reconstruct an arch.
  • the separated tooth models are assembled and registered with the assistance of a 3D point picking devices.
  • the coordinates of the tooth models are picked up by 3D point picking devices such as stylus or Microscribe devices before separation.
  • Unique registration marks can be added on each tooth model in an arch before separation.
  • the tooth models and the registration marks can be labeled by unique IDs.
  • the tooth arch can later be assembled by identifying tooth models having the same registration marks as were picked from the Jaw.
  • 3D point picking devices can be used to pick the same points again for each tooth model to confirm the tooth coordinates.
  • the base is designed in step 7130 to receive the tooth models.
  • the base and tooth models include complimentary features to allow them to be assembled together.
  • the tooth model has a protruding structure attached to it.
  • the features at the base and tooth models can also include a registration slot, a notch, a protrusion, a hole, an interlocking mechanism, and a jig.
  • the protruding structure can be obtained during the casting process or be created after casting by using a CNC machine on each tooth.
  • the positions of the receiving features in the base are determined by either the initial positions of the teeth in an arch or the desired teeth positions during a treatment process (step 7140).
  • the digital tooth models are developed in step 7150. First, the surfaces of the two physical tooth models are measured. A negative impression of a patient's teeth is obtained. A plurality of points on the surfaces of the negative impression is measured by a position measurement device. The coordinates of the points in three dimensional space are obtained.
  • a plurality of points representing the surfaces of the negative impression is then used to construct a mesh to digitally represent the surfaces of the patient's teeth in three dimensions.
  • FIG. 106 illustrates a triangulated mesh 7840 that simulates the surfaces of a patient's tooth.
  • the mesh opening can also include other shapes with four, five or more sides or nodes.
  • the mesh points are interpolated into one or more continuous surfaces to represent the surface of the patient's tooth, which serves as a digital model for the tooth.
  • the interference between two physical tooth models representing the patient's teeth can be predicted using the digital models of the two patient's teeth, in step 7160.
  • First interference depths are calculated for each digital tooth model.
  • a coordinate system 7845 comprising x, y, and z axes is established for a digital tooth model 7850.
  • a plurality of lines 7855 parallel to the z-axis are specified, typically at constant intervals.
  • the lines 7855 intersect with the surfaces of the digital tooth model 7850.
  • the distance between the intersection points, of the segment width, of each line 7855 is called buffer width.
  • the buffer widths are calculated along each of the x, y, and z directions.
  • An orthogonal bounding box 7860 can be set up as shown in FIG. 108 to assist the calculation of the buffer widths.
  • the bounding box defines maximum range for the digital tooth model along each direction in the coordinate system 7865.
  • the bounding box 7860 includes three pairs of rectangle faces in three directions. To calculate the buffer width along the z direction, a grid of fixed intervals is set up over the rectangular x-y face 7870 of the bounding box 7860.
  • the intervals of the grid 7880 along x and y direction, shown in FIG. 109, are defined in accordance with the precision requirement.
  • the grid nodes define start and end points for the lines 7855.
  • the grid nodes are indexed.
  • the segment width i.e. the buffer width
  • the buffer widths can be rescaled and stored for example in 8 bit or 16 bit values.
  • the interference between two physical tooth models to be fabricated based on the digital tooth models can be predicted using the corresponding digital tooth models. As shown in FIG. 1 10, the two digital tooth models 7882 and 7884 overlap in the overlapping portion 7886. The buffer widths of each of the digital tooth models 7882 and 7884 are translated into a common coordinate system. For each of the line 7855, intersection points for each of the digital tooth models 7882 and 7884 are determined or retrieved. The interference depth or the depth of overlapping portion 7886 can be calculated along the line in the z direction. The calculation of the interference depth is repeated for each pair of the x-y grid nodes similar to the procedure described above for each digital tooth model. The maximum interference depth can be determined among all the interference depths between the two digital tooth models.
  • a center point can be calculated by averaging the four neighbors.
  • An edge center point can be calculated by averaging the two neighbors.
  • Points can also be inserted by linear interpolation weighted by distances or by Spline interpolation.
  • the coordinate systems for the digital tooth models 7882 and 7884 are translated or rotated so that their axes are aligned, as shown in the coordinate system (xl, yl, zl) and the coordinate system (x2, y2, z2) in FIG. 1 1 1. That is, the x axes, y axes and z axes are respectively parallel in the two coordinate systems.
  • the buffer widths are then recalculated along parallel axes for the two digital tooth models 7882 and 7884 in the aligned (or common) coordinate systems.
  • the buffer width values can therefore be additive to accurately derive the width of the overlapping portions 7900 (or collision depth, or interference depth).
  • the overlapping portion 7888 can be considered as a discrete three dimensional object 7902 as shown in FIG. 1 12. If the two coordinate systems are aligned, the width of the overlapping portion 7900 can be simply calculated by the overlapping length of the buffer widths.
  • the widths of the overlapping portion 7904 can be separately calculated along three orthogonal directions such as along the directions of the three axes (x, y, z) of the aligned coordinate system 7910, as shown in FIG. 1 13.
  • the aligned coordinate systems can also include spherical and cylindrical coordinate systems.
  • the digital tooth models that overlap can be moved apart at the design stage to prevent interference between the physical tooth models after they are fabricated and assembled.
  • the optimized direction is close to the axis of the shortest interference depth. In optimizing the movement direction, more weight is therefore given to the shorter directions of shorter interference depths. In one embodiment, as shown in FIG.
  • the vector sum 7918 of vectors 7912, 7914, 7916 respectively having magnitudes of 1/Xdepth, 1/Ydepth, and 1/Zdepth along the x, y and x directions represent an optimized direction weighted toward directions of the shortest interference depths or shortest depth of overlapping portion.
  • the digital tooth models 7906, 7908 are moved apart along the optimal movement direction by an amount determined by the magnitude of the vector sum 7918. In one variation, each of the digital tooth models 7906, 7908 moves half of the required distance of movement.
  • adjustment movement may be required and performed on a multiple pairs of tooth models.
  • the positional adjustment can be conducted in iterative cycles before obtaining the final arch configurations for all tooth models at a step of an orthodontic treatment.
  • a tolerance range for the gaps between the adjacent tooth models can be specified. The iterative adjustment of the tooth models will be performed until all the gaps between adjacent tooth models are within the tolerance range.
  • the designed movements of the tooth models are recorded and will be compared to the actual movement of the teeth during the corresponding step of the treatment.
  • the total effective movement of all the movement steps of a tooth in an orthodontic treatment is the vector sum of each individual movements.
  • the total interference depth ("final result") of the orthodontic treatment is the sum of a plurality of movement vectors "move 1", “move 2", “move 3" etc. between two digital tooth models over a plurality of steps in the orthodontic treatment.
  • the simulation of the interference between digital tooth models can serve as prediction of the interference between the physical tooth models after they are fabricated and assembled to form a physical dental base mode.
  • the information regarding the interference between the physical tooth models can be used to prevent such interference from occurring.
  • One method to prevent the interference is the adjust teeth positions in a dental arch model, as described above.
  • Another method to prevent such interference is by adjusting features affixed to the physical tooth models.
  • the tooth models can be affixed with one or more pins at their bottom portions for the tooth models to be inserted into the base.
  • the two adjacent tooth models may interfere with each other when they are inserted into a base.
  • the pin configurations are selected in step 7170 to prevent such interference between adjacent tooth models.
  • FIG. 100 Two adjacent tooth models 7670 and 7680 are shown in FIG. 100.
  • the tooth models 7670, 7680 are respectively affixed with pins 7675 and pins 7685.
  • the orthodontic treatment requires the two adjacent tooth models 7670 and 7680 to be tilted away from each other in a tooth arch model. As a result, the pins 7675 and the pins 7685 interfere with or collide into each other.
  • FIG. 101 two adjacent tooth models 7690 and 7695 are required to tilt toward each other by the orthodontic treatment.
  • the tooth models 7690 and 7695 are affixed with pins having equal pin lengths. The tooth models 7690 and 7695 can collide into each other when they are inserted into a base 7700 because the insertion angles required by the long insertion pins.
  • FIG. 102 illustrates a tooth model 7705 having two pins 7710 and 7715 affixed to the bottom portion.
  • the pins 7710 and 7715 are designed to have different lengths.
  • FIGS. 103A and 103B detailed perspective views illustrating an example of how two tooth models having the pin configurations shown in FIG. 102 can avoid interfering with each other.
  • FIG. 103 A shows the front perspective view of two tooth models 7720 and 7730 each of which is respectively affixed pins 7725 and 7735.
  • the pins 7725 and pins 7735 are configured to have different lengths so that the pins do not run into each other when they are inserted into a base (not shown in FIG. 103 A for clarity).
  • the avoidance of interference between the tooth models 7720 and 7730 is also illustrated in a perspective bottom view in FIG. 103B.
  • the pin configurations for tooth models can be selected by different methods.
  • a digital dental arch model that represents the physical tooth model is first produced or received.
  • the digital dental arch model defines the positions and orientations of the two adjacent physical tooth models in the physical dental arch model according to the requirement of the orthodontic treatment.
  • the positions of the physical tooth models including the pins are simulated to examine the interference between two
  • the pin configurations are adjusted to avoid any interference that might occur in the simulation.
  • the pin configurations can include pins lengths, pin positions at the underside of the tooth models, and the number of pins for each tooth model.
  • the tooth models affixed with pins having the selected pin configurations can fabricated by Computer Numerical Control (CNC) based manufacturing in response to the digital dental arch model.
  • CNC Computer Numerical Control
  • the tooth portions of the tooth models can remain the same while the pins affixed to the tooth portion being adjusted depending on the relative orientation of positions between adjacent tooth models.
  • the base can include different socket configurations adapted to receive compatible pin configurations selected for different steps of the orthodontic treatment.
  • the physical tooth models and their pin configurations can be labeled by a predetermined sequence to define the positions of the physical tooth models on the base for each step of the orthodontic treatment.
  • different pin configurations are utilized to allow longer pins affixed to the tooth models, which results in more stable physical tooth arch model.
  • the tooth portion of the tooth models may be reused for different steps of an orthodontic treatment (e.g., generating dental aligners for different steps of the treatment).
  • Modular sockets can be prepared on the underside of the tooth models. Pins of different lengths can be plugged into the sockets to prevent interference between adjacent tooth models.
  • the base plate is taken through a CNC process to create the female structures for each individual tooth (step 7180). Then the base is placed over the casting container in which the impression is already present and the container is filled with epoxy. The epoxy gets filled up in the female structures and the resulting mold has the male studs present with each tooth model that can be separated afterwards.
  • FIG. 92 shows a tooth model 7210 with male stud 7220 after mold separation.
  • the base 7230 comprises a female feature 7240 that can receive the male stud 7220 when the tooth model 7210 is assembled to the base 7230.
  • a tooth model 7310 includes a female socket 7315 that can be drilled by CNC based machining after casting and separation.
  • a male stud 7320 that fits the female socket 7315 can be attached to the tooth
  • the resulted tooth model 7330 includes male stud 7310 that allows it to be attached to the base.
  • FIG. 94 shows a tooth model 7410 having two pins 7415 sticking out and a base 7420 having registration slots 7425 adapted to receive the two pins 7415 to allow the tooth model 7410 to be attached to the base 7420.
  • FIG. 95 shows a tooth model 7510 having one pins 7515 protruding out and a base 7520 having a hole 7525 adapted to receive the pin 7515 to allow the tooth model 7510 to be attached to the base 7520.
  • the tooth model can include two or more pins wherein the base will have complementary number of holes at the corresponding locations for each tooth model.
  • the tooth model 7600 can also include cone shaped studs 7605 as shown in FIG. 96. The studs can also take a combination of configurations described above.
  • the studs protruding our of the tooth model 7608 can take different shapes 7606 such as oval, rectangle, square, triangle, circle, semi-circle, each of which correspond to slots on the base having identical shapes that can be drilled using the CNC based machining.
  • the asymmetrically shaped studs can help to define a unique orientation for the tooth model on the base.
  • FIG. 98A shows a base 7610 having a plurality of sockets 7615 and 7620 for receiving the studs of a plurality of tooth models.
  • the positions of the sockets 7615, 7620 are determined by either her initial teeth positions in a patient's arch or the teeth positions during the orthodontic treatment process.
  • the base 7610 can be in the form of a plate as shown in FIG. 98A, comprising a plurality of pairs of sockets 7615, 7620. Each pair of sockets 7615, 7620 is adapted to receive two pins associated with a physical tooth model.
  • Each pair of sockets includes a socket 7615 on the inside of the tooth arch model and a socket 7620 on the outside of the tooth arch model.
  • FIG. 98B Another of a base 7625 is shown in FIG. 98B.
  • a plurality of pairs of female sockets 7630, 7635 are provided in the base 7625.
  • Each pair of the sockets 7630, 7635 is formed in a surface 7640 and is adapted to receive a physical tooth model 7645.
  • the bottom portion of the physical tooth model 7645 includes a surface 7655. The surface 7655 comes to contact with the surface 7640 when the physical tooth model 7645 is inserted into the base 7625, which assures the stability of the physical tooth model 7645 over the base 7625.
  • a tooth model 7660 compatible with the base 7610 is shown in FIG. 99.
  • the tooth model 7660 includes two pins 7665 connected to its bottom portion.
  • the two pins 7665 can be plugged into a pair of sockets 7615 and 7620 on the base 7610.
  • each pair of sockets 7615 and 7620 uniquely defines the positions of a tooth model.
  • the orientation of the tooth model is also uniquely defined if the two pins are labeled as inside and outside, or the sockets and the pins are made asymmetric inside and outside.
  • Each tooth model may include correspond to one or a plurality of studs that are to be plugged into the corresponding number of sockets.
  • the male studs and the sockets may also take different shapes as described above.
  • the disclosed methods and system can include teeth duplicate with removable or retractable pins, as shown in FIGS. 104 and 105.
  • a tooth model 7760 is placed on a flat surface 7805 in a recess created in the base 7795.
  • the base 7795 include through holes 7780 and 7785.
  • the tooth model 7800 includes at the bottom potion drilled holes 7775 and 7790 that are in registration and alignment with the through holes 7780 and 7785. Pins 7760 can then be inserted along directions 7765, 7770 into the through holes 7780 and 7785 in the base and then holes 7775 and 7790 in the base to affix the tooth models 7800 into the base 7795.
  • the tooth model 7810 includes holes 7815.
  • Pins 7830 and 7835 can be inserted into the holes 7815 in spring load mechanisms 7820, 7825.
  • the pins 7825 are retractable with compressed springs to avoid interference during insertion or after the installation of the tooth model over the base. After the tooth models are properly mounted and fixed, the pins 7825 can extend to their normal positions to maximize position and angle control. The overall pin lengths can be cut to the correct lengths to be compatible with the spring load mechanisms to prevent interference between tooth models.
  • a tooth arch model is obtained after the tooth models are assembled to the base 7610 (step 7190).
  • the base 7610 can comprise a plurality of configurations in the female sockets 7615. Each of the configurations is adapted to receive the same physical tooth models to form a different arrangement of at least a portion of a tooth arch model.
  • the base 7610 can be fabricated by a system that includes a computer device adapted to store digital tooth models representing the physical tooth models.
  • the digital tooth model can be obtained by various scanning techniques.
  • a computer processor can then generate a digital base model compatible with the digital tooth models.
  • An apparatus fabricates the base using CNC based manufacturing in accordance with the digital base model. The base fabricated is adapted to receive the physical tooth models.
  • the physical tooth models may be labeled by a predetermined sequence that defines the positions of the physical tooth models on the base 7610.
  • the labels can include a barcode, a printed symbol, hand-written symbol, a Radio Frequency Identification (RFID).
  • RFID Radio Frequency Identification
  • the female sockets 7615 can also be labeled by the parallel sequence for the physical tooth models.
  • tooth models can be separated and repaired after the base.
  • the tooth models can be removed, repaired or replaced, and re-assembled without the replacement of the whole arch model.
  • the materials include, but not limited to, polymers, urethane, epoxy, plastics, plaster, stone, clay, acrylic, metals, wood, paper, ceramics, and porcelain.
  • the base can comprise a material such as polymers, urethane, epoxy, plastics, plaster, stone, clay, acrylic, metals, wood, paper, ceramics, porcelain, glass, and concrete.
  • the arch model which comprise of individual tooth models, can be used in different dental applications, such as dental crown, dental bridge, dental aligner fabrication, biometrics, and shell fabrication for teeth whitening.
  • aligner fabrication for example, each stage of the teeth treatment may corresponds to a unique physical dental arch model.
  • the aligners can be fabricated using different physical dental arch models one at a time as the teeth movement progresses during the treatment. At each stage of the treatment, the desirable teeth positions for the next stage are calculated. A physical dental arch model having modified teeth positions is fabricated using the process described above. A new aligner is made using the new physical dental arch model.
  • each base is specific to an arch configuration. Therefore, complex and costly mechanisms such as micro-actuators, for adjusting multiple degrees of freedom for each tooth model, may not be needed in the aligner fabrication process.
  • different stages of the arch model can share the same tooth models.
  • the positions for the tooth models at each stage of the orthodontic treatment can be modeled using orthodontic treatment software.
  • Each stage of the arch model may use a separate base.
  • one base can be used in a plurality of stages of the arch models.
  • the base may include a plurality of sets of receptive positions for the tooth models. Each set corresponds to one treatment stage.
  • the tooth models can be reused through the treatment process. Much of the cost of making multiple tooth arch models in orthodontic treatment may, therefore, be eliminated.
  • methods for producing a physical dental arch model based on a three-dimensional (3D) digital dental arch model comprise the following: smoothening the digital dental arch model to make the digital dental arch model suitable for CNC based manufacturing; segmenting the digital dental arch model into at least two digital components; producing manufacturable physical components using Computer Numerical Control (CNC) based manufacturing in accordance with the manufacturable digital components; and assembling the physical manufacturable components to form the physical dental arch model.
  • CNC Computer Numerical Control
  • systems for producing a physical dental arch model comprise: a computer storage device that stores a three-dimensional (3D) digital dental arch model; a computer processor that can smoothen the digital data in the digital dental arch model and segment the digital dental arch model into at least two manufacturable digital components suitable for CNC based manufacturing; and an apparatus that can produce manufacturable physical components in accordance with the manufacturable digital components, wherein the manufacturable physical components can be assembled to form the physical dental arch model.
  • 3D three-dimensional
  • physical dental arch models assembled by a plurality of components are described.
  • One variation comprises: two or more manufacturable physical components produced by Computer Numerical Control (CNC) based manufacturing in response to manufacturable digital components segmented from a three- dimensional (3D) digital dental arch model; and a base adapted to receive the manufacturable physical components.
  • CNC Computer Numerical Control
  • Implementations may include one or more of the following.
  • a method for producing a physical dental arch model based on a three-dimensional (3D) digital dental arch model comprises smoothening the digital dental arch model to make the digital dental arch model suitable for CNC based manufacturing, segmenting the digital dental arch model into at least two manufacturable digital components, producing manufacturable physical components using Computer Numerical Control (CNC) based manufacturing in accordance with the manufacturable digital components and assembling the manufacturable physical components to form the physical dental arch model.
  • CNC Computer Numerical Control
  • the method can further include determining if the smoothened digital dental arch model satisfies one or more predetermine criteria for CNC based manufacturing.
  • the method can further include running a CNC simulator to determine if the smoothened digital dental arch model satisfies one or more predetermine criteria for CNC based manufacturing.
  • the digital dental arch model can include removing sharp gaps and divots in the teeth arch in the digital dental arch model.
  • the manufacturable digital components can include a portion of a tooth, a whole tooth, a plurality of teeth, or a complete teeth arch.
  • the manufacturable digital components and the manufacturable physical components can include features that permit the manufacturable physical components to be assembled into the physical dental arch model.
  • the features can include one or more of a pin, a notch, a protrusion, a hole, an interlocking mechanism, a jig, and a pluggable or an attachable feature.
  • the method can further include attaching or plugging the manufacturable physical components into each other to form the physical dental arch model.
  • the CNC based manufacturing can includes milling, stereolithography, laser machining, and molding.
  • the physical dental arch model can comprise a material selected from the group consisting of polymers, urethane, epoxy, plastics, plaster, stone, clay, acrylic, metals, wood, paper, ceramics, and porcelain.
  • the method can further include obtaining a cast for a teeth arch from a patient and scanning the cast to obtain the digital data for the digital dental arch model.
  • the method can further include generating a digital model for a base compatible with the digital dental arch model and producing the base that can be assembled with the manufacturable physical components.
  • the base can comprise one or more features to assist the assembling with the manufacturable physical components, said features comprising one or more of a pin, a notch, a protrusion, a hole, an interlocking mechanism, a jig, and a pluggable or attachable feature.
  • the method can further include attaching or plugging the manufacturable physical components into the base to form the physical dental arch model over the base.
  • the method can further include producing the physical base using CNC based manufacturing.
  • a system for producing a physical dental arch model comprises a computer storage device that stores a three-dimensional (3D) digital dental arch model; a computer processor that can smoothen the digital data in the digital dental arch model and segment the digital dental arch model into at least two manufacturable digital components suitable for CNC based manufacturing, and an apparatus that can produce manufacturable physical components in accordance with the manufacturable digital components, wherein the manufacturable physical components can be assembled to form the physical dental arch model.
  • the apparatus can produce manufacturable physical components in accordance with the manufacturable digital components using Computer Numerical Control (CNC) based manufacturing.
  • the system can further comprise an apparatus that can produce a physical base that is adapted to receive the manufacturable physical components form the physical dental arch model on the base.
  • Implementations of the system may include one or more of the following.
  • a physical dental arch model assembled from a plurality of manufacturable physical components comprises two or more manufacturable physical components produced by Computer Numerical Control (CNC) based manufacturing in response to manufacturable digital components segmented from a three-dimensional (3D) digital dental arch model, and a base adapted to receive the manufacturable physical components.
  • the base can be produced by Computer Numerical Control manufacturing.
  • the digital model is first smoothened to remove gaps and divots that cannot be reproduced in a physical model by a machine.
  • the digital dental arch model is then broken down to small manufacturable components that can be readily handled by automated machining such as computer numerical control (CNC) based milling.
  • the manufacturable components can be an individual tooth, multi tooth segment, or a part of a tooth. Features are added to the manufacturable components to allow them to be attached, plugged or locked into each other.
  • the manufacturable physical components manufactured can be assembled to construct a physical dental archphysical dental arch model for various dental applications such as dental crown, dental bridge, aligner fabrication, biometrics, and teeth whitening.
  • the arch model can be assembled from segmented manufacturable components that can individually be manufactured by automated, precise numerical manufacturing techniques.
  • the manufacturability of the manufacturable components are simulated, verified and refined if necessary prior to manufacturing. As a result, complex arch shapes that cannot be made can now be practically manufactured. Waste and cycle times are reduced in the process from design, testing, pilot, to production.
  • the manufacturable components can be attached to each other and/or onto a base.
  • the assembled physical dental archphysical dental arch model specifically corresponds to the patient's arch.
  • there is no need for complex and costly mechanisms such as micro-actuators for adjusting multiple degrees of freedom for each tooth component.
  • manufacturable physical components e.g., physical tooth models
  • the manufacturable physical components can be hollow inside and have outer surfaces that allow proper union of the components.
  • the manufacturable physical components can be assembled in pressure forming.
  • the manufacturable physical components can be pre-fabricated similar to LEGO blocks having standard registration and attaching features for assembling.
  • the manufacturable physical components can be automatically assembled by robotic arms under computer control. In one variation, the manufacturable physical components can be separated, repaired or replaced, and reassembled after the assembly.
  • FIG. 116 is a flow chart illustrating one example of a method for producing a physical dental arch model.
  • a digital model is acquired from a patient's arch in step 8110.
  • the digital model is three dimensional and can be obtained by 3D scanning of a cast produced from the patient's arch.
  • the digital model includes a mesh of points in three dimensions that define the surfaces of an entire or a large portion of an upper or lower arch.
  • step 8120 the digital dental arch model is smoothened by computer processing.
  • a software takes the digital dental arch model as input.
  • One or more criteria for the degree of smoothness can also be provided by a user.
  • Undesirable features such as sharp gaps and divots are removed from the digital dental arch model.
  • the criteria for the degree of smoothness can be required by the specific dental applications.
  • the gaps between the teeth may be filled-up in the digital model, since some variations of the plastic aligners may not reach into the gaps between the teeth.
  • the criteria for the degree of smoothness can also be adjusted by type of the tools used to manufacture the physical components as described below.
  • Computer Numerical Control or CNC based manufacturing refers to the automated and computer controlled machining.
  • the CNC equipment have two or more directions of motion, called axes. These axes can be precisely and automatically positioned along their lengths of travel.
  • the two most common axis types are linear (driven along a straight path) and rotary (driven along a circular path).
  • CNC machines allow motions to be actuated by servomotors under control of the CNC, and guided by the part program.
  • the motion type rapid, linear, and circular
  • the axes to move the amount of motion and the motion rate (feed rate) can be programmable in the CNC machine tools.
  • CNC based manufacturing In addition to CNC based milling, the CNC based manufacturing also include other computer numerical controlled manufacturing processes such as stereolithography, laser machining, and molding. Other examples of CNC based manufacturing include Laminated Object Manufacturing, Selective Laser Sintering, Fused Deposition Modeling, Solid Ground Curing, 3D ink jet printing.
  • Geometry modification by moving vertices Sharp gaps can be closed by specifying the desired boundaries and modifying the mesh to the desired boundaries in the problem regions.
  • Subdivision of surfaces and movement Similar to Technique (3), the arch surfaces are subdivided in the regions of surface modification for greater smoothness and continuity.
  • Convex hull creation of sub parts to be used as filling objects in the gaps The gap regions are first located and the points defining edges of the sharp gaps are identified. A convex hull is computed based on these points. The convex hull is joined with the original mesh to fill the gaps using Boolean union. (6) Using parametric surfaces to model fill objects that will be used fit in the gaps.
  • FIG. 117 illustrates an example of the smoothening effects of the gap filling by comparing the surfaces 8210 of before gap fillings and the surfaces 8220 after the gap fillings.
  • a simulation can be conducted using the smoothened the digital dental arch model as input to check and verify the smoothness of the digital dental arch model.
  • the simulation can be run using a simulator software in response to the smoothness criteria required by the manufacturing process such as CNC based milling or the dental applications. Refinement ad smoothening iterations may be called for if the smoothness criteria are not completely satisfied.
  • the smoothened digital dental arch model is segmented into manufacturable digital components suitable for CNC manufacturing.
  • a typical arch in the digital dental arch model includes a whole upper or lower arch or a portion of an arch comprising a plurality of teeth.
  • the physical components can be a portion of a tooth 8310, a whole individual tooth 8320, or sometimes a segment of teeth arch including several teeth.
  • the criteria for the size, location, and the number of physical components can be based on both orthodontic needs and manufacturing requirements.
  • the orthodontic criteria requires the tracking of how the original locations of the physical components and which components can be moved together as a group, which physical components must be moved independently, and which teeth cannot be moved.
  • the manufacturing requirements relate mainly to the manufacturability of the digital components, which may supersede the orthodontic criteria.
  • a single tooth can be divided into multiple components to make its model manufacturable.
  • the segmented digital components can be evaluated by a simulator software to verify their manufacturability by a specific manufacture process such as CNC based milling, which may suggest refinement in the size, location, and numbers of the segmentation.
  • the simulation can also include an evaluation and estimation of the physical strength after the assembly, as described below, to determine if the assembled physical components are strong enough to withstand the physical forces in a pressure forming process.
  • the smoothening of the digital dental arch model may occur during the segmentation.
  • Different segmented digital components may receive different types or degree of smoothening so that the smoothening is tailored to the segments and manufacturing requirements.
  • the arch model can be segmented to small manufacturable components such that the components can be manufactured by automated, precise numerical manufacturing techniques.
  • the manufacturability of the digital components are also simulated, verified and refined prior to manufacturing (step 8140).
  • step 8140 complex arch shapes that cannot be made can be detected and modified such that they can be manufactured. Therefore, waste and cycle times may be reduced in the process from design, testing, pilot, to production.
  • inter-proximal regions in segmenting arch into digital components.
  • the inter-proximal regions involve such complexity and details that CNC based manufacturing such as cutting or milling cutting can result in losing details.
  • an inter ⁇ proximal region 8440 is removed between a tooth model 8410 and a tooth model 8420 along the lines 8430. This can be achieved over tooth models in a tooth arch model by using a CNC machine, or by data processing over the digital dental arch model.
  • a thin gap 8450 is formed between tooth model 8410 and tooth model 8420.
  • a wedge 8460, shown in FIG. 1 19C is first designed using wedge design software and then made using CNC based manufacturing technique.
  • the wedge 8470 can be inserted into the gap 8450 to complete the digital tooth arch model or the physical tooth arch model.
  • the wedge making and insertion can take into account of the movement of the tooth models 8410, 8420 during the orthodontic treatment.
  • the wedge 8480 is made to be slightly sheared.
  • the wedge 8490 inserted between the tooth models 8410, 8420 can therefore induce a relative movement between the tooth models 8410, 8420.
  • the relative movement can include translational and directional adjustment in different degrees of freedoms.
  • the resulted tooth arch model can then be used to made dental aligners.
  • FIGS. 120A, 120B, 120C and 120D illustrate examples of the manufacturable physical components 8510, 8520, 8530, 8540 that respectively include features 8515, 8525, 8535, 8545 that allow them to be attached to each other in order to form a whole or part of a physical dental arch.
  • FIG.120A shows a feature 8515 having a cubic base for a physical component 8510.
  • FIG. 120B shows a feature 8525 having a star- shaped base for a physical component 8520.
  • the star-shaped base defines unique orientation when physical component 8520 is assembled with another physical component.
  • FIGS. 120C and 120D show features 8535 and 8545 respectively comprising two and three pins in the physical components 8530 and 8540.
  • the two pins ensure uniquely defined orientation when physical component 8530 is assembled with another physical component.
  • the three pins in feature 8545 ensure unique configuration when physical component 8540 is assembled with another physical component.
  • the physical components may include features such as a pin, a registration slot, a notch, a protrusion, a hole, an interlocking mechanism, a
  • the adjacent manufactured manufacturable physical components may include matching male (e.g. mushroom, push pins) and female features (e.g. hole, notches etc.) for attachment.
  • the male and female features can be fabricated for example by casting mold that include female and male matching features in the mold, each responsible for making respective male and female features.
  • the adjacent manufacturable physical components can be attached together by simply pushing male feature into the female feature, for example, by pressing a pushpin into a receiving hole.
  • the physical components can be labeled with unique identifications, and assembled and detached in predetermined sequences.
  • the assembling and detachment can be automated by for example a robotic arm under the control of a computer in accordance with the predetermined sequences.
  • the manufacturable physical components 8610 can include a feature 8620 that allow it to be attached or plugged to a based plate.
  • the manufacturable physical components 8630 can also include two pins 8620 for attaching to a base.
  • the manufacturable physical components 8730 can be assembled over the base 8710 to form a physical dental archphysical dental arch model 8700 as shown in FIG. 122.
  • the base 8710 is designed in step 8150 for the manufacturable components 8730.
  • the base 8710 comprises one or more features 8720 which are adapted to receive the features 8740 of the manufacturable physical components 8730 for assembling of the physical dental archphysical dental arch model 8700.
  • the features 8720 receiving the manufacturable components 8730 guarantee unique positions and orientations for manufacturable components 8730 in the final physical dental arch model 8700.
  • the features 8720 can include a pin, a notch, a protrusion, a hole, an interlocking mechanism, a jig, and a pluggable or attachable feature. All or a subset of the manufacturable physical components 8730 (step 8160) can be attached to the base 8710. For example, the manufacturable physical components 8730 (step 8160) can be readily plugged attached to slots prepared on the base 8710.
  • features 8720 and features 8740 are designed to be fit each other, which for example, can include matching notches and pins.
  • the features 8720 and features 8740 can be selected in software designs from predefined structures and then add to the root direction of the manufacturable components 8610, 8730 and the top of the base 8710.
  • features 8720 and features 8740 can be designed in software and finished by a combination of manufacturing (steps 8160, 8170) and assembling (step 8180).
  • steps 8720 and features 8740 can be notches or holes.
  • a pin can be plugged into the notches to assemble the manufacturable components 8730 and the top of the base 8710.
  • Features 8720 and features 8740 can include asymmetric shapes such as an asymmetric star to ensure a unique orientation in the fitting between the base 8710 and the manufacturable components 8730.
  • the manufacturable components are assembled in pressure forming.
  • the manufacturable physical components may be hollow inside and have outer surfaces that match the manufacturable digital components to allow proper union of the manufacturable physical components.
  • the manufacturable physical components can be pre ⁇ fabricated similar to LEGO blocks.
  • the surfaces of the manufacturable physical components may include standard registration and attaching features for them to join together.
  • the LEGO-like manufacturable physical components can be automatically assembled by robotic arms under computer control.
  • manufacturable physical components can be separated and repaired after the assembly.
  • the attaching features between manufacturable physical components allow the components to be detached in a sequence. Broken component can be removed, repaired or replaced, followed by re-assembling.
  • the manufacturable physical components 8610, 8730 are manufactured in step 8160 using CNC based manufacturing techniques.
  • the segmented manufacturable digital components are provided to as input files to a CNC machine.
  • the manufacturable physical components 8610, 8730 are manufactured individually.
  • the precision and yield of the CNC based manufacturing are high because manufacturability has been considered and verified as part of the designs of the manufacturable components.
  • Common materials for the manufacturable components that are well know to one of ordinary skill in the art include, by not limited to, polymers, urethane, epoxy, plastics, plaster, stone, clay, acrylic, metals, wood, paper, ceramics, and porcelain.
  • the physical dental arch model may optionally include a base on which teeth components can be attached.
  • the base 8710 is next manufactured in step 8170.
  • the base 8710 can be designed to possess smooth surfaces so that it complies with CNC manufacturing requirements.
  • the CNC based manufacturing of the base 8710 can include the use of a prefabricated base part and precision drilling of notches on the prefabricated base part to define features 8720.
  • the positions of the manufacturable components 8710 can then be precisely defined in the physical dental archphysical dental arch model 8700.
  • the physical dental archphysical dental arch model 8700 is constructed in step 8180 by assembling the manufacturable physical components 8730 and the base 8710.
  • the manufacturable physical components 8730 can also be assembled onto the base 8710 in different arrangements such as one pin and two pins as illustrated in FIG. 122.
  • the joining features at the base can also include a registration slot, a notch, a protrusion, a hole, an interlocking mechanism, and a jig. In another arrangement, only even numbered teeth can be plugged into the base while the odd numbered teeth are slot in between the even numbered teeth from their sides.
  • the physical dental arch model 8700 can be used in different dental applications such as dental crown, dental bridge, aligner fabrication, biometrics, and teeth whitening.
  • aligner fabrication for example, each stage of the teeth treatment may correspond to a unique physical dental arch model. Aligners can be fabricated using different physical dental arch models one at a time as the teeth movement progresses during the treatment. At each stage of the treatment, the desirable teeth positions for the next stage are calculated. A physical dental arch model having modified teeth positions is fabricated using the process described above. A new aligner is then made using the new physical dental arch model.
  • each base is specific to an arch configuration. There is no need to reconfigure or manipulate a multiple of degrees of freedom for each manufacturable component once it is plugged into the base.
  • the different physical components 8810, 8820, 8830 can be assembled to form a whole or a portion of a physical dental arch model 8800 without a base.
  • the different physical components 8810, 8820, 8830 can be attached or plugged into each other at joining features 8850 that can be pins, registration slot, a notch, etc.
  • different stages of the physical dental arch model share the same manufacturable physical components. Only a new base having new set of receptive positions for the manufacturable physical components are required for each stage of the treatment.
  • the manufacturable physical components can be reused through the treatment process.
  • the positions for the manufacturable physical components at each stage of the treatment can be modeled using an orthodontic treatment software.
  • One variation comprises: producing a digital dental aligner model suitable for CNC based manufacturing based on the digital dental arch model; segmenting the digital dental aligner model into a plurality manufactuable digital components; producing aligner components using Computer Numerical Control (CNC) based manufacturing in accordance with the digital aligner components; and assembling the aligner components to form the physical dental aligner.
  • CNC Computer Numerical Control
  • systems for producing a physical dental aligner are described.
  • One variation comprises: a computer processor capable of producing a digital dental aligner model and segmenting the digital dental aligner model into a plurality of digital aligner components suitable for CNC based manufacturing; and an apparatus capable of fabricating aligner components in accordance with the digital aligner components, wherein the aligner components can be assembled to form the physical dental aligner.
  • physical dental aligners assembled from a plurality of aligner components are described.
  • One variation comprises: a plurality of aligner components produced by Computer Numerical Control (CNC) based manufacturing in response to digital aligner components segmented from a three-dimensional (3D) digital dental aligner model.
  • CNC Computer Numerical Control
  • Implementations may include one or more of the following.
  • a method for producing a physical dental aligner includes producing a digital dental aligner model suitable for CNC based manufacturing based on the digital dental arch model, segmenting the digital dental aligner model into a plurality manufactuable digital components, producing aligner components using Computer Numerical Control (CNC) based manufacturing in accordance with the digital aligner components, and assembling the aligner components to form the physical dental aligner.
  • the physical dental aligner can include a shell that comprises an outer surface and at least inner surface that is capable of aligning one or more teeth.
  • the shell can comprise multiple layers.
  • the shell can comprise varying thicknesses in different areas that is capable of producing forces to render predetermined teeth movement.
  • the method can further comprise smoothening the outer surface and the one or more inner surfaces in the digital dental aligner model to produce a smoothened digital dental aligner model.
  • the method can further comprise producing a digital dental aligner model based on a digital dental arch model.
  • the method can further comprise automatically assembling the aligner components using a robot arm to form the physical dental aligner.
  • the aligner components can include features that permit the aligner components to be assembled into the physical dental aligner.
  • the features can include one or more of registration slots, a pin, a notch, a protrusion, a hole, an interlocking mechanism, a jig, and a pluggable or an attachable feature.
  • the method can further comprise attaching or sealing the aligner components into each other to form the physical dental aligner.
  • the method can further comprise assembling the aligner components in a predetermined sequence to form the physical dental aligner.
  • the method can further comprise polishing or retouching the assembled aligner components to form the physical dental aligner.
  • the CNC based manufacturing includes one or more of milling, stereo lithography, laser machining, molding, and casting.
  • the physical dental aligner may be fabricated based on various materials that are well know to one of ordinary skill in the art, including, but not limited to, plastics, polymers, urethane, epoxy, plaster, stone, clay, acrylic, metals ceramics, and porcelain.
  • the physical dental aligner may comprise surface textures that simulate the cosmetic appearance of teeth.
  • the physical dental aligner may be configured with multiple layers each comprising the same or different materials.
  • Implementations may include one or more of the following.
  • a physical dental aligner assembled from a plurality of aligner components includes a plurality of aligner components produced by Computer Numerical Control (CNC) based manufacturing in response to digital aligner components segmented from a three-dimensional (3D) digital dental aligner model.
  • the physical dental aligner can further comprise physical features associated with the aligner components that permit the aligner components to be assembled into the physical dental aligner.
  • the features can include one or more of a pin, a notch, a protrusion, a hole, an interlocking mechanism, a jig, and a pluggable or an attachable feature.
  • a digital dental aligner model is developed based on a digital dental arch model.
  • the digital dental aligner model is then segmented down to small manufacturable aligner components that can be readily handled by automated machining such as computer numerical control (CNC) based milling.
  • CNC computer numerical control
  • the aligner components manufactured can be assembled to construct a dental aligner for various dental applications, e.g. retainers, mouth guard.
  • the dental aligner can be assembled by from segmented aligner components that can individually be manufactured by automated, precise numerical manufacturing techniques.
  • the manufacturability of the aligner components can be simulated, verified and refined prior to manufacturing. As a result, complex aligner shapes that cannot be made can be modified before manufacturing. Therefore, waste and cycle times are reduced in the process from design, testing, pilot, to production.
  • the aligner components can be attached to each other and/or onto a base.
  • the assembled aligner specifically corresponds to the patient's arch.
  • there is no need for complex and costly mechanisms such as micro- actuators for adjusting multiple degrees of freedom for each tooth component.
  • the aligner components can be pre-fabricated similar to LEGO blocks having standard registration and attaching features for assembling.
  • the aligner components can be automatically assembled by robotic arms under computer control.
  • the aligner components can be separated, repaired or replaced, and reassembled after the assembly.
  • the physical aligner components can include a shell have multiple layers. The outer surface of the shell can be polished and retouched to simulate the aesthetic appearance of a patient's teeth. The inner surface is capable of aligning a patient's teeth.
  • the process illustrated in FIG. 116 is utilized for producing a dental aligner.
  • dental aligner refers to a dental device for correcting malocclusion.
  • method and apparatus discussed herein may also be utilized to fabricate a dental shell.
  • the dental shell may be designed to serve as a tooth alignment device, a tooth whitening tray, a retainer, or for various other applications that are well known to one of ordinary skill in the art.
  • a digital dental arch model is developed in step 81 10 through 8120 as described in above in the construction of a physical dental arch model using CNC.
  • a digital aligner model is next developed based on the digital dental arch model in step 8130.
  • the digital aligner model comprises inner surfaces and outer surfaces. Since the inner surfaces of the aligner will be in contact with the outer surface of the patient's teeth, the inner surfaces of the digital aligner model approximately follow the contours of the outer surface of the digital dental arch model, so that the dental aligner will snap on the arch. Moreover, the inner and outer surfaces of digital aligner are designed to various shapes and thickness to apply the right forces to achieve the movement of the teeth in accordance with a treatment plan.
  • step 8140 the digital aligner model are segmented into digital aligner components suitable for CNC manufacturing.
  • a typical aligner in the digital aligner model includes an upper or lower aligner respectively for the upper and lower arch or a portion of an arch comprising a plurality of teeth.
  • An aligner 8300 is shown in FIG. 1 18B.
  • the aligner components 8310, 8320 can correspond to a portion of a tooth, a whole individual tooth, or sometimes a segment of arch including several teeth.
  • the criteria for the size, location, and the number of aligner components may be based on both orthodontic needs and manufacturing requirements.
  • the orthodontic criteria require the tracking of how the original locations of the aligner components and which components can be moved together as a group, which aligner components must be moved independently, and which teeth cannot be moved.
  • the manufacturing requirements relate to the manufacturability of the digital aligner components, which may supersedes the orthodontic criteria. For example, a single tooth can be divided into multiple components to make its model manufacturable.
  • the segmented digital components can be evaluated by a simulator software to verify their manufacturability by a specific manufacture process such as CNC based milling, which may suggest refinement in the size, location, and numbers of the segmentation.
  • the simulation can also include an evaluation and estimation of the physical strength after the assembly, as described below, to determine if the assembled aligner components are strong enough to withstand the physical forces in a pressure forming process.
  • the digital aligner model can be smoothened during the segmentation.
  • Different segmented digital components may receive different types or degree of smoothening so that the smoothening is tailored to the segments and manufacturing requirements.
  • the aligner model is segmented to small manufacturable aligner components that can be manufactured by automated, precise numerical manufacturing techniques.
  • the manufacturability of the digital components is simulated, verified and refined prior to manufacturing. As a result, complex aligner shapes that cannot be made can be modified and then manufactured. Therefore, waste and cycle times can be reduced in the process from design, testing, pilot, to production.
  • step 8150 features are added to the aligner components to assist the assembling of the aligner components to form an aligner.
  • the features may include a pin, a registration slot, a notch, a protrusion, a hole, an interlocking mechanism, a socket, a jig, and a pluggable or an attachable feature.
  • the adjacent manufactured aligner components may include matching male (e.g. mushroom, push pins) and female features (e.g. hole, notches etc.) for attachment.
  • the male and female features can be fabricated for example by casting mold that include female and male matching features in the mold, each responsible for making respective male and female features.
  • the adjacent aligner components can attached together by simply pushing male feature into the female feature, for example, by pressing a pushpin into a receiving hole.
  • special care can be applied to the inter-proximal regions in segmenting arch into digital components.
  • the inter-proximal regions involve such complexity and details that CNC based manufacturing such as cutting or milling cutting can result in losing details.
  • an inter ⁇ proximal region 8440 is removed between a tooth model 8410 and a tooth model 8420 along the lines 8430. This can be achieved by data processing over the digital dental arch model.
  • a thin gap 8450 is formed between tooth model 8410 and tooth model 8420.
  • a wedge 8460 shown in FIG. 1 19C, is then made using CNC based manufacturing technique similar to other manufacturable digital components.
  • the wedge 8470 can be inserted into the gap 8450 to complete the digital tooth arch model.
  • the wedge making and insertion can take into account of the movement of the tooth models 8410, 8420 during the orthodontic treatment.
  • the wedge 8480 is made to be slightly sheared.
  • the wedge 8490 inserted between the tooth models 8410, 8420 can therefore induce a relative movement between the tooth models 8410, 8420.
  • the relative movement can include translational and directional adjustment in different degrees of freedoms.
  • the resulted tooth arch model can then be used to made dental aligners.
  • FIGS. 120A, 120B, 120C and 120D illustrate examples of the features in the aligner components 8510, 8520, 8530, 8540.
  • the features 8515, 8525, 8535, 8545 allow the aligner components 8510, 8520, 8530, 8540 to be attached to each other to form a whole or part of a physical aligner.
  • FIG. 120A shows a feature 8515 having a cubic base for a aligner component 8510.
  • FIG. 120B shows a feature 8525 having a star-shaped base for a aligner component 8520.
  • the star-shaped base defines unique orientation when aligner component 520 is assembled with another aligner component.
  • 120C and 120D show features 8535 and 8545 respectively comprising two and three pins in the aligner components 8530 and 8540.
  • the two pins ensure uniquely defined orientation when aligner component 8530 is assembled with another aligner component.
  • the three pins in feature 8545 ensure unique configuration when aligner component 8540 is assembled with another aligner component.
  • the aligner components 8310, 8320 are manufactured in step 8160 using
  • the segmented digital aligner components are provided to as CNC objects input to a CNC machine.
  • the aligner components 8310, 8320 are manufactured individually. In the disclosed methods and systems, the precision and yield of the CNC based manufacturing are high because manufacturability has been considered and verified as part of the designs of the aligner components.
  • Common materials for the aligner components include polymers, urethane, epoxy, plastics, plaster, stone, clay, acrylic, metals, wood, paper, ceramics, and porcelain. A mechanism may be required to hold the components in place during the milling process.
  • the aligner is milled out of a plastic block in accordance with digital aligner model.
  • the milled out portion can be a portion of a tooth or a group of teeth.
  • the inner hollow portion of the partially milled plastic block is then filled up with a soft holding material under heating.
  • the holding material is soft at elevated temperatures and is hardened at room temperature.
  • the holding material forms a handle after it cools off to room temperature.
  • the partially milled plastic block can be held from outside while it is milled by CNC based manufacturing.
  • An aligned is produced after machining.
  • the holding material is subsequently removed by heating.
  • the holding material can be wax, silicon, Epoxy or other kind of removable glue.
  • the outer portion of the aligner component is first fabricated using CNC based manufacturing out of a plastic block.
  • the partially milled plastic block is then inverted and filled with a holding material that has been softened under heating.
  • the holding material wraps the top portion of the partially milled plastic block.
  • the material is hardened after cooling off and firmly grabs the partially milled plastic block in place.
  • the inner portion of the aligner arch can be machined while the partially milled plastic block is held at the hardened holding material.
  • An aligned is produced after machining.
  • the holding material is finally removed by heating.
  • the holding material can be wax, silicon, Epoxy or other kind of removable glue.
  • a special clamp can also be used to hold the partially milled aligner parts in place while the rest of the aligner is milled using the CNC machine
  • the physical aligner model 8600 is assembled in step 8170 by assembling the aligner components.
  • FIG. 121B illustrates how the aligner components 8610, 8620, 8630 can be assembled to form a whole or a portion of a physical aligner model 8600.
  • the different aligner components 8610, 8620, 8630 can be attached or plugged into each other at joining features 8650 that can be pins, registration slot, a notch, etc.
  • the physical aligners can be used in different dental applications such as dental crown, dental bridge, dental retainer, mouth guard and teeth whitening. For aligner fabrication, for example, each stage of the teeth treatment may correspond a unique physical aligner model.
  • Aligners can be fabricated based on the digital dental arch model as the teeth movement progresses during the treatment. At each stage of the treatment, the desirable teeth positions for the next stage are calculated.
  • a physical aligner model is fabricated using the process described above for modifying teeth positions in step 8180.
  • the disclosed methods and system allow variable shape and thickness in the aligner design. Moreover, the disclosed methods and system may provide wider range of aligner material selections. Analyses over aligner shape may be conducted to ensure a desired shape of aligner to be produced to achieve the desired movements at each stage of the orthodontic treatment. In addition, aligners having optimized shapes can achieve certain movements that the prior art cannot achieve. The aligners can be made thinner and more cosmetic, allowing more comfort in wearing. The manufacturing process is more consistent and easy.
  • the aligner components may be labeled with unique identifications, and assembled and detached in predetermined sequences.
  • the assembling and detachment can be automated by for example a robotic arm under the control of a computer in accordance with the predetermined sequences.
  • the aligner components are assembled in pressure forming.
  • the aligner components may be hollow inside and have outer surfaces that match the digital aligner components to allow proper union of the aligner components.
  • the aligner components can be pre-fabricated similar to
  • the surfaces of the aligner components may include standard registration and attaching features for them to join together.
  • the LEGO-like aligner components can be automatically assembled by robotic arms under computer control.
  • the aligner components can be separated and repaired after the assembly.
  • the attaching features between aligner components allow the components to be detached in a sequence. Broken component can be removed, repaired or replaced, followed by re-assembling.
  • the method may include the steps of applying a first layer of model-forming material to a cast, curing the first layer of model-forming material, applying a second layer of model-forming material and curing the second layer of model forming material. Many more layers may also be included, and each layer may be cured before applying the next layer. Thus, a third layer of model-forming material can be applied, and cured, a fourth layer, etc.
  • the method may also include a step for removing the dental model from the cast.
  • the model-forming material can be referred to as casting material, and may be any appropriate material, including but not limited to plaster, polymeric materials (including plastics, polyurethanes, etc.), ceramic materials, metals, alloys, or combinations thereof).
  • the model-forming material may be a plaster or cement.
  • the model-forming material is polyurethane or Epoxy.
  • the Epoxy may comprise two or more components that are mixed before using them (e.g., a resin and a hardener).
  • the method may include a step of mixing the resin and the hardener to prepare the model-forming material.
  • the step of applying the first layer of model-forming material may include brushing the model forming material against the cast. Brushing may form a thin coating layer.
  • the model-forming material may be applied by any appropriate technique. As mentioned, the model-forming layer may be brushed on (e.g., with a brush or other applicator). The model forming material may also be sprayed on (e.g., with a sprayer, nozzle, etc.), or poured. In some variations, the layer may be applied by a combination of application techniques.
  • a first layer may be applied around a support or framework (e.g., skeleton) about which additional layers are added.
  • a support may be placed into the cast and additional layers of materials may be applied around it.
  • a support is formed by first applying a high-shrinkage material into at least a part of the cast, and allowed to shrink. Additional layers may be applied to correct the shape as described herein.
  • the model forming material forming each layer may be cured in any appropriate manner. Curing typically involves hardening of the model-forming material from a pourable solution (e.g., a liquid, suspension, etc.) into a gel (e.g., semi-solid) and/or a solid. Thus, the model forming material may be cured for approximately 5 minutes, 10 minutes, 20 minutes, 30 minutes, 45 minutes, 1 hour, 2 hours, 4 hours, 5 hours, 6 hours, 8 hours, 12 hours or 24 hours, or more than 24 hours. The temperature that each layer is cured at may also be controlled.
  • a pourable solution e.g., a liquid, suspension, etc.
  • a gel e.g., semi-solid
  • the temperature that each layer is cured at may also be controlled.
  • the model-forming material may be cured for some amount of time at approximately room temperature (e.g., 25 0 C), or approximately 3O 0 C, 35 0 C, 4O 0 C, 5O 0 C, 6O 0 C.
  • the temperature may be limited by preventing it from exceeding a maximum temperature or falling below a minimum temperature.
  • the airflow over the model-forming material as it is being cured may also be controlled.
  • the temperature of the model as it is being formed may be controlled during curing or at any step of the formation of the model (including the entire process).
  • the temperature may be controlled by in appropriate manner, including but not limited to heating (e.g., in an oven), cooling (e.g., by blowing air over it, refrigeration, etc.) or by any combination thereof.
  • the thickness or amount of model-forming material, or the rate at which model-forming material is applied is controlled to help regulate the temperature. For example, thinner layers or smaller amounts (e.g., drops or pellets) of material may be added during formation of the model to regulate the temperature of the model (e.g., by preventing the bulk heating that may result), including during curing. Thus, the amount of material forming each layer may be controlled.
  • the amount of material may be controlled by limiting the absolute amount of model-forming material (e.g., less than about 5g » 1Og, 15g, 2Og, 25g, 30g, 35g, 4Og, etc.) or by limiting the thickness of the layer (e.g., less than about 0.5 mm thick, 1 mm thick, 2 mm thick, 5 mm thick, 10 mm thick, etc.) or the level of material applied to the case (e.g., to a position with respect to the teeth, gingiva, etc.).
  • the absolute amount of model-forming material e.g., less than about 5g » 1Og, 15g, 2Og, 25g, 30g, 35g, 4Og, etc.
  • the thickness of the layer e.g., less than about 0.5 mm thick, 1 mm thick, 2 mm thick, 5 mm thick, 10 mm thick, etc.
  • the level of material applied to the case e.g., to a position with respect to the teeth, ging
  • Other methods can also be used to control the temperature of the model during curing, or at any step.
  • cooling or heating may be used to control the model temperature before any layer is cast.
  • the resin or the hardener (or both) may be heated or cooled before, or during the mixing.
  • the resin and hardener may be cooled or heated separately, during the mixing process, or after mixing. Whether cooling or heating is required may depend upon the application requirements.
  • the Epoxy components in forming dental aligners using Epoxy, the Epoxy components (resin and hardener) may be cooled during mixing to maintain a low temperature (e.g., room temperature or lower).
  • the layers may also be treated before, during or after curing.
  • One or more layers may be treated to improve bonding of the layers to additional layers.
  • the surface of a layer may be laser or chemically etched, scored, or the like.
  • Adhesives may also be used. An adhesive may be added on all or a part of a layer before adding another layer.
  • the model-forming material may include a stabilizer.
  • the model-forming material may include a thermal stabilizer such as Al powder, glass powder (or fibers), or the like.
  • the stabilizer may also be a structural stabilizer (such as a fibrous material).
  • the stabilizer may be mixed with the resin before the addition of the hardener.
  • a casting chamber may also be used during the method of making a dental model.
  • the cast may be placed into a casting chamber, and secured.
  • the casting chamber may closeable, and may include one or more ports for venting, or for the addition of model-forming material.
  • the casting chamber help form the shape of the dental model (e.g., in those region of the dental model that extend beyond the cast, including fiduciary markers such as pins, etc.).
  • the method of forming a dental model may also include a step of annealing the dental model.
  • Annealing may serve to further harden the dental model, and may be done as a post-processing step.
  • the dental model may be annealed by baking it (e.g., by subjecting the dental model to an elevated temperature).
  • the model may be annealed by exposing the dental model (or the dental model in the casting chamber and/or cast) to about 4O 0 C, 5O 0 C, 6O 0 C, 7O 0 C, 8O 0 C, or 90 0 C for greater than about 2 hours (e.g., for about 2 hours, about 3 hours, about 4 hours, about 8 hours, about 12 hours, etc.).
  • Epoxy for a first layer applying the first layer of Epoxy to a cast by brushing at least a portion of the Epoxy on at least a portion of the cast and pouring at least a portion of the Epoxy into the cast, curing the first layer of Epoxy, mixing Epoxy for the second layer, applying the second layer of Epoxy, and curing the second layer of Epoxy.
  • a third layer, fourth layer, fifth layer, etc. may be also be applied after mixing the Epoxy for each layer.
  • the Epoxy may be cured between each layer by waiting an appropriate amount of time, and/or by exposing the cast and model-forming material to an appropriate temperature, as described above. Any appropriate Epoxy may be used, including Epoxy to which stabilizer has been added (e.g., Al powder).
  • dental models comprising a plurality of solid layers formed from sequentially cured layers of Epoxy, wherein at least one layer includes a stabilizer.
  • Any appropriate stabilizer may be used, including Al powder or fibers, glass powder or fibers, etc.
  • the dental model (e.g., tooth arch model) is formed from an imprint taken from the subject's oral cavity (e.g., the upper or lower dental arch).
  • This imprint from which the dental model is formed may be referred to as a cast, or a mold.
  • the cast may at least partially consist of an imprint (a negative impression) taken directly from a subjects mouth, or it may be made using measurements made from a subject (e.g., by direct measurement or recorded measurement).
  • a cast can be filled with a model-forming material (also referred to as a casting material), which can be solidified into a physical model of a region of the subject's oral cavity, such as the upper or lower dental arch.
  • a model-forming material also referred to as a casting material
  • Reference marks may be simultaneously molded or included in the dental model, so that the dental model can be coordinated with the subject's actual dental structures (e.g., teeth). The more accurate the model, the better coordination between the model and the subject.
  • FIG. 124 illustrates one variation of a method of making a dental model
  • the dental model is formed in a multi-step procedure from a settable material, such as Epoxy, which is sequentially layered into the cast and allowed to set up within the cast. Forming the dental model in sequential layers in this manner may allow the cast to be made without deforming or shrinking, producing a more accurate dental model.
  • the dental model may be formed of Epoxy by serially adding Epoxy material to the cast, and allowing the Epoxy to cure before adding additional Epoxy. After each addition, the Epoxy is allowed to set up and/or cure. The amount of Epoxy added may be small enough that deformation during formation, curing or annealing of the model is minimized.
  • the amount of Epoxy added may also be small enough (or applied in a thin enough layer) so that heat generated by the curing or setting of the Epoxy does not increase the temperature of the model significantly as it is formed.
  • a stabilizer e.g., a thermal stabilizer
  • the impression is first placed in a casting chamber and secured into place 9102.
  • the casting chamber is not used, however a casting chamber may make it easier to manipulate or handle the cast and dental model as it is being formed.
  • the casting chamber may also provide a stable orientation for the cast or dental model.
  • the casting chamber may help orient fiduciary markers.
  • the casting chamber may be used to help shape at least a region of the dental model.
  • the casting chamber may provide a shape to a region of the dental model that does not reflect the subject's oral cavity (e.g., the base region, including the pins).
  • the casting chamber typically includes a cavity into which the cast may be placed.
  • the casting chamber may also include an orientation, so that the cast is oriented within the casting chamber.
  • the casting chamber includes at least one holdfast for holding the cast within the cavity.
  • the cast may be held in position by clamps, screws, adhesive, etc.
  • FIG. 125 One variation of a casting chamber including a cast is shown in FIG. 125.
  • the casting chamber 9200 has an opening 9202, into which a negative imprint (cast) 9204 has been secured by malleable putty 9206.
  • the putty is the holdfast which acts to secure the cast within the casting chamber.
  • the casting chamber may be made in any appropriate shape and size, but is preferably large enough to hold casts for a variety of different-sized subjects.
  • the casting chamber may be made of any appropriate material.
  • the casting chamber may be made of a thermally conductive material (e.g., a metal or alloy such as steel, aluminum, etc.). Thermally conductive materials may be particularly helpful for cooling or heating the model during the steps of formation (e.g., during curing, etc).
  • the casting chamber may also include temperature controlling components, such as heating/cooling elements and/or sensors.
  • the casting chamber may also include ports open to atmosphere or for connecting to air or other fluid sources.
  • the casting chamber may include one or more air ports for venting or cooling the material used to form the model.
  • the casting chamber may also include one or more ports for applying model- forming material within the casting chamber.
  • the casting chamber is configured to house a negative impression of a patient's tooth arch for casting a positive dental mold.
  • the casting chamber may also include a cover.
  • the casting chamber may include a cover that can secure the top of the casting chamber.
  • the casting chamber may also include handles, grips and/or guides to assist with handling the casting chamber and/or model.
  • the cast (and/or the casting chamber) may be prepared for the addition of any model-forming material 9104 (e.g., Epoxy or Polyurethane).
  • the cast and/or the casting chamber may be coated with a material (e.g., lubricant, adhesive, hardener, colorant, etc.) before the addition of the model-forming material.
  • the cast and/or casting chamber is lubricated so that the model can be more readily removed after it has been formed.
  • the cast and/or casting chamber may be coated with a material that will comprise the outer layer of the dental model. Any appropriate material may be used to treat the cast and/or casting chamber.
  • a lubricious material e.g., an oil-based lubricant, water-based lubricant, or the like
  • an additional lubricious coating is not needed because the cast is formed from a material that incorporates a lubricant (e.g., polymeric materials such as vinyls, etc.).
  • a coating or treating material may be applied to the cast and/or casting chamber in any appropriate manner, including spraying, dipping, rinsing, painting, or the like.
  • the cast and casting chamber may also be prepared by controlling the temperature.
  • the cast and casting chamber may be prepared by wetting the cast surface.
  • a petroleum-based lubricant e.g., VaselineTM
  • the lubricant can be applied to the inside of the casting chamber, the inner part of the cast chamber lid, any spaces between the casting chamber and the putty holding the cast, as well as any spaces between the cast and the putty.
  • the model-forming material may be prepared 9106.
  • the model-forming material may be any appropriate material or materials for adding to the cast to build the model.
  • the model-forming materials is a settable material that can be poured, sprayed, painted, or otherwise applied into the cast and/or casting chamber so that it conforms to the space created by the cast.
  • the model-forming material is a flowable material (e.g., a liquid) that sets up or hardens to form a solid after curing.
  • the model-forming material includes a granular solid having a small particle size, so that the individual particles may fit within the imprint of the cast. The solids may then be crosslinked or otherwise hardened to form a solid shape.
  • the model- forming material is a polymeric material such as polyurethanes (e.g., DynacastTM) or Epoxy.
  • the model-forming material may also comprise non-polymeric materials, including inorganic materials (e.g., plasters, dental stone, etc.). Inorganic model-forming materials may also be formulated as a liquid, suspension or paste that is applied to the cast and that then hardens into a solid model that can be removed from the cast. Other examples of model-forming materials include metals (such as lead, etc.), plastics (e.g., polymers) and the like.
  • inorganic model-forming materials e.g., plasters, dental stone, etc.
  • Inorganic model-forming materials may also be formulated as a liquid, suspension or paste that is applied to the cast and that then hardens into a solid model that can be removed from the cast.
  • Other examples of model-forming materials include metals (such as lead, etc.), plastics (e.g., polymers) and the like.
  • the model-forming material may be Epoxy such as
  • the Epoxy may be a two-component Epoxy, comprising a resin and a hardener that can be mixed immediately before use.
  • the mixture of resin and hardener typically forms a viscous liquid material that can be applied to the cast.
  • the model forming material may also include one or more stabilizers to prevent deforming or shrinking of the model as it is formed or hardened.
  • a stabilizer e.g., a thermal stabilizer
  • Epoxy model-forming material
  • the model-forming material may then be added or applied to the cast to form the first layer of the model 91 10.
  • the first layer within the cast is then cured, or allowed to at least partially harden 9112.
  • the first layer of model-forming material is allowed to completely harden or cure before preparing and applying the next layer.
  • the model is formed in a multi-step process, allowing the model-forming material to "cure" (at least partially) between the steps.
  • the multi-step process includes the forming of two or more layers by the sequential application of the model-forming material within the cast.
  • the first layer can be applied as a thin coating that covers the cast or part of the cast.
  • Shrinkage or other deformation of the model may be avoided by limiting the amount (or thickness) of model-forming material applied to the cast.
  • some model-forming materials may generate heat (especially during curing) that may result in shrinkage or deformation during (or after) formation of the model. The heat generated by the model-forming material may be controlled to prevent such effects.
  • FIGS. 126A and 126B show graphs of the temperature of different amounts or thicknesses of one variation of model-forming material (e.g., Epoxy).
  • Epoxy model-forming material
  • FIG. 126A various amounts of Epoxy (5g and 14g) are cured in an oven set to 40 0 C. The peak temperature during curing of this Epoxy occurs about 20 min. after mixing. After about 30 min at 40°C, the Epoxy mixture experiences significant hardening.
  • FIG. 126B shows the temperature taken from different amounts of Epoxy (5g, 1Og, 15g, and 25g) as they are cured in the open air over time. The head generated by the Epoxy during curing is dependent upon the mass of the Epoxy mix.
  • the amount of Epoxy applied to the cast can be limited.
  • the total mix weight of the Epoxy added may be kept less than 5g, 1Og, 15g, 2Og, 25g, 30g, 35g, etc.
  • the temperature of the model-forming material can be controlled by cooling, heating, or enhancing cooling or heating (e.g., by controlling thickness), at any stage during formation of the model.
  • the model may be cooled during curing by refrigeration or by blowing air on the layer. In some variations, controlling the size or thickness of the layer may help regulate the temperature, as described herein.
  • Each layer of model-forming material may be added in any appropriate manner.
  • the model-forming layer may be added by pouring an amount (e.g., less than 2Og, less than 15g, less than 1Og, less than 5g) of prepared Epoxy into the cast and allowed to cure.
  • a layer of model-forming material may be painted on or into the cast.
  • Epoxy may be applied using a paintbrush to coat the cast.
  • a layer of model-forming material may be sprayed into the cast.
  • the cast e.g., the entire casting chamber
  • the cast may be agitated to help remove any bubbles that may have formed during the application of the material to the cast.
  • the cast and model material may then be cured (at any appropriate temperature, including room temperature) for the appropriate amount of time in order for the model-forming material to set up or hardened.
  • the model-forming material transitions from a liquid material into a gel, and finally into a solid, over time.
  • the time between the application of each layer may therefore be based upon the time required for the material to transition from the liquid to the gel or solid state.
  • Hardening of the model-forming material may also be material and/or temperature dependent. Thus, the temperature at which each layer is allowed to cure may be controlled.
  • model-forming material may be added to the cast for each layer.
  • the layers are added to avoid the formation of a large mass of model-forming material that could result in a region of elevated temperature as the mass cures or sets, since heating of the model-forming material might cause expansion and then shrinkage of the model and/or cast.
  • the first layer may comprise less than about 0.5 in3 of material per tooth in the model. However, the average volume of each tooth is approximately 2.5 in3. Thus multiple layers may be added to form the model.
  • the model comprises at least three layers.
  • different amounts of material may be added for each layer.
  • the first layer(s) generally include less material than later layers, since the first layer(s) may be closest to the surface of the cast, and therefore it may be important to minimize shrinkage or deformation of these detail-rich surfaces.
  • different layers may comprise different materials.
  • a layer of adhesive may be used between different layers to help adhere the different layers together.
  • the different layers may also be treated to aid in adhesion of layers to each other or to other components of the model (e.g., pins, labels, etc).
  • the surface of a layer may be treated by etching or scoring (e.g., laser and/or chemical etching).
  • FIG. 127 illustrates the addition of different layers to form a dental model.
  • the first layer 9403 coats the surface of the cast 9401. After applying the first layer, it is at least partly cured, and a second layer 9405 is applied. The second layer is then at least partly cured, and a third layer 9407 is applied. A pin 9409 is shown added to the second layer. Pins may be used so that the model can be attached (and properly oriented) on a base plate. Pins may be pre-coated with model-forming material (e.g., the ends of the pins that insert into the model). In some variations, the pins are added with the last layer of model-forming material. As described above, more than three layers may be applied, and the layers may be added in a different manner. For example, the first layer may be added as a horizontal stratum, rather than as a coating of the cast or previous layer.
  • the later layers may be thicker than the previous layers because the layers that have already been applied in the model may prevent deformation of the forming model by the layers added layer.
  • the initial layers applied to form the model may be continuous or connected layers that (once applied and cured to form part of the model) can provide structure and rigidity to the model as it is being formed.
  • the last layer can be cast with the chamber closed, and can be quite thick (e.g., > 5 mm). The heat generated or retained by this layer as it cures may be difficult to control because it is so thick, which may result in distortion of the layer and/or the model.
  • the layers already applied by the model may prevent possible deformation of this thicker layer from deforming the model as a whole.
  • the cast may be agitated (e.g., shaken on a shaker) to remove any air bubbles from the layer.
  • Subsequent layers may be made of the same model-forming material, or they may comprise different model-forming materials, and may be applied by the same method (e.g., pouring, brushing, spraying, etc.), or a different method.
  • the multi-step process allows different layers to include different materials, or different amounts of the same materials (e.g., hardeners, stabilizers, etc.).
  • steps 91 16-9124 can be repeated for each n layer, until all layers (1 to n) have been added.
  • the model-forming material e.g., Epoxy
  • any stabilizer e.g., thermal stabilizer
  • the material can then be added to the cast to form the next layer 9120.
  • Each layer can be at least partially cured for any appropriate amount of time 9122.
  • the second, third... n layer can be cured for between 10 minutes and 12 hours at room temperature (or at any appropriate temperature, such as 40 0 C).
  • steps 9116-9124 are repeated for each n layer, until all layers (1 to n) have been added 9124.
  • model-forming material is added so that it cures and sets up as it is added to the cast.
  • FIG. 128 illustrates one variation of this method.
  • a small amount of material 9503 is added to form pellets 9505 within the cast 9501.
  • the model-forming material 9503 may be premixed and kept from curing by being sealed within an applicator 9508.
  • the model forming material may cure only when exposed to air, or at a predetermined temperature.
  • the material can be applied in small amounts or layers (including layers of pellets, horizontal layers and non- horizontal layers) at least partially cure before adding more model-forming material. Pins or other fiduciary markers may also be added.
  • the addition of material is suspended and resumed during formation of the model in order to ensure that the fiduciary markers are properly positioned.
  • the model may be formed with one or more supports, scaffolds or cores.
  • a framework may be placed within the cast, and the model-forming material can be layered around the framework to from the model.
  • a core is formed of a material (including a model-forming material) that is allowed to shrink.
  • the core may be a first layer of material that is placed in the mold, and then allowed to shrink. Additional layers can then be added around this core as described herein, so that the model fills in or corrects the model shape until it conforms to the cast.
  • stabilizers may be included as part of the model- forming material.
  • Stabilizers may be thermal stabilizers, such as Al powder, fiberglass, glass powder, etc. Any appropriate stabilizer may be used.
  • the amount of stabilizer may be added as a weight percent of the total model-forming material.
  • the stabilizer comprises about 2%, 5%, 10%, 20%, 25%, 30%, 40%, 50%, 70% of the model-forming material, by weight.
  • the stabilizer may provide regions within the model that are not as affected by the heat- or curing-induced shrinkage of the model- forming material (e.g., Epoxy). The amount of stabilizer used may be maximized while still allowing the model-forming material to retain sufficient structural strength.
  • FIGS. 129A and 129B illustrate a stabilizer that decreases the shrinkage in a model block of Epoxy.
  • the stabilizer used in this example is Al powder.
  • FIG. 129A shows the model block. This "standard” is first used to make a negative model (cast) from which Epoxy model is made. The entire block is cast from one batch of Epoxy prepared without stabilizer (HH-003 Epoxy 1 and HH-003 Epoxy 2) and with stabilizer (HH-003 Epoxy (IMPOOl)). All three models were then measured in each of five different dimensions, Dl to D5, as illustrated in FIG. 129A, and these measurements were compared to the actual sizes of each of these dimensions from the original standard block. The data shown in FIG.
  • 129B illustrates that, in general, the block in which stabilizer (IMPOOl) was included shrunk less than the blocks without stabilizer (HH-003 Epoxy 1 and HH-003 Epoxy 2).
  • the measurements given in the table for the dimensions were obtained by dividing the measured dimension of the Epoxy model from the dimension of the original standard, and subtracting 1.000 (one).
  • the model may be post- processed by undergoing one or more additional steps.
  • the model may be annealed by exposing it to a temperature that strengthens the material.
  • the model may be baked at an elevated temperature (e.g., a temperature or temperatures between 4O 0 C and 9O 0 C) for an appropriate annealing time (e.g., 2 to 8 hours).
  • the methods of forming a dental model described above may allow the fabrication of precise models by preventing shrinkage and deformation, particularly shrinkage or deformation due to thermal effects of the model-forming material. Shrinkage and deformation may result in inaccurate models, because it may change the overall shape of the dental model, and may shift the location and orientation of pins or fiduciary markers on the dental model. Deformation may also damage the cast used to form the model.
  • the casting process may be used with pins or any other appropriate fiduciary markers. It may be particularly useful to position pins so that the dental model may result in a coordinated dental arch model, such as a digital dental arch model.
  • a coordinated dental arch model such as a digital dental arch model.
  • the negative impression of the patient's tooth arch is coupled (e.g., glued, bonded, interlocked, etc.) to a container such as the casting chamber (as described above).
  • a three-dimensional position input device e.g., MicroScribe®, stylus, etc.
  • a MicroScribe® can be inserted into the negative impression of a tooth to approximate the root position for that particular tooth.
  • the MicroScribe® is inserted into the cavity along the longitudinal orientation of the tooth, and, if necessary, further adjusted to a position that approximates the position of the root of the tooth.
  • a computer is then used to record the position of the MicroScribe®, which corresponds to the approximate root position.
  • the placement of the MicroScribe® is controlled by an operator.
  • an automated system having optical and/or tactile feedbacks is utilized to position the MicroScribe®.
  • the approximated root for each tooth may be defined by one or more positioning/placement of micro-scribes.
  • the micro-scribe may be placed within each tooth cavity to define a proximate position of the root for each of the teeth.
  • the micro-scribe is used to define two positions or longitudinal axis, which in combination approximates the position of the root for a tooth. Pin-like objects placed on a positive tooth model may be utilized later to simulate the positions defined by the micro-scribe, which in turn represents the approximate position of the root.
  • the MicroScribe® is implemented to define four points within each of the tooth cavity within the negative impression of the tooth arch. The four MicroScribe® defined points are then utilized to define the position for the placement of two pins or an asymmetric peg/interface which can simulate the root of the tooth.
  • the MicroScribe® is implemented to sample a series of points that represent the profile of each of the tooth cavity within the negative impression. For example, three or more points on the surface of the cavity, which represents a tooth, may be sampled by the MicroScribe® to define an approximate surface profile of the tooth. The approximate surface profile is than used to define and approximate root position. For example, two pin positions may be calculated to fit within the approximate surface profile along the longitudinal axis of the tooth.
  • a sectional plan is defined at the base of the tooth based on the MicroScribe® sampling of the negative impress representing the gingival tissue.
  • a pair of pin, with a pre-set distance "d" is then positioned perpendicular to this sectional plan, and centered within the tooth that is defined by the approximate surface profile defined by the MicroScribe®.
  • a cover plate e.g., the lid of the casting chamber
  • the holes may be drilled with a Computer Numeric Control (CNC) machinery utilizing data collected from the micro-scribe measurements.
  • CNC Computer Numeric Control
  • the cover plate and the container e.g., casting chamber
  • the cover plate and the container are manufactured with matching reference markers, such that the coordinate system relied on by the micro-scribe can be properly transposed over to the cover plate. Pins are then inserted into the holes on the cover plate.
  • the cover plate is shaped to fit on top of the casting chamber holding the negative impression of the tooth arch.
  • the position of the pins should correspond to the approximate root positions defined by the micro-scribe.
  • the model may then be fabricated, as described herein. Once the polymer cures, a positive arch is created within the negative impression, with the pins bonded to the positive arch. The user may then decouple the negative impression from the positive arch, resulting in a positive tooth arch of the patient with a plurality of pins that simulates the root position.
  • the positive arch may be scanned (e.g., laser 3D scanning, etc.) to generate a three-dimensional digital representation of the tooth arch, which may be utilized later in this process to align the individual tooth.
  • the pin positions can be utilized to determine the relative positions of the teeth in the patient's tooth arch, since the pin positions were defined by the micro-scribe relative to the negative impression of the patient's tooth arch.
  • an optional scan of either the positive tooth arch model or the negative tooth arch impression may be performed to determine the relative positions of the teeth in the tooth arch.
  • the optional scan may also be utilized along with the pin information for determining the relative positions of the teeth within the tooth arch.
  • the optional scan is utilized alone, without the pin information, to determine the relative positions of the teeth within the tooth arch.
  • Epoxy e.g., RenShapeTM Epoxy
  • the Epoxy comprises a resin and a hardener that are kept separate until shortly before mixing and applying to the cast.
  • a thermal stabilizer e.g., Aluminum powder
  • the majority of the steps are performed at room temperature (e.g., 22 0 C ⁇ 2 0 C) unless otherwise indicated.
  • the casting chamber is prepared by affixing the cast within the casting chamber and applying sealant and/or lubricant to exposed non-cast surfaces.
  • sealant and/or lubricant for example, VaselineTM petroleum jelly is applied to exposed surfaces of the casting chamber and the inner surfaces of the chamber lid.
  • the cast in this example is held within the casting chamber by putty as shown in FIG. 125, and exposed surfaces of the putty may also be coated with VaselineTM.
  • Epoxy Immediately before the Epoxy is used, it must be prepared (mixed).
  • a stabilizer may be added and mixed with the resin before the hardener is added.
  • an appropriate amount of Aluminum powder can be added to the resin and mixed by stirring until the Aluminum power is uniformly distributed in the resin.
  • the Epoxy is prepared by mixing 14g of the Epoxy resin (including the stabilizer) with 3g of Epoxy hardener (to give a weight ratio of approximately 7: 1, resin mix to hardener). The resin and hardener mixture should be mixed well.
  • the prepared resin can be applied as a first layer to the casting chamber.
  • a brush e.g., a paint brush
  • a brush may be used to apply a very thin layer of Epoxy on the cast. Applying with a paint brush may help get rid of air bubbles that might otherwise form on the surface of the cast.
  • the brush should be stroked across the surface to remove any air trapped within or below the Epoxy.
  • a layer of Epoxy can then be added (e.g., by pouring) into the "painted" cast. For example, the Epoxy may be added until it is just at the gingival line (e.g., approximately 1 mm above) within the cast, as shown in FIG. 125.
  • the casting chamber can then be agitated an industrial vibrator at a relatively high frequency for approximately 10 minutes, then placed in an oven set to 4O 0 C for 90 minutes.
  • the lid of the casting chamber may also be prepared.
  • a base plate for the dental model (into which the dental model can attach) can be attached to the lid of the casting chamber along with the pins that will be included as part of the dental model.
  • the base plate generally includes holes or slots that mate with the pins.
  • the pins are positioned into a base plate, and the base plate is affixed to the lid of the dental model.
  • the inside surface of the lid of the casting chamber may include holes that correspond to the pin holes in the base plate, so that pins can be inserted into the lid of the base plate.
  • the pins can be inserted into the hardening resin.
  • a layer of Epoxy is applied to at least the region of the pins that will be inserted into the dental model and the pins may be releasably secured within the base plate or the lid of the casting chamber.
  • the rest of the lid of the casting chamber may be coated with VaselineTM.
  • a brush can be used to apply Epoxy to the pins.
  • the lid of the base plate (including the coated pins) can then be placed on a vibrator to agitate it for at least 10 minutes.
  • the applied Epoxy is typically cured for approximately four hours at room temperature.
  • the casting chamber lid is fastened (e.g., by screwing or otherwise securing) to the casting chamber, and the Epoxy for the second layer is prepared by mixing the resin (plus the stabilizer) with the hardener.
  • the resin plus the stabilizer
  • 28g of resin (with hardener already added) may be well mixed with 4g of hardener (to form a 7: 1 weight ratio of resin mix to hardener).
  • each layer can include less than a predetermined amount of Epoxy in order to avoid generating excessive heat as the Epoxy cures, and damaging the model or the cast.
  • less than about 35g of resin, less than about 30g of resin, less than about 25g of resin, less than about 2Og of resin or less than about 15g of resin may be added to form each layer.
  • the second layer of resin is applied to the cast by pouring the properly mixed resin into the casting chamber.
  • the casting chamber is then placed on the industrial vibrator and agitated for 10 minutes.
  • Epoxy for the third layer is then mixed.
  • 28g of resin (with stabilizer) is mixed with 4g of hardener (in a 7: 1 ratio of resin mix to hardener).
  • the Epoxy is mixed well, and then an appropriate amount of Epoxy is poured into the casting chamber and vibrated on an industrial vibrator for approximately 10 minutes. Putty is then be used to block off the overflow port of the casting chamber, and the cast is allowed to cure for at least 12 hours before removing the (now solid) dental model.
  • the dental model can then be annealed to further harden the material.
  • Variations of the dental models produced by the methods described herein may be layered solids formed by layers of model-forming material, where each layer has been individually cured.
  • the layers may be visible, for example, when the model-forming material is different between each successive layer.
  • each layer e.g., the first layer, the second layer, etc.
  • each layer is composed of model-forming materials that have different compositions.
  • the ratio of resin and hardener used for the Epoxy may be different, or the amount of any stabilizer may be different.
  • the different proportions of resin and hardener may be detectable, and may also result in different properties (e.g., tensile strength, hardness, etc.) for the different layers, and the overall dental model.
  • the different layers of a dental model may be not be visible, but may be detected by analyzing a cross-section through the dental model.
  • the dental models comprising layered solids include one or more stabilizers, as described above.
  • a thermal stabilizer such as Al powder
  • Additional materials may also be used as stabilizers, including structural stabilizers.
  • fibrous material may be incorporated into the model-forming material of one or more of the layers (examples of structural stabilizers are synthetic fibers and organic fibers, including glass fibers, cotton fibers, cellulose-based fibers, etc). Fibrous materials may increase the structural strength and/or durability of the dental model.
  • Structural stabilizers may be included in at least the first layer of the dental model to provide external strength when the dental model is used, for example, to form dental aligners.

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  • Health & Medical Sciences (AREA)
  • Oral & Maxillofacial Surgery (AREA)
  • Dentistry (AREA)
  • Epidemiology (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Animal Behavior & Ethology (AREA)
  • General Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Veterinary Medicine (AREA)
  • Dental Tools And Instruments Or Auxiliary Dental Instruments (AREA)
  • Dental Prosthetics (AREA)

Abstract

Methods and apparatus for building physical and/or digital dental models are described herein. Methods and apparatus that can be utilized within the process of building a physical and/or digital dental model are also disclosed herein. In one implementation, individual physical tooth models are created and then arranged into a tooth arch to serve as the underlying template for fabricating a dental aligner. A registration feature may be implemented on each of the physical tooth models to track the positions of the individual physical tooth models relative to the other tooth models in the tooth arch. In one application, information regarding the registration features is mapped from the digital space into the physical space and vice versa. By tracking changes in the registration features, one can arrange individual physical tooth models to form a physical tooth arch that reflects the arrangement of the teeth in a digital tooth model.

Description

METHODS AND APPARATUSES FOR MANUFACTURING DENTAL ALIGNERS
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of U.S. Patent Application No.
10/979,823, entitled "METHOD AND APPARATUS FOR MANUFACTURING AND CONSTRUCTING A PHYSICAL DENTAL ARCH MODEL," filed November 2, 2004, U.S. Patent Application No. 10/979,497, entitled "METHOD AND APPARATUS FOR MANUFACTURING AND CONSTRUCTING A DENTAL ALIGNER," filed November 2, 2004, U.S. Patent Application No. 10/979,504, entitled "PRODUCING AN ADJUSTABLE PHYSICAL DENTAL ARCH MODEL," filed November 2, 2004, U.S. Patent Application No. 10/979,824, entitled "PRODUCING A BASE FOR PHYSICAL DENTAL ARCH MODEL," filed November 2, 2004, U.S. Patent Application No. 1 1/013,156, entitled "PRODUCING NON-INTERFERING TOOTH MODELS ON A BASE," filed December 14, 2004, U.S. Patent Application No. 11/013,160, entitled "SYSTEM AND METHODS FOR CASTING PHYSICAL TOOTH MODEL," filed December 14, 2004, U.S. Patent Application No. 1 1/013,158, entitled "PRODUCING A PHYSICAL TOOTH MODEL COMPATIBLE WITH A PHYSICAL DENTAL ARCH MODEL," filed December 14, 2004, U.S. Patent Application No. 11/013,159, entitled "PRODUCING A BASE FOR ACCURATELY RECEIVING DENTAL TOOTH MODELS," filed December 14, 2004, U.S. Patent Application No. 1 1/013,157, entitled "PRODUCING ACCURATE BASE FOR A DENTAL ARCH MODEL," filed December 14, 2004, U.S. Patent Application No. 11/013,154, entitled "PREVENTING INTERFERENCE BETWEEN TOOTH MODELS," filed December 14, 2004, U.S. Patent Application No. 11/013,155, entitled "ACCURATELY PREDICTING AND PREVENTING INTERFERENCE BETWEEN TOOTH MODELS," filed December 14, 2004, U.S. Patent Application No. 1 1/013,152, entitled "BASE FOR PHYSICAL DENTAL ARCH MODEL," filed December 14, 2004, U.S. Patent Application No. 1 1/012,924, entitled "ACCURATELY PRODUCING A BASE FOR PHYSICAL DENTAL ARCH MODEL," filed December 14, 2004, U.S. Patent Application No. 1 1/013, 145, entitled "FABRICATING A BASE COMPATIBLE WITH PHYSICAL TOOTH MODELS," filed December 14, 2004, U.S. Patent Application No. 1 1/050,126, entitled "METHODS FOR PRODUCING NON-INTERFERING TOOTH MODELS, filed February 3, 2005, U.S. Patent Application No. 1 1/074,301, entitled "DENTAL ALIGNER FOR PROVIDING ACCURATE DENTAL TREATMENT, filed March 7, 2005, U.S. Patent Application No. 1 1/074,299, entitled "PRODUCING PHYSICAL DENTAL ARCH MODEL HAVING INDIVIDUALLY ADJUSTABLE TOOTH MODELS," filed March 7,
2005, U.S. Patent Application No. , entitled "MULTI-LAYER CASTING
METHODS AND DEVICES," filed October 24, 2005, and this application also claims the benefit of U.S. Provisional Application No. 60/673,851, entitled, "COMPUTER AIDED ORTHODONTIC TREATMENT PLANNING," filed April 22, 2005 and U.S. Provisional Application No. 60/676,546, entitled "DIGITIZATION OF DENTAL ARCH MODEL," filed April 29, 2005. Each of these U.S. Patent Applications and U.S. Provisional Patent Applications is incorporated herein by reference in its entirety for all purposes.
BACKGROUND
[0002] Orthodontics is the practice of manipulating a patient's teeth to provide better function and appearance. Typically, brackets are bonded to a patient's teeth and coupled together with an arched wire. The combination of the brackets and wire provide a force on the teeth causing them to move. Once the teeth have moved to a desired location and are held in a place for a certain period of time, the body adapts bone and the surrounding soft-tissue to maintain the teeth in the desired location. To further assist in retaining the teeth in the desired location, a patient may be fitted with a retainer.
[0003] To achieve tooth movement, orthodontists utilize their expertise to first determine a three-dimensional mental image of the patient's physical orthodontic structure and a three-dimensional mental image of a desired physical orthodontic structure for the patient, which may be assisted through the use of X-rays and/or models. Based on these mental images, the orthodontist further relies on his/her expertise to place the brackets and/or bands on the teeth and to manually bend (i.e., shape) wire, such that a force is asserted on the teeth to reposition the teeth into the desired physical orthodontic structure. As the teeth move towards the desired location, the orthodontist makes continual judgments as to the progress of the treatment, plans next steps in the treatment (e.g., determine new bend in the wire, reposition or replace brackets, decide whether a head gear is required, etc.), and evaluates the success of the previous steps. [0004] In general, the orthodontist makes manual adjustments to the wire and/or replaces or repositions brackets based on his or her expert opinion. Unfortunately, in the oral environment, it is difficult for a human being to accurately develop a visual three- dimensional image of an orthodontic structure due to the limitations of human sight and the physical structure of a human mouth. In addition, it is difficult to accurately estimate three- dimensional wire bends (with accuracy within a few degrees) and to manually apply such bends to a wire. Further, it is hard to determine an ideal bracket location to achieve the desired orthodontic structure based on the mental images. It is also extremely difficult to manually place brackets in what is estimated to be the ideal location. Accordingly, orthodontic treatment is an iterative process requiring multiple wire changes, with the process success and speed being very much dependent on the orthodontist's motor skills and diagnostic expertise. As a result of multiple wire changes, patient discomfort is increased as well as the cost. As one would expect, the quality of care varies greatly from orthodontist to orthodontist as does the amount of time required to treat a patient.
[0005] Over the years, various methods and devices have been developed to assist dentists with delivery of orthodontic treatments. Examples of these methods and devices are disclosed in U.S. Patent No. 6,699,037 B2 titled "METHOD AND SYSTEM FOR INCREMENTALLY MOVING TEETH" issued to Chishti et a!., dated March 2, 2004; U.S. Patent No. 6,682,346 B2 titled "DEFINING TOOTH-MOVING APPLIANCES COMPUTATIONALLY" issued to Chishti et al., dated January 27, 2004; U.S. Patent No. 6,471,511 titled "DEFINING TOOTH-MOVING APPLIANCES COMPUTATIONALLY" issued to Chishti et al., dated October 29, 2002; U.S. Patent No. 5,645,421 titled "ORTHODONTIC APPLIANCE DEBONDER" issued to Slootsky, dated July 8, 1997; U.S. Patent No. 5,618,176 titled "ORTHODONTIC BRACKET AND LIGATURE AND METHOD OF LIGATING ARCHWIRE TO BRACKET" issued to Andreiko et al., dated April 8, 1997; U.S. Patent No. 5,607,305 titled "PROCESS AND DEVICE FOR PRODUCTION OF THREE-DIMENSIONAL DENTAL BODIES" issued to Andersson et al., dated March 4, 1997; U.S. Patent No. 5,605,459 titled "METHOD OF AND APPARATUS FOR MAKING A DENTAL SET-UP MODEL" issued to Kuroda et al., dated February 25, 1997; U.S. Patent No. 5,587,912 titled "COMPUTER AIDED PROCESSING OF THREE-DIMENSIONAL OBJECT AND APPARATUS THEREFOR" issued to Andersson et al., dated December 24, 1996; U.S. Patent No. 5,549,476 titled "METHOD FOR MAKING DENTAL RESTORATIONS AND THE DENTAL RESTORATION MADE THEREBY" issued to Stern, dated August 27, 1996; U.S. Patent No. 5,533,895 titled "ORTHODONTIC APPLIANCE AND GROUP STANDARDIZED BRACKETS THEREFOR AND METHODS OF MAKING, ASSEMBLING AND USING APPLIANCE TO STRAIGHTEN TEETH" issued to Andreiko et al., dated July 9, 1996; U.S. Patent No. 5,518,397 titled "METHOD OF FORMING AN ORTHODONTIC BRACE" issued to Andreiko et al., dated May 21, 1996; U.S. Patent No. 5,474,448 titled "LOW PROFILE ORTHODONTIC APPLIANCE" issued to Andreiko et al., dated December 12, 1995; U.S. Patent No. 5,454,717 titled "CUSTOM ORTHODONTIC BRACKETS AND BRACKET FORMING METHOD AND APPARATUS" issued to Andreiko et al., dated October 3, 1995; U.S. Patent No. 5,452,219 titled "METHOD OF MAKING A TOOTH MOLD" issued to Dehoff et al., dated September 19, 1995; U.S. Patent No. 5,447,432 titled "CUSTOM ORTHODONTIC ARCHWIRE FORMING METHOD AND APPARATUS" issued to Andreiko et al., dated September 5, 1995; U.S. Patent No. 5,431,562 titled "METHOD AND APPARATUS FOR DESIGNING AND FORMING A CUSTOM ORTHODONTIC APPLIANCE AND FOR STRAIGHTENING OF TEETH THEREWITH" issued to Andreiko et al, dated July 11, 1995; U.S. Patent No. 5,395,238 titled "METHOD OF FORMING ORTHODONTIC BRACE" issued to Andreiko et al, dated March 7, 1995; U.S. Patent No. 5,382, 164 titled "METHOD FOR MAKING DENTAL RESTORATIONS AND THE DENTAL RESTORATIONS MADE THEREBY" issued to Stern, dated January 17, 1995; U.S. Patent No. 5,368,478 titled "METHOD FOR FORMING JIGS FOR CUSTOM PLACEMENT OF ORTHODONTIC APPLIANCES ON TEETH" issued to Andreiko et al, dated November 29, 1994; U.S. Patent No. 5,342,202 titled "METHOD FOR MODELING CRANIO-FACIAL ARCHITECTURE" issued to Deshayes, dated August 30, 1994; U.S. Patent No. 5,340,309 titled "APPARATUS AND METHOD FOR RECORDING JAW MOTION" issued to Robertson, dated August 23, 1994; U.S. Patent No. 5,338,198 titled "DENTAL MODELING SIMULATOR" issued to Wu et al, dated August 16, 1994; U.S. Patent No. 5,273,429 titled "METHOD AND APPARATUS FOR MODELING A DENTAL PROSTHESIS" issued to Rekow et al, dated December 28, 1993; U.S. Patent No. 5,186,623 titled "ORTHODONTIC FINISHING POSITIONER AND METHOD OF CONSTRUCTION" issued to Breads et al, dated February 16, 1993; U.S. Patent No. 5,139,419 titled "METHOD OF FORMING AN ORTHODONTIC BRACE" issued to Andreiko et al., dated August 18, 1992; U.S. Patent No. 5,059,1 18 titled "ORTHODONTIC FINISHING POSITIONER AND METHOD OF CONSTRUCTION" issued to Breads et al., dated October 22, 1991 ; U.S. Patent No. 5,055,039 titled "ORTHODONTIC POSITIONER AND METHODS OF MAKING AND USING SAME" issued to Abbatte et al., dated October 8, 1991 ; U.S. Patent No. 5,035,613 titled "ORTHODONTIC FINISHING POSITIONER AND METHOD OF CONSTRUCTION" issued to Breads et al., dated July 30, 1991 ; U.S. Patent No. 5,01 1,405 titled "METHOD FOR DETERMINING ORTHODONTIC BRACKET PLACEMENT" issued to Lemchen, dated April 30, 1991 ; U.S. Patent No. 4,936,862 titled "METHOD OF DESIGNING AND MANUFACTURING A HUMAN JOINT PROSTHESIS" issued to Walker et al., date June 26, 1990; U.S. Patent No. 4,856,991 titled "ORTHODONTIC FINISHING POSITIONER AND METHOD OF CONSTRUCTION" issued to Breades et al., dated August 15, 1989; U.S. Patent No. 4,798,534 titled "METHOD OF MAKING A DENTAL APPLIANCE" issued to Breads, dated January 17, 1989; U.S. Patent No. 4,755,139 titled "ORTHODONTIC ANCHOR APPLIANCE AND METHOD FOR TEETH POSITIONING AND METHOD OF CONSTRUCTING THE APPLIANCE" issued to Abbatte et al., dated July 5, 1988; U.S. Patent No. 3,860,803 titled "AUTOMATIC METHOD AND APPARATUS FOR FABRICATING PROGRESSIVE DIES" issued to Levine, dated January 14, 1975; U.S. Patent No. 3,660,900 titled "METHOD AND APPARATUS FOR IMPROVED ORTHODONTIC BRACKET AND ARCH WIRE TECHNIQUE" issued to Andrews, dated may 9, 1972; each of which is incorporated herein by reference in its entirety for all purposes.
[0006] The practice of orthodontics and other dental treatments including preparation of a denture can benefit from a computer model that is representative of the position of the teeth in a tooth arch. The computer model may be prepared based on an impression model taken from the patient. The computer model may be utilized to assist the dentist in planning an orthodontic treatment regimen by providing visual feedback of possible treatment steps in particular treatment regimen.
[0007] In particular, the computer modeling tool may be useful in designing and manufacturing removable aligning appliances for orthodontic treatment. In this system, an impression model of the dentition of the patient is obtained by the orthodontist and shipped to a remote appliance manufacturing center, where information regarding the patient's teeth is captured by a computer. A computer model of the dentition in a target situation is generated at the appliance manufacturing center and made available for viewing to the orthodontist over the Internet. The orthodontist indicates changes he or she wishes to make to individual tooth positions. Later, another virtual model may be provided over the Internet and the orthodontist reviews the revised model, and indicates any further changes. After one or more of such iterations, the target situation is agreed upon. One or more of the removable aligning appliances (e.g., devices, shells, etc) are manufactured and delivered to the orthodontist. When implemented on a patient's teeth, the appliances move the teeth toward the desired or target positions.
[0008] Repositioning is accomplished with a series of appliances configured to receive the teeth in a cavity and incrementally reposition individual teeth in a series of at least three successive steps, usually including at least four successive steps, often including at least ten steps, sometimes including at least twenty-five steps, and occasionally including forty or more steps. Most often, the methods and systems will reposition teeth in from ten to twenty-five successive treatment steps, although complex cases involving many of the patient's teeth may take forty or more steps. The successive use of a number of such appliances permits each appliance to be configured to move individual teeth in small increments. The movements provided by successive appliances, of course, will usually not be the same for any particular tooth. Thus, one point on a tooth may be moved by a particular distance as a result of the use of one appliance and thereafter moved by a different distance and/or in a different direction by a later appliance.
[0009] The individual appliances include a polymeric shell having the teeth- receiving cavity formed therein, typically by molding as described below. Each individual appliance will be configured so that its tooth-receiving cavity has a geometry corresponding to an intermediate or end tooth arrangement intended for that appliance. That is, when an appliance is first worn by the patient, certain of the teeth will be misaligned relative to an undeformed geometry of the appliance cavity. The appliance, however, is sufficiently resilient to accommodate or conform to the misaligned teeth, and will apply sufficient resilient force against such misaligned teeth in order to reposition the teeth to the intermediate or end arrangement desired for that treatment step.
[0010] Aligners have been fabricated from molds created using a stereo lithography process. Several drawbacks exist with the stereo lithography process, however. The materials used by stereo lithography processes may be toxic and harmful to human health. Also, the stereo lithography process builds the aligner mold layer by layer and thus causes the resulting aligners to have a step-like spacing between the layers. Such spacing has a tendency to house germs and bacteria while it is worn by a patient. Furthermore, the stereo lithography process requires creation of a different aligner mold at each stage of the treatment. The process can be costly and produces waste, which is environmental unfriendly.
SUMMARY OF THE INVENTION
[0011] Methods and apparatus for building physical and/or digital dental models are described herein. In one implementation, individual physical tooth models are created and then arranged into a tooth arch to serve as the underlying template for fabricating a dental aligner. A registration feature may be implemented on each of the physical tooth models to track the positions of the individual physical tooth models relative to the other tooth models in the tooth arch.
[0012] In one variation, a computer can be utilized to determine and/or record a position of a registration feature for each of the teeth in a patient's tooth arch. These recorded positions of the registration features may be altered to represent a tooth arch having a modified teeth arrangement. By mapping the positions of the registration features onto a base, and then positioning the physical tooth models on the base according to the positions of the registration features, a physical tooth arch having the modified tooth arrangement can be built on the base. For example, this modified tooth arch may represent the target tooth arch at one stage of an orthodontic treatment process. A polymeric sheet may then be formed over the physical tooth arch model to create a dental aligner.
[0013] In another variation, positions for the registration features, each of which corresponds to a tooth in a patient's tooth arch, are determined based on either a negative impression or a positive model of a patient's tooth arch. By tracking the positions of the registration features, the relative position between the teeth in a given tooth arch can be ascertained. In one implementation, information regarding the registration features can be mapped from the digital space into the physical space and vice versa. By tracking the changes in the registration feature information, when the position of one or more of the teeth in a digital model of a tooth arch is modified, one can later map the positions of the registration features into the physical space, and thereby arrange the corresponding physical tooth models into a tooth arch having the modified teeth arrangement. In one example, the positions of the registration features are mapped onto a base plate by creating receptacles that are organized according to the positions of the registration features. The base plate can then be utilized to receive the individual physical tooth models, each of which has a corresponding registration mark, and form a physical tooth arch that reflects the arrangement of the teeth in the digital tooth arch model.
[0014] Various methods and/or apparatus that can be utilized within the process of building physical and/or digital dental models are also disclosed herein. These methods and apparatus include casting physical models, acquiring positions of physical tooth models in a tooth arch, creating a base for receiving physical tooth models, adjusting positions of tooth models on a base using adjustment jigs, digitizing tooth models, predicting and preventing interference between tooth models, constructing a physical dental arch model using CNC, and constructing a dental aligner using CNC.
[0015] These and other embodiments, features and advantages of the present invention will become more apparent to those skilled in the art when taken with reference to the following more detailed description of the invention in conjunction with the accompanying drawings that are first briefly described.
BRIEF DESCRIPTION OF THE DRAWINGS [0016] FIG. 1 is a flow chart for producing a dental aligner in one variation.
[0017] FIG. 2 is a perspective view of a casting chamber that may be used to cast a dental arch in one variation.
[0018] FIG. 3 illustrates a base plate for a dental arch attached to a casting chamber lid according to one variation.
[0019] FIG. 4 illustrates the use of a position measurement device to measure the locations and/or orientations of features in a negative impression of a dental arch according to one variation.
[0020] FIG. 5 illustrates a base plate having sockets by which physical tooth models may be attached to form a dental arch according to one variation. [0021] FIG. 6 illustrates sockets formed in a recess in a base plate according to one variation.
[0022] FIG. 7 illustrates a base plate attached to the lid of a casting chamber and placed over the casting chamber so that pins attached to the base plate are positioned within a negative impression of a tooth arch according to one variation.
[0023] FIG. 8 illustrates a positive mold of a patient's tooth arch according to one variation.
[0024] FIG. 9 illustrates individual physical tooth models separated from the positive mold of FIG. 8 according to one variation.
[0025] FlG. 1OA illustrates a scanning system used to digitize physical tooth models according to one variation.
[0026] FIG. 1 OB illustrates a top view of physical tooth models mounted to a scan plate in the scanning system of FIG. 1OA according to one variation.
[0027] FIG. 1OC illustrates a side view of physical tooth models mounted to a scan plate in the scanning system of FIG. 1OA according to one variation.
[0028] FIG. 11 illustrates a physical tooth model mounted to a scan plate in the scanning system of FIG. 1OA by inserting pins on the tooth model into sockets in the scan plate according to one variation.
[0029] FIG. 12 illustrates examples of graphic projections of the individual digital representations of physical tooth models according to one variation.
[0030] FIG. 13 illustrates a digital representation of a tooth arch generated from the digital representations of individual tooth models shown in FIG. 12 according to one variation.
[0031] FIG. 14 illustrates a digital scan of a complete tooth arch superimposed over a digital model of a tooth arch generated from combining digital representations of individual teeth according to one variation.
[0032] FIG. 15 illustrates a graphical projection of a digital arch tooth arch model into which simulated roots have been incorporated according to one variation. [0033] FIG. 16 illustrates roots being created for individual digital tooth models according to one variation.
[0034] FIG. 17 illustrates generation of a digital tooth arch model from individual digital tooth models comprising crowns and roots according to one variation.
[0035] FIG. 18 illustrates a digital model of a tooth arch in which the position and/or orientation of one of the teeth (shaded for emphasis) has been modified according to one variation.
[0036] FIG. 19 illustrates a digital model of a removable alignment appliance created based on the digital model of a modified tooth arch of FIG. 18 according to one variation.
[0037] FIG. 20 illustrates a removable alignment appliance created based on the digital model of FIG. 19 according to one variation.
[0038] FIG. 21 illustrates a base plate configured to receive physical tooth models to form a physical tooth arch that corresponds to the digital model of a modified tooth arch of FIG. 18 according to one variation.
[0039] FIG. 22 illustrates a physical model of a modified tooth arch that corresponds to the digital model of a modified tooth arch of FIG. 18 according to one variation.
[0040] FIG. 23 illustrates a physical tooth model attached by pins to sockets in a recessed portion of a base plate according to one variation. The pins, surface of the recess, and bottom surface of the tooth model are angled with respect to the surface of the base plate.
[0041] FIG. 24 illustrates a polymeric sheet being placed over a physical model of a modified tooth arch for heat and vacuum formation of a removable aligner according to one variation.
[0042] FIG. 25 illustrates a removable aligner formed from the set-up of FIG. 24 according to one variation.
[0043] FIG. 26 illustrates a removable after excess material has been trimmed away according to one variation. [0044] FIG. 27 illustrates a base plate configured for receiving multiple sets of physical tooth models for forming four separate physical arch models according to one variation.
[0045] FIG. 28 illustrates the base plate of FIG. 17 with physical tooth models attached to form four separate physical arch models according to one variation.
[0046] FIG. 29A is a flow chart for producing a dental aligner in one variation.
[0047] FIG. 29B is a flow chart for producing a dental aligner in one variation.
[0048] FIG. 30 is a flow chart for producing a physical dental arch model in accordance with one variation.
[0049] FIG. 31 illustrates a tooth model and a base respectively comprising complimentary features for assembling the tooth model with the base according to one variation.
[0050] FIG. 32 illustrates fixing a stud to a tooth model comprising a female socket to produce a tooth model having a protruded stud according to one variation.
[0051] FIG. 33 illustrates a tooth model comprising two pins that allow the tooth model to be plugged into two corresponding holes in a base according to one variation.
[0052] FIG. 34 illustrates a tooth model comprising a protruded pin that allows the tooth model to be plugged into a hole in a base according to one variation.
[0053] FIG. 35 illustrates cone shaped studs protruded out of the bottom of a tooth model according to one variation.
[0054] FIG. 36 illustrates example shapes for the studs at the bottom of a tooth model according to one variation.
[0055] FIG. 37A illustrates an example of a base comprising a plurality of female sockets for receiving a plurality of tooth models for forming a physical dental arch model according to one variation.
[0056] FIG. 37B illustrates another example of a base comprising a plurality of female sockets for receiving a plurality of tooth models for forming a physical dental arch model according to one variation. [0057] FIG. 38 illustrates a tooth model that can be assembled to the base in FIG.
37A according to one variation.
[0058] FIG. 39 illustrates a laser cutting system for fabricating features in a base for receiving tooth models according to one variation.
[0059] FIG. 40 illustrates a base comprising multiple sets of sockets for receiving a plurality of dental arches in different configurations according to one variation.
[0060] FIG. 41 is a flow chart for producing a physical dental arch model in accordance with one variation.
[0061] FIG. 42 illustrates an example of a mechanical location device for acquiring the coordinates of the physical tooth models according to one variation.
[0062] FIG. 43 is a flow chart for producing a physical dental arch model in accordance with one variation.
[0063] FIG. 44 illustrates an example of an optical location device for acquiring the coordinates of the physical tooth models according to one variation.
[0064] FIG. 45 is a flow chart for producing a physical dental arch model in accordance with one variation.
[0065] FIGS. 46A - 46D illustrate adjustment jigs that are capable of providing different positional and rotational adjustment for tooth models according to one variation.
[0066] FIG. 47 illustrates another arrangement of adjustment jigs for rotational adjustment of tooth models according to one variation.
[0067] FIG. 48 illustrates adjustment jigs for different increments of translational adjustments according to one variation.
[0068] FIG. 49 shows a rotational adjustment jig mounted on top of a translational adjustment jig according to one variation.
[0069] FIG. 50 shows a jig having a universal joint mounted on a translation stage according to one variation.
[0070] FIG. 51 is a flow chart for producing a physical dental arch model in accordance with one variation. [0071] FIG. 52 illustrates an example in which the pins at the bottom portions of two adjacent tooth models interfere with each other.
[0072] FIG. 53 illustrates an example in which two adjacent tooth models mounted on a base interfere with each other at the tooth portions of the tooth models.
[0073] FIG. 54 illustrates a tooth model having pin configurations that prevent the tooth models from interfering with each other according to one variation.
[0074] FIG. 55 A is a front view of two tooth models having pin configurations of
FIG. 54 according to one variation.
[0075] FIG. 55B is a perspective bottom view of two tooth models having pin configurations of FIG. 54 according to one variation.
[0076] FIG. 56 illustrates a mechanism for fixing tooth models to a base using removable pins according to one variation.
[0077] FIG. 57 illustrates a mechanism for fixing tooth models to a base using spring-loaded pins to prevent interference between tooth models according to one variation.
[0078] FIG. 58 illustrates a mechanism for fixing tooth models to a base using spring-loaded pins to prevent interference between tooth models according to one variation.
[0079] FIG. 59 illustrates a mechanism for fixing tooth models to a base using spring-loaded pins to prevent interference between tooth models according to one variation.
[0080] FIG. 60 illustrates an exemplary flow chart for producing a physical dental arch model.
[0081] FIG. 61 illustrates a tooth model and a base respectively comprising complimentary features for assembling the tooth model with the base.
[0082] FIG. 62 illustrates fixing a stud to a tooth model comprising a female socket to produce a tooth model having a protruded stud.
[0083] FIG. 63 illustrates a tooth model comprising two pins that allow the tooth model to be plugged into two corresponding holes in a base.
[0084] FIG. 64 illustrates a tooth model comprising a protruded pin that allows the tooth model to be plugged into a hole in a base. [0085] FIG. 65 illustrates cone shaped studs protruded out of the bottom of a tooth model.
[0086] FIG. 66 illustrates exemplified shapes for the studs at the bottom of a tooth model.
[0087] FIG. 67A illustrates an example of a base comprising a plurality of female sockets for receiving a plurality of tooth models for forming a physical dental arch model.
[0088] FIG. 67B illustrates another example of a base comprising a plurality of female sockets for receiving a plurality of tooth models for forming a physical dental arch model.
[0089] FIG. 68 illustrates a tooth model that can be assembled to the base in FIG.
8A.
[0090] FIG. 69 illustrates an exploded top perspective view of a casting chamber, a chamber lid, and a base for casting a physical tooth model.
[0091] FIG. 70 illustrates an exploded bottom perspective view of a casting chamber, a chamber lid, and a base for casting a physical tooth model.
[0092] FIG. 71 is a cross-sectional view illustrating an example where the chamber lid is placed over the chamber and pins located on the base, which is attached to the chamber lid, are positioned in the cavity of the negative impression.
[0093] FIG. 72 illustrates the physical tooth models which are created from the casting chamber shown in FIG. 71. A full tooth arch is casted and then separated into individual tooth models.
[0094] FIG. 73 is a flow chart illustrating another example for casting a physical tooth arch. In this example, a base layer simulating the gum portion is provided to isolate the cast of the tooth arch to the crown portion of the tooth arch.
[0095] FIG. 74 shows perspective views of a casting chamber, a dental impression that can be fixed in the casting chamber, and a lid for the chamber.
[0096] FIG. 75 shows the front view of a lid attached with solidified casting material on its underside after first molding in the casting chamber.
[0097] FIG. 76 shows a front view of a reference base attached to the chamber lid. [0098] FIG. 77 illustrates the making a hole on the base portion, which includes a gum profile, of the casting material adhered to the underside of the lid.
[0099] FIG. 78 shows a tooth model similar to the model of FIG. 4 with additional pins.
[0100] FIG. 79 shows a cross-sectional view of one pin.
[0101] FIG. 80 illustrates the lid positioned over the chamber, aligning the gum profile of the base with the negative impression. As shown, the gum profile of the base is provided to displace cast material and therefore isolating the cast to the crown position.
[0102] FIG. 81 illustrates positive tooth models created from the casting chamber of
FIG. 80. The tooth models have a profile isolated to the crown position.
[0103] FIG. 82 illustrates a container for casting a dental base or base component that can receive physical tooth models.
[0104] FIG. 83 illustrates a plurality of base components molded by a plurality of containers.
[0105] FIG. 84 a base comprising multiple sets of sockets for receiving a plurality of dental arches in different configurations.
[0106] FIG. 85 is a flow chart illustrating an example for digitizing a patient's tooth arch.
[0107] FIG. 86 illustrates an exemplified mechanical location device for acquiring the coordinates of the physical tooth models.
[0108] FIG. 87 illustrates an arch model component having registration features.
[0109] FIG. 88 is a top view of a scan plate mounted with a plurality of arch model components.
[0110] FIG. 89 is a side view of a scanning system including a scan plate mounted with a plurality of arch model components.
[0111] FIG. 90 is a block diagram illustrating an exemplary system for digitizing the tooth arch model components from a patient's tooth arch model.
[0112] FIG. 91 is an example of a flow chart for producing a physical dental arch model. [0113] FIG. 92 illustrates a tooth model and a base respectively comprising complimentary features for assembling the tooth model with the base.
[0114] FIG. 93 illustrates fixing a stud to a tooth model comprising a female socket to produce a tooth model having a protruded stud.
[0115] FIG. 94 illustrates a tooth model comprising two pins that allow the tooth model to be plugged into two corresponding holes in a base.
[0116] FIG. 95 illustrates a tooth model comprising a protruded pin that allows the tooth model to be plugged into a hole in a base.
[0117] FIG. 96 illustrates cone shaped studs protruded out of the bottom of a tooth model.
[0118] FIG. 97 illustrates exemplified shapes for the studs at the bottom of a tooth model.
[0119] FIG. 98A illustrates an example of a base comprising a plurality of female sockets for receiving a plurality of tooth models for forming a physical dental arch model.
[0120] FIG. 98B illustrates another example of a base comprising a plurality of female sockets for receiving a plurality of tooth models for forming a physical dental arch model.
[0121] FIG. 99 illustrates a tooth model that can be assembled to the base in FIGS.
98 A and 98B.
[0122] FIG. 100 illustrates an example in which the pins at the bottom portions of two adjacent tooth models interfere with each other.
[0123] FIG. 101 illustrates an example in which two adjacent tooth models mounted on a base interfere with each other at the tooth portions of the tooth models.
[0124] FIG. 102 illustrates a tooth model having pin configurations that prevent the tooth models from interfering with each other.
[0125] FIG. 103 A is a front view of two tooth models having pin configurations of
FIG. 102.
[0126] FIG. 103B is a perspective bottom view of two tooth models having pin configurations of FIG. 102. [0127] FlG. 104 illustrates a mechanism for fixing tooth models to a base using removable pins.
[0128] FIG. 105 illustrates a mechanism for fixing tooth models to a base using spring-loaded pins to prevent interference between tooth models.
[0129] FIG. 106 illustrates a triangulated mesh that simulates the surfaces of a patient's tooth.
[0130] FIG. 107 illustrates the calculation of the interference depth.
[0131] FIG. 108 illustrates the set-up of an orthogonal bounding box for calculating the interference depth.
[0132] FIG. 109 shows the grid over a rectangular face of a bounding box for the digital tooth model.
[0133] FIG. 1 10 illustrates the calculation of the interference depth between two tooth models.
[0134] FIG. 1 1 1 illustrates two digital tooth models having aligned coordinate systems.
[0135] FIG. 1 12 illustrates the discrete digital model for an object.
[0136] FIG. 1 13 illustrates the interference depth between two digital tooth models along two directions.
[0137] FIG. 1 14 illustrates the optimized direction of the interference depth between two digital tooth models in a three dimensional system.
[0138] FIG. 1 15 illustrates the sum of the depths of interference between two digital tooth models over a multiple steps.
[0139] FIG. 1 16 is an example of a flow chart for producing a physical dental arch model.
[0140] FIG. 1 17 illustrates the smoothening of the digital dental arch model in preparation for a CNC based manufacturing of physical dental arch model.
[0141] FIG. 1 18A illustrates the segmentation of digital dental arch model into segmented components suitable for CNC based manufacturing in accordance with the present invention. [0142] FIG. 118B illustrates the segmentation of digital aligner model into segmented components suitable for CNC based manufacturing in accordance with the present invention.
[0143] FIGS. 1 19A-D illustrates the segmentation of an inter-proximal region by removing a space around the inter-proximal region and replacing it by a wedge.
[0144] FIGS. 120A-D illustrates physical tooth components comprising features that allow them to be plugged or attached into a base.
[0145] FIG. 121 A illustrates how a tooth component fits into a base component.
[0146] FIG. 121B illustrates an aligner assembled from a plurality of aligner components each comprising features that assist the assembling.
[0147] FIG. 122 illustrates exemplified arrangements for fitting one or more physical tooth components into a base.
[0148] FIG. 123 illustrates a portion of an arch assembled by a plurality of physical tooth components each comprising features that assist the attachment to attach to each other to form a physical dental arch model without a base.
[0149] FIG. 124 illustrates one method of casting a multi-layer dental model, as described herein.
[0150] FIG. 125 illustrates a casting chamber for forming a dental model, as described herein.
[0151] FIG. 126A is a graph showing the temperature over time of different amounts of Epoxy during curing in an oven.
[0152] FIG. 126B is a graph showing the temperature of different amounts of
Epoxy during curing in the open air.
[0153] FIG. 127 illustrates an example of the formation of a dental model.
[0154] FIG. 128 illustrates another variation of forming a dental model.
[0155] FIG. 129A illustrates a model block of Epoxy.
[0156] FIG. 129B is a chart illustrating the presence of stabilizer decrease shrinkage of Epoxy. DETAILED DESCRIPTION OF THE INVENTION
[0157] The following detailed description should be read with reference to the drawings. The drawings, which are not necessarily to scale, depict selective embodiments and are not intended to limit the scope of the invention. The detailed description illustrates by way of example, not by way of limitation, the principles of the invention. This description will clearly enable one skilled in the art to make and use the invention, and describes several embodiments, adaptations, variations, alternatives and uses of the invention, including what is presently believed to be the best mode of carrying out the invention.
[0158] Before describing the present invention, it is to be understood that unless otherwise indicated this invention need not be limited to applications in orthodontic treatments. As one of ordinary skill in the art having the benefit of this disclosure would appreciate, variations of the invention may be utilized in various other dental applications, such as fabrication and/or treatment planning for dental crowns, dental bridges, and dental aligners. Computer models of a tooth arch as disclosed herein may also be modified to support research and/or teaching applications. Moreover, it should be understood that variations of the present invention may be applied in combination with various dental diagnostic and treatment devices to improve and/or modify the condition of a patient's teeth.
[0159] It must also be noted that, as used in this specification and the appended claims, the singular forms "a," "an" and "the" include plural referents unless the context clearly indicates otherwise. Thus, for example, the term "a tooth" is intended to mean a single tooth or a combination of teeth, "a fluid" is intended to mean one or more fluids, or a mixture thereof. Furthermore, as used herein, "generating", "creating", and "formulating" a digital representation mean the process of utilizing computer calculation to create a numeric representation of one or more objects. For example, a digital representation may comprise a file saved on a computer, wherein the file includes numbers that represent a three-dimensional projection of a tooth arch. In another variation, a digital representation comprises a data set including parameters that can be utilized by a computer program to recreate a digital model of the desired objects. [0160] This application discloses methods and apparatus that may be used, for example, for manufacturing dental aligners. The term "dental aligner" may refer to any dental device for rendering corrective teeth movement or for correcting malocclusion. One or more dental aligners can be worn on the subject's teeth so that a subject wearing the dental aligners will gradually have his or her teeth repositioned by the dental aligner "pushing" (or pulling) against the teeth and/or gums (gingiva). Additional uses for the disclosed methods and apparatuses other than manufacturing dental aligners are also contemplated.
[0161] Referring to FIG. 1, an exemplary process for fabricating a dental aligner is illustrated. Variations of the methods and apparatus may, but do not necessarily, include combinations of two or more of the steps illustrated in the flow chart of FIG. 1. Variations of the methods and apparatus need not include all of the steps shown in FIG. 1. Moreover, the steps shown in FIG. 1 need not be executed in the order depicted. Variations on the methods and apparatus may also include process steps and apparatus not shown in FIG. 1.
[0162] Referring now to step 100 in FIG. 1 , in some variations a negative impression of a patient's dental arch is made. Suitable techniques for forming such negative impressions may include, but are not limited to, conventional processes known to one of ordinary skill in the art as well as processes disclosed in examples below.
[0163] In some variations, physical models of the patient's teeth are produced. For example, in some variations the patient's pre-treatment arch is cast from a negative impression of the patient's arch made in step 100. Suitable casting techniques may include, but are not limited to, conventional techniques known to one of ordinary skill in the art and improvements thereof. The cast of the dental arch may be separated into physical models of individual teeth or groups of teeth that can be arranged on a base (e.g., base plate) to model the patient's tooth arch. For example, the tooth models may be arranged to form the pretreatment tooth arch, a projected tooth arrangement at one of manage treatment stages, or the intended post-treatment tooth arch.
[0164] In some variations in which a digital model of the pre-treatment dental arch has already been provided (see step 1 10, for example), a physical model of the patient's pre-treatment dental arch may be produced from the digital model of the dental arch. In such variations physical models of individual teeth or groups of teeth may be manufactured from the digital model using, for example, computer numerical control (CNC) based manufacturing techniques. Suitable CNC manufacturing techniques include, but are not limited to, those disclosed in examples below. Such physical models of individual teeth or groups of teeth manufactured from a digital model can also be arranged on a base to model the patient's tooth arch at different stages during an orthodontic treatment.
[0165] Referring to step 105, positional information allowing assembly of tooth models to represent the pre-treatment arch may be collected if needed by, for example, characterizing the locations of features in the negative impression and/or characterizing the locations of features in or on a cast made from the negative impression prior to separating the cast into physical models of individual teeth or groups of teeth. In another variation, either a positive or a negative tooth arch model may be digitized (e.g., digitized through scanning), and position information of each of the individual teeth in the tooth arch is determined based on the digitized model of the tooth arch. Such features used to determine and track the relative positions of physical tooth models within a tooth arch may be referred to herein as registration features, registration marks, reference features, or reference marks. Registration features may include, but are not limited to, pins or other structures inserted into or formed on or in the tooth arch during or after casting as well as features of the teeth. The relative positions of such registration features may also be derived from a previously generated digital model of the dental arch. Suitable methods and apparatus for collecting positional information allowing the assembly of the tooth models into a physical dental arch model include, but are not limited to, those disclosed in examples below and variations/improvements thereof. As elaborated on in the examples below, the tooth models may be attached to the base using, for example, pins or other features on the tooth models that mate with receptacles, such as holes, sockets or other receiving features, arranged on the base. The locations, shapes, and dimensions of, for example, holes in the base and/or pins in the tooth models may be selected to prevent interference between pins or similar features during assembly of the physical arch model. Suitable methods and apparatus for attaching physical tooth models to a base include, but are not limited to, those disclosed in examples below and variations thereof.
[0166] A digital model of the pre-treatment dental arch is produced in some variations of the disclosed methods and apparatus (step 1 10). In some variations, the digital model is acquired by scanning or otherwise digitizing a negative impression of the dental arch and/or a cast of the dental arch made from the negative impression. Suitable techniques for scanning or otherwise digitizing a negative impression or a cast made from the negative impression include, but are not limited to, those disclosed in examples below. In some variations the digital model of the pre-treatment arch is acquired by scanning or otherwise digitizing physical models of individual teeth or groups of teeth to provide digital models of individual teeth or groups of teeth. Suitable methods and apparatus for scanning or otherwise digitizing physical models of individual teeth or groups of teeth include, but are not limited to, those disclosed in examples below. Digital models of individual teeth or groups of teeth may be assembled to form a digital model of the pre-treatment arch.
[0167] Positional information allowing assembly of digital models of teeth or groups of teeth into a digital model of the dental arch may be collected if needed by, for example, characterizing the locations of registration features in the negative impression and/or characterizing the locations of registration features in or on a cast (i.e., a positive model) made from the negative impression prior to separating the cast into physical models of individual teeth or groups of teeth. Suitable methods and apparatus for collecting positional information allowing the assembly of digital models of teeth or groups of teeth into a digital model of the dental arch include, but are not limited to, those disclosed in examples below and variations thereof. In some variations a digital model of a patient's pre-treatment arch includes digital models of the roots of the teeth. Suitable methods for modeling the roots include, but are not limited to, those disclosed in examples below and variations thereof.
[0168] In some variations a digital model of a target dental arch is produced (step
1 15). A target dental arch is a desired arrangement of a patient's teeth to be achieved, for example, by the use of dental aligners. A target dental arch may be the desired final arrangement of the patient's teeth or an arrangement to be achieved at an intermediate stage between the pre-treatment dental arch and the desired final dental arch. In some variations a target dental arch is produced by modifying the positions of teeth in a digital model of the arrangement of the patient's teeth at an earlier stage of treatment. For example, a digital model of a target arch may be produced by altering the positions of the teeth in a digital model of the pre-treatment arch. In some variations a digital model of a target arch is produced by assembling digital models of individual teeth or groups of teeth. Positional information allowing assembly of digital models of teeth or groups of teeth into a digital model of a target dental arch may be acquired if needed by, for example, characterizing the locations of physical models of individual teeth or groups of teeth in an existing digital model of the target arch. Suitable methods and apparatus for producing digital models of target dental arches include, but are not limited to, those disclosed in examples below. Like digital models of pre-treatment arches, digital models of target arches may also include digital models of the roots of the teeth.
[0169] In some variations a physical model of a target dental arch is produced by arranging individual physical tooth models to form a target dental arch (step 120). In some variations in which a digital model of the target dental arch has already been provided (see step 115), the physical model of the target dental arch may be produced by arranging physical models of teeth or groups of teeth on a base at positions selected in accordance with the digital model. The digital model may also be used to predict and avoid interference between tooth roots, between tooth crowns, and/or between pins or other features on or associated with the teeth or the base used to attach the teeth to the base.
[0170] In some variations, a dental aligner is fabricated based on the physical dental arch which comprises a plurality of physical tooth models (step 125). For example, a dental aligner can be fabricated by forming a sheet of suitable material over a physical model of the target dental arch. Such variations need not require the use of a digital model of the aligner. In other variations, a digital model of the dental aligner is produced based on either a digital or physical model of the target dental arch. In such variations the physical dental aligner may be manufactured from the digital model of the dental aligner using, for example, CNC based manufacturing techniques. Suitable CNC manufacturing methods and apparatus include but are not limited to those disclosed in examples below.
[0171] An exemplary process for manufacturing a dental aligner is described in detail next. A variation of the overall process is also disclosed in U.S. Provisional Application No. 60/673,851 , entitled, "COMPUTER AIDED ORTHODONTIC TREATMENT PLANNING," filed April 22, 2005 and U.S. Provisional Application No. 60/676,546, entitled "DIGITIZATION OF DENTAL ARCH MODEL," filed April 29, 2005. First, negative impressions of the patient's upper and lower tooth arches and, optionally, X-ray images of the teeth are taken through procedures that are well known to one of ordinary skill in the art. Although the X-ray images are not required in this process, they may be utilized either directly by a simulation program or indirectly by an operator to modify or enhance a digital tooth arch model if such a model is used in the overall process.
[0172] Referring to FIG. 2, in some variations a casting chamber 150 for casting a dental arch from a negative impression comprises a chamber body 155 and a lid 160. Chamber body 155 includes a cavity 165 in which the negative impression of the dental arch may be placed. Casting chamber body 155 and lid 160 also include pins and alignment holes, not shown, allowing lid 160 to be precisely and reproducibly placed on chamber body 155. FIG. 3 shows the underside of lid 160 to which has been attached a base plate 170 Lid 160 and base plate 170 also optionally include alignment pins and alignment holes, not shown, allowing base plate 170 to be precisely and reproducibly placed with respect to lid 160 and thus chamber body 155. Base plate 170 may serve as the reference for a physical model of a dental arch to be cast in casting chamber 150. Variations of casting chambers for casting dental arches are disclosed in U.S. Patent Application No. 1 1/013,160, entitled "SYSTEM AND METHODS FOR CASTING PHYSICAL TOOTH MODEL," filed December 14, 2004.
[0173] Referring now to FIG. 4, the negative impression 180 of the patient's tooth arch is placed in casting chamber body 155 and coupled (e.g., glued, bonded, interlocked, etc.) to the bottom 185 of casting chamber cavity 165. A three dimensional position input device (e.g., a 3-D digitizer) 190 is then utilized to determine the positions or approximate positions of teeth or tooth features within the tooth arch. Such features may later be used as registration features to track the relative position and orientation of teeth in a physical model of a dental arch. In one example, position input device 190 includes a stylus 195 that may be positioned at points within negative impression 180. Position input device 190 may measure, for example, the spatial orientation of stylus 195 and/or the position of its tip.
[0174] In some variations the position input device 190 is a mechanical location determination device such as, for example, a MicroScribe®, available from Immersion Corporation. In FIG. 4, for example, position input device 190 is depicted as such a mechanical location device. An example of utilizing a mechanical location device to characterize the locations of features in a negative impression of a dental arch is disclosed in U.S. Patent Application No. 1 1/013,159, entitled "PRODUCING A BASE FOR ACCURATELY RECEIVING DENTAL TOOTH MODELS," filed December 14, 2004. In other variations, position input device 190 may be, for example, an optical location device, optical scanner (e.g., laser scanner) imaging machines (e.g., CAT scanner, MRI scanner), ultrasound scanner, magnetic scanner. In yet other variations, optical and/or magnetic sensing techniques are utilized to measure the position of a stylus 195 or to otherwise determine the positions of features in negative impression 180. Examples of the use of such optical, imaging, or magnetic sensing techniques to characterize the locations of features in a negative impression of a dental arch are disclosed in U.S. Patent Application No. 1 1/013,157, entitled "PRODUCING ACCURATE BASE FOR A DENTAL ARCH MODEL," filed December 14, 2004.
[0175] Referring again to FIG. 4, to facilitate measurement of the positions of features in negative impression 180, position input device 190 and casting chamber body 155 may be fixed to a common platform 200. A coordinate system based on casting chamber body 155 can then be established by manipulating stylus 195 to measure the locations of two points on the casting chamber body 155 to define the x axis. The y axis may be established with a third reading. For example, the x-y plane may be defined on the surface that receives the negative impression. The z axis can be determined by taking the cross product of the x and y axes.
[0176] The positions of features in negative impression 180 may then be measured with respect to the coordinate system on chamber body 155 by placing stylus 195 at points on or in the features. For example, stylus 195 can be inserted into the negative impression of a tooth to approximate the root position for that particular tooth. In one variation, stylus 195 is inserted into the cavity along the longitudinal orientation of the tooth, and, if desirable, further adjusted to a position that approximates the position of the root of the tooth. A computer may then be used to record the position of stylus 195, which corresponds to the approximate root position. In one variation, the placement of stylus 195 is controlled by an operator. In another variation, an automated system having optical and/or tactile feedback is utilized to position stylus 195.
[0177] The approximate position of the root for each tooth may also be defined by one or more positionings/placements of stylus 195. In one variation, for example, stylus 195 is used to define two positions or longitudinal axes which in combination approximate the position of a registration feature, which may correspond to the position of the root of the teeth. Pin-like objects placed on a positive tooth model may be utilized later to simulate the positions or axes defined by stylus 195, which in turn can represent the approximate position of the root. In another variation, stylus 195 is used to define four points within each of the tooth cavities within the negative impression 180 of the tooth arch. The four defined points are then utilized to define the position for the placement of two pins or of an asymmetric peg/interface which can simulate the position of the registration feature.
[0178] In another variation, stylus 195 is used to sample a series of points that represent the profile of each of the tooth cavities within negative impression 180. For example, three or more points on the surface of a tooth cavity may be sampled to define an approximate surface profile of the tooth. The approximate surface profile may then be used to define an approximate root position. Two pin positions may be calculated to fit within the approximate surface profile along the longitudinal axis of the tooth. In one variation, a sectional plan is defined at the base of the tooth based on a sampling with stylus 195 of the negative impression representing the gingival tissue. A pair of pins, with a pre-set distance "d", is then positioned perpendicular to this sectional plan and centered within the tooth that is defined by the approximate surface profile determined by stylus 195.
[0179] In some variations, base plates for receiving dental arch models and physical tooth models are manufactured to have complimentary features (e.g., receptacles) allowing the tooth models to be mounted on the base plate to form the dental arch model. Features such as, for example, pins, studs, and sockets may be provided on the tooth models, such that the tooth models can be mounted on base plates. Examples of mounting features are disclosed in U.S. Patent Application No. 10/979,824, entitled "PRODUCING A BASE FOR PHYSICAL DENTAL ARCH MODEL," filed November 2, 2004. Referring to FIGS. 3 and 5, for example, in some variations a base plate 170 is provided with sockets 205 into which can be inserted pins 175 to be attached to physical tooth models. The pins or other features on the physical tooth models allowing attachment of the physical tooth models to base plate 170 may also serve as registration features allowing the relative positions and orientations of the physical tooth models to be tracked. In some variations such pins also approximate the position of roots, as described above.
[0180] In variations in which the position of base plate 170 attached to lid 160 can be precisely determined when lid 160 is attached to chamber body 155, the coordinate system in which position input device 190 (FIG. 4) characterized negative impression 180 can be properly transposed to the base plate 170. In such variations, the locations of the sockets 205 (i.e., receptacles) on the base plate 170 may be chosen based on the data collected with position input device 190 to correspond to the positions of the registration features determined based on the negative impression of the patient's tooth arch. Sockets 205 may be formed in base plate 170, for example, by CNC based machining, by laser machining, or by printing or forming sockets in a soft material which is later cured or hardened. Examples of various socket forming techniques are disclosed in U.S. Patent Application No. 10/979,824, entitled "PRODUCING A BASE FOR PHYSICAL DENTAL ARCH MODEL," filed November 2, 2004, U.S. Patent Application No. 1 1/013, 152, entitled "BASE FOR PHYSICAL DENTAL ARCH MODEL," filed December 14, 2004, U.S. Patent Application No. 11/012,924, entitled "ACCURATELY PRODUCING A BASE FOR PHYSICAL DENTAL ARCH MODEL," filed December 14, 2004, and U.S. Patent Application No. 1 1/013, 145, entitled "FABRICATING A BASE COMPATIBLE WITH PHYSICAL TOOTH MODELS," filed December 14, 2005.
[0181] Pin and socket positions chosen to correspond to teeth in a tooth arch might interfere in some circumstances. For example, tilted tooth orientations might result in pins on adjacent teeth colliding with each other when inserted into a base plate. In some variations, prior to final selection of pin and socket positions some or all adjacent pairs of teeth are examined for interference between pins. Where detected, such interference may be avoided, for example, by altering the configuration of the pins. For example, the position, orientation, or length of pins may be selected to avoid interference with pins on neighboring teeth. In addition, removable, retractable and/or spring-loaded pins may also be used. Socket positions and configurations may then be selected to compliment the non- interfering pin configurations. An example of detection and avoidance of potential interference between pins is disclosed in U.S. Patent Application No. 1 1/013,156, entitled "PRODUCING NON-INTERFERING TOOTH MODELS ON A BASE," filed December 14, 2004 and U.S. Patent Application No. 1 1/050,126, entitled "METHODS FOR PRODUCING NON-INTERFERING TOOTH MODELS, filed February 3, 2005.
[0182] In some variations sockets are formed to receive pins for teeth oriented at an angle with respect to the surface of base plate 170. Referring to FlG. 6, for example, in some variations a recess 210 having a flat surface 215 is formed in a base plate 170. Flat surface 215 can be tilted to accommodate tilted pins 175, which mate with matching tilted sockets 205 formed in base plate 170. Examples of sockets accommodating tilted teeth and pins are disclosed in U.S. Patent Application No. 11/013,156, entitled "PRODUCING NON-INTERFERING TOOTH MODELS ON A BASE," filed December 14, 2004.
[0183] As shown in FIGS. 3 and 7, after sockets 205 are formed, pins 175 are then inserted into sockets 205 and lid 160 is flipped over and placed on top of the chamber body 155 holding the negative impression 180 of the tooth arch. In this example, when the lid 160 and chamber body 155 are properly aligned, each pair of pins corresponds to a tooth in the tooth arch represented by the negative impression. In some variations, when lid 160 and chamber body 155 are properly aligned, the positions of pins 175 correspond to approximate root positions defined by position input device 190.
[0184] Next, a casting material is injected into the cavity 220 of the negative impression 180, which is positioned within the casting chamber cavity 165. Suitable casting materials include, but are not limited to, polymers and plasters. Optionally, heat, infra-red light, or ultraviolet light, for example, may be applied to promote curing of the casting material. Examples of casting processes and casting materials are disclosed in U.S. Patent Application No. 1 1/013,160, entitled "SYSTEM AND METHODS FOR CASTING PHYSICAL TOOTH MODEL," filed December 14, 2004, U.S. Patent Application No. 1 1/013,158, entitled "PRODUCING A PHYSICAL TOOTH MODEL COMPATIBLE WITH A PHYSICAL DENTAL ARCH MODEL," filed December 14, 2004. As shown in FIG. 8, the casting material cures to form a positive arch 225 within the negative impression, with pins 175 bonded to the positive arch. The user may then decouple the negative impression 180 from the positive arch 225, resulting in a positive tooth arch 225 of the patient with a plurality of pins 175 that, optionally, simulate the root positions.
[0185] In some variations positive arch 225 is cast by sequentially applying and curing multiple layers of casting material to form a layered model of the dental arch. Examples of multi-layer casting methods and devices are disclosed in U.S. Patent
Application No. , entitled "MULTI-LAYER CASTING METHODS AND
DEVICES," filed October 24, 2005.
[0186] In one variation a base plate is prepared with a base surface, which simulates the gum line, prior to and subsequently used in the casting of a positive arch 225 having the isolated crown portion without the gum portion. In this variation, a first positive dental arch including both crowns of the teeth and segments of the gum is cast from negative impression 180. The crown portions are then cut away to leave a gum portion in which sockets or other features may be formed as described above. This gum portion is them implemented on a base plate in casting the dental arch using, for example, another casting material that does not adhere to the solidified material of the base plate. Examples of methods and apparatus to cast a tooth arch isolated to the crown portions of the teeth are disclosed in U.S. Patent Application No. 1 1/013,158, entitled "PRODUCING A PHYSICAL TOOTH MODEL COMPATIBLE WITH A PHYSICAL DENTAL ARCH MODEL," filed December 14, 2004.
[0187] Optionally, the positive arch 225 resulting from the casting processes described above may be digitized to generate a three-dimensional digital representation of the dental arch. This digital model of the dental arch may be utilized later, for example, to align or to aid in alignment of tooth models formed by separating the positive arch into individual teeth or groups of teeth. The three dimensional digital representation may be constructed, for example, using conventional digitizing techniques such as laser 3-D scanning.
[0188] Next, the teeth on the positive tooth arch 225 are separated to form physical models 230 of the individual teeth, as shown in FIG. 9. Separation may be achieved by, for example, sawing, laser cutting, or other techniques that are well known to one of ordinary skill in the art. Individual physical tooth models 230 may be arranged to recreate positive tooth arch 225 or to represent a target dental arch by, for example, inserting their pins 175 into sockets appropriately arranged on a base plate. In one variation, rather than being attached directly to a base plate the individual physical tooth models 230 are attached to adjustment jigs which are then attached to the base plate. The adjustment jigs alter the position or orientation of the physical tooth models 230 compared to that obtained by attaching the physical tooth models 230 directly to a base plate. In another variation, the adjustment jigs enable the rotation of physical tooth models 230 around two axes. Examples illustrating the use of adjustment jigs with physical tooth models in a dental arch model are disclosed in U.S. Patent Application No. 10/979,504, entitled "PRODUCING AN ADJUSTABLE PHYSICAL DENTAL ARCH MODEL," filed November 2, 2004 and U.S. Patent Application No. 1 1/074,299, entitled "PRODUCING PHYSICAL DENTAL ARCH MODEL HAVING INDIVIDUALLY ADJUSTABLE TOOTH MODELS," filed March 7, 2005. [0189] Separating positive tooth arch 225 into individual physical tooth models 230 could result in the loss of the relative three dimensional coordinates of the physical tooth models 230 in tooth arch 225. This information may be found or preserved by several methods. Examples of such methods are disclosed in U.S. Patent Application No. 10/979,824, entitled "PRODUCING A BASE FOR PHYSICAL DENTAL ARCH MODEL," filed November 2, 2004. In one variation, the relative positions of the pins 175 in the tooth arch 225 can be utilized to determine the relative positions of the teeth to which they are attached. The relative positions of pins 175 can be known, for example, through the relative positions of sockets 205 formed in base plate 170 prior to the casting of tooth arch 225 onto pins 175 (FIGS. 3 and 7). The relative positions of pins 175 can also be known, for example, by defining their positions with respect to negative impression 180 using a position input device as described above (FIG. 4).
[0190] In another variation, either the positive arch 225 or the negative tooth arch impression 180 may be digitized by three-dimensional scanning using, for example, techniques such as laser scanning, optical scanning, destructive scanning, CT scanning, MRI scanning, and acoustic scanning. The resulting digital model of the arch may be utilized alone or in combination with the registration feature information (e.g., pin information) to determine the relative positions of the teeth in the tooth arch.
[0191] In another variation, the separated tooth models 230 are assembled to recreate positive arch 225 by geometry matching. Positive arch 225 is first digitized to obtain a 3D digital arch model. After separation, individual tooth models 230 are then scanned to obtain digital tooth models for individual teeth as described below, for example. The digital tooth models can be matched to the digital arch model using rigid body transformations. Each tooth is sequentially matched to result in rigid body transformations corresponding to the tooth positions that can reconstruct an arch.
[0192] In another variation, unique registration features are added to each pair of tooth models 230 before positive arch 225 is separated. Separated physical tooth models 230 can be assembled to recreate a positive arch 225 by matching physical tooth models having the same unique registration marks.
[0193] In yet another variation, individual physical tooth models 230 are assembled and registered with the assistance of three dimensional point picking devices such as position input device 190 described above (FIG. 4). The coordinates of registration features on the physical tooth models 230 are determined before separation of tooth arch 225. After separation, the coordinates of the registration features are use to arrange physical tooth models 230 to recreate tooth arch 225.
[0194] After the separation of positive tooth arch 225, individual physical tooth models 230 may be digitized as described next, for example, to form digital models of the individual teeth. These individual digital tooth models may then be used, for example, to create digital models of dental arches. Examples of digitization of individual physical tooth models and construction of a digital dental arch from digital models of teeth are disclosed in U.S. Provisional Application No. 60/676,546, entitled "DIGITIZATION OF DENTAL ARCH MODEL," filed April 29, 2005.
[0195] In one variation, physical tooth models 230 are digitized by scanning system
240 shown in FIG. 1OA. Scanning system 240 includes a scan plate 245 on which one or more physical tooth models 230 can be mounted. Scan plate 245 can be rotated by a rotation mechanism 250 under the control of a computer 255. The rotation mechanism 250 can include a motor and a gear transport mechanism that is coupled to the scan plate 245. As scan table 245 rotates, an image capture device 260 captures images of physical tooth models 230. The coordinates of a plurality of surface points on the physical tooth models 230 can be computed, for example, by triangulation using the captured image data. The surfaces of the physical tooth models 230 can be constructed by interpolating computed coordinates of the points on the surface. Image capture device 260 can be, for example, a digital camera, digital video camera, laser scanner, or other optical scanner. Some variations utilize a plurality of image capture devices. The throughput and accuracy of the digitization process may increase with the number of image capture devices used.
[0196] In one variation, the individual physical tooth models 230 are placed on scan plate 245 one at a time and scanned one at a time. In other variations, a plurality of individual physical tooth models 230 are place onto scan plate 245 and scanned together. For example, in one variation eight physical tooth models 230 are scanned at a time. In another variation sixteen physical tooth models 230 are scanned at a time. In general, the scanning throughput is increased with increased packing density on scan plate 245. However, higher packing density may decrease the distance between the physical tooth models 230, which may cause the adjacent physical tooth models 230 to block each other in image captures. Various techniques that are well known to one of ordinary skill in the art may be utilized to determine the desired packing density and distribution pattern for placement of physical tooth models 230 on scan plate 245.
[0197] FIG. 1OB is a top view, illustrating one variation of a tooth model platform for scanning. In this variation, a plurality of physical tooth models 230 are mounted to a scan plate 245. Physical tooth models 230 can have different sizes and shapes. In the example of FIG. 1OB the small circles may be, for example, about 10 mm in diameter and represent small teeth (e.g., lower incisors, canine, etc.) or tooth components. The large circles may be, for example, about 15mm in diameter and represent large teeth (e.g. upper central incisors, molars) or larger tooth components. In this example, physical tooth models 230 are placed, for example, at least about 5 mm apart from each other and at almost equal height to avoid overlap. Scan plate 245 may be about 150 mm in diameter, for example. The packing efficiency of physical tooth models 230 can be determined by their sizes, heights, and shapes and by their distribution on scan plate 245. As one of ordinary skill in the art having the benefit of this disclosure would appreciate, other distributions of physical tooth models 230 on a scan plate 245 differing from that shown in FIG. 1OB may also be suitable.
[0198] FIG. 1 OC shows a side view of scan plate 245 in one variation. Physical tooth models 230 are mounted on scan plate 245 in a substantially vertical orientation. Images of the physical tooth models are scanned or captured from a direction 265 oblique to the physical tooth models 230 such that their top and side surfaces can be captured at different angles as scan plate 245 is rotated. For example, the image capture direction 265 can be about 45 degree off vertical axis 270. Other relative orientations of the image capture direction 265 and the physical tooth models may also be suitable. In some variations scan plate 245 can be mounted on goniometer and/or translation stages which can provide up to 6 axes for 6 degree of freedom movements.
[0199] In one variation, pre-determined receptacles (e.g., sockets) are prepared on a base plate 245, such that the scanned digital data of each tooth profile is associated with the position of its corresponding receptacle. Referring to FIG. 1 1, in one example, physical tooth models 230 are mounted on scan plate 245 by inserting pins 175 on physical tooth models 230 into receiving features 275 formed in scanning plate 245. Receiving features 275 (e.g., receptacles) may be sockets or holes as described above with respect to the fabrication and use of base plates for dental arch models. The positions of receiving features 275 are precisely known. Hence, the positions and orientations of pins 175 and physical tooth models 230 during the scanning process can be determined in relation to the receiving features. Thus, once the surface of a physical tooth model 230 has been digitized, the coordinates of the surface of that tooth are known with respect to the positions of the pins in that tooth. That is, the location of points on the surface of a digitized tooth and the location of the pins in that tooth can be translated into the same coordinate system. Consequently, if the positions of the pins are known or defined, then the positions of points on the surface of the tooth are also known.
[0200] FIG. 12 illustrates examples of graphic projections of the individual digital representations 280 of selected teeth, each of which comprises a crown portion of the corresponding tooth. In one variation, a section of the gingival tissue (not shown) is also digitized.
[0201] Once the individual physical tooth models 230 have been digitized, the digital representations 280 of individual teeth may then be utilized by a computer program to generate a digital representation of the complete tooth arch. In one variation, digital tooth models 280 are used to generate a digital representation 285 of the tooth arch, shown in FIG. 13. Since the relative positions of the pins for each of the teeth is known, and the digital tooth models can be referenced to the pins during scanning, a computer can recalculate and arrange the individual digital tooth models based on the pin information to form the patient's pre-treatment tooth arch. Digital models of the tooth roots may be later incorporated into digital model 285 of the tooth arch, if desired.
[0202] In one example, the computer uses the relative locations of pins 175 in positive arch 225 to calculate the relative positions of corresponding digital tooth models 280 required to align digital dental arch model 285 with positive arch model 225. Optionally, alignment of the digital tooth models 280 in digital arch model 285 may be accomplished or aided by reference to a three-dimensional digital model of the patient's complete tooth arch generated from scanning or otherwise digitizing either negative impression 180 or positive tooth arch 225. As shown in FIG. 14, for example, a three- dimensional digital model 290 of the tooth arch generated from scanning a compete physical arch model may be superimposed on digital dental arch model 285, which was generated from combining digital tooth models 280. The overlaid individual tooth sections allow an operator and/or software to match up individual teeth between the two digital tooth arches. The position of each tooth within digital dental arch 285 may then be adjusted to match that of the corresponding tooth in the digital model 290 of the complete tooth arch. The adjusted digital arch model 285 may then be utilized for computer modeling or preparation of a dental appliance, for example.
[0203] In some variations, once the digital tooth arch 285 has been constructed, the computer program may then calculate, select, or otherwise create a simulated root for each of the teeth in digital arch model 285. FIG. 15 illustrates a graphical projection of a digital arch model 285 comprising both crowns 280 and roots 295. Digital simulation of tooth roots is disclosed, for example, in U.S. Provisional Application No. 60/676,546, entitled "DIGITIZATION OF DENTAL ARCH MODEL," filed April 29, 2005.
[0204] In one variation in which digital roots are created, a computer generates a digital model of the root portion for each of the crowns, based, for example, on the morphology, dimension, size, and/or shape of the crown. In another variation, an operator or a computer selects roots matching the crowns from a data library of predefined roots of different sizes and shapes. Optionally, the crowns in the dental arch and the roots in the data library are categorized as, for example, incisor, canine, premolar, or molar. Roots are then selected from the category matching that of the crown. Data from x-ray images may also be utilized in the root selection process. Once the root is selected or simulated, the computer may further modify its size to provide a better match between the root and the crown.
[0205] In one variation, a digital root is coupled to its digital crown to align an axis of the root with a primary axis of the crown. In another variation, the position and/or orientation of a digital root with respect to its digital crown are determined based on the morphology of the crown and/or x-ray information. Optionally, an operator may be presented with a visual representation of the complete digital tooth model (crown and root) and an opportunity to make manual adjustments to the position and/or orientation of the root. Such an adjustment may be based on x-ray or other clinical data, for example.
[0206] In some other variations digital tooth models 300 comprising roots 305 and crowns 310 are generated based on digital tooth models 280 prior to generation of a digital model of the complete tooth arch. FIG. 16 shows examples of the graphical projections of such individual tooth models 300. Various methods for generating roots for corresponding crowns, described in detail above, may be applied to create the root portion for each of the individual digital tooth models 300. In some variations, information regarding pin locations corresponding to approximate root positions may be applied to position/couple the root profile to the crown. For example, a computer program may utilize the pin location information to determine if the root portion is centered in relation to the crown portion. The direction of the pin and the amount of misalignment, if any, may also be calculated. As another example, a computer may use the pin information to determine whether the primary axis of the root is tilted in relation to the primary axis of the crown, such that the simulated root can be tilted by the corresponding amount and in the matching orientation.
[0207] Referring to FIG. 17, after individual digital tooth models 300 comprising crowns 310 and roots 305 have been generated, they may be used by a computer program to generate a digital model 315 of the dental arch. The relative positions of digital tooth models 300 in digital tooth arch model 315 may be determined, for example, by the methods described above with respect to the generation of digital tooth arch 285 (FIG. 13). Digital arch model 315 may then be utilized for computer modeling or preparation of a dental appliance, for example.
[0208] Although the construction of a digital representation of the lower tooth arch is described in the above example, one of ordinary skill in the art having the benefit of this disclosure would appreciate that a digital representation of a patient's upper tooth arch can also be prepared with the methods and apparatus described above.
[0209] Once a digital representation of the patient's tooth arch has been prepared, software may then be utilized to modify the position or orientation of one or more of the teeth within the digital tooth arch relative to the rest of the teeth in the tooth arch. The software may support a user interface to allow the user to modify the teeth within the digital tooth arch. FIG. 18 illustrates an example of a digital tooth arch 320 with the position/orientation of one of the teeth 325 within the tooth arch being modified.
[0210] An attempt to modify the position of a tooth in a physical or digital tooth arch model, or in a patient's actual tooth arch, may result in interference between teeth. For example, an attempted modification might require the crowns or roots of neighboring teeth to make contact or to overlap. In some variations, a digital model of a tooth arch may be used to predict and prevent such interference between physical tooth models in a physical dental arch model and/or between a patient's actual teeth. In one example, the position and/or orientation of a digital tooth model in a digital arch model is modified, and then the resulting overlap between digital tooth models in the digital arch model is calculated to predict and quantify the amount of interference that would result. If an attempted modification of the tooth arch results in interference, that modification may be rejected in favor of a modification that does not result in such interference. Examples of methods and apparatuses for predicting and preventing interference between tooth models are disclosed in U.S. Patent Application No. 1 1/013, 154, entitled "PREVENTING INTERFERENCE BETWEEN TOOTH MODELS," filed December 14, 2004 and U.S. Patent Application No. 1 1/013,155, entitled "ACCURATELY PREDICTING AND PREVENTING INTERFERENCE BETWEEN TOOTH MODELS," filed December 14, 2004.
[0211] A modified digital tooth arch may be utilized to fabricate a removable aligning appliance for orthodontic treatment. In one variation, a digital representation of a shell 330 configured to serve as an aligner is generated by a computer based on the modified digital representation of the tooth arch 320, as shown in FIG. 19. A physical shell 335 is then fabricated based on the digital representation of the shell 330. Various fabrication techniques that are well known to one of ordinary skill in the art may be utilized to create a physical object based on its digital representation. For example, three- dimensional polymeric printing techniques may be utilized to create a polymeric aligner based on the digital representation of the shell. FIG. 20 illustrates an example of a polymeric aligner 335 created based on the digital representation of the shell 330 shown in FIG. 19.
[0212] In other variations, the modified digital representation of the tooth arch 320 is provided as a reference to modify the arrangements of a corresponding physical model of the tooth arch. The desired aligner may then be fabricated using the modified physical model of the tooth arch. For example, a modification of the position or orientation of a digital tooth model in a digital arch model results in a corresponding modification of the positions and orientations of that tooth's pins with respect to the pins of the other teeth in the arch. The digital representation of modified tooth arch 320 can be configured to retain all of the revised pin positions. These revised pin positions may then be utilized to modify the physical model of the tooth arch such that the physical model corresponds to the modified digital representation of the tooth arch.
[0213] In one variation, the revised relative pin positions and orientations for the teeth in the digital arch model may be used to create a digital model of a base plate on which a corresponding physical model may be assembled. The digital base plate model may include, for example, the relative positions and orientations in a physical base plate of sockets into which pins on physical tooth models may be inserted to form a physical arch model that corresponds to the modified digital tooth arch. The digital base plate model may be used, for example, in CNC based manufacturing of a physical base plate. The creation and use of digital base plate models is disclosed, for example, in U.S. Patent Application No. 11/013,145, entitled "FABRICATING A BASE COMPATIBLE WITH PHYSICAL TOOTH MODELS," filed December 14, 2004.
[0214] Referring to FIG. 21, in one example sockets or holes 340 are drilled into a base plate 345 with CNC machinery, for example, so that the position and orientation of these holes 340 correspond to the revised pin position in the digital representation of the tooth arch 320. Sockets 340 may also be formed, for example, by laser machining, or by printing or forming sockets in a soft material which is later cured or hardened. Examples of socket forming techniques are disclosed in U.S. Patent Application No. 10/979,824, entitled "PRODUCING A BASE FOR PHYSICAL DENTAL ARCH MODEL," filed November 2, 2004, U.S. Patent Application No. 11/013,152, entitled "BASE FOR PHYSICAL DENTAL ARCH MODEL," filed December 14, 2004, U.S. Patent Application No. 11/012,924, entitled "ACCURATELY PRODUCING A BASE FOR PHYSICAL DENTAL ARCH MODEL," filed December 14, 2004, and U.S. Patent Application No. 1 1/013,145, entitled "FABRICATING A BASE COMPATIBLE WITH PHYSICAL TOOTH MODELS," filed December 14, 2005.
[0215] After sockets 340 are formed, physical models 230 of the patient's individual teeth, such as the ones shown in FIG. 9, can then be inserted onto the base plate 345 to form a tooth arch 350 that corresponds to the modified digital representation of the tooth arch 320, as shown in FIG. 22. As the individual teeth models 230 are placed onto the base plate 345, the operator may adjust the individual teeth (e.g., shaving, or rounding out sections of the tooth profile, etc.) to ensure that a proper fit between the teeth 230 on the tooth arch 350 can be achieved.
[0216] Pins and socket positions in a base plate chosen to correspond to teeth in a modified physical tooth arch model might interfere similarly to as described above with respect to the fabrication of base plate 170 (FIGS. 3 and 5). For example, tilted tooth orientations might result in pins on adjacent teeth colliding with each other when inserted into a base plate. In some variations, prior to final selection of socket positions some or all adjacent pairs of teeth are examined for interference between pins. Where detected, such interference may be avoided by, for example, altering the configuration of the pins. For example, the position, orientation, or length of pins may be selected to avoid interference with pins on neighboring teeth. In addition, removable, retractable and/or spring-loaded pins may also be used. Socket positions and configurations may then be selected to compliment the non-interfering pin configurations. Examples of methods and apparatuses for detection and avoidance of potential interference between pins are disclosed in U.S. Patent Application No. 1 1/013,156, entitled "PRODUCING NON-INTERFERING TOOTH MODELS ON A BASE," filed December 14, 2004 and U.S. Patent Application No. 1 1/050,126, entitled "METHODS FOR PRODUCING NON-INTERFERING TOOTH MODELS, filed February 3, 2005. In variations where the pins represent the roots of teeth, interference between the pins (and hence the represented roots) may be avoided by, for example, selecting a different modification of the tooth arch that does not result in interference.
[0217] In some variations sockets in a base plate for a modified tooth arch are formed to receive pins for teeth oriented at an angle with respect to the surface of the base plate. Referring to FIG. 23, for example, in some variations a recess 355 having a flat surface 360 is formed in a base plate 345. Flat surface 360 is tilted to accommodate a tilted tooth model 230. Tilted pins 175 mate with matching tilted sockets 340 formed in base plate 345. Examples of sockets accommodating tilted teeth are disclosed in U.S. Patent Application No. 1 1/013, 156, entitled "PRODUCING NON-INTERFERING TOOTH MODELS ON A BASE," filed December 14, 2004.
[0218] In one variation, the desired aligner may be fabricated using modified physical tooth arch model 350 in a vacuum forming process. For example, as shown in FIG. 24 a sheet of aligner material 365 may be placed over modified physical tooth arch model 350. Sheet 365 may be heated and then vacuum formed around physical tooth arch model 350 by, for example, a vacuum pump that removes air at the bottom of base plate 345 to cause the softened aligner material 365 to fittingly form around physical dental arch model 350. Suitable aligner materials include but are not limited to polymers. An example of vacuum formation of an aligner on a modified physical tooth arch model is disclosed in U.S. Patent Application No. 11/074,301, entitled "DENTAL ALIGNER FOR PROVIDING ACCURATE DENTAL TREATMENT, filed March 7, 2005. In one variation, gaps or voids between teeth in the tooth arch model are filled before the aligner is vacuum formed so that the aligner may be removed from the dental arch at the conclusion of the vacuum forming process.
[0219] After the vacuum-formed sheet 370 of aligner material has sufficiently cooled, it may be removed from physical tooth arch model 350, as shown in, FIG. 25. Excess materials on the vacuum-formed polymeric sheet 370 may then be trimmed off to form a polymeric shell 375 that can serve as a removable aligner, as shown in FIG. 26.
[0220] In another variation, one or more copies of the digital representation of the tooth arch, which represents the original condition of the patient's tooth arch, may be created. Each of the duplicate digital tooth arches may be modified in varying degrees to represent the projected or intended position of the patient's teeth for a specific stage (i.e., treatment step) within a series of stages during the process of orthodontic treatment. The modified digital tooth arches may then be implemented to fabricate a series of removable aligners that match the modified digital tooth arches.
[0221] In one example, a base plate is configured with multiple sets of holes, where each set of holes forms an arch configured for receiving a plurality of positive teeth models to form a tooth arch. Referring to FIG. 27, for example, in one variation a base plate 380 comprises four sets of holes 385, 390, 395, and 400 representing four arches. The holes correspond to projected pin positions based on the digital representations of the four different arches. Corresponding positive teeth models are then inserted into the holes on the base plate 380 to form four positive arch models 405, 410, 415, and 420 as shown in FIG. 28. These four positive arch models may then be utilized to form four separate dental aligners. For example, a sheet of aligner material, such as a polymer sheet, may be placed over the four positive arches on the base plate and vacuum-formed to create the four dental aligners. In one variation, the four positive arch models represent tooth arrangement of four different treatment steps of an orthodontic treatment process. In another example, the four positive arch models represent arches of four different patients; each may be at a different stage of the treatment process.
[0222] Variations of a process for manufacturing a dental aligner are also described next with respect to FIG. 29A and FIG 29B. Referring to FIG. 29A, some variations of a process for manufacturing a dental aligner start by determining a position of a registration feature for each of the teeth within a patient's tooth arch (step 500). This may comprise, for example, determining a position of a registration feature for each of the teeth based on a negative impression of the patient's tooth arch. The positions of the registration features may be determined in some variations with a position determination device such as, for example, a microscribe. For example, determining a position of a registration feature may comprise scanning an inner surface of a negative mold of the patient's tooth arch. Such scanning may comprise, for example, scanning the inner surface of the negative mold with a position determining device such as, for example, a mechanical scanning device or an optical scanning device. Scanning an inner surface of a negative mold of the patient's tooth arch may comprise, for example, sampling locations on the inner surface profile of the negative mold and utilizing information of the inner surface profile to determine the position of the corresponding registration feature for each of the teeth within the patient's tooth arch. The registration features may be pins, for example. In some variations, the positions of the registration features may also be determined based on a positive tooth arch model of the patient's tooth arch.
[0223] In some variations, the next step (step 505) is to construct individual tooth models of teeth in the patient's tooth arch comprising registration features corresponding to those of step 500. Constructing individual tooth models may comprise, for example, fabricating a tooth arch model of a patient's tooth arch in which each of the teeth has its corresponding registration feature, and dividing the tooth arch model into individual tooth models. Fabricating a tooth arch model of a patient's tooth arch may comprise, for example, positioning a corresponding registration feature in each tooth location within a negative mold of the patient's tooth arch, and filling the negative mold with a polymer to form the tooth arch model.
[0224] In some variations, the next step (step 510) is to prepare a base for receiving the individual tooth models. This may comprise, for example, creating a receptacle on the base for each of the tooth models, such that when all the tooth models are coupled to the receptacles the tooth models form a tooth arch. The receptacles may be configured, for example, to receive the registration feature of the corresponding tooth model. In one example, each of the registration features comprises a pair of pins, and each of the receptacles comprises a pair of holes configured to receive the pins. In some variations the base is prepared to have receptacles for receiving the tooth models to form a modified teeth arrangement that differs from a teeth arrangement of the patient's tooth arch. The modified tooth arrangement may be created utilizing a computer, for example. In some variations the computer may have a visualization interface to create the modified teeth arrangement. In some variations, bases may be prepared utilizing a CNC machine.
[0225] In step 515, the individual tooth arch models are attached to the base to form a tooth arch. The tooth arch formed by the individual tooth models attached to the base may be, for example, a target tooth arch in an orthodontic treatment process.
[0226] In step 520 a dental aligner may be fabricated. This may comprise fabricating the dental aligner on the tooth arch formed by the individual tooth models. In one example, fabricating a dental aligner comprises placing a polymeric sheet over the tooth arch formed by the individual tooth models and heat forming the polymeric sheet over the tooth arch. The tooth arch on which the dental aligner is fabricated may be, for example, a modified teeth arrangement that, for example, comprises a projected teeth arrangement of the patient's tooth arch in a stage of an orthodontic treatment process.
[0227] Referring now to FIG. 29B, some variations of a process for manufacturing a dental aligner utilize a physical model of a tooth arch constructed from individual physical tooth models of teeth in a patient's tooth arch with reference to a digital model of the tooth arch. Some of these variations start by generating a digital model for each of the individual physical tooth models (step 600). In some variations, generating a digital model of an individual physical tooth model comprises scanning the individual physical tooth model. This may comprise, for example, fabricating the individual physical tooth model and then scanning it to create the digital model of the physical tooth model. In some variations, fabricating an individual physical tooth model comprises acquiring a negative impression of a patient's tooth arch, casting a positive mold of the negative impression, and separating the positive mold to form at least one individual physical tooth model. [0228] In some variations the next step (step 605) is to generate a digital model of the tooth arch from the digital models of the individual physical tooth models. In some variations, in step 610 the teeth in the digital model of the tooth arch are arranged to have relative positions with respect to each other corresponding to the relative positions that the teeth in a patient's tooth arch have with respect to each other. In one example, this comprises determining a position of a registration feature for each of a plurality of teeth within the patient's tooth arch, where each registration feature identifies a relative position of its tooth in relation to other teeth within the patient's tooth arch, representing the registration features in corresponding digital models of individual physical tooth models, and arranging the teeth in the digital model of the tooth arch such that the registration features in the digital model of the tooth arch have relative positions with respect to each other corresponding to the relative positions that the registration features determined for the teeth in the patient's tooth arch have with respect to each other.
[0229] In some variations, in step 615 the position of at least one of the teeth in the digital model of the tooth arch is modified compared to the position of the corresponding tooth in the patient's current tooth arch.
[0230] Next, in step 620 the individual physical tooth models are arranged to have relative positions with respect to each other corresponding to the relative positions that the teeth in the modified digital model of the tooth arch have with respect to each other. In one example, each of the individual physical tooth models includes a registration feature represented in the digital model of the tooth arch, and the individual physical tooth models are arranged such that their registration features have relative positions with respect to each other that correspond to the relative positions that the registration features in the modified digital model of the tooth arch have with respect to each other. In one variation, registration features included in the individual physical tooth models are configured to attach the individual physical tooth modes to a base to form a physical model of a tooth arch. In one example, the registration features included in the physical tooth models comprise pins.
[0231] In another example, each of the individual physical tooth models includes a registration feature represented in the digital model of the tooth arch, and features on the base at which the registration features may be attached are formed at locations with relative positions with respect to each other corresponding to the relative positions that the registration features represented in the digital model of the tooth arch have with respect to each other. The registration features included in the physical tooth models may comprise pins, for example. The features on the base may comprise, for example, receptacles into which the registration features included in the individual physical tooth models may be inserted.
[0232] In step 625 a dental aligner may be formed over the individual physical tooth models. In one example, this comprises placing a polymeric sheet over the tooth arch formed by the individual tooth models and heat forming the polymeric sheet over the tooth arch.
Base for Receiving a Physical Dental Arch Model
[0233] Examples and variations of apparatus and methods for generating a base for receiving physical tooth models in a physical dental arch model are described below.
[0234] Some variations of these apparatus and methods use Computer Numerical
Controlled (CNC) manufacturing. CNC manufacturing includes methods and apparatus known to one of ordinary skill in the art, and improvements thereof, for computer controlled manufacturing of physical models based on digital representations. CNC manufacturing can include, for example, milling, stereolithography, laminated object manufacturing, selective laser sintering, fused deposition modeling, solid ground curing, 3D ink jet printing, laser machining, molding, and casting.
[0235] Bases may be fabricated from materials including, but not limited to, polymers, thermal elastic materials, urethane, epoxy, plastics, plaster, stone, clay, acrylic, latex, dental PVS, resin, metals, wax, wood, paper, ceramics, porcelain, glass, sand, ice, and concrete.
[0236] In one aspect, methods for producing a base for physical tooth models are described. The methods may comprise, for example, receiving digital tooth models representing the physical tooth models, generating a digital base model compatible with the digital tooth models, and producing a base using CNC manufacturing in accordance with the digital base model. The methods may also comprise, for example, receiving position information for the physical tooth models on the physical base, and forming features on a base plate in accordance with the position information to produce the physical base. The features formed on the base are configured to receive the physical tooth models. The methods may also comprise, for example, receiving position information for the physical tooth models on the physical base, and forming features on a base plate in accordance with the position information to produce the physical base. The features formed on the base plate complement features on the tooth models.
[0237] The methods may also comprise, for example, receiving positional information for sockets for receiving physical tooth models on the base, causing relative movement between a laser and a base plate, emitting a laser beam from the laser to the base plate, and producing a socket in the base plate with the emitted laser beam. Physical tooth models having one or more pins, protrusions, or other pluggable features may be attached to the base to form a physical dental arch by inserting the pluggable features into sockets in the base. The features in the physical tooth models may be shaped in accordance with the profile of the emitted laser beam that produces the sockets in the base plate.
[0238] In another aspect, systems for producing a base for physical tooth models are described. The systems may comprise, for example, a computer device adapted to store digital tooth models representing the physical tooth models, a computer processor that is capable of generating a digital base model compatible with the digital tooth models, and an apparatus that can fabricate the base using CNC based manufacturing in accordance with the digital base model. The systems may also comprise, for example, a computer configured to store position information for physical tooth models comprising features for attaching the tooth models to a base, and apparatus under the control of the computer configured to fabricate on a base plate features complementary to the features on the tooth models in response to the position information to thereby produce a physical base for receiving the physical tooth models. The system may also comprise, for example, a computer adapted to store positional information for sockets to be formed on a base plate, a transport system configured to move the base under the control of the computer, and a laser configured to emit a laser beam onto the base plate to form a socket in the base plate after the base plate is moved to a position in accordance to the positional information stored in the computer.
[0239] In another aspect, bases for physical tooth models are described. These bases may comprise, for example, a base portion and a plurality of features adapted for receiving the physical tooth models. The plurality of features may be fabricated by CNC based manufacturing, for example. In one variation, a base plate may comprise a plurality of pairs of sockets. Each pair of sockets may be adapted to receive two pins associated with a physical tooth model.
[0240] Implementations may include one or more of the following. A method for producing a base for physical tooth models may include receiving digital tooth models representing the physical tooth models, generating a digital base model compatible with the digital tooth models, and producing a base capable of receiving the physical tooth models using CNC based manufacturing in accordance with the digital base model. The base may comprise one or more features to assist the reception of the physical tooth models. The physical tooth models may include features that are complementary to the features in the base. For example, the features in the base and the features in the physical tooth models may join together to attach the physical tooth models to the base. Such features on the base and the physical tooth models may include, but are not limited to, one or more pins, registration slots, notches, protrusions, holes, interlocking mechanisms, jigs, and pluggable or attachable features. The features may be arranged on the base to receive physical tooth models in arrangements corresponding to at least a portion of a tooth arch model.
[0241] In some variations, a digital base model compatible with the physical tooth models is produced. The coordinates of the physical tooth models may be accounted for in the digital base model. Receiving features such as holes and sockets in the base may be specified in the digital base model. The relative positions of the receiving features may be acquired, for example, by scanning and digitizing a patient's tooth arch to produce a digital model of the tooth arch. The base may be fabricated in accordance with the digital base model. This may ensure the accurate assembly of the physical tooth models on the physical base.
[0242] In one variation the same physical tooth models may be attached to the base in two or more different configurations. In another variation two or more bases are produced having features arranged in different configurations for receiving physical tooth models. In one variation, the physical tooth models may be labeled by a predetermined sequence that defines the positions of the physical tooth models on the base. The labels may include, but are not limited to, one or more of a barcode, a printed symbol, a hand¬ written symbol, and a Radio Frequency Identification (RFID). [0243] In another variation the physical tooth models may be attached to each other to form a physical dental arch or part of a physical dental arch that can be attached to a base.
[0244] Physical tooth models may be fabricated in accordance with digital tooth models. Alternatively, digital tooth models may be acquired by scanning and digitizing physical tooth models.
[0245] Implementations may also include one or more of the following. A system for producing a base for physical tooth models may include a computer device adapted to store digital tooth models representing the physical tooth models, a computer processor that is capable of generating a digital base model compatible with the digital tooth models, and an apparatus that can fabricate the base to receive the physical tooth models using CNC based manufacturing in accordance with the digital base model. The base can comprise one or more features to assist the reception of the physical tooth models. The physical tooth models can comprise one or more features to assist the physical tooth models to be received by the base.
[0246] Implementations may also include one or more of the following. A base for physical tooth models may include a base portion and a plurality of features fabricated by CNC manufacturing, for example, to receive the physical tooth models. The plurality of features may be fabricated in accordance with a digital base model produced in response to the physical tooth models.
[0247] In one variation a base for physical tooth models includes a base plate having a plurality of pairs of sockets. Each pair of sockets is adapted to receive two pins associated with a physical tooth model. The base can further include a plurality of tooth models each having two pins connected at its bottom portion. Each pair of sockets can include a socket on the inside of the tooth arch model and a socket on the outside of the tooth arch model.
[0248] In some variations the physical tooth models include features to allow them to be attached, plugged or locked to a base. In some variations the physical tooth models may be pre-fabricated having standard registration and attaching features for assembling. In one example the physical tooth models may be automatically assembled onto a base by a robotic arm under computer control. [0249] In some variations the physical dental arch model obtained by the disclosed system and methods may be used for various dental applications such as dental crowns, dental bridges, aligner fabrication, biometrics, and teeth whitening. In some variations the arch model may be assembled from segmented manufacturable components that can be individually manufactured by automated, precise numerical manufacturing techniques.
[0250] In some variations the same physical tooth models may be used to form different tooth arch models having different teeth configurations. In such variations the tooth models may be reused as tooth positions are changed during a treatment process. Much of the cost of making multiple tooth arch models in orthodontic treatment may therefore be eliminated.
[0251] In some variations the same base can support different tooth arch models having different teeth configurations. In such variations the base may include more than one set of receiving features that can receive tooth models at different positions. For example, the base may include a plurality of configurations of sockets, with each configurations adapted to receive physical tooth models to form a different arrangement of a tooth arch model. This may reduce cost in the dental treatment of teeth alignment.
[0252] In addition, in some variations the physical tooth models in a physical dental arch model may be easily separated, repaired or replaced, and reassembled without the replacement of the whole arch model.
[0253] In one variation, a method for producing a physical dental arch model generally includes the steps illustrated in FIG. 30. In some variations the order of these steps is altered, some of these steps are not included, and/or additional steps are included. In the process illustrated in FIG. 30, an individual tooth model is created in step 2500. An individual tooth model is a physical model that can be part of a physical tooth arch model. Physical tooth arch models can be used in various dental applications. In step 2505 registration features are added to the individual tooth model to allow it to be attached to another individual tooth model or to a base. In some variations steps 2500 and 2505 happen together, making a separate step 2505 optional. In step 2510 a base is designed for receiving the tooth model. Step 2510 may precede steps 2500 and 2505 in some variations. In step 2515 the tooth model positions in a tooth arch model are determined. In some variations this step may precede steps 2500, 2505, and 2510. A base including features for receiving the individual tooth models is fabricated in step 2520. The base may be fabricated in accordance with a digital model. Step 2520 may precede steps 2500 and 2505 in some variations. In step 2525 the tooth models are attached to the base.
[0254] Details of the process in FIG. 30 are now described. Individual tooth models can be obtained in step 2500 by a number of different methods. The tooth models can be created by casting, for example. A negative impression is first made from a patient's arch using for example PVS. A positive of the patient's arch is next made by pouring a casting material into the negative impression. After the material is dried, the mold may then be taken out with the help of an impression knife. A positive of the arch is thus obtained.
[0255] In one approach, the negative impression of the patient's arch is placed in a specially designed container. A casting material is then poured into the container over the impression to create a model. A lid is subsequently placed over the container. The container is opened and the mold can be removed after the specified time.
[0256] Examples of casting materials include, but are not limited to, auto polymerizing acrylic resin, thermoplastic resin, light-polymerized acrylic resins, polymerizing silicone, polyether, plaster, epoxies, or a mixture of materials. The casting material may be selected based on the uses of the cast. For example, the material may be chosen to be easy to cut to obtain individual tooth models. The material may also be chosen to be strong enough for the tooth model to take the pressure in a pressure forming process subsequently used for producing a dental aligner.
[0257] In one variation, features that can allow tooth models to be attached to a base (step 2505) can be added to the casting material in the casting process. Registration points or pins can be added to each tooth before the casting material is dried. Optionally, universal joints can be inserted at the top of the casting chamber using specially designed lids, which would hang the universal joints directly into the casting area for each tooth.
[0258] Individual tooth models may be cut from the positive arch. The cutting may be done in such a manner that the individual tooth models can be joined again to form a tooth arch. The separation of individual teeth from the mold can be achieved using a number of different cutting methods including, but not limited to, laser cutting and mechanical sawing. [0259] Separating the positive mold of the arch into tooth models may result in the loss of the relative 3D coordinates of the individual tooth models in an arch. Several methods may be used for finding the relative positions and orientations of the tooth models in the arch. In one variation, unique registration features are added to each pair of tooth models before the positive arch mold is separated. The separated tooth models can be assembled to form a physical dental arch model by matching tooth models having the same unique registration marks.
[0260] In another variation, the positive arch mold may be digitized by three- dimensional scanning using a technique such as, for example, laser scanning, optical scanning, destructive scanning, CT scanning and Sound Wave Scanning to obtain a digital arch model. The digital arch model may track and store the positions and orientations of the individual tooth models in the arch. In an alternative method for creating individual tooth models, the digital arch model may be smoothened and segmented and each segment may be physically fabricated by CNC based manufacturing to obtain individual tooth models. Unique registration marks may be added to the digital tooth models and made into physical features in the CNC based manufacturing.
[0261] In another variation, the separated tooth models may be assembled by geometry matching. The intact positive arch impression is first scanned to obtain a 3D digital arch model. Individual teeth are then scanned to obtain digital tooth models for individual teeth. The digital tooth models can be matched using rigid body transformations to the digital arch model. Inter-proximal areas, roots of the teeth, and the gingival areas may be ignored in the geometry match due to their complex shape. In one variation features such as cusps, points, crevasses, front faces and back faces of the teeth are matched with high precision. Each tooth may be sequentially matched to result in rigid body transformations corresponding to the tooth positions that can reconstruct the arch.
[0262] In another variation, the separated tooth models are assembled and registered with the assistance of a 3D point picking device. The coordinates of the tooth models are picked up by 3D point picking devices such as a stylus or microscribe device before separation. Unique registration marks can be added on each tooth model in an arch before separation. The tooth models and the registration marks can be labeled by unique IDs. The tooth arch can later be assembled by identifying tooth models having the same registration marks as were picked from the jaw. Such 3D point picking devices can be used to pick the same points again for each tooth model to confirm the tooth coordinates.
[0263] In step 2510 the base is designed to receive the tooth models. The base and tooth models may include complimentary features to allow them to be assembled together. For example, the tooth model may have a protruding structure attached to it. Such complimentary features may also include, but are not limited to, registration slots, notches, protrusions, holes, interlocking mechanisms, and jigs. Protruding structures can be obtained, for example, during the casting process or be created after casting by using a CNC machine on each tooth.
[0264] The positions of the receiving features in the base may be determined, for example, by the initial positions of the teeth in an arch or the desired positions of the teeth during a treatment process (step 2515). In one variation a digital model of a tooth arch may be used to select the positions of the receiving features in a base. The digital arch model may represent a patient's existing tooth arch or desired positions of the teeth. For example, a digital model of the base may be constructed in accordance with the locations of the teeth in the digital arch model and with the locations and orientations on the corresponding individual physical tooth models of features such as pins, for example, with which the individual physical tooth models will be attached to the base. The digital base model may specify the locations on the base of features such as sockets or holes, for example, that will receive features on the individual tooth models to attach the individual tooth models to the base. The base may be fabricated in accordance with the digital base model by, for example, CNC manufacturing. After fabrication of the base, physical tooth models may be inserted into the receiving features in the base to form a physical dental arch model matching the digital model. Fabrication of the base from a digital model may ensure accurate assembly of the physical dental arch model.
[0265] In one variation, in step 2520 the base plate is taken through a CNC process, for example, to create female structures for each individual tooth before a positive arch is cast from the negative impression. The base is then placed over a casting chamber containing the impression and the chamber is filled with epoxy. The female structures fill with epoxy and the resulting mold has male studs present on each tooth model to be later separated from the positive arch. For example, FIG. 31 shows a tooth model 2530 with male stud 2535 after mold separation. The base 2540 comprises a female feature 2545 that can receive the male stud 2535 when the tooth model 2530 is assembled to the base 2540.
[0266] In another variation, shown in FIG. 32, a tooth model 2550 includes a female socket 2555 that can be drilled by CNC based machining, for example, after casting and separation. A male stud 2560 that fits the female socket 2555 can be attached to the tooth model 2550 by for example, screwing or gluing. The resulting tooth model 2565 includes male stud 2560 that allows it to be attached to the base.
[0267] In some variations tooth models are provided with male protrusion features allowing the tooth models to be attached to a base. For example, FIG. 33 shows a tooth model 2570 having two pins 2575 sticking out and a base 2580 having registration slots 2585 adapted to receive the two pins 2575 to allow the tooth model 2570 to be attached to the base 2580. As another example, FIG. 34 shows a tooth model 2590 having one pin 2595 protruding out at an angle and a base 2600 having a hole 2605 adapted to receive pin 2595 to allow, the tooth model 2590 to be attached to the base 2600. As another example, FIG. 35 shows a tooth model 2610 having cone shaped studs 2615. Generally, the base will have a number of holes or receiving features complimentary to the number of male protrusions on the tooth models at the corresponding locations for each tooth model.
[0268] As shown FIG. 36, in variations in which tooth models 2620 are provided with studs 2625 the studs can take different shapes such as, for example, oval, rectangle, square, triangle, circle, and semi-circle. The shapes may be selected to correspond to slots on the base having identical shapes. Such slots can be drilled, for example, using CNC based machining. In some variations, studs that are asymmetrically shaped or protrude tilted at an angle to the tooth base can help to define a unique orientation for the tooth model on the base.
[0269] In some variations, as shown in FIG. 37A, a base 2630 has a plurality of sockets 2635 and 2640 for receiving the studs of a plurality of tooth models. The positions of the sockets 2635, 2640 may be determined, for example, by the initial positions of the teeth in a patient's arch or by tooth positions during an orthodontic treatment process. Base 2630 may be in the form, for example, of a plate comprising a plurality of pairs of sockets 2635, 2640 as shown in FIG. 37A. Each pair of sockets 2635, 2640 may be adapted to receive two pins associated with a physical tooth model. Each pair of sockets may include a socket 2635 on the inside of the tooth arch model and a socket 2640 on the outside of the tooth arch model.
[0270] Sockets 2635, 2640 may be drilled or milled, for example, by machining in accordance with a digital base model. The positions of the sockets 2635, 2640 may be specifically defined in the digital base model. Simulations may be done before hand to examine the interaction between the digital base model and digital tooth models to ensure the dental arch is as specified by the orthodontic treatment.
[0271] FIG. 37B shows a base 2645 according to another variation. A plurality of pairs of female sockets 2650, 2655 are provided in base 2645. Each pair of the sockets 2650, 2655 may be formed in a surface 2660 and may be adapted to receive a physical tooth model 2665. The bottom portion of physical tooth model 2665 includes a surface 2670. The surface 2670 makes contact with the surface 2660 when the physical tooth model 2665 is inserted into the base 2645, which assures the stability of the physical tooth model 2665 over the base 2645.
[0272] FIG. 38 shows one variation of a tooth model 2675 compatible with a base
2630 (FIG. 37A). Tooth model 2675 includes two pins 2680 connected to its bottom portion. The two pins 2680 can be plugged into a pair of sockets 2635 and 2640 on the base 2630. Thus each pair of sockets 2635 and 2640 may uniquely define the positions of a tooth model. The orientation of the tooth model may also be uniquely defined if the two pins are labeled as inside and outside, or the sockets and the pins are made asymmetric inside and outside. Each tooth model may include one or a plurality of studs or pins that are to be plugged into a corresponding number of sockets in a base. In some variations, male studs and corresponding sockets may take different shapes as described above. In some variations, a tooth model sits on a small surface milled in the base and features such as pins or studs prevent the tooth model from rotating or shifting.
[0273] A physical tooth arch model may be obtained, for example, by assembling tooth models on a base such as base 2630 (step 2525). In some variations, base 2630 may comprise a plurality of configurations of female sockets 2635 and 2640. In some variations, each of the configurations may be adapted to receive the same physical tooth models to form a different arrangement of at least a portion of a tooth arch model. [0274] In one variation bases such as base 2630 can be fabricated by a system that includes a computer device adapted to store digital tooth models representing the physical tooth models. As described above, the digital tooth models can be obtained by various scanning techniques. A computer processor may then generate a digital base model compatible with the digital tooth models. An apparatus fabricates the base using, for example, CNC based manufacturing in accordance with the digital base model. The base fabricated is adapted to receive the physical tooth models.
[0275] In one variation, features for receiving tooth models such as sockets or holes, for example, are formed in a base using laser-based technologies. For example, a laser beam may be focused precisely at the locations of the receiving features. The intensity and duration of the laser beam may then be controlled, for example, to heat, melt or vaporize the base material to form the receiving features.
[0276] As shown in FIG. 39, in one example the laser 2685 may be a carbon dioxide laser under CNC control. The laser beam 2690 may be focused on a base plate 2695 by an optical system 2700 comprising a pressurized gas inlet 2705. The cutting process may be automated by a computer 2710. The base plate 2695 may be transported by a transport system 2715 such as a motorized X-Y stage under the control of computer 2710, for example. The coordinates of female sockets 2720 may be input to the CNC machine. The coordinate information may be derived from the digital dental arch model and/or digital base models as previously described.
[0277] The base plate 2695 may be moved into positions allowing the laser beam to be focused at the intended locations where the sockets are to be made. A laser beam may be emitted under the control of the computer 2710 and focused at the intended locations. The laser beam 2690 may heat the illuminated areas on the base plate to cause heating, melting, ablation, and/or evaporation of the base plate material. The socket 2720 may be cut by the laser beam under the control of the computer 2710. A microscope may be mounted for examining the result of the cutting for minor refinement.
[0278] In one variation, the intensity and temporal duration of the emitted laser beam 2690 may be controlled according to the properties of the base plate 2695 so that the socket 2720 can be produced accurately in width, depth and shape. In another variation, the pins in the under side of physical tooth models may be shaped in accordance with the spatial profile of the emitted laser beam 2690. This may ensure that the pins affixed to the tooth models are compatible with and fit the sockets. In one example, the emitted laser beam 2690 may produce a cone shaped socket in the base plate 2695 and the tooth model may include cone shaped studs such as studs 2615 on tooth model 2610 shown in FIG. 35.
[0279] In another variation, a plurality of laser beams may be used to form the socket 2720. Different laser beam may include different intensity, frequencies, spatial profiles, and directions of illumination. For example, one laser may be used to burn a large hole and another laser may be used to cut fine features to the final shape of the socket.
[0280] In some variations, bases formed by laser fabrication technologies need no further finishing after the sockets are formed. Laser fabrication may have the advantage, in some variations, of not requiring physical contact with the base.
[0281] In some variations, the laser optics may include other arrangements. For example, a flying optics system may include mirrors that can scan the laser beam across a stationary base in two dimensions. In another example, a fixed optics system may keep the laser and optics stationary while the work piece is moved in both X and Y axes, as shown in FIG. 39. In another example, a hybrid system may move the laser and optics in one axis and the base in another axis.
[0282] In one variation physical tooth models may be labeled by a predetermined sequence that defines the positions of the physical tooth models on, for example, the base 2630. Such labels may include, but are not limited to, a barcode, a printed symbol, a hand¬ written symbol, and a Radio Frequency Identification (RPID). Female sockets such as sockets 2635, for example, may also be labeled by the parallel sequence for the physical tooth models.
[0283] In one variation, physical tooth models can be removed from a base, repaired or replaced, and re-assembled without the replacement of the whole arch model.
[0284] Tooth models may be fabricated from materials including, but not limited to, polymers, urethane, epoxy, plastics, plaster, stone, clay, acrylic, metals, wood, paper, ceramics, and porcelain. Bases may be fabricated from materials including, but not limited to, polymers, urethane, epoxy, plastics, plaster, stone, clay, acrylic, metals, wood, paper, ceramics, porcelain, glass, and concrete. [0285] In some variations a physical dental arch model may be used in dental applications such as, for example, dental crowns, dental bridges, aligner fabrication, biometrics, and teeth whitening. For aligner fabrication, for example, each stage of the teeth treatment may correspond to a unique physical dental arch model. Aligners may be fabricated, for example, using different physical dental arch models one at a time as tooth movement progresses during the treatment. In one variation, at each stage of the treatment the desired tooth positions for the next stage are determined. A physical dental arch model having modified teeth positions is fabricated using the process described above. A new aligner may be made using the new physical dental arch model.
[0286] In some variations physical models of a dental arch at different treatment stages may share the same tooth models. In some variations, each physical arch model may use a separate base. In other variations, one base may be used for two or more physical arch models. In some variations, a base may include a plurality of sets of receiving features for physical tooth models, with each set corresponding to a different treatment stage. For example, as shown in FIG. 40 a base 2725 may comprise multiple sets of sockets 2730, 2735, 2740, and 2745 each for receiving a dental arch in a different configuration. In some variations each configuration may be adapted to receive the same physical tooth models to form a different arrangement of a tooth arch model.
[0287] In some variations the base may be assembled from a plurality of base components. The base components may comprise features to assist the assembly of the base components to form the base for the dental arch model such as, for example, pins, registration slots, sockets, notches, protrusions, holes, interlocking mechanisms, jigs, and pluggable or attachable features. In one variation the base components may be individually replaced to form a different base configuration without changing the base components that are not changed in the orthodontic steps.
Acquiring Positions of Physical Tooth Models in a Tooth Arch Model
[0288] Examples and variations of methods and apparatus for acquiring the positions of physical tooth models in a tooth arch model are described below. In some variations the positions may be acquired using mechanical location devices. In other variations the positions may be acquired, for example, using optical or magnetic location devices. The position information may then be used in the production of the physical tooth arch model.
[0289] In one aspect, methods for producing a base configured to receive physical tooth models are described. These methods may comprise, for example, acquiring the coordinates of the physical tooth models in the physical dental arch model using a mechanical or an optical location device, determining the configurations of first features affixed to the physical tooth models, and determining the locations of second features in the base in accordance with the coordinates of the physical tooth models in the physical dental arch model and the configurations of the first features. The second features may be configured to receive the first features affixed to the physical tooth models.
[0290] The first features may be, for example, pins or studs. The second features may be, for example, sockets or holes adapted to receive pins or studs.
[0291] In another aspect, methods for producing a base configured to receive physical tooth models comprise acquiring the coordinates of the physical tooth models in the physical dental arch model from an impression of a patient's arch using a mechanical or an optical location device, and determining the locations of the physical tooth models in the base in accordance with the coordinates of the physical tooth models in the physical dental arch model.
[0292] In another aspect, methods for acquiring the coordinates of a patient's dental arch comprise obtaining an impression of the patient's arch, touching a point on the surface of the impression with a stylus connected to a plurality of rigidly connected marking objects, capturing an image of the plurality of rigidly connected marking objects, determining the coordinates of the marking objects, and using the coordinates of the marking objects to calculate the position of the stylus to obtain the coordinates of the point on the surface of the impression.
[0293] In yet another aspect, physical dental arch models are described. The physical dental arch models comprise one or more physical tooth models each including a tooth portion and two or more first features affixed to the bottom of the tooth portion, and a base including a plurality of second features configured to receive the first features affixed to the physical tooth models. The locations of the second features may be determined by the coordinates acquired from the impression of a patient arch using a mechanical or an optical location device.
[0294] The first features may be, for example, pins or studs. The second features may be, for example, sockets or holes adapted to receive pins or studs.
[0295] In some variations the use of mechanical or optical location devices to acquire the coordinates of physical tooth models in a physical dental arch allows the production of a physical base with socket positions accurately placed to receive the pins of physical tooth models in the physical dental arch model.
[0296] In one variation a method for producing a physical dental arch model generally includes the steps illustrated in FIG. 41. In some variations the order of these steps is altered, some of these steps are not included, and/or additional steps are included. In the process illustrated in FIG. 41, in step 2800 the positions of physical tooth models in a tooth arch model are acquired using a mechanical location device. An individual tooth model is created in step 2805. An individual tooth model is a physical model that can be part of a physical tooth arch model. In step 2810 registration features are added to the individual tooth model to allow it to be attached to another individual tooth model or to a base. In some variations steps 2805 and 2810 happen together, making a separate step 2810 optional. In step 2815 the tooth model positions acquired in step 2800 are used to design a base having features such as sockets, for example, for receiving the tooth models. Step 2815 may precede steps 2805 and 2810 in some variations. The base is fabricated in step 2820. In step 2825 the tooth models are attached to the base.
[0297] In the process of FIG. 41, steps 2805 - 2825 may be substantially similar to corresponding steps in the process of FIG. 30 discussed above. Consequently, only step 2800 is now described.
[0298] In one variation a dental impression 2830 of a patient's arch may be made using, for example, a pre-designed container 2835, as shown in FIG. 42. The impression may be fixed in the container using an epoxy, for example. The relative positions of the patient's teeth may be measured off the impression using a mechanical location device 2840. An example of a mechanical location device is the Microscribe available from Immersion Corporation. Microscribe is a hand-held 3D digitizer that can develop a digital computer model for an existing 3D object. Other 3D digitizers that can be use to create three-dimensional digital representations of physical objects may also be suitable.
[0299] As shown in FIG. 42, in one variation the mechanical location device 2840 may include mechanical arms 2845, 2850 having one or more mechanical joints 2855. Mechanical joints 2855 may be equipped with precision bearings for smooth manipulation and internal digital optical sensors for decoding the motion and rotation of the mechanical arms 2845, 2850. The end segment may be a stylus 2857 that can be manipulated to touch points on the dental impression 2830 held in the container 2835. The mechanical location device 2840 may be fixed to a common platform with the container 2835.
[0300] In one variation, accurate 3D positional and angular information of the points that the stylus touches may be decoded and output at an electronic output port 2860. In some variations, information about six degrees of freedom may be obtained by an additional decoder for self-rotation of the stylus. Additional sensors may be placed at the tip of the stylus to measure the hardness of the surface of the object measured. Immersion Corporation's MicroScribe uses a pointed stylus attached to a CMM-type device to produce an accuracy of .009 inches, for example.
[0301] In one variation a user selects points of interest at each tooth position in the impression and places the stylus at those points. Positional and angular information may be decoded and then transmitted to a computer. In this way, Cartesian XYZ coordinates may be acquired, for example, for each tooth or for each first feature (e.g., pin or stud) location and orientation.
[0302] In some variations, a user may establish a coordinate system based on the container or chamber in which the arch impression is held. The user may establish this system by taking readings for two points on two sides of the container to define the x axis. Another reading on the plane establishes the x-y plane. An origin may then be determined on the x-y plane. The z axis may be established by taking the cross product of the x and y axes.
[0303] In some variations a user selects a plurality of points on the surfaces of the arch impression corresponding to each tooth. The 3D points measured from the impression surfaces may then be interpolated to create surfaces and solids integrated into an overall digital model. The number of points defining the curves and the number of curves depends on the desired resolution in the model. In some variations, surfacing functions offered by the design application software may be used to create and blend the model surfaces. For example, the model may be shaded or rendered, defined as a solid or animated depending on the designer's intentions. The teeth in the digital model may be labeled so that the order of the physical tooth models can be properly defined for the physical dental arch model. In some variations, readings acquired by the stylus can be rendered in real time to allow the user to visualize the digital tooth models. Optionally, the coordinate axes and points may be rendered in the software using different colored cylinders/spheres etc. so as to distinguish the different meanings of values.
[0304] In one variation, for each tooth the user will first take a reading that will establish the center of two pins on or to be attached to the tooth and their orientation vector. Then the user will take two more points that will give the direction to move from the center of the pins. The dimensions and positions of the two pins may be calculated using these values. The pins may then be visually rendered in the software. The user may fine tune these readings as required. After the readings for each pin have been acquired, their locations and orientations may be saved
[0305] In some variations, a digital arch model including a plurality of digital tooth models is developed based on the locations and orientations of features such as, for example, pins or studs and/or on the coordinates of physical tooth models acquired by the mechanical location device. The digital arch model may be used, for example, to control CNC based drilling or milling of features (e.g., holes or sockets) in a base to receive features such as, for example, pins or studs on physical tooth models in a physical dental arch model.
[0306] One example of a detailed process for defining pin locations is as follows: 1) establish a new coordinate system based on the arch impression-container chamber, a) take 3D coordinate readings for two points (on the left and right side of the container) that will establish the x axis, b) take a number of readings on the plane that will be the x-y plane, c) calculate the circumcenter of these two sets of points on each side, d) find the midpoint of the circumcenter and mark it as the origin, e) establish the y axis by taking the perpendicular bisector of this line segment, f) establish the z axis by taking the cross product of the x and y axes; 2) find the highest point inside the container chamber ,a) take readings for many points on the impression, b) use the max value of z as the highest point; 3) acquire the pin readings for each tooth in the arch impression, a) take a reading that will establish the center of the two pins, and their orientation vector, b) take two more points that will give the direction to move from the center of the pins, c) calculate the dimensions and positions of two pins using the values above, and visually render the pins in the software, d) allow the user to fine tune these readings as required; 4) save the data in any of a number of formats including, but not limited to, csv (comma separated), XML, database based, or plain text file.
[0307] In another variation, a method for producing a physical dental arch model generally includes the steps illustrated in FIG. 43. In some variations the order of these steps is altered, some of these steps are not included, and/or additional steps are included. In the process illustrated in FIG. 43, in step 2865 the positions of physical tooth models in a tooth arch model are acquired using an optical location device. An individual tooth model is created in step 2870. In step 2875 registration features are added to the individual tooth model to allow it to be attached to another individual tooth model or to a base. In some variations steps 2870 and 2875 happen together, making a separate step 2875 optional. In step 2880 the tooth model positions acquired in step 2865 are used to design a base having features such as sockets, for example, for receiving the tooth models. Step 2880 may precede steps 2870 and 2875 in some variations. The base is fabricated in step 2885. In step 2890 the tooth models are attached to the base.
[0308] In the process of FIG. 43, steps 2870 - 2890 may be substantially similar to corresponding steps in the process of FIG. 41 discussed above. Consequently, only step 2865 is now described.
[0309] In one variation an impression 2895 of a patient's tooth arch is obtained and held in a container 2900, as shown in FIG. 44. The relative positions of the patient's teeth, for example, may be measured off impression 2895 using an optical location system 2905 comprising, for example, a location device 2910 and a camera system 2915. In one variation location device 2910 comprises, for example, three marking objects 2920, 2925, and 2930 that are connected by "T" shaped linking arms 2935. Marking objects 2920, 2925, 2930 may be shaped, for example, as spheres, boxes, or triangles and may be of different shapes and colors for ease of pattern recognition. For example, the marking objects may be balls of different colors such as, for example, red, green and black. Location device 2910 also comprises a stylus 2940 that may be placed in contact with the surface of the impression 2895. The six degrees of freedom of the location device 2910 may be obtained by various techniques.
[0310] As shown in FIG. 44, in one variation the tip of stylus 2940 is brought in contact with a point on the impression surface and camera system 2915 captures images of the location device 2910. Camera system 2915 may include a plurality of cameras that point at location device 2910 from different viewing angles. The positions and orientations of the "T" shaped linking arms 2935, and thus the location and orientation of stylus 2940 as well as the location of the point in impression 2895 it contacts, may be obtained by image analysis. For example, the center of each marking object 2920, 2925, 2930 may be determined and the coordinates of marking objects 2920, 2925, 2930 obtained using triangulation techniques. The "T" shape of linking arms 2935 may be reconstructed. Distances may be derived by pattern recognition. The tip of stylus 2940 may then be moved to a different point on the surface of impression 2895 and images of location device 2910 again captured and analyzed. In this way coordinates may be acquired, for example, for the surfaces of the teeth in impression 2895 and/or for each first feature (e.g., pin or stud).
[0311] In another variation, the image analysis and processing may include a search for a specific object in a binary image including objects of various shapes, positions, and orientations. Such a search is often referred to as "chamfer matching." Chamfer matching uses an edge matching technique in which the edge points of one image are transformed by a set of parametric transformation equations to edge points of a similar image that is slightly different. For example, spherically shaped marking objects may be fit to pre¬ designed circles in the image. The positions of the marking objects 2920, 2925, 2930 may be obtained exactly using chamfer matching. These positions may be used to determine the position of the tip of the stylus 2940 on the surface of the dental impression 2895.
[0312] The captured images may contain noise in some variations. The noise, which may affect the accuracy of coordinate calculations, may be removed by several techniques such as, for example, transparent pen. Care should be taken to avoid producing artificial information with the noise removal process, as that may also affect the accuracy of calculations. [0313] In another variation, markers that reflect infra-red (IR) light may be attached to the marking objects 2920, 2925, 2930, and light emitting diodes (LEDs) that emit IR light may be mounted on or near one or more cameras to illuminate the marking objects. The camera lenses may be shielded with IR pass filters. The light emitted from the LEDs is reflected by the markers and then captured by the cameras. The centers of the marker images may be matched from the various camera views using triangulation to compute their frame-to-frame positions in 3D space. The coordinates of the markers and hence of the stylus may then be calculated. In one variation seven video cameras connected to a computer image marking objects that may have seven or more reflective markers attached.
[0314] In another variation, the marking objects 2920, 2925, 2930 may be marked by reflectors that reflect light in visible wavelengths. The reflectors serve as reference points in the successive images to assist in tracking the movement of the marking objects.
[0315] In yet another variation, a magnetic motion capture system is used to track the locations of the marking objects. Magnets and magnetic sensors may be attached to each of the marking objects 2920, 2925, 2930. The magnets and the sensors may be connected with cables to a magnetic motion tracking system. The sensors detect low- frequency magnetic fields generated by the magnets. The detected signals may be used to calculate the locations of the transmitting sources, that is, the magnets. Positional and rotational information about the balls can be obtained, stored, and displayed by a computer system, for example. In one variation a magnetic motion tracking system includes six or more sensors per marking object.
[0316] Similarly to as described above with respect to FIG. 41, a digital arch model including a plurality of digital tooth models may be developed based on the locations and orientations of features such as, for example, pins or studs and/or on the coordinates of physical tooth models acquired by the location device. The digital arch model may then be used, for example, to control CNC based manufacturing of a base to receive physical tooth models in a physical dental arch model.
Adjustment Jigs and Adjustable Tooth Models
[0317] Examples and variations of methods and apparatus for adjusting the positions of physical tooth models in a physical model of a dental arch are described below. [0318] In one aspect, methods for producing a physical dental arch model having one or more physical tooth models are described. The methods may comprise, for example, producing a digital base model compatible with the physical tooth models, producing a base having receiving features using CNC based manufacturing in accordance with the digital base model, producing adjustment jigs, and assembling the physical tooth models and adjustment jigs with the base at the receiving features to form the physical dental arch model.
[0319] In another aspect, methods for producing a physical dental arch model having one or more adjustable physical tooth models are described. The methods may comprise, for example, providing a universal joint including an inner rotative joint member and an outer joint member housing the inner rotative joint member, attaching one of the inner rotative joint member and the outer joint member to a receiving feature on a base, attaching a physical tooth model to another one of the inner rotative joint member and the outer joint member of the universal joint; and rotating the physical tooth model relative to the base.
[0320] In another aspect, systems for producing a physical dental arch model are described. The systems may comprise, for example, a computer storage device adapted to store digital tooth models for the physical tooth models, a computer processor that is capable of generating a digital base model compatible with the digital tooth models, and an apparatus that can fabricate the base having receiving features using CNC based manufacturing in accordance with the digital base model. The physical tooth models can be assembled with adjustment jigs at the receiving features of the base to form the physical dental arch model.
[0321] In another aspect, physical dental arch models are described. The physical dental arch models may comprise, for example, a base having receiving features, physical tooth models associated with the receiving features on the base, and adjustment jigs adapted to be assembled with the physical tooth models at the receiving features of the base. The physical dental arch models may also comprise, for example, an adjustment jig configured to receive a physical tooth model and to enable rotations of the physical tooth model around at least two separate axes, and a base configured to receive the adjustment jig such that the physical tooth model can rotate relative to the base around at least the two separate axes. The physical dental arch models may also comprise, for example, a universal joint including an inner rotative joint member and an outer joint member housing the inner rotative joint member, a base configured to receive one of the inner rotative joint member and the outer joint member, and a physical tooth model to be attached to another one of the inner rotative joint member and the outer joint member such that the physical tooth model can rotate relative to the base.
[0322] Implementations may include one or more of the following. A method for producing a physical dental arch model having one or more physical tooth models may include producing a digital base model compatible with the physical tooth models, producing a base having receiving features using CNC based manufacturing in accordance with the digital base model, producing adjustment jigs, and assembling the physical tooth models and adjustment jigs with the base at the receiving features to form the physical dental arch model. The adjustment jigs may be capable of adjusting one or more translational and/or rotational degrees of freedom of the physical tooth models. In one variation, an adjustment jig comprises a universal joint.
[0323] In some variations, a physical tooth model may be associated with one or more jigs at a receiving feature of the base. Two jigs at a receiving feature of the base may adjust a combination of translational and/or rotational degrees of freedom of the physical tooth models. Rotational adjustment may be achieved in combination with translational adjustment to allow flexible adjustment of the physical tooth models in all six degrees of freedom. In some variations, the jigs may be labeled in accordance with the degrees of freedom and the extent of the adjustment they can make to the position or orientation of physical tooth models.
[0324] In some variations physical tooth models can be assembled in two or more different configurations on the same base by using sets of jigs corresponding to the different configurations. The different tooth configurations may correspond, for example, to different stages of an orthodontic treatment process. This may reduce the cost of making tooth arch models for orthodontic treatments.
[0325] Implementations may also include one or more of the following. A system for producing a physical dental arch model having one or more physical tooth models may comprise a computer storage device adapted to store digital tooth models for the physical tooth models, a computer processor that is capable of generating a digital base model compatible with the digital tooth models, and an apparatus that can fabricate the base having receiving features using CNC based manufacturing in accordance with the digital base model. The physical tooth models may be assembled with adjustment jigs at the receiving features of the base to form the physical dental arch model. The adjustment jigs may be capable of adjusting the translational or rotational degrees of freedom of the physical tooth models over the base. The system may further comprise a device that is capable of fabricating the adjustment jigs to be assembled with the physical tooth models at the receiving features of the base.
[0326] In one variation a method for producing a physical dental arch model generally includes the steps illustrated in FIG. 45. In some variations the order of these steps is altered, some of these steps are not included, and/or additional steps are included. In the process illustrated in FIG. 45, an individual tooth model is created in step 3000. In step 3005 registration features are added to the individual tooth model to allow it to be attached to another individual tooth model or to a base. In some variations steps 3000 and 3005 happen together, making a separate step 3005 optional. In step 3010 a base is designed for receiving the tooth model. Step 3010 may precede steps 3000 and 3005 in some variations. In step 3015 the tooth model positions in a tooth arch model are determined. In some variations this step may precede steps 3000, 3005, and 3010. A base including features for receiving the individual tooth models is fabricated in step 3020. Step 3020 may precede steps 3000 and 3005 in some variations. In step 3025 adjustment jigs are fabricated. In step 3030 the orientations and micro-positions of the tooth models in the tooth arch model are determined so that appropriate jigs can be selected for each tooth model. In step 3035 the tooth models are attached to the base with adjustment jigs to form the tooth arch model.
[0327] In the process of FIG. 45, steps 3000-3020 may be substantially similar to corresponding steps in the process of FIG. 30 discussed above. Consequently, only the fabrication and use of adjustment jigs is now described.
[0328] The positions and orientations of physical tooth models in a physical model of a dental arch may need to be adjusted during an orthodontic treatment process. These adjustments may be achieved by using adjustment jigs that are assembled between the tooth models and the base. In one variation, an adjustment jig is a device that includes a first feature that allows it to be attached or plugged to a base and a second feature that allows it to receive a physical tooth model. Such attachment features may include, but are not limited to, pins, slots, notches, protrusions, holes, and interlocking mechanisms. A physical tooth model attached to a base via such an adjustment jig may have a position and/or orientation altered compared to that which would result from attaching the physical tooth model directly to the base.
[0329] In one variation, adjustment jigs may be fabricated using CNC based manufacturing. For example, once desired tooth positions and orientations are known they may be input into a digital arch model and used to drive CNC fabrication of the jigs. Each adjustment jig may be fabricated to provide a specific combination of positional and orientational adjustment.
[0330] Adjustment jigs may take various forms. Some example adjustment jigs, according to one variation, are shown in FIG. 46A-46D. FIG. 46A shows an adjustment jig 3040 comprising a body portion 3045, two pins 3050 (first feature) connected to the bottom of the body portion 3045, and two pins 3055 (second feature) connected to the top of the body portion 3045. The pins 3050 may be plugged, for example, into sockets 2635, 2640 on base 2630 shown in FIG. 37A discussed above. Pins 3055 are adapted to be plugged, for example, into sockets made in the bottom of a physical tooth model. Adjustment jig 3040 provides a physical tooth model an upward positional translation (i.e. extrusion), compared to an average height, without rotational adjustment. Similarly, adjustment jig 3060 shown in FIG. 46B provides a tooth model a downward positional translation (i.e. intrusion), compared to an average height, without rotational adjustment. Adjustment jig 3065 shown in FIG. 46C provides a tooth model a tipping rotation off the vertical axis. Adjustment jig 3070 shown in FIG. 46D provides a tooth model a combination of a tipping rotation off the vertical axis and a torsional rotation around the vertical axis.
[0331] In another variation, adjustment jigs may include studs 3080 as shown in
FIG. 47. Rotational adjustment of tooth models may be achieved by studs 3080 that may be plugged into the sockets on a base 3085 at the low ends. The upper ends of the studs 3080 may be plugged into sockets in physical tooth models to assemble the tooth models to the base with a desired rotational adjustment.
[0332] FIG. 48 illustrates adjustment jigs according to another variation. In FIG.
48 adjustment jigs 3090, 3095, 3100 provide different increments of translational adjustments. In this variation, translational adjustments may be along one-dimension or two dimensions. Adjustment jigs 3090, 3095, 3100 may be used in combination with adjustment jigs 3040, 3060, 3065, 3070, and studs 3080.
[0333] FIG. 49 shows a rotational adjustment jig 3105 according to another variation. Rotational adjustment jig 3105 may be used, for example, alone or in combination with other adjustment jigs. For example, FIG. 49 shows rotational adjustment jig 3105 mounted on top of a translational adjustment jig 31 10.
[0334] A tooth arch model may be obtained, for example, by plugging adjustment jigs or combinations of adjustment jigs into sockets in a base, and then attaching physical tooth models to the adjustment jigs. In some variations adjustment jigs may be shared by different tooth models in a tooth arch model and/or shared between different stages of an orthodontic treatment.
[0335] In one variation adjustment jigs may be labeled as to their degree of adjustment by, for example, a barcode, a printed symbol, a hand-written symbol, or a Radio Frequency Identification (RFID). Corresponding sockets in a base may also be labeled by the parallel sequence for the physical tooth models.
[0336] In some variations, a treatment plan specifies the exact positional and orientational adjustments for each tooth model. Appropriate adjustment jigs may be used for each physical tooth model at each receiving location on the base to realize the specified positional and orientational adjustments. This capability may reduce the need for making different tooth arch model at each stage of the orthodontic treatment, and thus may reduce the cost of the treatment.
[0337] In another variation, shown in FIG. 50, an adjustment jig 31 15 may include a universal joint 3120 mounted on a translation stage 3125. Translation stage 3125 may be attached to a physical base comprising, for example, one or more receiving features configured to receive the adjustment jig. The receiving features may include, but are not limited to, pins, slots, notches, protrusions, holes, interlocking mechanisms, and other pluggable or attachable feature. The combination of the universal joint 3120 and the translation stage 3125 may enable the physical tooth model to be adjusted with six degrees of freedom relative to the base as well as relative to adjacent physical tooth models in the physical dental arch model. [0338] In the example of FIG. 50, the universal joint 3120 includes an inner rotative joint member 3130 and an outer joint member 3135 that houses the inner rotative joint member 3130. The inner rotative joint member 3130 comprises a spherical outer surface. The inner rotative joint member 3130 is affixed with a pin or handle 3140 that is adapted to be attached to a physical tooth model. The physical tooth model may include features to assist the physical tooth model to be mounted on the adjustment jig. The features may include, but are not limited to, pins, slots, notches, protrusions, holes, interlocking mechanisms, and other pluggable or attachable features.
[0339] In the example of FIG. 50, the outer joint member 3135 may be a shell having a spherical inner surface that is adapted to make contact with the spherical outer surface of the inner rotative joint member 3130. This may allow flexible rotation of the inner rotative joint member 3130 and the associated tooth model attached to it. The rotational adjustment may include polar rotations, azimuthal rotations, and self rotations around the pin or handle 3140. This allows orientational adjustment of the physical tooth model relative to the base. After a rotational adjustment is made, the inner rotative joint member 3130 may be clamped to the outer joint member 3135 by clamp mechanism 3145 to stop their relative rotation. The translational movement may be similarly stopped by, for example, set screws.
[0340] In another variation, outer joint member 3135 may be attached to a physical tooth model and inner rotative joint member 3130 may be attached to the base or to the translation stage 3125. The orientations of the physical tooth model may be adjusted relative to the base similarly to as described above.
[0341] In one variation, the degree of orientational and positional adjustments of the physical tooth models may be measured and calibrated with precision position measurement devices such as, for example, the Microscribe available from Immersion Corporation. Adjustments may be made, for example, in accordance with a digital dental arch model that defines the rigid-body rotations and translations necessary for each physical tooth model at each step of the treatment. A digital dental arch model may also allow simulations of the adjustments and prevention of interference between adjacent tooth models. [0342] In one variation, the physical tooth models, their associated adjustment jigs, and the corresponding receiving features on the base may be labeled in accordance with a predetermined configuration of physical tooth models in the physical dental arch model. The receiving features on the base correspond to teeth in the patient's arch. Physically, the receiving features may be defined by their positions on the base. The adjustment jigs and the physical tooth models may be tagged, for example, by alphanumerical symbols, barcodes and/or Radio Frequency Identification (RFID) which define the correspondence of the jigs to the patient's teeth. The physical tooth models and their associated adjustment jigs may later be assembled to the corresponding receiving features on the base in accordance with the predetermined configuration of physical tooth models in the physical dental arch model. The adjustment jigs may also allow the physical models to be adjusted or reassembled in accordance with another configuration of physical tooth models in the physical dental arch model.
[0343] In one variation, the fabrication of the physical tooth models may include the use of their associated adjustment jigs to ensure compatibility and precision in the assembling of the physical arch model. For example, when a physical tooth model is being molded in a casting chamber, a universal joint may be directly inserted into the casting material using specially designed lids for the casting chamber.
[0344] In another variation, the physical tooth models, the adjustment jigs having the universal joint, and the base having the receiving features may all be included in a combined digital model. This may be accomplished, for example, using CAD software. The model may be segmented into CNC manufacturable components. The compatibility between the segmented components may be simulated prior to their manufacture. The physical dental arch model may then be obtained by assembling the fabricated components.
Selecting Pin Configurations, Tooth Positions, and/or Tooth Orientations to Avoid Interference between Tooth Models
[0345] One issue with assembling physical tooth models into a physical dental arch model is that adjacent physical tooth models may sometimes interfere with each other. Such interference may occur, for example, between tooth portions of two neighboring tooth models when they are inserted into a base plate or between pins on the tooth models used to attach the tooth models to a base. Examples and variations of methods and apparatus for avoiding interference between physical tooth models in a physical dental arch model are described below.
[0346] In one aspect, methods for producing a physical arch model are described.
The methods may comprise, for example, determining the positions and orientations of two adjacent physical tooth models in the physical dental arch model, and selecting the configurations of pins to be affixed to the bottoms of the two adjacent physical tooth models such that the two adjacent physical tooth models do not interfere with each other when the two physical tooth models are mounted to a base by inserting the pins into corresponding sockets in the base.
[0347] The methods may also comprise, for example, determining the positions and orientations of a first physical tooth model, determining the positions and orientations of a second physical tooth model that is adjacent to the first physical tooth model, checking for interference between the first physical tooth model and the second physical tooth model, modifying the positions and orientations of at least one of the physical tooth models to prevent interference if interference is detected, and fabricating the first physical tooth model and the second physical tooth model in accordance with the modified positions and orientations of the first physical tooth model and/or the second physical tooth model.
[0348] The methods may also comprise, for example, producing a digital dental arch model that simulates the positions and orientations of a first physical tooth model and the positions and orientations of a second physical tooth model that is adjacent to the first physical tooth model, checking for interference between the first physical tooth model and the second physical tooth model, modifying the positions and orientations of at least one of the physical tooth models in the digital dental arch model to prevent interference if interference is detected, and fabricating the first physical tooth model and the second physical tooth model in accordance with the modified digital arch model.
[0349] The methods may also comprise, for example, producing a digital dental arch model that simulates the positions and orientations of a first physical tooth model and the positions and orientations of a second physical tooth model that is adjacent to the first physical tooth model, where the physical tooth models include mounting features allowing them to be mounted to a base, checking for interference between the physical tooth models, modifying the configurations of the mounting features of one or both of the physical tooth models to prevent interference if interference is detected, and fabricating the physical tooth models including the mounting features in accordance with the modified digital arch model.
[0350] In another aspect, physical dental arch models are described. The physical dental arch models may comprise, for example, a base comprising a plurality of sockets that are configured to receive physical tooth models, and two physical tooth models each comprising a tooth portion and two or more pins affixed to the bottom of the tooth portion. Pins of the two physical tooth models are configured to prevent interference between the two physical tooth models when they are inserted in the base.
[0351] In some variations, the positions and the orientations of tooth models may be iteratively modified until all interference between adjacent tooth models in an arch model are removed before the physical tooth models are fabricated.
[0352] Some variations may enable adjacent physical tooth models in a physical dental arch model to be assembled without interference between the tooth models. This may result in the positions and orientations of the tooth models more accurately representing desired configurations in orthodontic treatments.
[0353] In some variations pin configurations on physical tooth models may be modified to prevent interference without otherwise changing the physical tooth models. This may allow physical tooth models to be reused as tooth positions are changed during a treatment process. Reuse of physical tooth models may reduce the cost of making physical tooth arch models in some variations.
[0354] In some variations receiving features in a base may be modified to receive tooth models having different pin configurations to avoid interference between adjacent tooth models in a tooth arch model and/or to avoid interference during insertion of the physical tooth models.
[0355] In one variation a method for producing a physical dental arch model generally includes the steps illustrated in FIG. 51. In some variations the order of these steps is altered, some of these steps are not included, and/or additional steps are included. In the process illustrated in FIG. 51, an individual tooth model is created in step 3200. In step 3205 registration features such as pins, for example, are added to the individual tooth model to allow it to be attached to another individual tooth model or to a base. In some variations steps 3200 and 3205 happen together, making a separate step 3205 optional. In step 3210 a base is designed for receiving the tooth model. Step 3210 may precede steps 3200 and 3205 in some variations. In step 3215 the tooth model positions in a tooth arch model are determined. In some variations this step may precede steps 3200, 3205, and 3210. In step 3220 some or all adjacent tooth models are checked to determine if they will interfere with each other during or after being mounted on a base to form a tooth arch. If no interference is detected, the process skips to step 3230. If interference is detected in step 3220, then in step 3225 the configurations of features on the physical tooth models such as pins, for example may be selected and/or modified to prevent the interference. A base including features for receiving the individual tooth models is fabricated in step 3230. In step 3235 the tooth models are attached to the base.
[0356] In the process of FIG. 51 , steps 3200-3215 and 3230-3235 may be substantially similar to corresponding steps in the process of FIG. 30 described above. Consequently, only the detection and prevention of interference between physical tooth models is now described.
[0357] In one variation, in step 3220 some or all pairs of adjacent tooth models in a digital dental arch model are examined to detect or predict interference or collision between teeth in the arch. Such interference or collision may occur, for example, between physical tooth models and/or between features such as pins, for example, affixed to the physical tooth models to allow attachment of the physical tooth models to a base to form the dental arch.
[0358] For example, FIG. 52 shows two interfering physical tooth models 3240 and
3245. An orthodontic treatment requires physical tooth models 3240 and 3245 to tilt away from each other. As a result, pins 3250 on tooth model 3240 and pins 3255 on tooth model 3245 interfere or collide with each other. In another example, shown in FIG. 53, two adjacent tooth models 3250 and 3265 are required to tilt toward each other by an orthodontic treatment. Tooth models 3250 and 3265 may collide with each other when they are inserted into a base 3270 because of the required insertion angles.
[0359] In one variation, if interference between tooth models is detected, then in step 3225 the configurations of the features used to attach the physical tooth models to the base may be selected and/or modified to avoid the interference. For example, the lengths, positions, orientations, and number of pins affixed to the tooth models may be adjusted to avoid interference. In some variations, adjustment of the configurations of features on the tooth models to avoid interference may be an iterative process.
[0360] The configurations of pins or other features used to attach physical tooth models to a base may be selected or modified by various methods to prevent interference between tooth models. In one variation, a digital dental arch model that represents the physical tooth model is first produced or received. The digital dental arch model defines the positions and orientations of the tooth models in the physical dental arch model. These positions and orientations may be in accordance, for example, with the requirements of an orthodontic treatment. The positions of the physical tooth models including the pins or similar features may be simulated to examine the interference between adjacent physical tooth models mounted on a base. The pin configurations in the digital model may be adjusted to avoid any interference that might occur in the simulation. In one variation, physical tooth models having the selected pin configurations may be fabricated by Computer Numerical Control (CNC) based manufacturing in accordance with the digital dental arch model.
[0361] For example, FIG. 54 illustrates a tooth model 3275 having two pins 3280 and 3285 affixed to its bottom portion. To prevent interference between tooth model 3275 and neighboring tooth models, the pins 3280 and 3285 are designed to have different lengths. FIG. 55A and FIG. 55B are two perspective views showing how the pin configuration shown in FIG. 54 may prevent interference between two tooth models. FIG. 55A shows a front perspective view of tooth model 3290 including pins 3295 and tooth model 3300 including pins 3305. Pins 3295 and pins 3305 are configured to have different lengths so that they do not collide with each other when they are inserted into a base (not shown). FIG. 55B is a bottom perspective view of the same pair of tooth models.
[0362] In another variation, physical tooth models may include retractable or removable pins. In the example of FIG. 56, for example, a tooth model 3310 is placed on a flat surface 3315 in a recess created in a base 3320. Base 3320 includes through holes 3325 and 3330. Tooth model 3310 includes in its bottom portion holes 3335 and 3340 that are in registration and alignment with through holes 3325 and 3330. Pins 3345 may be inserted along directions 3350, 3355 into through holes 3325 and 3330 in the base and into holes 3335 and 3340 in the physical tooth model to affix the tooth model 3310 to the base 3320. Using removable pins may avoid interference during or after installation of the tooth model on a base.
[0363] In another variation, the features affixed to a physical tooth model to allow the physical tooth model to be attached to a base may include a spring loaded pin mechanism. In the example shown in FIG. 57, tooth model 3360 includes holes 3365 and spring-loaded mechanisms 3370. Pins 3375 may be inserted into holes 3365 and spring load mechanisms 3370. Pins 3375 are retractable with compressed springs to avoid interference during or after installation of the tooth model on a base. After the tooth models are properly mounted and fixed, the pins 3375 may extend to their normal positions to maximize position and angle control. The overall pin lengths may be cut to be compatible with the spring load mechanisms to prevent interference between tooth models.
[0364] In another variation, the features affixed to a physical tooth model to allow the physical tooth model to be attached to a base may include spring loaded pin mechanisms having pins of different lengths. In FIG. 58, for example, tooth model 3380 includes retractable pins 3375 and 3385 of different lengths. Using pins of different lengths may avoid interference during or after installation of the tooth model on a base.
[0365] In another variation, the features affixed to a physical tooth model to allow the physical tooth model to be attached to a base may include spring loaded pin mechanisms having tilted pins. In FIG. 59, for example, tooth model 3390 includes retractable pins 3395 inserted into holes 3400 and spring-loaded mechanisms 3405 at an angle relative to the bottom of the tooth model. Inserting pins 3395 at such an angle may avoid interference during or after installation of the tooth model on a base.
[0366] In some variations, the ability to select or modify pin configurations to prevent interference between tooth models may allow the use of longer pins and result in a more stable physical tooth arch model.
[0367] In some variations, modular sockets may be prepared on the undersides of physical tooth models. Pins of different lengths may be plugged into the sockets to prevent interference between adjacent tooth models.
[0368] In some variations, the methods described above are also applicable to prevent tooth model interference in precision mount of tooth models in casting chambers. In such cases, the shape and the height of the tooth models may be modified to avoid interference of teeth during insertion or at the corresponding treatment positions.
Apparatuses and Methods for Casting Physical Tooth Models
[0369] Examples and variations of apparatus and methods for casting physical tooth models are described below. In one example, the apparatus comprises: a chamber body having a cavity adapted to hold the negative impression of the patient's tooth and to receive a cast material; and a chamber lid configured to seal the cast material in the casting chamber to permit the casting material to solidify in the casting chamber thereby forming a physical tooth model representing the patient's tooth. In one variation, the apparatus further includes a plurality of registration features (e.g., pins) arranged to correspond to the tooth arch, wherein each of the teeth in the tooth arch has at least one corresponding registration feature. Once a positive tooth arch (i.e., a physical tooth model) is cast within the negative impression, the each of the registration features is associated (e.g., portion of the registration feature is embedded within the positive tooth arch) with a corresponding tooth in the positive tooth arch.
[0370] In another variation, the casting chamber for casting a physical tooth model representing a patient's tooth comprises: a chamber body having a cavity adapted to hold the negative impression of the patient's tooth and to receive a cast material and chamber walls surrounding the cavity, wherein the negative impression and the chamber body are registered by a registration unit; and a chamber lid configured to seal the cast material in the casting chamber to permit the casting material to solidify in the casting chamber thereby forming a physical tooth model representing the patient's tooth.
[0371] In another aspect, a method for producing a physical tooth model is described. In one variation the method comprises: holding a negative impression of a patient's tooth in a casting chamber by a registration unit; pouring a cast material over the negative impression of the patient's tooth; and solidifying the cast material to produce the physical tooth model.
[0372] In another variation, the method for producing a physical tooth model comprises receiving a negative impression of a patient's tooth in a casting chamber; pouring a casting material over the negative impression of the patient's tooth; solidifying the casting material wherein the casting material is attached to the lid of the casting chamber; and cutting a tooth portion off the solidified casting material to produce a reference base portion of the casting material attached to the lid of the casting chamber, wherein the reference base is configured to mold the physical tooth model.
[0373] In another aspect, the method for producing a physical tooth model comprises receiving a negative impression of a patient's tooth in a casting chamber; pouring a casting material over the negative impression of the patient's tooth; solidifying the casting material wherein the casting material is attached to the lid of the casting chamber; cutting a tooth portion off the solidified casting material to produce a reference base attached to the lid of the casting chamber, and producing first features in the reference base to assist the molding of the physical tooth model having second features complimentary to the first features using the reference base.
[0374] In yet another aspect, a casting system for producing a physical tooth model, is described. In one variation, the system comprises a casting chamber configured to hold a negative impression of a patient's tooth and to receive casting material that can subsequently solidify in the casting chamber; a chamber lid configured to hold the solidified casting material and to produce a reference base by cutting off the tooth portion, wherein the reference base is adapted to mold the physical tooth model.
[0375] Variations may include one or more of the following features. In one variation the casting system is configured for molding a reference base (e.g., gum portion) and using the reference base to mold a physical tooth model. The reference base can include features to allow the fabrication of features in the physical tooth model to allow the physical tooth model to be fixed to a base. The reference base also serves as position reference for precisely locating the features on the physical tooth model as required by orthodontic treatment.
[0376] In one variation, the same physical tooth models can be used to form different tooth arch model having different teeth configurations. The tooth models can be reused as tooth positions are changed during a treatment process. Much of the cost of making multiple tooth arch models in orthodontic treatment is therefore eliminated
[0377] Variations may include one or more of the following features. In one variation, the apparatus and method allows physical tooth models be produced inexpensively and reliably in a simple system with minimal parts. In another variation, the physical tooth models are molded to the correct shape including features to allow them to be inserted, attached, or plugged to a dental base. In another variation, the physical tooth models can be pre-fabricated having standard registration and attaching features for assembling. In another variation, the physical tooth models can be automatically assembled onto a base by a robotic arm under computer control. In yet another variation, there is no need for complex and costly units such as micro-actuators for adjusting multiple degrees of freedom for each tooth model.
[0378] The physical dental arch model obtained through the disclosed apparatus and methods may be used for various dental applications such as dental crown, dental bridge, aligner fabrication, biometrics, and teeth whitening. In one variation, the arch model may be assembled from segmented manufacturable components that can be individually manufactured by automated, precise numerical manufacturing techniques.
[0379] In another variation, the same base can support different tooth arch model having different teeth configurations. The base can include more than one set of receiving features that can receive tooth models at different positions. The reusable base further reduces cost in the dental treatment of teeth alignment.
[0380] Variations of the apparatus and methods may permit the physical tooth models in the physical dental arch model be easily separated, repaired or replaced, and reassembled after the assembly without the need to replace the complete arch model.
[0381] In yet another variation, the manufacturable components can be attached to a base. The assembled physical dental arch model specifically corresponds to the patient's arch. Therefore, complex and costly mechanisms such as micro-actuators for adjusting multiple degrees of freedom for each tooth model may not be needed. The described methods and system may be simple to make and easy to use.
[0382] An exemplary process for producing a physical dental arch model is illustrated in FIG. 60. In one variation, the process includes the following steps. First, individual tooth models are created in step 51 10. An individual tooth model is a physical model that can be part of a physical tooth arch model, which can be used in various dental applications. Registration features are next added to the individual tooth model to allow them to be attached to each other or a base in step 5120. A base is designed for receiving the tooth model in step 5130. The tooth model positions in a tooth arch model are next determined in step 5140. A base is fabricated in step 5150. The base includes features for receiving the individual tooth model. The tooth models are then attached to the base at the predetermined positions using the pre-designed features in step 5160.
[0383] One variation of the detail process in FIG. 60 is now described. Individual tooth models can be obtained in step 5110 in a number of different methods. For example, the tooth model can be created by casting. A negative impression is first made from a patient's arch or a patient's tooth using for example PVS. The negative impression of the patient's arch is placed in a specially designed chamber. A casting material is then poured into the chamber over the impression to create a model. A lid is subsequently placed over the chamber. The chamber is opened and the mold can be removed after the specified time.
[0384] Examples of casting materials include, but not limited to, auto polymerizing acrylic resin, thermoplastic resin, light-polymerized acrylic resins, polymerizing silicone, polyether, plaster, epoxies, or a mixture of materials. The casting material can be selected based on the uses of the cast. In one variation , the material is selected for easy cutting to obtain individual tooth model. Additionally, the material selected is strong enough for the tooth model to take the pressure in pressure form for producing a dental aligner.
[0385] FIG. 69 and FIG. 70 respectively illustrate exploded top and bottom perspective views casting chamber 5701 including a chamber body 5710, a chamber lid 5702, and a chamber base 5703 for casting a physical tooth model. Chamber body 5710 assembly includes a cavity 5720 and a mounting plate 5730 inside the chamber cavity 5720.
[0386] A negative impression of a patient's tooth or arch can be glued or fastened to the mounting plate 5730. At the bottom surface of the impression mounting plate 5730, there are two precision alignment liners that mate with two precision locating pins on the chamber cavity 5720 bottom surface. The two precision locating pins and liners allow precise locating of the impression repetitively. Furthermore, multiple through holes 5733 through the bottom of the cast chamber to the cavity 5720 provide access to the impression mount plate to assist the removal of the impression mounting plate 5730 from the cast chamber. *• [0387] The chamber lid 5702 is mated precisely to the casting chamber body 5710 by two precision locating liners 5715 on the chamber lid 5702 and two precision alignment pins (not shown) which can be inserted into the aligners 5722 on the casting chamber assembly's top surface. The two precision locating liners 5715 on the chamber lid 5702 and the aligners 5722 on the chamber body 5710 may also serve as position references for measurement and machining. These features allow repetitive cast of the teeth with precise locations of the teeth.
[0388] On the bottom of the casting chamber 5701, there are two additional precision alignment liners 5735. The two liners register with two precision locating pins on the casting chamber base 5703 sub-assembly, which allows precise installation of cast chambers to the chamber base for measurement and machining.
[0389] Chamber lid 5702 can include a variable spacer 5750 and a casting adaptor.
The thickness of the variable spacer is determined by measuring the height of the impression inside the casting chamber cavity 5720. The maximum thickness of the spacer is used so that the distance of the casting adaptor and the impression is minimum when the lid 5702 is tightly placed on the casting chamber body 5710. To achieve the minimum distance between the casting adaptor and the teeth, the adaptor can have a horse-shoe- shaped extrusion machined out of plastics or metal parts. A plurality of pins 5755 (i.e., registration features) are positioned on the variable spacer.
[0390] In one variation, the casting adaptor is a machined part. Measurements of the specific teeth impression are used to calculate the required machine operations. There are multiple undersized holes on the adaptor to hold the metal pins tightly during the casting process. The locations and orientations of the pins are calculated from measurements of the impression inside the cavity 5720 of the chamber body 5710. In some cases, a horse-shoe-shaped extrusion step is also machined based on specific measurement.
[0391] The casting chamber lid 5702 includes multiple threaded through holes 5716 around the cavity 5720 of the casting chamber 5701. These holes serve as a lifting unit to overcome the large forces involved in de-molding. Metal bolts or screws are pushed through the threaded holes to lift the chamber lid 5702 and the cured mold out of the impression. [0392] A plurality of through holes on the casting chamber lid 5702 allows the fastening of the chamber lid 5702 to the Chamber body 5710 during the cast and cure process. The chamber lid 5702 is fixed tightly to the casting Chamber body 5710, maintaining the precision locations during processes such as vibrating, elevated temperature cure process as well as transportation during the cure process.
[0393] In one variation, the casting chamber lid 5702 also has a slotted through window 5740. This window acts a view port as well as an overflow reservoir for the plastics liquid. The chamber lid 5702 also includes a handle 5728 for easy carrying and handling of the chamber lid 5702. In another variation, the window allows UV light irradiation through the window to assist the polymerization and solidification of the casting material in the casting chamber 5701. The cast material can be solidified by cooling or heating, irradiation by UV or IR light, or by microwave radiation. The cast material can comprise one or more crosslinking agents that can cause the polymerization and solidification of the cast material to produce the physical tooth model. In another variation, the window is placed on the side wall of the chamber 5710.
[0394] Chamber base 5703 is can be fixed to a platform using the multiple through holes 5736. The platform can also host measurement devices. The two precision locating pins on the chamber body 5710 mate with the two precision liners 5738 on the bottom of a chamber body 5710, thus produce repetitively precision mount of the casting chambers 5701 on to the chamber base 5703.
[0395] In one variation, the casting system comprises precision locating pins and liners in a casting chamber 5701, a chamber lid 5702 and a chamber base. Precision measurement and computer software can also be used to produce the positions of the receiving features of the physical tooth model. The receiving features enable the physical tooth mode to be mounted or attached to a physical base. The receiving features can include a pin, a registration slot, a socket, a notch, a protrusion, a hole, an interlocking mechanism, a jig, and a pluggable or attachable feature. The physical base as shown in FIGS. 61-68 include complimentary second features for receiving the first features to enable the physical tooth models to be mounted to the physical base. The positions of the first features may be used for determining the locations of the second features in the physical base in fabricating the base. [0396] Referring to FIG. 71, a cross-sectional view of one variation of a casting chamber is shown. The casting system 5762 comprises a chamber 5765 having a negative impression 5762 of a patient's tooth arch secured therein, a lid 5760 having a variable spacer 5764, and plurality of pins 5766 positioned on the variable spacer 5764. Each pair of pins 5764 is positioned to correspond to a tooth in the tooth arch of the negative impression 5766. A positive tooth arch can then be cast within the negative impression 5767, resulting in a positive dental arch mold having pins 5766 extending from the base portion of each of the teeth in the positive dental arch mold. The positive mold can ten be separated into individual tooth models 5770, as shown in FIG. 72. In this example, each of the tooth models 5770 comprises a crown portion, a base portion and a pair of pins 5776 extending form the base portion.
[0397] In one implementation, the precision units in the casting chamber design can also be used in other manufacturing processes such as 2D scanning of the negative impression, base plate machining, and/or bite setting measurement. 2D scanning as used in this example is a manufacturing process where an impression for a patient's teeth are measured for the positions and orientations of the simulated "roots" - the metal pins. A measurement device such as a digitizer is mounted rigidly on a flat platform. Multiple pairs of precision locating pins on the platform can receive the mating precision liners on the bottom of the casting chamber 5701. The locating pins positions relative to the measurement device are precisely machined and measured, providing position references for the measurements. In one variation, the measurement device must have the capabilities of measuring 5-degree of freedoms at each reading in order to provide accurate and efficient measurements.
[0398] After a casting chamber 5701 is placed on top of this measurement platform, the chamber can be fixed or clamped down tightly with fasteners through the mounting holes on the casting chamber 5701. The measurement device such as a digitizer is first calibrated against the particular chamber, by measuring the locations of two precision locating pins at the top of the surface. After calibration, the locations and orientations of each tooth are measured. Two or more points for each tooth are measured. In one implementation, the gingival shape/profile is also measured. Other measurements can include the height of the impression, etc. These positions and orientation data is stored in a computer to be used for later treatment and manufacturing processes. [0399] In one variation, bite setting positions of the upper teeth and lower teeth of a patient is also measured using references to the precision locating liners on the casting chamber lid. After both the lower teeth and the upper teeth of a patient are cast, and de- molded, the two chamber lids with the upper teeth and the lower teeth are set to their nature bite setting position. Springs and universal joints may be used to hold the upper and lower teeth with chamber lids in the bite setting position. A measurement device is then used to measure the relationships between the pair of the precision locating liners on both chamber lids. With the assistance of known positions of the teeth to each chamber lids that are measured and calculated during the machining of the base plate, the nature bite position of the upper and lower teeth are then calculated.
[0400] Features that allow tooth models to be attached to a base (step 5120) can be added to the casting material during the casting process. In one variation, registration points or pins are added to each tooth before the casting material has dried. In yet another variation, universal joints are inserted at the top of the casting chamber using specially designed lids, which would hang the universal joints directly into the casting area for each tooth.
[0401] In step 5110, individual tooth models are next cut from the positive tooth arch. In one variation, the positive tooth arch is cut to obtain individual teeth in such a manner that they can be joined again to form a tooth arch. The separation of individual teeth from the mold can be achieved using a number of different cutting methods including laser cutting and mechanical sawing.
[0402] Separating the positive mold of the arch into tooth models may result in the loss of the relative 3D coordinates of the individual tooth models in the arch. Several methods may be implemented in step 5120 for finding relative position of the tooth models. In one variation, unique registration features are added to each pair of tooth models before the positive arch mold is separated. The separated tooth models can be assembled to form a physical dental arch model by matching tooth models having the same unique registration marks.
[0403] The positive arch mold can also be digitized by a three-dimensional scanning using a variety of techniques, such as laser scanning, optical scanning, destructive scanning, CT scanning, and acoustic wave scanning. A digital arch model can be obtained through the 3D scanning. The physical digital arch model is subsequently smoothed and segmented. Each segment can be physically fabricated by CNC based manufacturing to obtain individual tooth models. The physical digital arch model tracks and stores the positions of the individual tooth models. Unique registration marks can be added to the digital tooth models that can be made into a physical feature through CNC base manufacturing.
[0404] Examples of CNC based manufacturing include, but not limited to, CNC based milling, stereolithography, Laminated Object Manufacturing, Selective Laser Sintering, Fused Deposition Modeling, Solid Ground Curing, and 3D ink jet printing.
[0405] In another variation, the separated tooth models are assembled by geometry matching. The intact positive arch impression is first scanned to obtain a 3D physical digital arch model. Individual teeth are then scanned to obtain digital tooth models for individual teeth. The digital tooth models can be matched using rigid body transformations to match a physical digital arch model, due to complex shape of the arch, inter-proximal areas, root of the teeth and gingival areas may be ignored in the geometry match. High precision may be desirable for matching features such as cusps, points, crevasses, the front faces and back faces of the teeth. Each tooth is sequentially matched to result in rigid body transformations corresponding to the tooth positions, and a tooth arch is reconstructed therefrom.
[0406] In another variation, the separated tooth models are assembled and registered with the assistance of a 3D point picking devices. The coordinates of the tooth models are picked up by 3D point picking devices such as stylus or Microscribe devices before separation. Unique registration marks can be added on each tooth model in an arch before separation. The tooth models and the registration marks can be labeled by unique IDs. The tooth arch can later be assembled by identifying tooth models having the same registration marks as were picked from the Jaw. 3D point picking devices can be used to pick the same points again for each tooth model to confirm the tooth coordinates.
[0407] In one variation, a base is made to receive the tooth models. The base and tooth models include complementary features to allow them to be assembled together. The tooth model has a protruding structure attached to it. The features at the base and tooth models can also include one or more of following: a registration slot, a socket, a notch, a protrusion, a hole, an interlocking mechanism, and a jig. The protruding structure can be obtained during the casting process or be created after casting by using a CNC machine on each tooth. The positions of the receiving features in the base are determined by either the initial positions of the teeth in an arch or the desired teeth positions during a treatment process.
[0408] Before casting the arch from the impression, the base plate is taken through a CNC process to create the female structures for each individual tooth (step 5150). Then the base is placed over the casting chamber in which the impression is already present, and the chamber is filled with epoxy. The epoxy gets filled up in the female structures and the resulting mold has the male studs present with each tooth model that can be separated afterwards. FIG. 61 shows a tooth model 5210 with male stud 5220 after mold separation. The base 5230 comprises a female feature 5240 that can receive the male stud 5220 when the tooth model 5210 is assembled to the base 5230.
[0409] In another variation, as shown in FIG. 62, a tooth model 5310 includes a female socket 5315 that can be drilled by CNC based machining after casting and separation. A male stud 5320 that fits the female socket 5315 can be attached to the tooth model 5310 by for example, screwing, glue application, etc. The resulted tooth model 5330 includes male stud 5310 that allows it to be attached to the base.
[0410] Male protrusion features over the tooth model can be fabricated in a number of arrangements. FIG. 63 shows a tooth model 5410 having two pins 5415 protruding therefrom and a base 5420 having registration slots 5425 adapted to receive the two pins 5415 to allow the tooth model 5410 to be attached to the base 5420. FIG. 64 shows a tooth model 5510 having one pin 5515 protruding out and a base 5520 having a hole 5525 adapted to receive the pin 5515 to allow the tooth model 5510 to be attached to the base 5520. In general, the tooth model can include two or more pins wherein the base will have a corresponding number of holes at the corresponding locations for each tooth model. The tooth model 5530 can also include cone shaped studs 5535 as shown in FIG. 65. The studs can also take a combination of configurations described above.
[0411] As shown FIG. 66, the studs protruding from the tooth model 5540 can take different shapes 5545 such as oval, rectangle, square, triangle, circle, semi-circle, each of which correspond to slots on the base having matching shapes that can be drilled using the CNC based machining. The asymmetrically shaped studs can help to define a unique orientation for the tooth model on the base.
[0412] FIG. 67A shows a base 5550 having a plurality of sockets 5555 and 5560 for receiving the studs of a plurality of tooth models. The positions of the sockets 5555, 5560 are determined by either initial teeth positions in a patient's arch or the teeth positions during the orthodontic treatment process. The base 5550 can be in the form of a plate as shown in FIG. 67A, including a plurality of pairs of sockets 5555,' 5560. Each pair of sockets 5555, 5560 is adapted to receive two pins associated with a physical tooth model.
[0413] Each pair of sockets includes a socket 5555 on the inside of the tooth arch model and a socket 5560 on the outside of the tooth arch model.
[0414] Another variation of a base 5565 is shown in FIG. 67B. A plurality of pairs of female sockets 5570, 5575 are provided in the base 5565. Each pair of the sockets 5570, 5575 is formed in a surface 5580 and is adapted to receive a physical tooth model 5585. The bottom portion of the physical tooth model 5585 includes a surface 5590. The surface 5590 contacts the surface 880 when the physical tooth model 5585 is inserted into the base 5565, which assures the stability of the physical tooth model 5585 over the base 5565.
[0415] A tooth model 5595 compatible with the base 5550 is shown in FIG. 68. The tooth model 5595 includes two pins 5600 connected to its bottom portion. The two pins 5600 can be plugged into a pair of sockets 5555 and 5560 on the base 5550. Thus each pair of sockets 5555 and 5560 uniquely defines the positions of a tooth model. The orientation of the tooth model is also uniquely defined if the two pins are labeled as inside and outside, or the sockets and the pins are made asymmetric inside and outside. In general, each tooth model may include correspond to one or a plurality of studs that are to be plugged into the corresponding number of sockets. The male studs and the sockets may also take different shapes as described above.
[0416] A tooth arch model is obtained after the tooth models are assembled to the base 5550 (step 5160). The base 5550 can have a plurality of configurations in the female sockets 5555. Each of the configurations is adapted to receive the same physical tooth models to form a different arrangement of at least a portion of a tooth arch model. In one variation, the different arrangement represents the projected tooth position in the various treatment steps for an orthodontic treatment process. [0417] The base 5550 can be fabricated by a system that includes a computer device adapted to store digital tooth models representing the physical tooth models. As described above, the digital tooth model can be obtained by various scanning techniques. A computer processor can then generate a digital base model compatible with the digital tooth models. An apparatus fabricates the base using CNC based manufacturing in accordance with the digital base model. The fabricated base is adapted to receive the physical tooth models.
[0418] The physical tooth models can be identified or labeled by a predetermined sequence that define the positions of the physical tooth models on the base 5550. The labels can include a barcode, a printed symbol, hand-written symbol, a Radio Frequency Identification (RFID). The female sockets 5555 can also be labeled by the parallel sequence for the physical tooth models.
[0419] In one variation, tooth models can be separated from the base for repair.
The tooth models can be removed, repaired or replaced, and re-assembled without the replacement of the whole arch model.
[0420] Materials for the tooth models can include polymers, urethane, epoxy, plastics, plaster, stone, clay, acrylic, metals, wood, paper, ceramics, and porcelain. The base can comprise a material such as polymers, urethane, epoxy, plastics, plaster, stone, clay, acrylic, metals, wood, paper, ceramics, porcelain, glass, and concrete.
[0421] One of ordinary skill in the art having the benefit of this disclosure would appreciate that the arch model can be used in different dental applications such as dental crown, dental bridge, aligner fabrication, biometrics, and teeth whitening. For aligner fabrication, for example, each stage of the teeth treatment may correspond a unique physical dental arch model. Removable appliances such as aligners can be fabricated using different physical dental arch models one at a time as the teeth movement progresses during the treatment. At each stage of the treatment, the desirable teeth positions for the next stage are calculated. A physical dental arch model having modified teeth positions is fabricated using the process described above. A new aligner is made using the new physical dental arch model.
[0422] In one variation, each base is specific to an arch configuration. There is no need for complex and costly mechanisms such as micro-actuators for adjusting multiple degrees of freedom for each tooth model. The described methods and system is simple to make and easy to use.
[0423] Different stages of the arch model can share the same tooth models. The positions for the tooth models at each stage of the orthodontic treatment can be modeled using orthodontic treatment software. Each stage of the arch model may use a separate base. In one variation, one base is used in a plurality stages of the arch models. The base may include a plurality of sets of receptive positions for the tooth models. Each set corresponds to one treatment stage. The tooth models can be reused through the treatment process. Therefore, much of the cost of making multiple tooth arch models in orthodontic treatment may be avoided.
[0424]
[0425] In another variation, an exemplary process, for producing a physical dental arch model is illustrated in FIG. 73. In one implementation, the process includes the following steps. First a reference base is molded for an individual tooth model in step 5100. The individual tooth model is next molded with the assistance of the reference base in step 51 10. An individual tooth model is a physical model that can be part of a physical tooth arch model, which can be used in various dental applications. Registration features are next added to the individual tooth model to allow them to be attached to each other or a base in step 5120. A base is designed for receiving the tooth model in step 5130. The tooth model positions in a tooth arch model are next determined in step 5140. A base is fabricated in step 5150. The base includes features for receiving the individual tooth model. The tooth models are finally attached to the base at the predetermined positions using the pre-designed features in step 5160.
[0426] Details of the process in FIG. 73 are now described. The making of a physical tooth model can include two steps: first the molding of a reference base for the tooth model in step 5100, and second, casting the physical tooth model with the assistance of the reference base in step 51 10. Both steps can be implemented using the same casting chamber 5815, as shown in FIG. 74. A horse-shoe shaped negative impression 5810 from a patient's upper or lower arch can be fixed into a mounting plate by pins in the specially designed casting chamber 5815. A chamber lid 5805 can close the casting chamber 5815 while allowing casting materials to be poured into the casting chamber 5815 through holes 5806.
[0427] Examples of the casting material include but not limited to, resin, epoxy mixture, polymers, thermal elastic material, urethane, plaster, clay, acrylic, latex, dental PVS, metal, aluminum, ice, wax, and one or more crosslinking agents that can cause the polymerization. The casting material is poured over the impression to first fill the teeth areas above the gum line in the impression. The casting material is subsequently poured over the rest of the areas and then filled to the outer rim of the casting chamber 5815 to leave ample thickness for the base portion that can be used as the reference base, as described below.
[0428] Air bubbles can be removed from the casting material to reduce surface tension before curing. Air bubbles trapped in the epoxy may also distort the original anatomy of teeth and supporting structures. The casting chamber 5815 having the closed chamber lid 5805 is placed in an industrial vibrator to remove air bubbles introduced during the mixing and pouring procedure. The casting chamber 5815 is closed and the sealed by the chamber lid 5805 after air bubble stops coming out of the casting material. The excess casting material coming out of the container is wiped out by a cleaning agent.
[0429] The solidification of the casting material may take hours. The solidification casting process may be facilitated with the assistance of heating, cooling, UV or IR exposures through a window in the chamber lid. For example, Epoxy setting may require 4- 8 hours.
[0430] After the casting material is solidified in the casting chamber 5815, the solidified casting material can be detached from the negative impression by pushing by a screw through through-holes in the chamber body. The solidified casting material is attached to the chamber lid 5805 and can be removed from casting chamber 5815 by lifting the chamber lid 5805. A positive replica of impression is obtained attached to the underside of chamber lid 5805. FIG. 75 shows the front view of a chamber lid having the solidified material 5820 that includes a tooth portion 5825, a base portion 5832 (also called the gingival portion), and the chamber lid 1040.
[0431] After thoroughly checking the quality of the solidified casting material, the tooth potion 5825 that is a positive replica of negative impression is cut off from the base portion 5832. The cutting can be implemented along pre-defined horizontal lines approximately 10 mm below the lowest point of gum line. The cutting can be applied for example using disc-type saw cutting equipment. As a result, as shown in FIG. 76, a reference base 5835 is formed in attachment to the chamber lid 5840. In one variation, the reference base 5855 (e.g., a mold of the gum/base, portion of the tooth arch) is coupled to the casting chamber lid 5840 through a variable spacer 5836. In another variation, the reference base is directly attached to the chamber lid.
[0432] The reference base 5835 is used to cast physical tooth models using another casting material that does not adhere to the solidified material of the reference base, as described in relation to step 51 10. As shown in FIGS. 61 -65, the physical tooth models include features that enable them to be attached to a physical base. The features can include a registration slot, a socket, a notch, a protrusion, a hole, an interlocking mechanism, a pin, a protrusion etc. The positions of these features have to be accurately produced on the physical tooth models.
[0433] Features can be added to the reference base 5835 to facilitate the fabrication of the features on the physical tooth models to enable the physical tooth models to be attached to a base. For example, as shown in FIG. 77, a machine 5855 is used to drill or mill a hole in the reference base 5845 that is attached to the chamber lid 5855. The drilling and milling may be applied using CNC based manufacturing techniques. FIG. 78 shows a top view of one such machined hole 5860 in the reference base 5865. As shown in FIG. 79, a pin 5875 can be inserted into the hole 5880 in the reference base 5870. The pin 5875 can adhere to the casting material and fixed to the physical tooth model during the casting of the physical tooth model in step 5110. The pin 5875 that is affixed to the physical tooth model can therefore enable the physical tooth model to be attached to a dental base.
[0434] In another variation, features such as the holes 5860, 5880 are made on the reference base at precisely determined positions such that the physical tooth models can be mounted on to the base in accordance to the positional and orientational requirement of the orthodontic treatment. The positions of the features such as the holes 5860, 5880 on the reference base 5845, 5865 can be referenced to the chamber lid 5850 because the reference base 5845, 5865 are solidly fixed to the chamber lid 5850. A reference point such as the corner of the chamber lid is first picked on the chamber lid 5850. A location measurement device such as a Microscribe device can be used to determine the exact locations of the hole to be made relative to the reference position on the chamber lid 5850. The required location of the hole can be input from a digital arch model in which the positions and orientations of each tooth model are specified in accordance to the orthodontic treatment. The reference base as well as the chamber lid therefore serve as reference for physical tooth models to be fabricated.
[0435] Individual tooth model can be obtained in step 51 10 in a number of different methods. The tooth model can be created by casting. A negative impression is first made from a patient's arch using, for example, PVS. A positive of the patient's arch is next made by pouring a casting material into the negative impression. After the material is dried, the mould is then taken out with the help of the impression knife. A positive of the arch is thus obtained.
[0436] In yet another variation, the negative impression of the patient's arch is placed in a specially designed container. A casting material is then poured into the container over the impression to create a model. A lid is subsequently placed over the container. The container is opened and the mould can be removed after the specified time.
[0437] FIG. 80 illustrates an example where a gum portion 5888 (i.e., reference base) of a tooth arch is attached to a variable spacer 5889 on the casting chamber lid 5885. The negative impression 5892 of the patient's tooth arch is positioned inside the chamber 5890. Corresponding pins 5898 (i.e., registration features) are partially inserted in the gum portion. When the lid 5885 is placed over the chamber 5892 and aligned with the chamber 5892 through the locator pins 5891 on the chamber 5890 corresponding recesses 5893 on the lid 5885, the gum portion 5888 is aligned with the negative impression 5892 and may engage the negative impression. The resulting void between the gum portion 5888 and the negative impression 5892 is a space for casting the crown portion of the tooth arch.
[0438] FIG. 81 illustrates a positive tooth dental arch mold 5895 fabricated from the casting system 5894 shown in FIG. 80. The positive tooth arch is isolated to the crown portion 5896 of the tooth arch, with pins 5898 (i.e., registration features) extending directly from the crown portion 5896.
A Base For Receiving Physical Tooth Models [0439] Examples and variations of method for fabricating a base for receiving physical tooth models are described below. Various implementations of a base design are also discussed.
[0440] In one variation, the method includes providing cast materials in a container; pressing the underside of the physical tooth models into the cast materials to produce impressions in the cast materials; and solidifying the cast materials having the impressions to produce the base that is adapted to receive the physical tooth models.
[0441] In another variation, the method comprises: placing the physical tooth models in a container; pouring the cast materials over the underside of the physical tooth models in the container; and solidifying the cast materials having the impressions to produce the base that is adapted to receive the physical tooth models.
[0442] In yet another variation, the method comprises: transferring a cast materials in a container; placing the underside of a physical tooth model in the container such that the underside of the physical tooth model produces an impression in the cast materials; solidifying the cast materials having the impressions to produce a base component; and assembling a plurality of base components to form the base configured to receive the dental arch model.
[0443] Implementations of a system for producing a base may include one or more of the following. In one variation, the method for producing a base for physical tooth models includes providing cast materials in a container, pressing the underside of the physical tooth models into the cast materials to produce impressions in the cast materials, and solidifying the cast materials having the impressions to produce the base that is adapted to receive the physical tooth models. The casting a material can be selected from the group consisting of polymers, thermal elastic materials, urethane, epoxy, plaster, clay, acrylic, latex, dental PVS, resin, metal, aluminum, ice, wax, sand, and stone. The method can further include labeling the physical tooth models in a predetermined sequence that define the positions of the physical tooth models on the base. The method can further include defining the positions of the impressions on the base such that the physical tooth models received by the impressions form at least a portion of an arch.
[0444] The method can further include defining the positions of the impressions on the base in accordance with a digital arch models. The digital arch model can be produced by scanning and digitizing a patient arch. The method can further include cooling the cast materials to cause the solidification of the cast materials having the impressions. The method can further include illuminating UV irradiation on the cast materials to cause the solidification of the cast materials having the impressions. The method can further comprise applying crosslinking agents to the cast materials to cause the polymerization and solidification of the cast materials having the impressions. The physical tooth models can include first features to assist the reception of the physical tooth models by the base. The features can comprise one or more of a pin, a registration slot, a notch, a protrusion, a hole, an interlocking mechanism, a jig, and a pluggable or attachable feature. The impressions in the base can comprise second features complimentary to the first features to assist the reception of the physical tooth models by the base. The tooth models can comprise a material selected from the group consisting of polymers, urethane, epoxy, plastics, plaster, stone, clay, acrylic, metals, wood, paper, ceramics, and porcelain.
[0445] Implementations of the system may include one or more of the following.
[0446] In one variation, the method for producing a base for physical tooth models includes placing the physical tooth models in a container, pouring the cast materials over the underside of the physical tooth models in the container, and solidifying the cast materials having the impressions to produce the base that is adapted to receive the physical tooth models. The casting a material can be selected from the group consisting of polymers, thermal elastic materials, urethane, epoxy, plaster, clay, acrylic, latex, dental PVS, resin, metal, aluminum, ice, and wax. The physical tooth models can comprise first features to assist the reception of the physical tooth models by the base.
[0447] Implementations of the system may include one or more of the following.
The base components can comprise features to assist the assembly of the base components to form the base for the dental arch model. The features comprise one or more of a pin, a registration slot, a socket, a notch, a protrusion, a hole, an interlocking mechanism, a jig, and a pluggable or attachable feature.
[0448] Variations may include one or more of the following features. In one variation the base for receiving dental tooth models can be produced with simple, inexpensive and reliable methods and system. The casting chambers are can be used multiple times to reduce manufacturing cost. Furthermore, the base can be molded in a plurality of components. Only a component of the base needs to be re-molded if the position of one physical tooth model is changed in an orthodontic treatment. This further reduces treatment cost.
[0449] The physical tooth models can include features to allow them to be attached, plugged or locked to a base. The physical tooth models can be pre-fabricated having standard registration and attaching features for assembling. The physical tooth models can be automatically assembled onto a base by a robotic arm under computer control. The manufacturable components can be attached to a base. The assembled physical dental arch model specifically corresponds to the patient's arch. There is no need for complex and costly mechanisms such as micro-actuators for adjusting multiple degrees of freedom for each tooth model. The described methods and system is simple to make and easy to use.
[0450] FIG. 60 shows an exemplary process for producing a physical dental arch model. First individual tooth model is created in step 51 10. An individual tooth model can be a physical model that can be part of a physical tooth arch model, which can be used in various dental applications. Registration features are next added to the individual tooth model to allow them to be attached to each other or a base in step 5120. A positive dental arch is produced in step 5130. A cast container is prepared by forming a base in step 5140. A base is fabricated by casting in step 5150. The base includes features for receiving the individual tooth model. The tooth models are finally attached to the base at the predetermined positions using the pre-designed features in step 5160.
[0451] Details of process in FIG. 60 are now described. Individual tooth model can be obtained in step 51 10 using a number of different methods. In one embodiment, the tooth model can be created by casting. A negative impression is first made from a patient's arch using for example PVS. A mold or a positive of the patient's arch is next made by pouring a casting material into the negative impression and allowing the mold to dry to obtain a positive model of the arch with teeth mounted thereon. In an alternative approach, a negative impression of the patient's arch is placed in a specially designed container. The undersides of the tooth models are placed upward. A casting material is then poured onto the underside of the container over the impression to create a model. A lid is subsequently placed over the container. The container is opened and the mold can be removed after the specified time. Examples of casting materials include auto polymerizing acrylic resin, thermoplastic resin, light-polymerized acrylic resins, polymerizing silicone, polyether, plaster, epoxies, or a mixture of materials. The casting material for molding the tooth models can be selected based on the uses of the cast. The material should be easy for cutting to obtain individual tooth model. Additionally, the material needs to be strong enough for the tooth model to take the pressure in pressure form for producing a dental aligner.
[0452] Features that allow tooth models to be attached to a base (step 5120) can be added to the casting material in the casting process. Registration points or pins can be added to each tooth before the casting material has dried. Optionally, universal joints can be inserted at the top of the casting chamber using specially designed lids, which would hang the universal joints directly into the casting area for each tooth.
[0453] Still in step 51 10, individual tooth models are next cut from the arch positive. One requirement for cutting is to obtain individual teeth in such a manner that they can be joined again to form a tooth arch. The separation of individual teeth from the mold can be achieved using a number of different cutting methods including laser cutting and mechanical sawing.
[0454] Separating the positive mold of the arch into tooth models may result in the loss of the relative 3D coordinates of the individual tooth models in an arch. Several methods are provided in step 5120 for finding relative position of the tooth models. In one embodiment, unique registration features are added to each pair of tooth models before the positive arch mold is separated. The separated tooth models can be assembled to form a physical dental arch model by matching tooth models having the same unique registration marks.
[0455] The positive arch mold can also be digitized by a three-dimensional scanning using techniques such as laser scanning, optical scanning, destructive scanning, CT scanning and Sound Wave Scanning. A physical digital arch model is therefore obtained. The physical digital arch model is subsequently smoothed and segmented. Each segment can be physically fabricated by CNC based manufacturing to obtain individual tooth models. The physical digital arch model tracks and stores the positions of the individual tooth models. Unique registration marks can be added to the digital tooth models that can be made into a physical feature in CNC base manufacturing. [0456] Examples of CNC based manufacturing include CNC based milling,
Stereolithography, Laminated Object Manufacturing, Selective Laser Sintering, Fused Deposition Modeling, Solid Ground Curing, and 3D ink jet printing.
[0457] In another embodiment, the separated tooth models are assembled by geometry matching. The intact positive arch impression is first scanned to obtain a 3D physical digital arch model. Individual teeth are then scanned to obtain digital tooth models for individual teeth. The digital tooth models can be matched using rigid body transformations to match a physical digital arch model due to complex shape of the arch, inter-proximal areas, root of the teeth and gingival areas may be ignored in the geometry match. High precision is required for matching features such as cusps, points, crevasses, the front faces and back faces of the teeth. Each tooth is sequentially matched to result in rigid body transformations corresponding to the tooth positions that can reconstruct an arch.
[0458] In another embodiment, the separated tooth models are assembled and registered with the assistance of a 3D point picking devices. The coordinates of the tooth models are picked up by 3D point picking devices such as stylus or Microscribe devices before separation. Unique registration marks can be added on each tooth model in an arch before separation. The tooth models and the registration marks can be labeled by unique IDs. The tooth arch can later be assembled by identifying tooth models having the same registration marks as were picked from the Jaw. 3D point picking devices can be used to pick the same points again for each tooth model to confirm the tooth coordinates.
[0459] In one variation, to produce a base, positive dental arches are first produced together in 5130. The positive dental arches can be made from a negative impression of the patient's arch by casting as described above. Separate positive arches are made for upper jaw and the lower jaw. A base can be separated into a plurality of components, each of which can be molded as described below. The whole base can be assembled together by the components after they are separately molded.
[0460] A casting container 5900 is next prepared in step 5140 for casting a base or a base component 5910 to support a physical dental arch model, as shown in FIG. 82. The base component 5910 can include features 5920 that allow a plurality of base components 5910 to be assembled to form a base. Features 5920 can for examples include sockets, holes, pins, and protrusions that allow the base components 5910 to tightly join or interlock to each other. The base component 5910 can include pins 5930 that can enable the mounting of one or more tooth models to the base component 5910.
[0461] A physical dental arch model can include a plurality of tooth models, which can represent a whole or portion of a patient's arch. A casting material such as epoxy, plaster or a mixture of materials is poured into the contained. The casting material can be a paste, a fluid, a thick mixture of polymeric, ceramic, or colloidal materials. Examples of casting materials include auto polymerizing acrylic resin, thermoplastic resin, light- polymerized acrylic resins, polymerizing silicone, polyether, plaster, epoxies, or a mixture of materials. The casting materials can include crosslinking agents to the cast materials to cause the polymerization and solidification of the cast materials having the impressions. The casting material can be irradiated by UV light through a window opened on the casting container ion to cause the polymerization and the solidification of the cast materials having the impressions.
[0462] The undersides of a positive dental arch are then pressed into the casting material. The casting material can then be solidified by heating or cooling. The casting material can also be irradiated by UV light through a window opened on the casting container ion to cause the polymerization and the solidification of the cast materials having the impressions. The container is opened and the mold can be removed. A base as shown in FIGS. 61, 63, 64, 67A is obtained after the casting material is dried and solidified in step 5150.
[0463] The solidification of the casting materials can be accomplished by non¬ uniform treatment by heating, cooling, UV or IR illuminations, or microwave radiation. For example, heating wires can laid out in the casting container to specifically heat the fine features in the impressions for receiving the physical tooth models. The casting material may also comprise non-uniform distribution of ingredients. For example, the concentration of the crosslinking agents may be higher near the fine features in the impressions for receiving the physical tooth models.
[0464] In one variation, a base or base component for receiving dental tooth models can be produced with simple, inexpensive and reliable methods and system, as described herein. In one implementation, the casting chambers are can be used multiple times to reduce manufacturing cost. [0465] FIG. 83 illustrates a base 5962 comprising a plurality of base components
5940, 5950, 5960. The system of FIG. 83 illustrates casting of a base for receiving the tooth models. For example, second features, which determines first features (e.g., registration features on the tooth model) locations and orientations can be cast into the base plate for receiving the first features on the tooth models. Each of the base components 5940, 5950, 5960 is configured to receive a physical tooth model and can molded by one of a plurality of casting containers 5935, 5945, 5955. The base components 5940, 5950, 5960 are assembled to form a dental base 5962 for receiving physical tooth models. The base components 5940, 5950, 5960 can include features to assist the assembly of the base components 5940, 5950, 5960 to form the base 5960 for the dental arch model. The features comprise one or more of a pin, a registration slot, a socket, a notch, a protrusion, a hole, an interlocking mechanism, a jig, and a pluggable or attachable feature. FIG. 83, 5935-5955 should have interconnect features, to allow one to connect to the other, or insert to a common base to form an arch, these features can be configured to be small enough to avoid interference. The above features base may be pre-inserted to casting box, e.g, pins.
[0466] In one variation, the base component 5940, 5950, 5960 can be individually replaced for a different base configuration without changing the base components that are not changed in the orthodontic steps. The base can be molded in a plurality of base components 5940, 5950, 5960 that can be subsequently assembled to form the whole dental base. In one application, only one base component 5910 of the base needs to be re-molded if the position of one physical tooth model is changed in an orthodontic treatment. This may further reduce treatment costs.
[0467] FIG. 84 shows a base 5965 having multiple sets of sockets 5970, 5975,
5980, 5985, each of which can receive a dental arch in a different configuration. Different configurations of the base can be required during the process of an orthodontic treatment. The positions and orientations of the tooth models may differ step by step. The base can include a plurality of configurations in the sockets for the tooth models. Each configuration is adapted to receive the same physical tooth models to form a different arrangement of a tooth arch model.
[0468] In another variation, a positive impression is placed in a specially designed container as shown in FIG. 83. Casting material is then poured over the impression. A lid is subsequently placed top of the container for a specified period of time. The casting material can be solidified by heating or cooling. In another embodiment, UV light irradiated through a window opened on the casting container ion causes the polymerization and the solidification of the cast materials having the impressions. The container is opened and the mold can be removed. A base as shown in FIGS. 61 , 63, 64, 67A is obtained.
Digitization of Tooth Models
[0469] Examples and variations of apparatus and methods for digitizing a patient's tooth arch. One variation comprises producing a physical arch model for the patient's tooth arch, separating the physical arch model into a plurality of arch model components, mounting the arch model components on a scan plate, capturing one or more images of the arch model components, and developing digital representations of the arch model components using the captured one or more images.
[0470] Another variation comprises producing a physical arch model for the patient's arch, separating the physical arch model into a plurality of arch model components, mounting the arch model components on a scan plate, capturing one or more images of the arch model components, developing digital representations of the arch model components using the captured one or more images, and combining the digital representations for the arch model components into a digital arch model.
[0471] In another aspect, a system for digitizing a patient's arch is described. One variation of the system comprises a scan plate configured to be mounted with a plurality of arch model components that are separated from a physical arch model corresponding to the patient's arch, an image capturing device configured to capture at least one image of the arch model components, and a computer configured to develop digital representations of the arch model components using the captured one or more image.
[0472] Variations of the method and the system may include one or more of the following features. The disclosed system and methods may support the digitization of a patient's tooth arch at high throughput. In one variation, a plurality of tooth arch model components (i.e., individual tooth models) can be mounted on a rotatable scan table and scanned simultaneously. The system may be configured such that three dimensional scanning can be conducted on the arch model components at high throughput in parallel. For example, multiple scanning platforms may be setup next to each other to process a large number of tooth arches at the same time. The multiple scanning platforms may be configured with network connections to allow each of the scanning platform to communicate with a central computer, such that data and/or images collected from scanning can be send to a central computer for processing.
[0473] Variations of the methods and systems for digitizing a patient's tooth arch may allow one to achieve improved accuracy in scanning of the individual tooth model. In one configuration, the patient's tooth arch model is separated into components (e.g., individual tooth models) to allow three-dimensional scanning of the critical areas of the arch model components. The components and the scanning system may be configured such that the surfaces of the arch model components can be scanned in a fashion as to avoid obstruction by different parts of the same arch model component or other components mounted on the rotate-able scan table.
[0474] In one variation, registration marks, such as locking pins, are implemented in the tooth arch model components. These registration marks may improve scanning and digital reconstruction accuracy. In one variation, the digital representations of the tooth arch model components are translated into the common coordinates for the tooth arch model, and then combined to form the digital models of the patient's tooth arch. The digital arch models may be used as input or reference for various applications. For example, the digital tooth arch models may be utilized in CNC based manufacturing of dental arch models, dental arch base, and/or dental aligners for the patient. Furthermore, the digital representation of the tooth arch model may be utilized with root modeling techniques and/or implemented with computer display system for various dental and orthodontic applications.
[0475] FIG. 85 illustrates the process for digitizing a patient's arch. First, reference points and coordinates are determined for a patient's dental arch model in step 61 10. As shown in FIG. 86, a negative impression 6280 of a patient's arch can be first obtained. The negative dental impression 6280 can be fixed in a container 6290 using an epoxy. The container 6290 can be marked by one ore more reference marks 6295 that can define the coordinates of the impression 6280. The relative positions of the patient teeth are measured off the impression using a mechanical location device 6200. An example of a mechanical location device is a microscribe, available from Immersion and Phantom. Other 3D digitizer that can be utilized to develop a digital computer model for an existing 3D object may also be implemented. As shown in FIG. 86, the mechanical location device 6200 includes mechanical arms 6210, 6220 having one or more mechanical joints 6230. The mechanical joint 6230 is equipped with precision bearings for smooth manipulation and internal digital optical sensors for decoding the motion and rotation of the mechanical arms 6210, 6220. The end segment is a stylus 6240 that can be manipulated to touch surfaces on the dental impression 6280 held in the container 6290. The mechanical location device 6200 may be fixed to a common platform as the container 6290.
[0476] Accurate 3D positional and angular information of the points that the stylus touches can be decoded and output at the electronic output port 6270. The positional and orientational information can be obtained by an additional decoder for self-rotation of the stylus. Additional sensors may be placed at the tip of the stylus to measure the hardness of the surface of the measurement object. For example, Immersion Corp.'s MicroScribe® uses a pointed stylus attached to a CMM-type device to produce an accuracy of .009 inches.
[0477] In one variation, in measuring the teeth positions from the impression of the patient's teeth, the MicroScribe digitizer can be mounted on a fixture fixed to a base plate. The device can communicate with a host computer via USB, serial port, or other computer connections. The user then selects points of interest at each tooth positions in the impression and places the stylus at the point of interest. Positional and angular information are decoded and then transmitted to the computer. The coordinates (e.g., Cartesian XYZ, etc. )of the acquired points are then calculated and logged for each first feature location and orientation (or alternatively each tooth).
[0478] A user may establishe a new coordinate system based on the container chamber in which the arch impression is held. In one variation, the user establishes this system by taking readings for two points on two sides of the container to define the x-axis. Another reading on the plane establishes the x-y plane. An origin is then determined on the x-y plane. The z-axis will be established by taking the cross product of the x-axis and y- axis.
[0479] The user next selects a plurality of points on the surfaces of the arch impression corresponding to each tooth. The 3D points measured from the impression surfaces are then interpolated to create surfaces and solids integrated into an overall design. [0480] The user will start reading the pin readings. For each tooth, the user will first take a reading that will establish the center of the two pins, and their orientation vector. Then the user will take two more points that will give us the direction to move from the center of the pins, and finally the dimensions and positions of two pins will be calculated using these values, and the pins will be visually rendered in the software. In one variation, the system allows the user may fine-tune these readings as required.
[0481] After the readings for each pin has been acquired, the first feature locations and orientations are saved, which can be further fine tuned and visualized. A digital dental arch model can include a plurality of digital tooth models. The digital dental model can be developed based on the first feature locations and orientations or alternatively the coordinates of the physical tooth models acquired by the mechanical location device. The exported data can be used to control CNC based drilling and milling.
[0482] The number of points defining the curves and number of curves depends on the desired resolution in the model. Surfacing functions offered by the design application are used to create and blend the model surfaces. The model may be shaded or rendered, defined as a solid or animated depending on the designer's intentions. The teeth may be labeled so the order of the physical tooth models are can properly be defined for the physical dental arch model. All the readings acquired by the stylus can be rendered in real time to allow the user to visualize the digital tooth models. The coordinate axes and points can be rendered in the software using different colored cylinders/spheres etc. so as to distinguish the different meanings of values.
[0483] The negative impression 6280 in the container 6290 can be filled with malleable casting material, which after solidification forms a physical arch model of the patient's arch (step 6120). The one ore more reference marks 6295 (i.e., registration features) are simultaneously molded on the physical arch model such that the surface points on the physical arch model can be accurately translated back to the original coordinates for the negative arch impression.
[0484] The physical dental arch model is then separated into a plurality arch model components 6300 in step 6130. The arch model can include the upper arch, the lower arch (the jaw), a segment of an upper or lower arch comprising one or more teeth, or a fraction of a tooth. In one variation, the arch model components 6300 are cut vertically, such as that registration features 6310 in the base portion 320 can be vertically mounted to a scan plate 6520 as shown in FIG. 89. The vertical mounting of the arch model components 6510 allows them to be scanned relatively uniformly around their longitudinal axis along the length of the tooth, which may be beneficial for constructing uniform surfaces in the digital representation of the arch model components.
[0485] In one variation, the criteria for separating the arch model into arch model components are to ensure each arch model component can be easily scanned by one or more image capture devices as described below. In another variation, the arch model component is cut to a substantially convex shape such that the surfaces of the arch model component can be captured by an image capture device without being obstructed by another part of the same arch model component.
[0486] Next, registration features are produced in the arch model components, such as in step 6140. FIG. 87 shows an arch model component 6300 that is separated from the arch model. The arch model component 6300 includes registration features 6310 that are adapted to be attached to the receiving features in the scan plate as described below. The registration features 6310 can include pins, protrusions, slots, holes, etc., which are complimentary to the receiving features on the receiving features in the scan plate as described below. Alternatively, the registration features 6310 can be produced in the arch model before the arch model is separated into arch model components 6300.
[0487] In one example, the arch model components are digitized by a scanning system 6600 as shown in FIG. 90. The scanning system 6600 includes a scan table 6620 on which one or more arch model components 6610 can be mounted. The scan table 6620 can be rotated by a rotation mechanism 6630 under the control of a computer 6640. The rotation mechanism 6630 can include a motor and a gear transport mechanism that is coupled to the scan plate 6620. As the scan table is turned to an angular position, an image capture device 6650 captures an image of the arch model components 6610. The image capture device 6650 can be a digital camera, and a digital video camera, laser scanner, other optical scanners, etc. There can also be provided a plurality of image capture devices. The throughput and accuracy may increase with the number of the image capture devices.
[0488] The optical axis of the image capture device can be for example 45 degree off the vertical axis (or the top surface of the scan table). As described above, in one variation the arch model components 6610 cut off the arch model are of elongated shapes that can be mounted vertically over the scan table. As the scan plate 6620 is rotated by the rotation mechanism 6630, the vertically mounted arch model components 6610 can be scanned (i.e. image captured) at relatively uniform angle.
[0489] In one variation, the individual tooth arch model components 6610 are placed on the scan table one at a time, and scanned one at a time. In another variation, a plurality of individual tooth arch model components 6610 are place onto a single scan table and scanned together.
[0490] When a multiple tooth arch model components are packed onto a scan plate
6620 and scanned together, one may consider the arrangements of the plurality of tooth arch model components so that each of the components can be scanned by the scanner. The user may planned the distribution of the arch model components 6610 on the scan plate prior to the placement of the arch model components on the scan plate (e.g., step 6150) to improve the accuracy image scanning and improve throughput of the system.
[0491] In general, the scanning throughput is increased with increased packing density on the scan plate. On the other hand, higher packing density may decreases the distance between the arch model components, which may cause the adjacent arch model components to block each other in image captures. Various techniques, which are well known to one of ordinary skill in the art, may be utilized to determine the desired packing density and distribution pattern for placement of the tooth arch components on the scan plate.
[0492] FIG. 88 illustrates the top view of arch model components 6410 over scan plate 6400. The arch model components 6410 can have different sizes and shapes. For example, the small circles may be 10 mm in diameter and represent small teeth (, e.g. lower incisors, cannie, etc.) or tooth components. Large circles may be 15mm in diameter, which may represent large teeth (e.g. upper central incisors, molars) or larger tooth components. The arch components are placed at lease 5 mm apart from each other and almost equal height to avoid overlap. The scan plate 400 may be 150 mm in diameter. The scanning volume can be an extruded octane or a cylinder 20 mm in height. The packing efficiency of the arch model components 6410 is determined by the sizes, the height, the shapes and the distribution of the arch model components 6410. [0493] FIG. 89 shows a side view of a scanning platform 6500. The arch model components 6510 are substantially vertically mounted over the scan plate 6520. The image scanning (i.e. capture) direction 6530 of oblique to the arch model components 6510 such that the top and side surfaces of the arch model components 6510 can be captured at different angles as the scan plate 6520 is rotated. For example,, the image scanning direction 6530 can be 45 degree off the vertical axis. The scan plate 6520 can be mounted goniometer and translation stage, which can provide up to 6 axes for 6 degree of freedom movements.
[0494] In one arrangement, each arch model component is projected along the image capture direction (e.g. 45 degrees of vertical axis of the scan plate 6400) around its axis to produce a shadow around the arch model component. In one variation, the arch model components can be distributed such that there are no overlaps between the shadow areas of the adjacent arch model components. The distributions of the arch model components 6410 can be varied to ensure that there is no obstruction of views between adjacent arch model components. The distributions can be iterated to maximize the packing density.
[0495] In one variation, a model is prepared to simulate the shadow cast by the objects on the plate when the objects are being scanned in the designated scanning directions. One or more scanner may be implemented. The projection of the scanner may be direction to same over lapping region. The position of the object may then be adjusted, such that all the shadows are close to each other, but with no overlaps. This configuration may then be utilized for scanning of the toot arch components. This model for determining a desired scanning configuration may be performed with either a physical model or a computer model.
[0496] In another arrangement, for each distribution of arch model components as shown in FIG. 88, the image scanning direction can be optimized. For example, a patient's arch model is separated into 20 arch model components. The position of the 20 arch model components can be first simulated on a scan plate. The image scanning direction 6530 can be varied to optimize the quality of the image capture.
[0497] In another variation, the operator creates each individual shadow projection based on one scanning direction. The articles/objects on the scan plate are arranged to ensure all the shadows are close to each other with no overlaps. Then based on the plate design for all of the scanning directions, the final plate design is determined. A computer may be implemented to calculate a configuration for distributing the objects on the plate for scanning, such that each of the individual tooth arch components can be scanned in the process. Each scanning direction's shadow collision is calculated separately, and the final readjustment may be determined through several iterations of calculation to minimize interference.
[0498] In yet another arrangement, the shadows of the adjacent arch model components are allowed to overlap to certain extent, which means that certain surface areas on the arch model components are blocked from image scanning at certain directions. It is configured such that the overlap does not block a significant angular span of each surface area of an arch model component. This assures that the surface area blocked at certain direction can be scanned at other similar directions.
[0499] In another variation, individual shadow maps are projected based on two or more scanning directions. Shadows from each scan direction may be colored coded to determine which area the scanner is able to scan from a given scanning direction. The combined data for the shadow cast from all directions are mapped. The distribution of the objects on the scan plate can be adjusted to ensure that the combined shadow map shows the shadows close to each other with minimal or no overlaps. The color coded shadows may be utilized to associate problems with specific scanning direction. In one configuration, shadow maps are close to each other with no overlaps that show color loss, such that all the area can allow shadow overlaps, but there is no shadow color overlap. In another variation, the objects are positioned such that any area on the scan article is seen at least once by the scanner at a certain scan angle.
[0500] After the positions of the arch model components are optimized, the arch model components 6510 are mounted on the scan plate 6520 in step 6160. The images of the arch model components 6510 are captured or scanned at different directions in step 6170 as the scan plate is rotated. The coordinates of a plurality of surface points on the arch model components are computed by triangulation using the captured image data. The surfaces of the arch model components are constructed by interpolating computed coordinates of the points on the surface. Since the registration features of the arch component models and the receiving features of the scan plate are precisely known and inter-translate-able, the coordinates of the surfaces of the arch model components can be translated to the original coordinates of the reference marks in the container 6290 (casting chamber).
[0501] The registration features 6310 and the receiving features on the scan plate
6520 can together define the relative positions of the arch model components 6300. The positions of the registration features 6310 on each arch model component 6300 are precisely defined. The receiving features are also produced at precise locations on the scan table 6520. The captured image data can be interpreted to define the relative positions of the arch model components 6510 relative to the receiving features on the scan plate 6520. Thus, the coordinates of the arch model components 6510 can be transformed into the original coordinates defined by the reference marks 6295 for the impression of the patient's arch.
[0502] Once the surfaces of all arch model components are translated into the original coordinates, the digital representations of the arch model components can be combined into a digital arch model.
[0503] In one variation, the digital arch model obtained in the above example is used as input data to produce physical arch models using CNC based manufacturing, such as milling, stereo lithography, laser machining, molding, and casting. Additionally, digital arch model can be manipulated and modeled to simulate the teeth positions at each step of an orthodontic treatment of a patient's teeth. Furthermore, interference between adjacent tooth models can be prevented by simulation of teeth movement with a computer ahead of time.
Predicting and Preventing Interference Between Tooth Models
[0504] Examples and variations of methods and apparatus for predicting and/or preventing interference between physical tooth models are disclosed below. These method and apparatus may be implemented in the construction of a physical dental arch model for the fabrication of dental aligner.
[0505] In one aspect, methods for preventing interference between two or more physical tooth models in a physical dental arch model is described below. In one variation, the method comprises: acquiring the coordinates of a plurality of points on the surfaces of each of the two physical tooth models; digitally representing the surfaces of each of the two physical tooth models by a mesh of points in three dimensions using the acquired coordinates, wherein the meshes representing the surfaces of the two physical tooth models intersect at least at one point to form an overlapping portion; and calculating the depth of the overlapping portion between the two meshes to quantify the interference of the two physical tooth models.
[0506] In another variation, the method comprises: acquiring the coordinates of a plurality of points on the surfaces of each of the two physical tooth models; digitally representing the surfaces of each of the two physical tooth models by a mesh of points in three dimensions using the acquired coordinates, wherein the meshes representing the surfaces of the two physical tooth models intersect at least at one point to form an overlapping portion; calculating the depth of the overlapping portion between the two meshes; and adjusting the positions or the orientations of at least one of the two physical tooth models in accordance with the depth of the overlapping portion between the two physical tooth models to prevent the interference between the physical tooth models.
[0507] In yet another variation, the method comprises: acquiring the coordinates of a plurality of points on the surfaces of each of the two physical tooth models; digitally representing the surfaces of each of the two physical tooth models by a mesh of points in three dimensions using the acquired coordinates; interpolating each of the two meshes to produce one or more surfaces to represent the boundaries of one of the two physical tooth models, wherein the interpolated surfaces intersect at least at one point to form an overlapping portion; and calculating the depth of the overlapping portion between the two interpolated surfaces to quantify the interference of the two physical tooth models.
[0508] In another variation, the method comprises: digitally representing the surfaces of each of the two physical tooth models by a mesh of points in three dimensions; interpolating the meshes of points to produce interpolated surfaces to represent the boundaries of the two physical tooth models, wherein the interpolated surfaces representing the boundaries of the two physical tooth models intersect at least at one point to form an overlapping portion; specifying a straight line running through the overlapping portion and intersecting the two interpolated surfaces representing the boundaries of the two physical tooth models; and calculating the length of the straight line in the overlapping portion to quantify the interference between the two physical tooth models. [0509] In another variation, the method comprises: digitally representing the surfaces of each of the two physical tooth models by a mesh of points in three dimensions; interpolating the meshes of points to produce interpolated surfaces to represent the boundaries of the two physical tooth models, wherein the interpolated surfaces representing the two physical tooth models intersect at least at one point to form an overlapping portion; developing aligned coordinate systems or a common coordinate system for the two interpolated surfaces representing the two physical tooth models; specifying a straight line running through the overlapping portion and intersecting the two interpolated surfaces representing the boundaries of the two physical tooth models; and calculating the length of the straight line in the overlapping portion to quantify the interference between the two physical tooth models.
[0510] In yet anther variation, the method comprises: digitally representing the surfaces of each of the two physical tooth models by a mesh of points in three dimensions; interpolating the meshes of points to produce interpolated surfaces to represent the boundaries of the two physical tooth models, wherein the interpolated surfaces representing the boundaries of two physical tooth models intersect at least at one point to form an overlapping portion; specifying three orthogonally oriented straight lines each running through the overlapping portion and intersecting the two interpolated surfaces representing the boundaries of the two physical tooth models; calculating the lengths of three orthogonally oriented straight lines in the overlapping portion; defining three vectors along the three orthogonally oriented straight lines, each of the vectors having a magnitude of the inverse of the corresponding length of the overlapping portion; calculating a vector sum of the three vectors to determine the direction and the distance required for the interpolated surfaces representing the boundaries of the two physical tooth models to move apart to avoid interference between the two physical tooth models; and moving apart the interpolated surfaces representing the boundaries of the two physical tooth models in accordance to the vector sum to avoid interference between the two physical tooth models.
[0511] In one implementation, adjacent physical tooth models in a physical dental arch model are simulated. The interference between the two physical tooth models can be predicted before they are assembled to form a physical arch model. The positions and the orientations of the tooth models can be adjusted/modified to prevent the interference. As a result, the precision and effectiveness of the orthodontic treatments can be improved. [0512] In another implementation, the physical tooth models can are used multiple times, each time they are utilized to form a different tooth arch pattern. The configurations of the base plate receptacles for receiving the pins on the physical tooth models can be modified without modifying the tooth models themselves. By monitoring interference between teeth in a digital environment, one can move the teeth in a digital environment and created a tooth distribution pattern that is realistic and can be implemented with the physical tooth models. In one variation, by detecting interference, one can prevent a tooth model being moved into a position that overlaps a tooth in an adjacent position. In another variation, the boundaries of the individual tooth are utilized to predict the movement of tooth during the treatment process.
[0513] Moreover, the physical tooth models can be reused as tooth positions are changed during a treatment steps. For example, the physical tooth can be positioned on a first based in a first pattern representing the target tooth positions in step one of the treatment cycle. An aligner is then fabricated utilizing this first tooth arch pattern. A second based can then be made to receiving the same set of physical tooth model but configuring them to form a second pattern representing the target tooth positions in step two of the treatment process. A second aligner is then fabricated utilizing this second tooth arch pattern. Therefore, much of the cost of making multiple tooth arch models in the orthodontic treatment process may then be eliminated. The tooth models can be configured with pins or other registration features to assist with their assembly on a base.
[0514] In another implementation, the same base is configured to support different tooth arch models having different teeth configurations/patterns. The base can include more than one sets of receiving features that can receive tooth models at different positions. The reusable base may further reduce cost in the dental treatment of teeth alignment. Furthermore, the receiving features/receptacles on the base can be modified to receive tooth models having different pin configurations to avoid interference between the adjacent tooth models in a tooth arch model.
[0515] The physical tooth models include features to allow them to be attached, plugged, locked, or otherwise attached to the base. The physical tooth models can be pre¬ fabricated to include registration features which can be utilized to determine the position and/or orientation of the tooth. The registration feature can further be configure to be used for assembly of the physical tooth models on a base plate. In one variation, the physical tooth models can be automatically assembled onto a base by a robotic arm under computer control.
[0516] One of ordinary skill in the art having the benefit of this disclosure would appreciate that the apparatus and methods disclosed herein may be used for various dental applications, such as dental crown, dental bridge, aligner fabrication, biometrics, teeth whitening, etc. In one variation, the arch model can be assembled from segmented manufacturable components that are individually manufactured by automated, precise numerical manufacturing techniques.
[0517] In another implementation, the physical tooth models in the physical dental arch model can be easily separated, repaired or replaced, and reassembled after the assembly without the replacement of the whole arch model. The manufacturable components can be attached to a base. The assembled physical dental arch model specifically corresponds to the patient's arch at the pretreatment configuration or at one of the targeted steps' configuration during the dental alignment treatment process.
[0518] FIG. 91 illustrates an example for producing a physical dental arch model.
In this example, the process includes the following steps. First individual tooth model is created in step 71 10. An individual tooth model is a physical model that can be part of a physical tooth arch model, which can be used in various dental applications. Registration features are next added to the individual tooth model to allow them to be attached to each other or a base in step 7120. In one variation, steps 71 10 and 7120 are merged together, such that the registration features are created during the process of fabricating individual tooth models.
[0519] A base is designed for receiving the tooth model in step 7130. The base for receiving the physical tooth models may be designed/prepared before the individual physical tooth models are fabricated. The tooth model positions in a tooth arch model are next determined in step 7140. The digital tooth models are developed in step 7150. The interference between the physical tooth models is predicted in step 7160. In step 7170, the pin configurations affixed to the tooth models are selected to prevent interference between adjacent tooth models when they are mounted on the base. A base is fabricated in step 7180. The base includes features/receptacles for receiving the individual tooth model having the selected pin configurations. The tooth models are finally attached to the base at the predetermined positions using the pre-designed features in step 7190.
[0520] The individual tooth models can be obtained in step 7110 in a number of different methods. For example, the tooth model can be created by casting. A negative impression is first made from a patient's arch using for example PVS. A positive of the patient's arch is next made by pouring a casting material into the negative impression. After the material is dried, the mold is then taken out with the help of the impression knife. A positive of the arch is thus obtained.
[0521] In another variation, the negative impression of the patient's arch is placed in a specially designed container. A casting material is then poured into the container over the impression to create a model. A lid is subsequently placed over the container. The container is opened and the mold can be removed after the specified time.
[0522] Examples of casting materials include, but not limited to, auto polymerizing acrylic resin, thermoplastic resin, light-polymerized acrylic resins, polymerizing silicone, polyether, plaster, epoxies, or a mixture of materials. The casting material can be selected based on the uses of the cast. In one variation, the material is selected to allow for ease of cutting in obtaining individual tooth models. Additionally, the material may be selected to be strong enough for the tooth model to take the pressure in pressure form for producing a dental aligner.
[0523] Features (e.g., pins) that can allow tooth models to be attached to a base
(step 7120) can be added to the casting material in the casting process. In one variation, registration points or pins can be added to each tooth before the casting material is dried. In another variation, universal joints can be inserted at the top of the casting chamber using specially designed lids, which would hang the universal joints directly into the casting area for each tooth.
[0524] In step 7110, individual tooth models are next cut from the arch positive. In one variation, the teeth are cut obtain individual teeth in such a manner that they can be joined again to form a tooth arch. The separation of individual teeth from the mold can be achieved using a number of different cutting methods including laser cutting and mechanical sawing.
I l l [0525] Separating the positive mold of the arch into tooth models may result in the loss of the relative 3D coordinates of the individual tooth models in an arch. Various methods may be implemented in step 7120 for determining the relative positions of the physical tooth models. In one variation, unique registration features (e.g., pins) are added to each pair of tooth models before the positive arch mold is separated. The separated tooth models can be assembled to form a physical dental arch model by matching tooth models having the same unique registration marks (e.g., producing a base having features/receptacles for receiving the registration marks on the tooth models, such that when the tooth models are inserted on the base plate a tooth arch is formed).
[0526] The positive arch mold can also be digitized by a three-dimensional scanning using a technique such as laser scanning, optical scanning, destructive scanning, CT scanning and Sound Wave Scanning. A digital dental arch model is therefore obtained. The digital dental arch model is subsequently smoothened and segmented. Each segment can be physically fabricated by CNC based manufacturing to obtain individual tooth models. The digital dental arch model tracks and stores the positions of the individual tooth models. Unique registration marks can be added to the digital tooth models that can be made into a physical feature in CNC base manufacturing.
[0527] Examples of CNC based manufacturing include, but not limited to, CNC based milling, Stereolithography, Laminated Object Manufacturing, Selective Laser Sintering, Fused Deposition Modeling, Solid Ground Curing, and 3D ink jet printing.
[0528] In another variation, the separated tooth models are assembled by geometry matching. The intact positive arch impression is first scanned to obtain a 3D digital dental arch model. Individual teeth are then scanned to obtain digital tooth models for individual teeth. The digital tooth models can be matched using rigid body transformations to match a digital dental arch model. Due to complex shape of the arch, inter-proximal areas, root of the teeth and gingival areas may be ignored in the geometry match. In one variation, high precision scanning is utilized to obtain high resolution digital objects for matching of features such as cusps, points, crevasses, the front and back faces of the teeth. Each tooth is sequentially matched to result in rigid body transformations corresponding to the tooth positions that can reconstruct an arch. [0529] In another variation, the separated tooth models are assembled and registered with the assistance of a 3D point picking devices. The coordinates of the tooth models are picked up by 3D point picking devices such as stylus or Microscribe devices before separation. Unique registration marks can be added on each tooth model in an arch before separation. The tooth models and the registration marks can be labeled by unique IDs. The tooth arch can later be assembled by identifying tooth models having the same registration marks as were picked from the Jaw. 3D point picking devices can be used to pick the same points again for each tooth model to confirm the tooth coordinates.
[0530] The base is designed in step 7130 to receive the tooth models. The base and tooth models include complimentary features to allow them to be assembled together. The tooth model has a protruding structure attached to it. The features at the base and tooth models can also include a registration slot, a notch, a protrusion, a hole, an interlocking mechanism, and a jig. The protruding structure can be obtained during the casting process or be created after casting by using a CNC machine on each tooth. The positions of the receiving features in the base are determined by either the initial positions of the teeth in an arch or the desired teeth positions during a treatment process (step 7140).
[0531] The digital tooth models are developed in step 7150. First, the surfaces of the two physical tooth models are measured. A negative impression of a patient's teeth is obtained. A plurality of points on the surfaces of the negative impression is measured by a position measurement device. The coordinates of the points in three dimensional space are obtained.
[0532] In one variation, a plurality of points representing the surfaces of the negative impression is then used to construct a mesh to digitally represent the surfaces of the patient's teeth in three dimensions. FIG. 106 illustrates a triangulated mesh 7840 that simulates the surfaces of a patient's tooth. The mesh opening can also include other shapes with four, five or more sides or nodes. The mesh points are interpolated into one or more continuous surfaces to represent the surface of the patient's tooth, which serves as a digital model for the tooth.
[0533] The interference between two physical tooth models representing the patient's teeth can be predicted using the digital models of the two patient's teeth, in step 7160. First interference depths are calculated for each digital tooth model. As shown in FIG. 107, a coordinate system 7845 comprising x, y, and z axes is established for a digital tooth model 7850. Along the z direction, as shown in FIG. 107, a plurality of lines 7855 parallel to the z-axis are specified, typically at constant intervals. The lines 7855 intersect with the surfaces of the digital tooth model 7850. The distance between the intersection points, of the segment width, of each line 7855 is called buffer width. The buffer widths are calculated along each of the x, y, and z directions.
[0534] An orthogonal bounding box 7860 can be set up as shown in FIG. 108 to assist the calculation of the buffer widths. The bounding box defines maximum range for the digital tooth model along each direction in the coordinate system 7865. The bounding box 7860 includes three pairs of rectangle faces in three directions. To calculate the buffer width along the z direction, a grid of fixed intervals is set up over the rectangular x-y face 7870 of the bounding box 7860.
[0535] The intervals of the grid 7880 along x and y direction, shown in FIG. 109, are defined in accordance with the precision requirement. The grid nodes define start and end points for the lines 7855. The grid nodes are indexed. The segment width (i.e. the buffer width) is calculated for each pair of indexed grid nodes at the two opposite rectangular faces o the bounding box 7860. The buffer widths can be rescaled and stored for example in 8 bit or 16 bit values.
[0536] The interference between two physical tooth models to be fabricated based on the digital tooth models can be predicted using the corresponding digital tooth models. As shown in FIG. 1 10, the two digital tooth models 7882 and 7884 overlap in the overlapping portion 7886. The buffer widths of each of the digital tooth models 7882 and 7884 are translated into a common coordinate system. For each of the line 7855, intersection points for each of the digital tooth models 7882 and 7884 are determined or retrieved. The interference depth or the depth of overlapping portion 7886 can be calculated along the line in the z direction. The calculation of the interference depth is repeated for each pair of the x-y grid nodes similar to the procedure described above for each digital tooth model. The maximum interference depth can be determined among all the interference depths between the two digital tooth models.
[0537] In one variation, to improve collision detection accuracy, more points will be inserted between the points of a mesh opening to interpolate the values of its neighbors. For example, a center point can be calculated by averaging the four neighbors. An edge center point can be calculated by averaging the two neighbors. Points can also be inserted by linear interpolation weighted by distances or by Spline interpolation.
[0538] Sometimes the coordinate axes of two digital tooth models 7882 and 7884 of off angle than approximately parallel. The calculation of the width of the overlapping portion 7886 may not be accurate if it is based on the buffer widths of the digital tooth models 7882 and 7884. In one implementation, the coordinate systems for the digital tooth models 7882 and 7884 are translated or rotated so that their axes are aligned, as shown in the coordinate system (xl, yl, zl) and the coordinate system (x2, y2, z2) in FIG. 1 1 1. That is, the x axes, y axes and z axes are respectively parallel in the two coordinate systems. The buffer widths are then recalculated along parallel axes for the two digital tooth models 7882 and 7884 in the aligned (or common) coordinate systems. The buffer width values can therefore be additive to accurately derive the width of the overlapping portions 7900 (or collision depth, or interference depth).
[0539] The overlapping portion 7888 can be considered as a discrete three dimensional object 7902 as shown in FIG. 1 12. If the two coordinate systems are aligned, the width of the overlapping portion 7900 can be simply calculated by the overlapping length of the buffer widths.
[0540] To more accurately describe the degree of overlapping between the two digital tooth models 7906, 7908, the widths of the overlapping portion 7904 (or the interference depths) can be separately calculated along three orthogonal directions such as along the directions of the three axes (x, y, z) of the aligned coordinate system 7910, as shown in FIG. 1 13. The aligned coordinate systems can also include spherical and cylindrical coordinate systems.
[0541] In one variation, the digital tooth models that overlap can be moved apart at the design stage to prevent interference between the physical tooth models after they are fabricated and assembled. To move apart two colliding tooth models, it may desirable to select a movement direction to minimize the distance of the movement. In one variation, the optimized direction is close to the axis of the shortest interference depth. In optimizing the movement direction, more weight is therefore given to the shorter directions of shorter interference depths. In one embodiment, as shown in FIG. 114, the vector sum 7918 of vectors 7912, 7914, 7916 respectively having magnitudes of 1/Xdepth, 1/Ydepth, and 1/Zdepth along the x, y and x directions represent an optimized direction weighted toward directions of the shortest interference depths or shortest depth of overlapping portion.
[0542] After the optimal movement direction is determined as shown in FIG. 114, the digital tooth models 7906, 7908 are moved apart along the optimal movement direction by an amount determined by the magnitude of the vector sum 7918. In one variation, each of the digital tooth models 7906, 7908 moves half of the required distance of movement.
[0543] In a digital arch model involving a plurality of tooth models, adjustment movement may be required and performed on a multiple pairs of tooth models. The positional adjustment can be conducted in iterative cycles before obtaining the final arch configurations for all tooth models at a step of an orthodontic treatment. In another variation, a tolerance range for the gaps between the adjacent tooth models can be specified. The iterative adjustment of the tooth models will be performed until all the gaps between adjacent tooth models are within the tolerance range. The designed movements of the tooth models are recorded and will be compared to the actual movement of the teeth during the corresponding step of the treatment.
[0544] In this variation the total effective movement of all the movement steps of a tooth in an orthodontic treatment is the vector sum of each individual movements. As shown as FIG. 115, the total interference depth ("final result") of the orthodontic treatment is the sum of a plurality of movement vectors "move 1", "move 2", "move 3" etc. between two digital tooth models over a plurality of steps in the orthodontic treatment.
[0545] The simulation of the interference between digital tooth models can serve as prediction of the interference between the physical tooth models after they are fabricated and assembled to form a physical dental base mode. The information regarding the interference between the physical tooth models can be used to prevent such interference from occurring. One method to prevent the interference is the adjust teeth positions in a dental arch model, as described above. Another method to prevent such interference is by adjusting features affixed to the physical tooth models.
[0546] The tooth models can be affixed with one or more pins at their bottom portions for the tooth models to be inserted into the base. The two adjacent tooth models may interfere with each other when they are inserted into a base. The pin configurations are selected in step 7170 to prevent such interference between adjacent tooth models.
[0547] Two adjacent tooth models 7670 and 7680 are shown in FIG. 100. The tooth models 7670, 7680 are respectively affixed with pins 7675 and pins 7685. The orthodontic treatment requires the two adjacent tooth models 7670 and 7680 to be tilted away from each other in a tooth arch model. As a result, the pins 7675 and the pins 7685 interfere with or collide into each other. In another example, as shown in FIG. 101, two adjacent tooth models 7690 and 7695 are required to tilt toward each other by the orthodontic treatment. The tooth models 7690 and 7695 are affixed with pins having equal pin lengths. The tooth models 7690 and 7695 can collide into each other when they are inserted into a base 7700 because the insertion angles required by the long insertion pins.
[0548] In another variation, the interference between adjacent tooth models mounted on an arch can be resolved by properly designing and selecting configurations of the pins affixed to the bottom portion of the tooth models. FIG. 102 illustrates a tooth model 7705 having two pins 7710 and 7715 affixed to the bottom portion. To prevent interference of the tooth model 7705 with its neighboring tooth models, the pins 7710 and 7715 are designed to have different lengths.
[0549] FIGS. 103A and 103B detailed perspective views illustrating an example of how two tooth models having the pin configurations shown in FIG. 102 can avoid interfering with each other. FIG. 103 A shows the front perspective view of two tooth models 7720 and 7730 each of which is respectively affixed pins 7725 and 7735. The pins 7725 and pins 7735 are configured to have different lengths so that the pins do not run into each other when they are inserted into a base (not shown in FIG. 103 A for clarity). The avoidance of interference between the tooth models 7720 and 7730 is also illustrated in a perspective bottom view in FIG. 103B.
[0550] The pin configurations for tooth models can be selected by different methods. In one variation, a digital dental arch model that represents the physical tooth model is first produced or received. The digital dental arch model defines the positions and orientations of the two adjacent physical tooth models in the physical dental arch model according to the requirement of the orthodontic treatment. The positions of the physical tooth models including the pins are simulated to examine the interference between two
17 adjacent physical tooth models mounted on the base. The pin configurations are adjusted to avoid any interference that might occur in the simulation. The pin configurations can include pins lengths, pin positions at the underside of the tooth models, and the number of pins for each tooth model.
[0551] The tooth models affixed with pins having the selected pin configurations can fabricated by Computer Numerical Control (CNC) based manufacturing in response to the digital dental arch model. At different steps of an orthodontic treatment, the tooth portions of the tooth models can remain the same while the pins affixed to the tooth portion being adjusted depending on the relative orientation of positions between adjacent tooth models. Furthermore, the base can include different socket configurations adapted to receive compatible pin configurations selected for different steps of the orthodontic treatment. The physical tooth models and their pin configurations can be labeled by a predetermined sequence to define the positions of the physical tooth models on the base for each step of the orthodontic treatment.
[0552] In one variation, different pin configurations are utilized to allow longer pins affixed to the tooth models, which results in more stable physical tooth arch model. The tooth portion of the tooth models may be reused for different steps of an orthodontic treatment (e.g., generating dental aligners for different steps of the treatment). Modular sockets can be prepared on the underside of the tooth models. Pins of different lengths can be plugged into the sockets to prevent interference between adjacent tooth models.
[0553] In one example, before casting the arch from the impression, the base plate is taken through a CNC process to create the female structures for each individual tooth (step 7180). Then the base is placed over the casting container in which the impression is already present and the container is filled with epoxy. The epoxy gets filled up in the female structures and the resulting mold has the male studs present with each tooth model that can be separated afterwards. FIG. 92 shows a tooth model 7210 with male stud 7220 after mold separation. The base 7230 comprises a female feature 7240 that can receive the male stud 7220 when the tooth model 7210 is assembled to the base 7230.
[0554] In another variation, as shown in FIG. 93, a tooth model 7310 includes a female socket 7315 that can be drilled by CNC based machining after casting and separation. A male stud 7320 that fits the female socket 7315 can be attached to the tooth
18 model 7310 by for example, screwing, glue application, etc. The resulted tooth model 7330 includes male stud 7310 that allows it to be attached to the base.
[0555] Male protrusion features over the tooth model can exist in a number of arrangements. FIG. 94 shows a tooth model 7410 having two pins 7415 sticking out and a base 7420 having registration slots 7425 adapted to receive the two pins 7415 to allow the tooth model 7410 to be attached to the base 7420. FIG. 95 shows a tooth model 7510 having one pins 7515 protruding out and a base 7520 having a hole 7525 adapted to receive the pin 7515 to allow the tooth model 7510 to be attached to the base 7520. In general, the tooth model can include two or more pins wherein the base will have complementary number of holes at the corresponding locations for each tooth model. The tooth model 7600 can also include cone shaped studs 7605 as shown in FIG. 96. The studs can also take a combination of configurations described above.
[0556] As shown FIG. 97, the studs protruding our of the tooth model 7608 can take different shapes 7606 such as oval, rectangle, square, triangle, circle, semi-circle, each of which correspond to slots on the base having identical shapes that can be drilled using the CNC based machining. The asymmetrically shaped studs can help to define a unique orientation for the tooth model on the base.
[0557] FIG. 98A shows a base 7610 having a plurality of sockets 7615 and 7620 for receiving the studs of a plurality of tooth models. The positions of the sockets 7615, 7620 are determined by either her initial teeth positions in a patient's arch or the teeth positions during the orthodontic treatment process. The base 7610 can be in the form of a plate as shown in FIG. 98A, comprising a plurality of pairs of sockets 7615, 7620. Each pair of sockets 7615, 7620 is adapted to receive two pins associated with a physical tooth model.
[0558] Each pair of sockets includes a socket 7615 on the inside of the tooth arch model and a socket 7620 on the outside of the tooth arch model.
[0559] Another of a base 7625 is shown in FIG. 98B. A plurality of pairs of female sockets 7630, 7635 are provided in the base 7625. Each pair of the sockets 7630, 7635 is formed in a surface 7640 and is adapted to receive a physical tooth model 7645. The bottom portion of the physical tooth model 7645 includes a surface 7655. The surface 7655 comes to contact with the surface 7640 when the physical tooth model 7645 is inserted into the base 7625, which assures the stability of the physical tooth model 7645 over the base 7625.
[0560] A tooth model 7660 compatible with the base 7610 is shown in FIG. 99.
The tooth model 7660 includes two pins 7665 connected to its bottom portion. The two pins 7665 can be plugged into a pair of sockets 7615 and 7620 on the base 7610. Thus, each pair of sockets 7615 and 7620 uniquely defines the positions of a tooth model. The orientation of the tooth model is also uniquely defined if the two pins are labeled as inside and outside, or the sockets and the pins are made asymmetric inside and outside. Each tooth model may include correspond to one or a plurality of studs that are to be plugged into the corresponding number of sockets. The male studs and the sockets may also take different shapes as described above.
[0561] In another variation, the disclosed methods and system can include teeth duplicate with removable or retractable pins, as shown in FIGS. 104 and 105. A tooth model 7760 is placed on a flat surface 7805 in a recess created in the base 7795. The base 7795 include through holes 7780 and 7785. The tooth model 7800 includes at the bottom potion drilled holes 7775 and 7790 that are in registration and alignment with the through holes 7780 and 7785. Pins 7760 can then be inserted along directions 7765, 7770 into the through holes 7780 and 7785 in the base and then holes 7775 and 7790 in the base to affix the tooth models 7800 into the base 7795.
[0562] In another variation, the tooth model 7810 includes holes 7815. Pins 7830 and 7835 can be inserted into the holes 7815 in spring load mechanisms 7820, 7825. The pins 7825 are retractable with compressed springs to avoid interference during insertion or after the installation of the tooth model over the base. After the tooth models are properly mounted and fixed, the pins 7825 can extend to their normal positions to maximize position and angle control. The overall pin lengths can be cut to the correct lengths to be compatible with the spring load mechanisms to prevent interference between tooth models.
[0563] In one variation, described methods are implemented to prevent tooth model interference in precision mount of tooth models in casting chambers. In such cases, the shape and the height of the tooth models can be modified to avoid interference of teeth during insertion or at the corresponding treatment positions. [0564] A tooth arch model is obtained after the tooth models are assembled to the base 7610 (step 7190). The base 7610 can comprise a plurality of configurations in the female sockets 7615. Each of the configurations is adapted to receive the same physical tooth models to form a different arrangement of at least a portion of a tooth arch model.
[0565] In one variation, the base 7610 can be fabricated by a system that includes a computer device adapted to store digital tooth models representing the physical tooth models. As described above, the digital tooth model can be obtained by various scanning techniques. A computer processor can then generate a digital base model compatible with the digital tooth models. An apparatus fabricates the base using CNC based manufacturing in accordance with the digital base model. The base fabricated is adapted to receive the physical tooth models.
[0566] The physical tooth models may be labeled by a predetermined sequence that defines the positions of the physical tooth models on the base 7610. The labels can include a barcode, a printed symbol, hand-written symbol, a Radio Frequency Identification (RFID). The female sockets 7615 can also be labeled by the parallel sequence for the physical tooth models.
[0567] In one variation, tooth models can be separated and repaired after the base.
The tooth models can be removed, repaired or replaced, and re-assembled without the replacement of the whole arch model.
[0568] Various materials may be utilized for the fabrication of the tooth models.
Examples of the materials include, but not limited to, polymers, urethane, epoxy, plastics, plaster, stone, clay, acrylic, metals, wood, paper, ceramics, and porcelain. The base can comprise a material such as polymers, urethane, epoxy, plastics, plaster, stone, clay, acrylic, metals, wood, paper, ceramics, porcelain, glass, and concrete.
[0569] One of ordinary skill in the art having the benefit of this disclosure would appreciate that the arch model, which comprise of individual tooth models, can be used in different dental applications, such as dental crown, dental bridge, dental aligner fabrication, biometrics, and shell fabrication for teeth whitening. For aligner fabrication, for example, each stage of the teeth treatment may corresponds to a unique physical dental arch model. In one variation, the aligners can be fabricated using different physical dental arch models one at a time as the teeth movement progresses during the treatment. At each stage of the treatment, the desirable teeth positions for the next stage are calculated. A physical dental arch model having modified teeth positions is fabricated using the process described above. A new aligner is made using the new physical dental arch model.
[0570] In one variation, each base is specific to an arch configuration. Therefore, complex and costly mechanisms such as micro-actuators, for adjusting multiple degrees of freedom for each tooth model, may not be needed in the aligner fabrication process.
[0571] In another variation, different stages of the arch model can share the same tooth models. The positions for the tooth models at each stage of the orthodontic treatment can be modeled using orthodontic treatment software. Each stage of the arch model may use a separate base. In another variation, one base can be used in a plurality of stages of the arch models. The base may include a plurality of sets of receptive positions for the tooth models. Each set corresponds to one treatment stage. The tooth models can be reused through the treatment process. Much of the cost of making multiple tooth arch models in orthodontic treatment may, therefore, be eliminated.
Constructing a Physical Dental Arch Model Using CNC
[0572] Examples and variations of methods and apparatus for constructing a physical dental arch model are described below. In one variation, a CNC machine is utilized in the production process. Implementations may include one or more of the following.
[0573] In one aspect, methods for producing a physical dental arch model based on a three-dimensional (3D) digital dental arch model are described. In one variation, the method comprises the following: smoothening the digital dental arch model to make the digital dental arch model suitable for CNC based manufacturing; segmenting the digital dental arch model into at least two digital components; producing manufacturable physical components using Computer Numerical Control (CNC) based manufacturing in accordance with the manufacturable digital components; and assembling the physical manufacturable components to form the physical dental arch model.
[0574] In another aspect, systems for producing a physical dental arch model are described. In one variation, the system comprises: a computer storage device that stores a three-dimensional (3D) digital dental arch model; a computer processor that can smoothen the digital data in the digital dental arch model and segment the digital dental arch model into at least two manufacturable digital components suitable for CNC based manufacturing; and an apparatus that can produce manufacturable physical components in accordance with the manufacturable digital components, wherein the manufacturable physical components can be assembled to form the physical dental arch model.
[0575] In yet another aspect, physical dental arch models assembled by a plurality of components are described. One variation comprises: two or more manufacturable physical components produced by Computer Numerical Control (CNC) based manufacturing in response to manufacturable digital components segmented from a three- dimensional (3D) digital dental arch model; and a base adapted to receive the manufacturable physical components.
[0576] Implementations may include one or more of the following. A method for producing a physical dental arch model based on a three-dimensional (3D) digital dental arch model comprises smoothening the digital dental arch model to make the digital dental arch model suitable for CNC based manufacturing, segmenting the digital dental arch model into at least two manufacturable digital components, producing manufacturable physical components using Computer Numerical Control (CNC) based manufacturing in accordance with the manufacturable digital components and assembling the manufacturable physical components to form the physical dental arch model.
[0577] The method can further include determining if the smoothened digital dental arch model satisfies one or more predetermine criteria for CNC based manufacturing. The method can further include running a CNC simulator to determine if the smoothened digital dental arch model satisfies one or more predetermine criteria for CNC based manufacturing. The digital dental arch model can include removing sharp gaps and divots in the teeth arch in the digital dental arch model. The manufacturable digital components can include a portion of a tooth, a whole tooth, a plurality of teeth, or a complete teeth arch. The manufacturable digital components and the manufacturable physical components can include features that permit the manufacturable physical components to be assembled into the physical dental arch model. The features can include one or more of a pin, a notch, a protrusion, a hole, an interlocking mechanism, a jig, and a pluggable or an attachable feature. The method can further include attaching or plugging the manufacturable physical components into each other to form the physical dental arch model. [0578] The CNC based manufacturing can includes milling, stereolithography, laser machining, and molding. The physical dental arch model can comprise a material selected from the group consisting of polymers, urethane, epoxy, plastics, plaster, stone, clay, acrylic, metals, wood, paper, ceramics, and porcelain. The method can further include obtaining a cast for a teeth arch from a patient and scanning the cast to obtain the digital data for the digital dental arch model. The method can further include generating a digital model for a base compatible with the digital dental arch model and producing the base that can be assembled with the manufacturable physical components.
[0579] The base can comprise one or more features to assist the assembling with the manufacturable physical components, said features comprising one or more of a pin, a notch, a protrusion, a hole, an interlocking mechanism, a jig, and a pluggable or attachable feature. The method can further include attaching or plugging the manufacturable physical components into the base to form the physical dental arch model over the base. The method can further include producing the physical base using CNC based manufacturing.
[0580] Implementations may include one or more of the following. A system for producing a physical dental arch model comprises a computer storage device that stores a three-dimensional (3D) digital dental arch model; a computer processor that can smoothen the digital data in the digital dental arch model and segment the digital dental arch model into at least two manufacturable digital components suitable for CNC based manufacturing, and an apparatus that can produce manufacturable physical components in accordance with the manufacturable digital components, wherein the manufacturable physical components can be assembled to form the physical dental arch model. The apparatus can produce manufacturable physical components in accordance with the manufacturable digital components using Computer Numerical Control (CNC) based manufacturing. The system can further comprise an apparatus that can produce a physical base that is adapted to receive the manufacturable physical components form the physical dental arch model on the base.
[0581] Implementations of the system may include one or more of the following. A physical dental arch model assembled from a plurality of manufacturable physical components, comprises two or more manufacturable physical components produced by Computer Numerical Control (CNC) based manufacturing in response to manufacturable digital components segmented from a three-dimensional (3D) digital dental arch model, and a base adapted to receive the manufacturable physical components. The base can be produced by Computer Numerical Control manufacturing.
[0582] In another example, after a digital model of an arch is acquired from a patient, the digital model is first smoothened to remove gaps and divots that cannot be reproduced in a physical model by a machine. The digital dental arch model is then broken down to small manufacturable components that can be readily handled by automated machining such as computer numerical control (CNC) based milling. The manufacturable components can be an individual tooth, multi tooth segment, or a part of a tooth. Features are added to the manufacturable components to allow them to be attached, plugged or locked into each other. The manufacturable physical components manufactured can be assembled to construct a physical dental archphysical dental arch model for various dental applications such as dental crown, dental bridge, aligner fabrication, biometrics, and teeth whitening. The arch model can be assembled from segmented manufacturable components that can individually be manufactured by automated, precise numerical manufacturing techniques.
[0583] In one variation, the manufacturability of the manufacturable components are simulated, verified and refined if necessary prior to manufacturing. As a result, complex arch shapes that cannot be made can now be practically manufactured. Waste and cycle times are reduced in the process from design, testing, pilot, to production.
[0584] In another variation, the manufacturable components can be attached to each other and/or onto a base. The assembled physical dental archphysical dental arch model specifically corresponds to the patient's arch. In one implementation, there is no need for complex and costly mechanisms such as micro-actuators for adjusting multiple degrees of freedom for each tooth component.
[0585] One or more of the following feature can also be implemented in the manufacturable physical components (e.g., physical tooth models). The manufacturable physical components can be hollow inside and have outer surfaces that allow proper union of the components. The manufacturable physical components can be assembled in pressure forming. The manufacturable physical components can be pre-fabricated similar to LEGO blocks having standard registration and attaching features for assembling. The manufacturable physical components can be automatically assembled by robotic arms under computer control. In one variation, the manufacturable physical components can be separated, repaired or replaced, and reassembled after the assembly.
[0586] FIG. 116 is a flow chart illustrating one example of a method for producing a physical dental arch model. First, a digital model is acquired from a patient's arch in step 8110. The digital model is three dimensional and can be obtained by 3D scanning of a cast produced from the patient's arch. The digital model includes a mesh of points in three dimensions that define the surfaces of an entire or a large portion of an upper or lower arch.
[0587] Next, in step 8120, the digital dental arch model is smoothened by computer processing. A software takes the digital dental arch model as input. One or more criteria for the degree of smoothness can also be provided by a user. Undesirable features such as sharp gaps and divots are removed from the digital dental arch model.
[0588] In one variation, the criteria for the degree of smoothness can be required by the specific dental applications. For example, in applications where the physical tooth arch model is to be implemented for fabrication of plastic aligner, the gaps between the teeth may be filled-up in the digital model, since some variations of the plastic aligners may not reach into the gaps between the teeth. In certain applications, it is also undesirable to have aligners with fine features inside the gaps region because this could potentially create resistance to desired tooth movement in an orthodontics treatment procedure.
[0589] The criteria for the degree of smoothness can also be adjusted by type of the tools used to manufacture the physical components as described below. Computer Numerical Control or CNC based manufacturing refers to the automated and computer controlled machining. In one variation, the CNC equipment have two or more directions of motion, called axes. These axes can be precisely and automatically positioned along their lengths of travel. The two most common axis types are linear (driven along a straight path) and rotary (driven along a circular path). Instead of causing motion by manually turning cranks and handwheels as is required on conventional machine tools, CNC machines allow motions to be actuated by servomotors under control of the CNC, and guided by the part program. The motion type (rapid, linear, and circular), the axes to move, the amount of motion and the motion rate (feed rate) can be programmable in the CNC machine tools.
[0590] In addition to CNC based milling, the CNC based manufacturing also include other computer numerical controlled manufacturing processes such as stereolithography, laser machining, and molding. Other examples of CNC based manufacturing include Laminated Object Manufacturing, Selective Laser Sintering, Fused Deposition Modeling, Solid Ground Curing, 3D ink jet printing.
[0591] For manufacturing a physical dental arch model, however, the typical drill bit in CNC based milling may be too big to reach into the gaps and holes in a teeth arch model. In addition, CNC milling that is around one axis may make it difficult to machine the complex shapes within the gaps between teeth. Several techniques can be implemented to remove the gaps in the digital dental arch model to produce a smoothened digital dental arch model. For example: (1) Boolean union with primitive 3D objects. Graphics Constructive Solid Geometry primitives or self developed predefined geometries can be inserted into the gaps in the digital dental arch model and then combine with the original 3D digital mesh. (2) Extrusion. The surfaces near the gaps are extruded to fill the gaps in the original 3D digital mesh. (3) Geometry modification by moving vertices. Sharp gaps can be closed by specifying the desired boundaries and modifying the mesh to the desired boundaries in the problem regions. (4) Subdivision of surfaces and movement. Similar to Technique (3), the arch surfaces are subdivided in the regions of surface modification for greater smoothness and continuity. (5) Convex hull creation of sub parts to be used as filling objects in the gaps. The gap regions are first located and the points defining edges of the sharp gaps are identified. A convex hull is computed based on these points. The convex hull is joined with the original mesh to fill the gaps using Boolean union. (6) Using parametric surfaces to model fill objects that will be used fit in the gaps.
[0592] "FIG. 117 illustrates an example of the smoothening effects of the gap filling by comparing the surfaces 8210 of before gap fillings and the surfaces 8220 after the gap fillings. A simulation can be conducted using the smoothened the digital dental arch model as input to check and verify the smoothness of the digital dental arch model. The simulation can be run using a simulator software in response to the smoothness criteria required by the manufacturing process such as CNC based milling or the dental applications. Refinement ad smoothening iterations may be called for if the smoothness criteria are not completely satisfied.
[0593] Next, in Step 8130, the smoothened digital dental arch model is segmented into manufacturable digital components suitable for CNC manufacturing. A typical arch in the digital dental arch model includes a whole upper or lower arch or a portion of an arch comprising a plurality of teeth. As shown in FIG. 118A, the physical components can be a portion of a tooth 8310, a whole individual tooth 8320, or sometimes a segment of teeth arch including several teeth.
[0594] The criteria for the size, location, and the number of physical components can be based on both orthodontic needs and manufacturing requirements. In one example, the orthodontic criteria requires the tracking of how the original locations of the physical components and which components can be moved together as a group, which physical components must be moved independently, and which teeth cannot be moved.
[0595] In certain applications, the manufacturing requirements relate mainly to the manufacturability of the digital components, which may supersede the orthodontic criteria. For example, a single tooth can be divided into multiple components to make its model manufacturable. The segmented digital components can be evaluated by a simulator software to verify their manufacturability by a specific manufacture process such as CNC based milling, which may suggest refinement in the size, location, and numbers of the segmentation. The simulation can also include an evaluation and estimation of the physical strength after the assembly, as described below, to determine if the assembled physical components are strong enough to withstand the physical forces in a pressure forming process.
[0596] In one variation, the smoothening of the digital dental arch model may occur during the segmentation. Different segmented digital components may receive different types or degree of smoothening so that the smoothening is tailored to the segments and manufacturing requirements. The arch model can be segmented to small manufacturable components such that the components can be manufactured by automated, precise numerical manufacturing techniques.
[0597] In one implementation, the manufacturability of the digital components are also simulated, verified and refined prior to manufacturing (step 8140). As a result, complex arch shapes that cannot be made can be detected and modified such that they can be manufactured. Therefore, waste and cycle times may be reduced in the process from design, testing, pilot, to production.
[0598] In another variation, special care is applied to the inter-proximal regions in segmenting arch into digital components. In many cases, the inter-proximal regions involve such complexity and details that CNC based manufacturing such as cutting or milling cutting can result in losing details. As shown in FIGS. 119A and 119B, an inter¬ proximal region 8440 is removed between a tooth model 8410 and a tooth model 8420 along the lines 8430. This can be achieved over tooth models in a tooth arch model by using a CNC machine, or by data processing over the digital dental arch model. A thin gap 8450 is formed between tooth model 8410 and tooth model 8420.
[0599] A wedge 8460, shown in FIG. 1 19C is first designed using wedge design software and then made using CNC based manufacturing technique. The wedge 8470 can be inserted into the gap 8450 to complete the digital tooth arch model or the physical tooth arch model. The wedge making and insertion can take into account of the movement of the tooth models 8410, 8420 during the orthodontic treatment. As shown FIG. 1 19D, the wedge 8480 is made to be slightly sheared. The wedge 8490 inserted between the tooth models 8410, 8420 can therefore induce a relative movement between the tooth models 8410, 8420. In general the relative movement can include translational and directional adjustment in different degrees of freedoms. The resulted tooth arch model can then be used to made dental aligners.
[0600] FIGS. 120A, 120B, 120C and 120D illustrate examples of the manufacturable physical components 8510, 8520, 8530, 8540 that respectively include features 8515, 8525, 8535, 8545 that allow them to be attached to each other in order to form a whole or part of a physical dental arch. FIG.120A shows a feature 8515 having a cubic base for a physical component 8510. FIG. 120B shows a feature 8525 having a star- shaped base for a physical component 8520. The star-shaped base defines unique orientation when physical component 8520 is assembled with another physical component. FIGS. 120C and 120D show features 8535 and 8545 respectively comprising two and three pins in the physical components 8530 and 8540. The two pins ensure uniquely defined orientation when physical component 8530 is assembled with another physical component. Similarly, the three pins in feature 8545 ensure unique configuration when physical component 8540 is assembled with another physical component.
[0601] The physical components (e.g., physical tooth models) may include features such as a pin, a registration slot, a notch, a protrusion, a hole, an interlocking mechanism, a
/jig, and a pluggable or an attachable feature. The adjacent manufactured manufacturable physical components may include matching male (e.g. mushroom, push pins) and female features (e.g. hole, notches etc.) for attachment. The male and female features can be fabricated for example by casting mold that include female and male matching features in the mold, each responsible for making respective male and female features. The adjacent manufacturable physical components can be attached together by simply pushing male feature into the female feature, for example, by pressing a pushpin into a receiving hole.
[0602] The physical components can be labeled with unique identifications, and assembled and detached in predetermined sequences. The assembling and detachment can be automated by for example a robotic arm under the control of a computer in accordance with the predetermined sequences.
[0603] The manufacturable physical components 8610 (FIG. 121A) can include a feature 8620 that allow it to be attached or plugged to a based plate. The manufacturable physical components 8630 can also include two pins 8620 for attaching to a base.
[0604] The manufacturable physical components 8730 can be assembled over the base 8710 to form a physical dental archphysical dental arch model 8700 as shown in FIG. 122. The base 8710 is designed in step 8150 for the manufacturable components 8730. The base 8710 comprises one or more features 8720 which are adapted to receive the features 8740 of the manufacturable physical components 8730 for assembling of the physical dental archphysical dental arch model 8700. The features 8720 receiving the manufacturable components 8730 guarantee unique positions and orientations for manufacturable components 8730 in the final physical dental arch model 8700. The features 8720 can include a pin, a notch, a protrusion, a hole, an interlocking mechanism, a jig, and a pluggable or attachable feature. All or a subset of the manufacturable physical components 8730 (step 8160) can be attached to the base 8710. For example, the manufacturable physical components 8730 (step 8160) can be readily plugged attached to slots prepared on the base 8710.
[0605] Features 8720 and features 8740 are designed to be fit each other, which for example, can include matching notches and pins. The features 8720 and features 8740 can be selected in software designs from predefined structures and then add to the root direction of the manufacturable components 8610, 8730 and the top of the base 8710. In another variation, features 8720 and features 8740 can be designed in software and finished by a combination of manufacturing (steps 8160, 8170) and assembling (step 8180). For example, both features 8720 and features 8740 can be notches or holes. A pin can be plugged into the notches to assemble the manufacturable components 8730 and the top of the base 8710. Features 8720 and features 8740 can include asymmetric shapes such as an asymmetric star to ensure a unique orientation in the fitting between the base 8710 and the manufacturable components 8730.
[0606] In one variation, the manufacturable components are assembled in pressure forming. The manufacturable physical components may be hollow inside and have outer surfaces that match the manufacturable digital components to allow proper union of the manufacturable physical components.
[0607] In another variation, the manufacturable physical components can be pre¬ fabricated similar to LEGO blocks. The surfaces of the manufacturable physical components may include standard registration and attaching features for them to join together. The LEGO-like manufacturable physical components can be automatically assembled by robotic arms under computer control.
[0608] In yet another variation, the manufacturable physical components can be separated and repaired after the assembly. The attaching features between manufacturable physical components allow the components to be detached in a sequence. Broken component can be removed, repaired or replaced, followed by re-assembling.
[0609] The manufacturable physical components 8610, 8730 are manufactured in step 8160 using CNC based manufacturing techniques. The segmented manufacturable digital components are provided to as input files to a CNC machine. The manufacturable physical components 8610, 8730 are manufactured individually. In the disclosed methods and systems, the precision and yield of the CNC based manufacturing are high because manufacturability has been considered and verified as part of the designs of the manufacturable components. Common materials for the manufacturable components that are well know to one of ordinary skill in the art include, by not limited to, polymers, urethane, epoxy, plastics, plaster, stone, clay, acrylic, metals, wood, paper, ceramics, and porcelain.
[0610] The physical dental arch model may optionally include a base on which teeth components can be attached. The base 8710 is next manufactured in step 8170. The base 8710 can be designed to possess smooth surfaces so that it complies with CNC manufacturing requirements. The CNC based manufacturing of the base 8710 can include the use of a prefabricated base part and precision drilling of notches on the prefabricated base part to define features 8720. The positions of the manufacturable components 8710 can then be precisely defined in the physical dental archphysical dental arch model 8700.
[0611] Finally, the physical dental archphysical dental arch model 8700 is constructed in step 8180 by assembling the manufacturable physical components 8730 and the base 8710. The manufacturable physical components 8730 can also be assembled onto the base 8710 in different arrangements such as one pin and two pins as illustrated in FIG. 122. The joining features at the base can also include a registration slot, a notch, a protrusion, a hole, an interlocking mechanism, and a jig. In another arrangement, only even numbered teeth can be plugged into the base while the odd numbered teeth are slot in between the even numbered teeth from their sides.
[0612] The physical dental arch model 8700 can be used in different dental applications such as dental crown, dental bridge, aligner fabrication, biometrics, and teeth whitening. For aligner fabrication, for example, each stage of the teeth treatment may correspond to a unique physical dental arch model. Aligners can be fabricated using different physical dental arch models one at a time as the teeth movement progresses during the treatment. At each stage of the treatment, the desirable teeth positions for the next stage are calculated. A physical dental arch model having modified teeth positions is fabricated using the process described above. A new aligner is then made using the new physical dental arch model.
[0613] In one implementation, each base is specific to an arch configuration. There is no need to reconfigure or manipulate a multiple of degrees of freedom for each manufacturable component once it is plugged into the base.
[0614] In another variation, as shown in FIG. 123, the different physical components 8810, 8820, 8830 can be assembled to form a whole or a portion of a physical dental arch model 8800 without a base. The different physical components 8810, 8820, 8830 can be attached or plugged into each other at joining features 8850 that can be pins, registration slot, a notch, etc.
[0615] In another implementation, different stages of the physical dental arch model share the same manufacturable physical components. Only a new base having new set of receptive positions for the manufacturable physical components are required for each stage of the treatment. The manufacturable physical components can be reused through the treatment process. The positions for the manufacturable physical components at each stage of the treatment can be modeled using an orthodontic treatment software.
Constructing A Dental Aligner Using CNC
[0616] Methods and apparatus similar to the ones described above for constructing a physical dental arch model using CNC can also be utilized to fabricate a dental aligner.
[0617] Examples and variations of methods and apparatus for constructing a dental aligner are described below. In one variation, a CNC machine is utilized in the production process. Implementations may include one or more of the following.
[0618] In one aspect, methods for producing a physical dental aligner are described.
One variation comprises: producing a digital dental aligner model suitable for CNC based manufacturing based on the digital dental arch model; segmenting the digital dental aligner model into a plurality manufactuable digital components; producing aligner components using Computer Numerical Control (CNC) based manufacturing in accordance with the digital aligner components; and assembling the aligner components to form the physical dental aligner.
[0619] In another aspect, systems for producing a physical dental aligner are described. One variation comprises: a computer processor capable of producing a digital dental aligner model and segmenting the digital dental aligner model into a plurality of digital aligner components suitable for CNC based manufacturing; and an apparatus capable of fabricating aligner components in accordance with the digital aligner components, wherein the aligner components can be assembled to form the physical dental aligner.
[0620] In yet another aspect, physical dental aligners assembled from a plurality of aligner components are described. One variation comprises: a plurality of aligner components produced by Computer Numerical Control (CNC) based manufacturing in response to digital aligner components segmented from a three-dimensional (3D) digital dental aligner model.
[0621] Implementations may include one or more of the following. A method for producing a physical dental aligner includes producing a digital dental aligner model suitable for CNC based manufacturing based on the digital dental arch model, segmenting the digital dental aligner model into a plurality manufactuable digital components, producing aligner components using Computer Numerical Control (CNC) based manufacturing in accordance with the digital aligner components, and assembling the aligner components to form the physical dental aligner. The physical dental aligner can include a shell that comprises an outer surface and at least inner surface that is capable of aligning one or more teeth. The shell can comprise multiple layers. The shell can comprise varying thicknesses in different areas that is capable of producing forces to render predetermined teeth movement. The method can further comprise smoothening the outer surface and the one or more inner surfaces in the digital dental aligner model to produce a smoothened digital dental aligner model. The method can further comprise producing a digital dental aligner model based on a digital dental arch model. The method can further comprise automatically assembling the aligner components using a robot arm to form the physical dental aligner.
[0622] The aligner components can include features that permit the aligner components to be assembled into the physical dental aligner. The features can include one or more of registration slots, a pin, a notch, a protrusion, a hole, an interlocking mechanism, a jig, and a pluggable or an attachable feature. The method can further comprise attaching or sealing the aligner components into each other to form the physical dental aligner. The method can further comprise assembling the aligner components in a predetermined sequence to form the physical dental aligner. The method can further comprise polishing or retouching the assembled aligner components to form the physical dental aligner. The CNC based manufacturing includes one or more of milling, stereo lithography, laser machining, molding, and casting. The physical dental aligner may be fabricated based on various materials that are well know to one of ordinary skill in the art, including, but not limited to, plastics, polymers, urethane, epoxy, plaster, stone, clay, acrylic, metals ceramics, and porcelain. The physical dental aligner may comprise surface textures that simulate the cosmetic appearance of teeth. The physical dental aligner may be configured with multiple layers each comprising the same or different materials.
[0623] Implementations may include one or more of the following. A physical dental aligner assembled from a plurality of aligner components includes a plurality of aligner components produced by Computer Numerical Control (CNC) based manufacturing in response to digital aligner components segmented from a three-dimensional (3D) digital dental aligner model. The physical dental aligner can further comprise physical features associated with the aligner components that permit the aligner components to be assembled into the physical dental aligner. The features can include one or more of a pin, a notch, a protrusion, a hole, an interlocking mechanism, a jig, and a pluggable or an attachable feature.
[0624] In one variation, a digital dental aligner model is developed based on a digital dental arch model. The digital dental aligner model is then segmented down to small manufacturable aligner components that can be readily handled by automated machining such as computer numerical control (CNC) based milling. Features are added to the aligner components to allow them be attached, plugged or locked into each other. The aligner components manufactured can be assembled to construct a dental aligner for various dental applications, e.g. retainers, mouth guard. The dental aligner can be assembled by from segmented aligner components that can individually be manufactured by automated, precise numerical manufacturing techniques.
[0625] In another variation, the manufacturability of the aligner components can be simulated, verified and refined prior to manufacturing. As a result, complex aligner shapes that cannot be made can be modified before manufacturing. Therefore, waste and cycle times are reduced in the process from design, testing, pilot, to production.
[0626] In another variation, the aligner components can be attached to each other and/or onto a base. The assembled aligner specifically corresponds to the patient's arch. In one implementation, there is no need for complex and costly mechanisms such as micro- actuators for adjusting multiple degrees of freedom for each tooth component.
[0627] One or more of the following feature can also be implemented in the fabrication of the aligner components. The aligner components can be pre-fabricated similar to LEGO blocks having standard registration and attaching features for assembling. The aligner components can be automatically assembled by robotic arms under computer control. The aligner components can be separated, repaired or replaced, and reassembled after the assembly. The physical aligner components can include a shell have multiple layers. The outer surface of the shell can be polished and retouched to simulate the aesthetic appearance of a patient's teeth. The inner surface is capable of aligning a patient's teeth.
[0628] In one variation, the process illustrated in FIG. 116 is utilized for producing a dental aligner. In this example "dental aligner" refers to a dental device for correcting malocclusion. One of ordinary skill in the art having the benefit of this disclosure would appreciate that method and apparatus discussed herein may also be utilized to fabricate a dental shell. The dental shell may be designed to serve as a tooth alignment device, a tooth whitening tray, a retainer, or for various other applications that are well known to one of ordinary skill in the art.
[0629] First, a digital dental arch model is developed in step 81 10 through 8120 as described in above in the construction of a physical dental arch model using CNC. A digital aligner model is next developed based on the digital dental arch model in step 8130. The digital aligner model comprises inner surfaces and outer surfaces. Since the inner surfaces of the aligner will be in contact with the outer surface of the patient's teeth, the inner surfaces of the digital aligner model approximately follow the contours of the outer surface of the digital dental arch model, so that the dental aligner will snap on the arch. Moreover, the inner and outer surfaces of digital aligner are designed to various shapes and thickness to apply the right forces to achieve the movement of the teeth in accordance with a treatment plan.
[0630] Next, in step 8140, the digital aligner model are segmented into digital aligner components suitable for CNC manufacturing. A typical aligner in the digital aligner model includes an upper or lower aligner respectively for the upper and lower arch or a portion of an arch comprising a plurality of teeth. An aligner 8300 is shown in FIG. 1 18B. The aligner components 8310, 8320 can correspond to a portion of a tooth, a whole individual tooth, or sometimes a segment of arch including several teeth.
[0631] The criteria for the size, location, and the number of aligner components may be based on both orthodontic needs and manufacturing requirements. In one variation, the orthodontic criteria require the tracking of how the original locations of the aligner components and which components can be moved together as a group, which aligner components must be moved independently, and which teeth cannot be moved. [0632] In another variation, the manufacturing requirements relate to the manufacturability of the digital aligner components, which may supersedes the orthodontic criteria. For example, a single tooth can be divided into multiple components to make its model manufacturable. The segmented digital components can be evaluated by a simulator software to verify their manufacturability by a specific manufacture process such as CNC based milling, which may suggest refinement in the size, location, and numbers of the segmentation. The simulation can also include an evaluation and estimation of the physical strength after the assembly, as described below, to determine if the assembled aligner components are strong enough to withstand the physical forces in a pressure forming process.
[0633] In one variation, the digital aligner model can be smoothened during the segmentation. Different segmented digital components may receive different types or degree of smoothening so that the smoothening is tailored to the segments and manufacturing requirements.
[0634] In one implementation, the aligner model is segmented to small manufacturable aligner components that can be manufactured by automated, precise numerical manufacturing techniques.
[0635] In another implementation, the manufacturability of the digital components is simulated, verified and refined prior to manufacturing. As a result, complex aligner shapes that cannot be made can be modified and then manufactured. Therefore, waste and cycle times can be reduced in the process from design, testing, pilot, to production.
[0636] In step 8150, features are added to the aligner components to assist the assembling of the aligner components to form an aligner. The features may include a pin, a registration slot, a notch, a protrusion, a hole, an interlocking mechanism, a socket, a jig, and a pluggable or an attachable feature. The adjacent manufactured aligner components may include matching male (e.g. mushroom, push pins) and female features (e.g. hole, notches etc.) for attachment. The male and female features can be fabricated for example by casting mold that include female and male matching features in the mold, each responsible for making respective male and female features. The adjacent aligner components can attached together by simply pushing male feature into the female feature, for example, by pressing a pushpin into a receiving hole. [0637] In another variation, special care can be applied to the inter-proximal regions in segmenting arch into digital components. In many cases, the inter-proximal regions involve such complexity and details that CNC based manufacturing such as cutting or milling cutting can result in losing details. As shown in FIGS. 1 19A and 1 19B, an inter¬ proximal region 8440 is removed between a tooth model 8410 and a tooth model 8420 along the lines 8430. This can be achieved by data processing over the digital dental arch model. A thin gap 8450 is formed between tooth model 8410 and tooth model 8420.
[0638] A wedge 8460, shown in FIG. 1 19C, is then made using CNC based manufacturing technique similar to other manufacturable digital components. The wedge 8470 can be inserted into the gap 8450 to complete the digital tooth arch model. The wedge making and insertion can take into account of the movement of the tooth models 8410, 8420 during the orthodontic treatment. As shown FIG. 1 19D the wedge 8480 is made to be slightly sheared. The wedge 8490 inserted between the tooth models 8410, 8420 can therefore induce a relative movement between the tooth models 8410, 8420. In general the relative movement can include translational and directional adjustment in different degrees of freedoms. The resulted tooth arch model can then be used to made dental aligners.
[0639] FIGS. 120A, 120B, 120C and 120D illustrate examples of the features in the aligner components 8510, 8520, 8530, 8540. The features 8515, 8525, 8535, 8545 allow the aligner components 8510, 8520, 8530, 8540 to be attached to each other to form a whole or part of a physical aligner. FIG. 120A shows a feature 8515 having a cubic base for a aligner component 8510. FIG. 120B shows a feature 8525 having a star-shaped base for a aligner component 8520. The star-shaped base defines unique orientation when aligner component 520 is assembled with another aligner component. FIGS. 120C and 120D show features 8535 and 8545 respectively comprising two and three pins in the aligner components 8530 and 8540. The two pins ensure uniquely defined orientation when aligner component 8530 is assembled with another aligner component. Similarly, the three pins in feature 8545 ensure unique configuration when aligner component 8540 is assembled with another aligner component.
[0640] The aligner components 8310, 8320 are manufactured in step 8160 using
CNC based manufacturing techniques. The segmented digital aligner components are provided to as CNC objects input to a CNC machine. The aligner components 8310, 8320 are manufactured individually. In the disclosed methods and systems, the precision and yield of the CNC based manufacturing are high because manufacturability has been considered and verified as part of the designs of the aligner components. Common materials for the aligner components include polymers, urethane, epoxy, plastics, plaster, stone, clay, acrylic, metals, wood, paper, ceramics, and porcelain. A mechanism may be required to hold the components in place during the milling process.
[0641] In one variation, the aligner is milled out of a plastic block in accordance with digital aligner model. The milled out portion can be a portion of a tooth or a group of teeth. The inner hollow portion of the partially milled plastic block is then filled up with a soft holding material under heating. The holding material is soft at elevated temperatures and is hardened at room temperature. The holding material forms a handle after it cools off to room temperature. The partially milled plastic block can be held from outside while it is milled by CNC based manufacturing. An aligned is produced after machining. The holding material is subsequently removed by heating. The holding material can be wax, silicon, Epoxy or other kind of removable glue.
[0642] In another variation, the outer portion of the aligner component is first fabricated using CNC based manufacturing out of a plastic block. The partially milled plastic block is then inverted and filled with a holding material that has been softened under heating. The holding material wraps the top portion of the partially milled plastic block. The material is hardened after cooling off and firmly grabs the partially milled plastic block in place. Then the inner portion of the aligner arch can be machined while the partially milled plastic block is held at the hardened holding material. An aligned is produced after machining. The holding material is finally removed by heating. The holding material can be wax, silicon, Epoxy or other kind of removable glue.
[0643] In yet another variation, a special clamp can also be used to hold the partially milled aligner parts in place while the rest of the aligner is milled using the CNC machine
[0644] The physical aligner model 8600 is assembled in step 8170 by assembling the aligner components. FIG. 121B illustrates how the aligner components 8610, 8620, 8630 can be assembled to form a whole or a portion of a physical aligner model 8600. The different aligner components 8610, 8620, 8630 can be attached or plugged into each other at joining features 8650 that can be pins, registration slot, a notch, etc. [0645] The physical aligners can be used in different dental applications such as dental crown, dental bridge, dental retainer, mouth guard and teeth whitening. For aligner fabrication, for example, each stage of the teeth treatment may correspond a unique physical aligner model. Aligners can be fabricated based on the digital dental arch model as the teeth movement progresses during the treatment. At each stage of the treatment, the desirable teeth positions for the next stage are calculated. A physical aligner model is fabricated using the process described above for modifying teeth positions in step 8180.
[0646] In one aspect, the disclosed methods and system allow variable shape and thickness in the aligner design. Moreover, the disclosed methods and system may provide wider range of aligner material selections. Analyses over aligner shape may be conducted to ensure a desired shape of aligner to be produced to achieve the desired movements at each stage of the orthodontic treatment. In addition, aligners having optimized shapes can achieve certain movements that the prior art cannot achieve. The aligners can be made thinner and more cosmetic, allowing more comfort in wearing. The manufacturing process is more consistent and easy.
[0647] The aligner components may be labeled with unique identifications, and assembled and detached in predetermined sequences. The assembling and detachment can be automated by for example a robotic arm under the control of a computer in accordance with the predetermined sequences.
[0648] In one variation, the aligner components are assembled in pressure forming.
The aligner components may be hollow inside and have outer surfaces that match the digital aligner components to allow proper union of the aligner components.
[0649] In another variation, the aligner components can be pre-fabricated similar to
LEGO blocks. The surfaces of the aligner components may include standard registration and attaching features for them to join together. The LEGO-like aligner components can be automatically assembled by robotic arms under computer control.
[0650] In yet another variation, the aligner components can be separated and repaired after the assembly. The attaching features between aligner components allow the components to be detached in a sequence. Broken component can be removed, repaired or replaced, followed by re-assembling.
Multi-Layer Casting [0651] Examples and variations of methods and apparatus for fabricating physical tooth models utilizing multi-layer casting techniques are described below. The method may include the steps of applying a first layer of model-forming material to a cast, curing the first layer of model-forming material, applying a second layer of model-forming material and curing the second layer of model forming material. Many more layers may also be included, and each layer may be cured before applying the next layer. Thus, a third layer of model-forming material can be applied, and cured, a fourth layer, etc. The method may also include a step for removing the dental model from the cast.
[0652] The model-forming material can be referred to as casting material, and may be any appropriate material, including but not limited to plaster, polymeric materials (including plastics, polyurethanes, etc.), ceramic materials, metals, alloys, or combinations thereof). For example, the model-forming material may be a plaster or cement. In some variations, the model-forming material is polyurethane or Epoxy. In case of Epoxy, the Epoxy may comprise two or more components that are mixed before using them (e.g., a resin and a hardener). Thus, the method may include a step of mixing the resin and the hardener to prepare the model-forming material.
[0653] The step of applying the first layer of model-forming material may include brushing the model forming material against the cast. Brushing may form a thin coating layer. The model-forming material may be applied by any appropriate technique. As mentioned, the model-forming layer may be brushed on (e.g., with a brush or other applicator). The model forming material may also be sprayed on (e.g., with a sprayer, nozzle, etc.), or poured. In some variations, the layer may be applied by a combination of application techniques.
[0654] A first layer may be applied around a support or framework (e.g., skeleton) about which additional layers are added. For example, a support may be placed into the cast and additional layers of materials may be applied around it. In some variations, a support is formed by first applying a high-shrinkage material into at least a part of the cast, and allowed to shrink. Additional layers may be applied to correct the shape as described herein.
[0655] The model forming material forming each layer may be cured in any appropriate manner. Curing typically involves hardening of the model-forming material from a pourable solution (e.g., a liquid, suspension, etc.) into a gel (e.g., semi-solid) and/or a solid. Thus, the model forming material may be cured for approximately 5 minutes, 10 minutes, 20 minutes, 30 minutes, 45 minutes, 1 hour, 2 hours, 4 hours, 5 hours, 6 hours, 8 hours, 12 hours or 24 hours, or more than 24 hours. The temperature that each layer is cured at may also be controlled. For example, the model-forming material may be cured for some amount of time at approximately room temperature (e.g., 25 0C), or approximately 3O0C, 350C, 4O0C, 5O0C, 6O0C. The temperature may be limited by preventing it from exceeding a maximum temperature or falling below a minimum temperature. In some variations, the airflow over the model-forming material as it is being cured may also be controlled.
[0656] The temperature of the model as it is being formed may be controlled during curing or at any step of the formation of the model (including the entire process). The temperature may be controlled by in appropriate manner, including but not limited to heating (e.g., in an oven), cooling (e.g., by blowing air over it, refrigeration, etc.) or by any combination thereof. In some variations, the thickness or amount of model-forming material, or the rate at which model-forming material is applied, is controlled to help regulate the temperature. For example, thinner layers or smaller amounts (e.g., drops or pellets) of material may be added during formation of the model to regulate the temperature of the model (e.g., by preventing the bulk heating that may result), including during curing. Thus, the amount of material forming each layer may be controlled. The amount of material may be controlled by limiting the absolute amount of model-forming material (e.g., less than about 5g» 1Og, 15g, 2Og, 25g, 30g, 35g, 4Og, etc.) or by limiting the thickness of the layer (e.g., less than about 0.5 mm thick, 1 mm thick, 2 mm thick, 5 mm thick, 10 mm thick, etc.) or the level of material applied to the case (e.g., to a position with respect to the teeth, gingiva, etc.).
[0657] Other methods can also be used to control the temperature of the model during curing, or at any step. For example, cooling or heating may be used to control the model temperature before any layer is cast. The resin or the hardener (or both) may be heated or cooled before, or during the mixing. For example, the resin and hardener may be cooled or heated separately, during the mixing process, or after mixing. Whether cooling or heating is required may depend upon the application requirements. For example, in forming dental aligners using Epoxy, the Epoxy components (resin and hardener) may be cooled during mixing to maintain a low temperature (e.g., room temperature or lower).
[0658] The layers may also be treated before, during or after curing. One or more layers may be treated to improve bonding of the layers to additional layers. For example, the surface of a layer may be laser or chemically etched, scored, or the like. Adhesives may also be used. An adhesive may be added on all or a part of a layer before adding another layer.
[0659] In some variations, the model-forming material may include a stabilizer.
For example, the model-forming material may include a thermal stabilizer such as Al powder, glass powder (or fibers), or the like. The stabilizer may also be a structural stabilizer (such as a fibrous material). For example, when the model-forming material is Epoxy, the stabilizer may be mixed with the resin before the addition of the hardener.
[0660] A casting chamber may also be used during the method of making a dental model. For example, the cast may be placed into a casting chamber, and secured. The casting chamber may closeable, and may include one or more ports for venting, or for the addition of model-forming material. The casting chamber help form the shape of the dental model (e.g., in those region of the dental model that extend beyond the cast, including fiduciary markers such as pins, etc.).
[0661] The method of forming a dental model may also include a step of annealing the dental model. Annealing may serve to further harden the dental model, and may be done as a post-processing step. For example, the dental model may be annealed by baking it (e.g., by subjecting the dental model to an elevated temperature). For example, the model may be annealed by exposing the dental model (or the dental model in the casting chamber and/or cast) to about 4O0C, 5O0C, 6O0C, 7O0C, 8O0C, or 900C for greater than about 2 hours (e.g., for about 2 hours, about 3 hours, about 4 hours, about 8 hours, about 12 hours, etc.).
[0662] Also described are methods of making a dental model including mixing
Epoxy for a first layer, applying the first layer of Epoxy to a cast by brushing at least a portion of the Epoxy on at least a portion of the cast and pouring at least a portion of the Epoxy into the cast, curing the first layer of Epoxy, mixing Epoxy for the second layer, applying the second layer of Epoxy, and curing the second layer of Epoxy. A third layer, fourth layer, fifth layer, etc., may be also be applied after mixing the Epoxy for each layer. In some variations, there is at least a 10 minute wait between mixing each layer of Epoxy. The Epoxy may be cured between each layer by waiting an appropriate amount of time, and/or by exposing the cast and model-forming material to an appropriate temperature, as described above. Any appropriate Epoxy may be used, including Epoxy to which stabilizer has been added (e.g., Al powder).
[0663] Also described are dental models comprising a plurality of solid layers formed from sequentially cured layers of Epoxy, wherein at least one layer includes a stabilizer. Any appropriate stabilizer may be used, including Al powder or fibers, glass powder or fibers, etc.
[0664] In one implementation, the dental model (e.g., tooth arch model) is formed from an imprint taken from the subject's oral cavity (e.g., the upper or lower dental arch). This imprint from which the dental model is formed may be referred to as a cast, or a mold. As described above, the cast may at least partially consist of an imprint (a negative impression) taken directly from a subjects mouth, or it may be made using measurements made from a subject (e.g., by direct measurement or recorded measurement).
[0665] For example, a cast can be filled with a model-forming material (also referred to as a casting material), which can be solidified into a physical model of a region of the subject's oral cavity, such as the upper or lower dental arch. Reference marks may be simultaneously molded or included in the dental model, so that the dental model can be coordinated with the subject's actual dental structures (e.g., teeth). The more accurate the model, the better coordination between the model and the subject.
[0666] FIG. 124 illustrates one variation of a method of making a dental model
9100 as described herein. In this variation of the method for making a dental model, the dental model is formed in a multi-step procedure from a settable material, such as Epoxy, which is sequentially layered into the cast and allowed to set up within the cast. Forming the dental model in sequential layers in this manner may allow the cast to be made without deforming or shrinking, producing a more accurate dental model. For example, the dental model may be formed of Epoxy by serially adding Epoxy material to the cast, and allowing the Epoxy to cure before adding additional Epoxy. After each addition, the Epoxy is allowed to set up and/or cure. The amount of Epoxy added may be small enough that deformation during formation, curing or annealing of the model is minimized. For example, the amount of Epoxy added may also be small enough (or applied in a thin enough layer) so that heat generated by the curing or setting of the Epoxy does not increase the temperature of the model significantly as it is formed. In some variations, a stabilizer (e.g., a thermal stabilizer) may be added to the Epoxy to help stabilize the material as it is added.
[0667] In FIG. 124, the impression is first placed in a casting chamber and secured into place 9102. In some variations, the casting chamber is not used, however a casting chamber may make it easier to manipulate or handle the cast and dental model as it is being formed. The casting chamber may also provide a stable orientation for the cast or dental model. For example, the casting chamber may help orient fiduciary markers. In some variations, the casting chamber may be used to help shape at least a region of the dental model. For example, the casting chamber may provide a shape to a region of the dental model that does not reflect the subject's oral cavity (e.g., the base region, including the pins).
[0668] The casting chamber typically includes a cavity into which the cast may be placed. The casting chamber may also include an orientation, so that the cast is oriented within the casting chamber. In some variations, the casting chamber includes at least one holdfast for holding the cast within the cavity. For example, the cast may be held in position by clamps, screws, adhesive, etc. One variation of a casting chamber including a cast is shown in FIG. 125. In FIG. 125, the casting chamber 9200 has an opening 9202, into which a negative imprint (cast) 9204 has been secured by malleable putty 9206. In this variation, the putty is the holdfast which acts to secure the cast within the casting chamber.
[0669] The casting chamber may be made in any appropriate shape and size, but is preferably large enough to hold casts for a variety of different-sized subjects. Furthermore, the casting chamber may be made of any appropriate material. For example, the casting chamber may be made of a thermally conductive material (e.g., a metal or alloy such as steel, aluminum, etc.). Thermally conductive materials may be particularly helpful for cooling or heating the model during the steps of formation (e.g., during curing, etc). The casting chamber may also include temperature controlling components, such as heating/cooling elements and/or sensors. The casting chamber may also include ports open to atmosphere or for connecting to air or other fluid sources. For example, the casting chamber may include one or more air ports for venting or cooling the material used to form the model. The casting chamber may also include one or more ports for applying model- forming material within the casting chamber. In one variation, the casting chamber is configured to house a negative impression of a patient's tooth arch for casting a positive dental mold.
[0670] The casting chamber may also include a cover. In some variations, the casting chamber may include a cover that can secure the top of the casting chamber. The casting chamber may also include handles, grips and/or guides to assist with handling the casting chamber and/or model.
[0671] Once the cast is secured within the casting chamber, the cast (and/or the casting chamber) may be prepared for the addition of any model-forming material 9104 (e.g., Epoxy or Polyurethane). For example, the cast and/or the casting chamber may be coated with a material (e.g., lubricant, adhesive, hardener, colorant, etc.) before the addition of the model-forming material. In some variations, the cast and/or casting chamber is lubricated so that the model can be more readily removed after it has been formed. In some variations, the cast and/or casting chamber may be coated with a material that will comprise the outer layer of the dental model. Any appropriate material may be used to treat the cast and/or casting chamber. For example, a lubricious material (e.g., an oil-based lubricant, water-based lubricant, or the like) may be used. In some variations, an additional lubricious coating is not needed because the cast is formed from a material that incorporates a lubricant (e.g., polymeric materials such as vinyls, etc.).
[0672] A coating or treating material may be applied to the cast and/or casting chamber in any appropriate manner, including spraying, dipping, rinsing, painting, or the like. The cast and casting chamber may also be prepared by controlling the temperature. In some variations, the cast and casting chamber may be prepared by wetting the cast surface. In one variation, a petroleum-based lubricant (e.g., Vaseline™) is applied to the inner surfaces of the casting chamber (excluding the cast). For example, in FIG. 125, the lubricant can be applied to the inside of the casting chamber, the inner part of the cast chamber lid, any spaces between the casting chamber and the putty holding the cast, as well as any spaces between the cast and the putty.
[0673] Once the cast and casting chamber have been prepared 9104, the model- forming material may be prepared 9106. The model-forming material may be any appropriate material or materials for adding to the cast to build the model. In general the model-forming materials is a settable material that can be poured, sprayed, painted, or otherwise applied into the cast and/or casting chamber so that it conforms to the space created by the cast. In some variations, the model-forming material is a flowable material (e.g., a liquid) that sets up or hardens to form a solid after curing. In some variations, the model-forming material includes a granular solid having a small particle size, so that the individual particles may fit within the imprint of the cast. The solids may then be crosslinked or otherwise hardened to form a solid shape. In some variations, the model- forming material is a polymeric material such as polyurethanes (e.g., Dynacast™) or Epoxy.
[0674] The model-forming material may also comprise non-polymeric materials, including inorganic materials (e.g., plasters, dental stone, etc.). Inorganic model-forming materials may also be formulated as a liquid, suspension or paste that is applied to the cast and that then hardens into a solid model that can be removed from the cast. Other examples of model-forming materials include metals (such as lead, etc.), plastics (e.g., polymers) and the like.
[0675] For example, the model-forming material may be Epoxy such as
RenShape™ or RenCast™. The Epoxy may be a two-component Epoxy, comprising a resin and a hardener that can be mixed immediately before use. The mixture of resin and hardener typically forms a viscous liquid material that can be applied to the cast. The model forming material may also include one or more stabilizers to prevent deforming or shrinking of the model as it is formed or hardened.
[0676] Returning to FIG. 124, a stabilizer (e.g., a thermal stabilizer) may be added to the model-forming material (exemplified in the figure as Epoxy) 108 before the first layer is applied to the cast. The model-forming material may then be added or applied to the cast to form the first layer of the model 91 10. The first layer within the cast is then cured, or allowed to at least partially harden 9112. In some variations, the first layer of model-forming material is allowed to completely harden or cure before preparing and applying the next layer.
[0677] As described above, the model is formed in a multi-step process, allowing the model-forming material to "cure" (at least partially) between the steps. In some variations, the multi-step process includes the forming of two or more layers by the sequential application of the model-forming material within the cast. For example, the first layer can be applied as a thin coating that covers the cast or part of the cast. Shrinkage or other deformation of the model may be avoided by limiting the amount (or thickness) of model-forming material applied to the cast. For example, some model-forming materials may generate heat (especially during curing) that may result in shrinkage or deformation during (or after) formation of the model. The heat generated by the model-forming material may be controlled to prevent such effects.
[0678] For example, FIGS. 126A and 126B show graphs of the temperature of different amounts or thicknesses of one variation of model-forming material (e.g., Epoxy). In FIG. 126A, various amounts of Epoxy (5g and 14g) are cured in an oven set to 400C. The peak temperature during curing of this Epoxy occurs about 20 min. after mixing. After about 30 min at 40°C, the Epoxy mixture experiences significant hardening. FIG. 126B, shows the temperature taken from different amounts of Epoxy (5g, 1Og, 15g, and 25g) as they are cured in the open air over time. The head generated by the Epoxy during curing is dependent upon the mass of the Epoxy mix. As the mass of the Epoxy mixture increases, the temperature generated by the curing (or the temperature retained by the Epoxy mixture) increases. Thus, to prevent the temperature inside of the impression from going above a given temperature (e.g., 600C), the amount of Epoxy applied to the cast can be limited. For example, the total mix weight of the Epoxy added may be kept less than 5g, 1Og, 15g, 2Og, 25g, 30g, 35g, etc. The temperature of the model-forming material can be controlled by cooling, heating, or enhancing cooling or heating (e.g., by controlling thickness), at any stage during formation of the model. For example, the model may be cooled during curing by refrigeration or by blowing air on the layer. In some variations, controlling the size or thickness of the layer may help regulate the temperature, as described herein.
[0679] Each layer of model-forming material may be added in any appropriate manner. For example, the model-forming layer may be added by pouring an amount (e.g., less than 2Og, less than 15g, less than 1Og, less than 5g) of prepared Epoxy into the cast and allowed to cure. In some variations, a layer of model-forming material may be painted on or into the cast. For example, Epoxy may be applied using a paintbrush to coat the cast. A layer of model-forming material may be sprayed into the cast. After addition of the model- forming layer to the cast, the cast (e.g., the entire casting chamber) may be agitated to help remove any bubbles that may have formed during the application of the material to the cast. The cast and model material may then be cured (at any appropriate temperature, including room temperature) for the appropriate amount of time in order for the model-forming material to set up or hardened. In some variations, the model-forming material transitions from a liquid material into a gel, and finally into a solid, over time. The time between the application of each layer may therefore be based upon the time required for the material to transition from the liquid to the gel or solid state. Hardening of the model-forming material may also be material and/or temperature dependent. Thus, the temperature at which each layer is allowed to cure may be controlled.
[0680] Any appropriate amount of model-forming material may be added to the cast for each layer. In general, the layers are added to avoid the formation of a large mass of model-forming material that could result in a region of elevated temperature as the mass cures or sets, since heating of the model-forming material might cause expansion and then shrinkage of the model and/or cast. For example, the first layer may comprise less than about 0.5 in3 of material per tooth in the model. However, the average volume of each tooth is approximately 2.5 in3. Thus multiple layers may be added to form the model. In some variations, the model comprises at least three layers. Furthermore, different amounts of material may be added for each layer. The first layer(s) generally include less material than later layers, since the first layer(s) may be closest to the surface of the cast, and therefore it may be important to minimize shrinkage or deformation of these detail-rich surfaces.
[0681] As described, different layers may comprise different materials. For example, a layer of adhesive may be used between different layers to help adhere the different layers together. The different layers may also be treated to aid in adhesion of layers to each other or to other components of the model (e.g., pins, labels, etc). For example, the surface of a layer may be treated by etching or scoring (e.g., laser and/or chemical etching).
[0682] FIG. 127 illustrates the addition of different layers to form a dental model.
In FIG. 127, the first layer 9403 coats the surface of the cast 9401. After applying the first layer, it is at least partly cured, and a second layer 9405 is applied. The second layer is then at least partly cured, and a third layer 9407 is applied. A pin 9409 is shown added to the second layer. Pins may be used so that the model can be attached (and properly oriented) on a base plate. Pins may be pre-coated with model-forming material (e.g., the ends of the pins that insert into the model). In some variations, the pins are added with the last layer of model-forming material. As described above, more than three layers may be applied, and the layers may be added in a different manner. For example, the first layer may be added as a horizontal stratum, rather than as a coating of the cast or previous layer.
[0683] In some variations, the later layers (e.g., the last layers added) may be thicker than the previous layers because the layers that have already been applied in the model may prevent deformation of the forming model by the layers added layer. Thus, the initial layers applied to form the model may be continuous or connected layers that (once applied and cured to form part of the model) can provide structure and rigidity to the model as it is being formed. For example, the last layer can be cast with the chamber closed, and can be quite thick (e.g., > 5 mm). The heat generated or retained by this layer as it cures may be difficult to control because it is so thick, which may result in distortion of the layer and/or the model. However, as described herein, the layers already applied by the model may prevent possible deformation of this thicker layer from deforming the model as a whole.
[0684] After each layer is added, the cast may be agitated (e.g., shaken on a shaker) to remove any air bubbles from the layer. Subsequent layers may be made of the same model-forming material, or they may comprise different model-forming materials, and may be applied by the same method (e.g., pouring, brushing, spraying, etc.), or a different method. Thus, the multi-step process allows different layers to include different materials, or different amounts of the same materials (e.g., hardeners, stabilizers, etc.). Returning to FIG. 124, steps 91 16-9124 can be repeated for each n layer, until all layers (1 to n) have been added. As described above, the model-forming material (e.g., Epoxy) may be prepared fresh for each layer 91 16, and any stabilizer (e.g., thermal stabilizer) may be included with the model-forming material 9118. The material can then be added to the cast to form the next layer 9120. Each layer can be at least partially cured for any appropriate amount of time 9122. For example, the second, third... n layer can be cured for between 10 minutes and 12 hours at room temperature (or at any appropriate temperature, such as 400C). Thus, in FIG. 124, steps 9116-9124 are repeated for each n layer, until all layers (1 to n) have been added 9124. [0685] In one variation of the method of making a dental model described herein, model-forming material is added so that it cures and sets up as it is added to the cast. For example, FIG. 128 illustrates one variation of this method. In FIG. 128, a small amount of material 9503 is added to form pellets 9505 within the cast 9501. As the material is applied, it immediately begins curing. Thus, the model-forming material 9503 may be premixed and kept from curing by being sealed within an applicator 9508. For example, the model forming material may cure only when exposed to air, or at a predetermined temperature. Thus, the material can be applied in small amounts or layers (including layers of pellets, horizontal layers and non- horizontal layers) at least partially cure before adding more model-forming material. Pins or other fiduciary markers may also be added. In some variations, the addition of material is suspended and resumed during formation of the model in order to ensure that the fiduciary markers are properly positioned.
[0686] In another variation, the model may be formed with one or more supports, scaffolds or cores. For example, such a framework may be placed within the cast, and the model-forming material can be layered around the framework to from the model. In one variation, a core is formed of a material (including a model-forming material) that is allowed to shrink. Thus, the core may be a first layer of material that is placed in the mold, and then allowed to shrink. Additional layers can then be added around this core as described herein, so that the model fills in or corrects the model shape until it conforms to the cast.
[0687] As described above, stabilizers may be included as part of the model- forming material. Stabilizers may be thermal stabilizers, such as Al powder, fiberglass, glass powder, etc. Any appropriate stabilizer may be used. For example, the amount of stabilizer may be added as a weight percent of the total model-forming material. In some variations, the stabilizer comprises about 2%, 5%, 10%, 20%, 25%, 30%, 40%, 50%, 70% of the model-forming material, by weight. The stabilizer may provide regions within the model that are not as affected by the heat- or curing-induced shrinkage of the model- forming material (e.g., Epoxy). The amount of stabilizer used may be maximized while still allowing the model-forming material to retain sufficient structural strength.
[0688] FIGS. 129A and 129B illustrate a stabilizer that decreases the shrinkage in a model block of Epoxy. The stabilizer used in this example is Al powder. FIG. 129A shows the model block. This "standard" is first used to make a negative model (cast) from which Epoxy model is made. The entire block is cast from one batch of Epoxy prepared without stabilizer (HH-003 Epoxy 1 and HH-003 Epoxy 2) and with stabilizer (HH-003 Epoxy (IMPOOl)). All three models were then measured in each of five different dimensions, Dl to D5, as illustrated in FIG. 129A, and these measurements were compared to the actual sizes of each of these dimensions from the original standard block. The data shown in FIG. 129B illustrates that, in general, the block in which stabilizer (IMPOOl) was included shrunk less than the blocks without stabilizer (HH-003 Epoxy 1 and HH-003 Epoxy 2). The measurements given in the table for the dimensions were obtained by dividing the measured dimension of the Epoxy model from the dimension of the original standard, and subtracting 1.000 (one).
[0689] Once the model has been formed as described above, it may be post- processed by undergoing one or more additional steps. For example, the model may be annealed by exposing it to a temperature that strengthens the material. For example, the model may be baked at an elevated temperature (e.g., a temperature or temperatures between 4O0C and 9O0C) for an appropriate annealing time (e.g., 2 to 8 hours).
[0690] The methods of forming a dental model described above may allow the fabrication of precise models by preventing shrinkage and deformation, particularly shrinkage or deformation due to thermal effects of the model-forming material. Shrinkage and deformation may result in inaccurate models, because it may change the overall shape of the dental model, and may shift the location and orientation of pins or fiduciary markers on the dental model. Deformation may also damage the cast used to form the model.
[0691] As described above, the casting process may be used with pins or any other appropriate fiduciary markers. It may be particularly useful to position pins so that the dental model may result in a coordinated dental arch model, such as a digital dental arch model. An exemplary process for generating a digital tooth arch model is described in detail below.
[0692] First, negative impressions of the patient's upper and lower tooth arches, and X-ray images of the teeth, are taken through procedures that are well known to one of ordinary skill in the art. Although the X-ray images are not required for generating the digital model of the tooth arch, X-ray images may be utilized either directly by the simulation program or indirectly by the operator to modify or enhance the digital tooth arch model.
[0693] The negative impression of the patient's tooth arch is coupled (e.g., glued, bonded, interlocked, etc.) to a container such as the casting chamber (as described above). A three-dimensional position input device (e.g., MicroScribe®, stylus, etc.) can then be utilized to determine an approximate root position for each of the teeth within the tooth arch. For example, a MicroScribe® can be inserted into the negative impression of a tooth to approximate the root position for that particular tooth. In one variation, the MicroScribe® is inserted into the cavity along the longitudinal orientation of the tooth, and, if necessary, further adjusted to a position that approximates the position of the root of the tooth. A computer is then used to record the position of the MicroScribe®, which corresponds to the approximate root position. In one variation, the placement of the MicroScribe® is controlled by an operator. In another variation, an automated system having optical and/or tactile feedbacks is utilized to position the MicroScribe®.
[0694] In addition, the approximated root for each tooth may be defined by one or more positioning/placement of micro-scribes. For example, the micro-scribe may be placed within each tooth cavity to define a proximate position of the root for each of the teeth. In another variation, the micro-scribe is used to define two positions or longitudinal axis, which in combination approximates the position of the root for a tooth. Pin-like objects placed on a positive tooth model may be utilized later to simulate the positions defined by the micro-scribe, which in turn represents the approximate position of the root.
[0695] In one example, the MicroScribe® is implemented to define four points within each of the tooth cavity within the negative impression of the tooth arch. The four MicroScribe® defined points are then utilized to define the position for the placement of two pins or an asymmetric peg/interface which can simulate the root of the tooth. In another example, the MicroScribe® is implemented to sample a series of points that represent the profile of each of the tooth cavity within the negative impression. For example, three or more points on the surface of the cavity, which represents a tooth, may be sampled by the MicroScribe® to define an approximate surface profile of the tooth. The approximate surface profile is than used to define and approximate root position. For example, two pin positions may be calculated to fit within the approximate surface profile along the longitudinal axis of the tooth. In one variation, a sectional plan is defined at the base of the tooth based on the MicroScribe® sampling of the negative impress representing the gingival tissue. A pair of pin, with a pre-set distance "d", is then positioned perpendicular to this sectional plan, and centered within the tooth that is defined by the approximate surface profile defined by the MicroScribe®.
[0696] Next, a cover plate (e.g., the lid of the casting chamber) is drilled with holes for holding pins that would correspond to root or pin positions defined by the MicroScribe®. The holes may be drilled with a Computer Numeric Control (CNC) machinery utilizing data collected from the micro-scribe measurements. In one variation, the cover plate and the container (e.g., casting chamber) are manufactured with matching reference markers, such that the coordinate system relied on by the micro-scribe can be properly transposed over to the cover plate. Pins are then inserted into the holes on the cover plate. The cover plate is shaped to fit on top of the casting chamber holding the negative impression of the tooth arch. When the cover plate and the container are properly aligned, the position of the pins should correspond to the approximate root positions defined by the micro-scribe. The model may then be fabricated, as described herein. Once the polymer cures, a positive arch is created within the negative impression, with the pins bonded to the positive arch. The user may then decouple the negative impression from the positive arch, resulting in a positive tooth arch of the patient with a plurality of pins that simulates the root position. Optionally, the positive arch may be scanned (e.g., laser 3D scanning, etc.) to generate a three-dimensional digital representation of the tooth arch, which may be utilized later in this process to align the individual tooth.
[0697] In one variation, the pin positions can be utilized to determine the relative positions of the teeth in the patient's tooth arch, since the pin positions were defined by the micro-scribe relative to the negative impression of the patient's tooth arch. In another variation, an optional scan of either the positive tooth arch model or the negative tooth arch impression may be performed to determine the relative positions of the teeth in the tooth arch. The optional scan may also be utilized along with the pin information for determining the relative positions of the teeth within the tooth arch. In yet another variation, the optional scan is utilized alone, without the pin information, to determine the relative positions of the teeth within the tooth arch.
[0698] An example of a casting method using a dental arch is described below. As mentioned previously, the methods, devices, and systems described herein are not limited to fabrication of dental models, although they may be particularly well-suited to this purpose.
[0699] In the following example, a dental model is fabricated using a two part
Epoxy (e.g., RenShape™ Epoxy) as the model-forming material. The Epoxy comprises a resin and a hardener that are kept separate until shortly before mixing and applying to the cast. In this example, a thermal stabilizer (e.g., Aluminum powder) is included, as described above. The majority of the steps are performed at room temperature (e.g., 220C ±2 0C) unless otherwise indicated.
[0700] The casting chamber is prepared by affixing the cast within the casting chamber and applying sealant and/or lubricant to exposed non-cast surfaces. For example, Vaseline™ petroleum jelly is applied to exposed surfaces of the casting chamber and the inner surfaces of the chamber lid. The cast in this example is held within the casting chamber by putty as shown in FIG. 125, and exposed surfaces of the putty may also be coated with Vaseline™.
[0701] Immediately before the Epoxy is used, it must be prepared (mixed). A stabilizer may be added and mixed with the resin before the hardener is added. For example, an appropriate amount of Aluminum powder can be added to the resin and mixed by stirring until the Aluminum power is uniformly distributed in the resin. In one variation, the Epoxy is prepared by mixing 14g of the Epoxy resin (including the stabilizer) with 3g of Epoxy hardener (to give a weight ratio of approximately 7: 1, resin mix to hardener). The resin and hardener mixture should be mixed well.
[0702] The prepared resin can be applied as a first layer to the casting chamber. A brush (e.g., a paint brush) may be used to apply a very thin layer of Epoxy on the cast. Applying with a paint brush may help get rid of air bubbles that might otherwise form on the surface of the cast. The brush should be stroked across the surface to remove any air trapped within or below the Epoxy. A layer of Epoxy can then be added (e.g., by pouring) into the "painted" cast. For example, the Epoxy may be added until it is just at the gingival line (e.g., approximately 1 mm above) within the cast, as shown in FIG. 125. The casting chamber can then be agitated an industrial vibrator at a relatively high frequency for approximately 10 minutes, then placed in an oven set to 4O0C for 90 minutes. [0703] The lid of the casting chamber may also be prepared. For example, a base plate for the dental model (into which the dental model can attach) can be attached to the lid of the casting chamber along with the pins that will be included as part of the dental model. The base plate generally includes holes or slots that mate with the pins. In some variations, the pins are positioned into a base plate, and the base plate is affixed to the lid of the dental model. Alternatively, the inside surface of the lid of the casting chamber may include holes that correspond to the pin holes in the base plate, so that pins can be inserted into the lid of the base plate. Thus, when the lid of the casting chamber is closed, the pins can be inserted into the hardening resin. To prepare the pins, a layer of Epoxy is applied to at least the region of the pins that will be inserted into the dental model and the pins may be releasably secured within the base plate or the lid of the casting chamber. The rest of the lid of the casting chamber may be coated with Vaseline™. A brush can be used to apply Epoxy to the pins. The lid of the base plate (including the coated pins) can then be placed on a vibrator to agitate it for at least 10 minutes. The applied Epoxy is typically cured for approximately four hours at room temperature.
[0704] Before applying the second layer of Epoxy to the cast, the casting chamber lid is fastened (e.g., by screwing or otherwise securing) to the casting chamber, and the Epoxy for the second layer is prepared by mixing the resin (plus the stabilizer) with the hardener. For example, 28g of resin (with hardener already added), may be well mixed with 4g of hardener (to form a 7: 1 weight ratio of resin mix to hardener). As described above, each layer can include less than a predetermined amount of Epoxy in order to avoid generating excessive heat as the Epoxy cures, and damaging the model or the cast. For example, less than about 35g of resin, less than about 30g of resin, less than about 25g of resin, less than about 2Og of resin or less than about 15g of resin may be added to form each layer. The second layer of resin is applied to the cast by pouring the properly mixed resin into the casting chamber. The casting chamber is then placed on the industrial vibrator and agitated for 10 minutes. In this example, there should be at least a ten minute difference between the mixing of the Epoxy for the second layer and the mixing of the Epoxy for the third layer.
[0705] Epoxy for the third layer is then mixed. For example, 28g of resin (with stabilizer) is mixed with 4g of hardener (in a 7: 1 ratio of resin mix to hardener). The Epoxy is mixed well, and then an appropriate amount of Epoxy is poured into the casting chamber and vibrated on an industrial vibrator for approximately 10 minutes. Putty is then be used to block off the overflow port of the casting chamber, and the cast is allowed to cure for at least 12 hours before removing the (now solid) dental model. As described above, the dental model can then be annealed to further harden the material.
[0706] Variations of the dental models produced by the methods described herein may be layered solids formed by layers of model-forming material, where each layer has been individually cured. The layers may be visible, for example, when the model-forming material is different between each successive layer. In some variations each layer (e.g., the first layer, the second layer, etc.) is composed of model-forming materials that have different compositions. For example the ratio of resin and hardener used for the Epoxy may be different, or the amount of any stabilizer may be different. The different proportions of resin and hardener may be detectable, and may also result in different properties (e.g., tensile strength, hardness, etc.) for the different layers, and the overall dental model. In some variations, the different layers of a dental model may be not be visible, but may be detected by analyzing a cross-section through the dental model.
[0707] In some variations, the dental models comprising layered solids include one or more stabilizers, as described above. For example, a thermal stabilizer (such as Al powder) may be added to at least one of the layers. Additional materials may also be used as stabilizers, including structural stabilizers. For example, fibrous material may be incorporated into the model-forming material of one or more of the layers (examples of structural stabilizers are synthetic fibers and organic fibers, including glass fibers, cotton fibers, cellulose-based fibers, etc). Fibrous materials may increase the structural strength and/or durability of the dental model. Structural stabilizers may be included in at least the first layer of the dental model to provide external strength when the dental model is used, for example, to form dental aligners.
[0708] This invention has been described and specific examples of the invention have been portrayed. While the invention has been described in terms of particular variations and illustrative figures, those of ordinary skill in the art will recognize that the invention is not limited to the variations or figures described. In addition, where methods and steps described above indicate certain events occurring in certain order, those of ordinary skill in the art will recognize that the ordering of certain steps may be modified and that such modifications are in accordance with the variations of the invention. Additionally, certain of the steps may be performed concurrently in a parallel process when possible, as well as performed sequentially as described above. Therefore, to the extent there are variations of the invention, which are within the spirit of the disclosure or equivalent to the inventions found in the claims, it is the intent that this patent will cover those variations as well. Finally, all publications and patent applications cited in this specification are herein incorporated by reference in their entirety as if each individual publication or patent application were specifically and individually put forth herein.

Claims

CLAIMS What is claimed is:
1. A method of constructing individual tooth models of teeth in a patient's tooth arch comprising: determining a position of a registration feature for each of the teeth within the patient's tooth arch, wherein each registration feature identifies a relative position of its tooth in relation to other teeth within the patient's tooth arch; and constructing the individual tooth models of teeth in the patient's tooth arch, wherein each of the tooth models comprises the corresponding registration feature.
2. The method according to claim 1, wherein constructing individual tooth models of teeth comprises: fabricating a tooth arch model of a patient's tooth arch, wherein each of the teeth in the tooth arch has its corresponding registration feature; and dividing the tooth arch models into individual tooth models.
3. The method according to claim 2, wherein fabricating a tooth arch model of a patient's tooth arch comprises: positioning a corresponding registration feature in each tooth location within a negative mold of the patient's tooth arch; and filling the negative mold with a polymer to form the tooth arch model.
4. The method according to claim 1, wherein determining a position of a corresponding registration feature for each of the teeth comprises: scanning an inner surface of a negative mold of the patient's tooth arch.
5. The method according to claim 4, wherein scanning an inner surface of a negative mold comprises scanning an inner surface of a negative mold with a position determining device.
6. The method according to claim 5, wherein the position determining device comprises a mechanical scanning device.
7. The method according to claim 6, wherein the position determining device comprises an optical scanning device.
8. The method according to claim 4, wherein scanning an inner surface comprises: sampling selective locations on the inner surface profile of the negative mold; and utilizing information of the inner surface profile of the negative mold to determine the position of the corresponding registration feature for each of the teeth within the patient's tooth arch.
9. The method according to claim 8, wherein each of the corresponding registration features comprises a pair of pins.
10. The method according to claim 1, wherein determining a position of a registration feature comprises determining the position of the registration feature for each of the teeth based on a negative impression of the patient's tooth arch.
1 1. The method according to claim 10, wherein determining a position of a registration feature further comprises utilizing a position determination device to determine the position of the registration feature.
12. The method according to claim 1 1, wherein the position determination device comprises a microscribe.
13. The method according to claim 1, wherein determining a position of a registration feature comprises determining the position of the registration feature for each of the teeth based on a positive tooth arch model of the patient's tooth arch.
14. The method according to claim 1, further comprising: preparing a base for receiving the individual tooth models. ^
15. The method according to claim 14, wherein preparing a base for receiving said individual tooth models comprises creating a receptacle on the base for each of the tooth models, such that when all the tooth models are coupled to the receptacles the tooth models forms a tooth arch.
16. The method according to claim 15, wherein the tooth arch formed by the individual tooth models represent a target tooth arch in an orthodontic treatment process.
17. The method according to claim 16, further comprising: fabricating a dental aligner on the tooth arch formed by the individual tooth models.
18. The method according to claim 16, further comprising: placing a polymeric sheet over the tooth arch formed by the individual tooth models; and heat forming the polymeric sheet over the tooth arch formed by the individual tooth models.
19. The method according to claim 15, wherein each of the receptacles is configured to receive the registration feature of the corresponding tooth model.
20. The method according to claim 1, further comprising: creating a modified teeth arrangement which differs from a teeth arrangement of the patient's tooth arch; and preparing a base having receptacles for receiving the tooth models to form a tooth arch having the modified teeth arrangement.
21. The method according to claim 20, wherein the modified teeth arrangement is created utilizing a computer.
22. The method according to claim 21, wherein the base is prepared utilizing a CNC machine.
23. The method according to claim 20, further comprising: inserting the tooth models into the receptacles on said base to form the tooth arch having the modified teeth arrangement.
24. The method according to claim 23, further comprising: forming a dental aligner over the tooth arch having the modified teeth arrangement.
25. The method according to claim 24, wherein the modified teeth arrangement comprises a projected teeth arrangement of the patient's tooth arch in a stage of an orthodontic treatment process.
26. The method according to claim 25, wherein each of the registration features comprises a pair of pins, and each of the receptacles comprises a pair of holes configured to receive said pins.
27. The method according to claim 25, wherein the modified teeth arrangement is created utilizing a computer.
28. The method according to claim 20, wherein creating a modified teeth arrangement comprises utilizing a computer having a visualization interface to create the modified teeth arrangement.
29. The method according to claim 20, wherein preparing a base having receptacles comprises creating the receptacles on the base utilizing a CNC machining device.
30. The method according to claim 1, further comprising: scanning at least a crown portion for each of the tooth models of teeth in the patient's tooth arch.
31. The method according to claim 1 , further comprising: generating a digital model of the patient's tooth arch based on at least the registration features.
32. The method according to claim 31 , further comprising: modifying a position of at least one of the teeth in the digital model of the patient's tooth arch to form a modified teeth arrangement; and creating a base for receiving the tooth models to form a tooth arch having the modified teeth arrangement.
33. The method according to claim 32, further comprising: placing said tooth models onto said base to form the tooth arch having the modified teeth arrangement.
34. The method according to claim 33, further comprising: forming a dental aligner over the tooth arch having the modified teeth arrangement.
35. The method according to claim 34, wherein the modified teeth arrangement comprises a teeth arrangement of the patient's tooth arch within a step in an orthodontic treatment process.
36. The method according to claim 1 , further comprising: modifying the position of at least one of the registration features in relation to the other registration features; preparing a base plate with receptacles which correspond to the positions of the registrations features including the registration feature with the modified position;
37. The method according to claim 36, further comprising: inserting the individual tooth models of teeth into the base plate, wherein each tooth model is inserted into one of the corresponding receptacle on the base plate.
38. The method according to claim 37, wherein each of the registration features comprises a pair of pins, and each of the receptacles comprises a pair of holes configured to receive a pair of pins.
39. The method according to claim 1, further comprising: recording the position for each of the registration features in a computer.
40. The method according to claim 39, further comprising: modifying the position of at least one of the registration features recorded in the computer.
41. The method according to claim 40, further comprising: preparing a base with receptacles corresponding to the positions of the registration features recorded in the computer.
42. The method according to claim 41, further comprising: inserting individual tooth models onto the base with the registration feature for each tooth inserted into its corresponding receptacle.
43. The method according to claim 39, further comprising: scanning at least the crown portion of each of the tooth models; and generating a digital representation of a tooth arch representative of the patient's tooth arch.
44. The method according to claim 43, wherein generating a digital representation of a tooth arch comprises utilizing at least the position for each of the registration features and a digital representation of the crown portion of the teeth to form the digital representation of the tooth arch.
45. The method according to claim 1, further comprising: fabricating a dental aligner based on the individual tooth models.
46. The method according to claim 1, further comprising: generating a digital tooth arch which represents a target tooth arch.
47. The method according to claim 46, further comprising: arranging the individual tooth models to form a physical tooth arch which represents the digital tooth arch.
48. The method according to claim 1, further comprising: organizing the individual tooth models to form a tooth arch; and fabricating a dental aligner on the tooth arch formed by the individual tooth models.
49. The method according to claim 48, wherein each of the individual tooth models comprises the registration feature extending from the based of the tooth model.
50. The method according to claim 48, wherein the tooth arch formed by the individual tooth models comprises a projected teeth arrangement of the patient's tooth arch in a stage of an orthodontic treatment process.
51. The method according to claim 1 , wherein each of the registration feature comprises a protrusion extending from a based portion of the corresponding tooth model, the protrusion is configured to engage a base plate and prevent the tooth model from rotating on the base plate.
52. A method of constructing a physical model of a tooth arch from individual physical tooth models of teeth in a patient's tooth arch, the method comprising: generating a digital model of the tooth arch from two or more digital models of individual physical tooth models.
53. The method of claim 52, further comprising generating a digital model for each of the individual physical tooth models.
54. The method of claim 53, wherein generating a digital model of an individual physical tooth model comprises scanning an individual physical tooth model.
55. The method of claim 54, further comprising: fabricating an individual physical tooth model; and scanning the fabricated individual physical tooth model.
56. The method of claim 55, further comprising: acquiring a negative impression of a patient's tooth arch; casting a positive mold of the negative impression; and separating the positive mold to form at least one individual physical tooth model.
57. The method of claim 52, further comprising arranging the teeth in the digital model of the tooth arch to have relative positions corresponding to relative positions of the teeth in the patient's tooth arch.
58. The method of claim 57, further comprising modifying a position of at least one of the teeth in the digital model of the tooth arch; and arranging the individual physical tooth models to have relative positions corresponding to relative positions of the teeth in the modified digital model of the tooth arch.
59. The method of claim 58, further comprising forming a dental aligner over the arrangement of physical tooth models.
60. The method of claim 52, further comprising: determining a position of a registration feature for each of a plurality of teeth within the patient's tooth arch, wherein each registration feature identifies a relative position of its tooth in relation to other teeth within the patient's tooth arch; representing the registration features in corresponding digital models of individual physical tooth models; and arranging the teeth in the digital model of the tooth arch such that the registration features in the digital model of the tooth arch have relative positions corresponding to relative positions of the registration features for the teeth in the patient's tooth arch.
61. The method of claim 60, further comprising: modifying a position of at least one of the teeth in the digital model of the tooth arch; constructing the individual physical tooth models of teeth in the patient's tooth arch, wherein each of the individual physical tooth models comprises the registration feature of the corresponding tooth in the patient's tooth arch; and arranging the individual physical tooth models such that relative positions of their registration features correspond to relative positions of the registration features in the modified digital model of the tooth arch.
62. The method of claim 61, further comprising forming a dental aligner over the arrangement of physical tooth models. ■"
63. The method of claim 61, wherein the registration features included in the individual physical tooth models are configured to attach the individual physical tooth models to a base to form the physical model of a tooth arch.
64. The method of claim 63, wherein the registration features included in the individual physical tooth models comprise pins.
65. The method of claim 52, further comprising arranging the teeth in the digital model of the tooth arch such that the relative position of at least one tooth in the digital model of the tooth arch differs from the relative position of a corresponding tooth in the patient's tooth arch.
66. The method of claim 65, further comprising arranging the individual physical tooth models to have relative positions that correspond to relative positions of the teeth in the digital model of the tooth arch.
67. The method of claim 66, further comprising forming a dental aligner over the arrangement of physical tooth models.
68. The method of claim 65, wherein each individual physical tooth model comprises a registration feature, the method further comprising: representing the registration features in the corresponding digital models of individual physical tooth models; and arranging the individual physical tooth models such that relative positions of their registration features correspond to relative positions of the registration features in the digital model of the tooth arch.
69. The method of claim 68, further comprising forming a dental aligner over the arrangement of individual physical tooth models.
70. The method of claim 68, wherein the registration features included in the individual physical tooth models are configured to attach the individual physical tooth models to a base to form the physical model of a tooth arch.
71. The method of claim 70, wherein the registration features included in the individual physical tooth models comprise pins.
72. The method of claim 52, further comprising arranging the physical tooth models to have relative positions that correspond to relative positions of the teeth in the digital model of the tooth arch.
73. A method of constructing a physical model of a tooth arch from individual physical tooth models of teeth in a patient's arch, the method comprising: arranging the individual physical tooth models on a base to have relative positions corresponding to relative positions of teeth in a digital model of the tooth arch.
74. The method of claim 73, wherein the digital model of the tooth arch represents the patient's current tooth arch.
75. The method of claim 73, wherein the digital model of the tooth arch represents a modification of the patient's current tooth arch.
76. The method of claim 75, further comprising forming a dental aligner over the arrangement of individual physical tooth models.
77 The method of claim 73, wherein the individual physical tooth models comprise registration features, the method further comprising: representing the registration features in the digital model of the tooth arch; and arranging the individual physical tooth models such that relative positions of their registration features correspond to relative positions of the registration features in the digital model of the tooth arch.
78. The method of claim 77, wherein the digital model of the tooth arch represents a modification of the patient's current tooth arch.
79. The method of claim 78, further comprising forming a dental aligner over the arrangement of individual physical tooth models.
80. The method of claim 77, wherein the registration features included in the individual physical tooth models are configured to attach the individual physical tooth models to the base to form the physical model of a tooth arch.
81. The method of claim 80, wherein the registration features included in the individual physical tooth models comprise pins.
82. The method of claim 73, wherein the individual physical tooth models comprise registration features, the method further comprising: representing the registration features in the digital model of the tooth arch; and forming features on the base at which the registration features may be attached; wherein relative locations of the features on the base correspond to relative locations of the registration features in the digital model of the tooth arch.
83. The method of claim 82, wherein the digital model of the tooth arch represents a modification of the patient's current tooth arch.
84. The method of claim 83, further comprising forming a dental aligner over the arrangement of individual physical tooth models.
85. The method of claim 82, wherein the registration features included in the individual physical tooth models comprise pins.
86. The method of claim 82, wherein the features on the base comprise receptacles into which the registration features included in the individual physical tooth models may be inserted.
87. The method of claim 73, further comprising: determining the position of a registration feature for each of a plurality of teeth within the patient's tooth arch, wherein each registration feature identifies a relative position of its tooth in relation to other teeth within the patient's tooth arch; representing the registration features in the digital model of the tooth arch; arranging the teeth in the digital model of the tooth arch such that the registration features in the digital model of the tooth arch have relative positions corresponding to relative positions of the registration features of the teeth in the patient's tooth arch; modifying a position of at least one of the teeth in the digital model of the tooth arch; constructing the individual physical tooth models of teeth in the patient's tooth arch, wherein each of the individual physical tooth models comprises the registration feature of the corresponding tooth in the patient's tooth arch; and arranging the individual physical tooth models on the base such that the relative positions of their registration features correspond to the relative positions of the registration features in the modified digital model of the tooth arch.
88. The method of claim 87, wherein the registration features included in the individual physical tooth models are configured to attach the individual physical tooth models to the base to form the physical model of a tooth arch.
89. The method of claim 88, wherein the registration features included in the individual physical tooth models comprise pins.
90. A method for producing a base or plurality of bases for physical tooth models, comprising: receiving digital tooth models representing the physical tooth models; generating a digital base model compatible with the digital tooth models; and producing a base or plurality of bases using CNC based manufacturing in accordance with the digital base model, said base being capable of receiving the physical tooth models.
91. The method of claim 90, wherein the base comprises one or more features to assist the reception of the physical tooth models.
92. The method of claim 91 , wherein the features comprise one or more of a pin, a registration slot, a notch, a protrusion, a hole, an interlocking mechanism, a jig, and a pluggable or attachable feature.
93. The method of claim 91, wherein the base comprises a plurality of configurations in the features, wherein each of configurations is adapted to receive the same physical tooth models to form a different arrangement of at least a portion of a tooth arch model.
94. The method of claim 93, further comprising: attaching the physical tooth models into the base in a first configuration; and attaching the same physical tooth models into the base in a second configuration.
95. The method of claim 90, further comprising: producing a plurality of bases adapted to receive the physical tooth models, wherein at least two of the plurality of bases have different configurations for receiving the physical tooth models; and assembling the physical tooth models with one of the plurality of bases.
96. The method of claim 90, wherein the physical tooth models comprise one or more features to assist the physical tooth models to be received by the base.
97. The method of claim 96, wherein the features comprises one or more of a pin, a registration slot, a notch, a protrusion, a hole, an interlocking mechanism, a jig, and a pluggable or attachable feature.
SUBSTITUTE SHEET (RULE 26)
98. The method of claim 90, wherein the physical tooth models are labeled by a predetermined sequence that defines the positions of the physical tooth models on the base.
99. The method of claim 98, wherein the labels can include one or more of a barcode, a printed symbol, hand-written symbol, a Radio Frequency Identification (RFID).
100. The method of claim 90, further comprising assembling the physical tooth models into each other to form a physical dental arch or part of a physical dental arch that can be assembled with the base.
101. The method of claim 99, wherein the CNC based manufacturing includes milling, stereolithography, laser machining, molding, and casting.
102. The method of claim 90, wherein the base comprises a material selected from the group consisting of polymers, urethane, epoxy, plastics, plaster, stone, clay, acrylic, metals, wood, paper, ceramics, porcelain, glass, and concrete.
103. The method of claim 90, wherein the physical tooth models are fabricated in accordance with the digital tooth models.
104. The method of claim 90, wherein the digital tooth models are acquired by scanning and digitizing the physical tooth models.
105. A system for producing a base for physical tooth models, comprising: a computer device adapted to store digital tooth models representing the physical tooth models; a computer processor that is capable of generating a digital base model compatible with the digital tooth models; and an apparatus that can fabricate the base using CNC based manufacturing in accordance with the digital base model, wherein the base fabricated is adapted to receive the physical tooth models.
106. The system of claim 105, wherein the base comprises one or more features to assist the reception of the physical tooth models.
107. The system of claim 105, wherein the physical tooth models comprise one or more features to assist the physical tooth models to be received by the base.
108. A base for physical tooth models, comprising: a base portion; and a plurality of features adapted to receive the physical tooth models; wherein the plurality of features are fabricated by Computer Numerical Control (CNC) based manufacturing.
109. The base of claim 108, wherein the plurality of features are fabricated in accordance with a digital base model produced in response to the physical tooth models.
1 10. A base for physical tooth models, comprising: a base plate having a plurality of pairs of sockets, wherein each pair of sockets is adapted to receive two pins associated with a physical tooth model.
1 11. The base of claim 1 10, further comprising a plurality of tooth models each having two pins connected at its bottom portion.
1 12. The base of claim 1 10, wherein each pair of sockets includes a socket on the inside of the tooth arch model and a socket on the outside of the tooth arch model.
1 13. A method for producing a physical base for receiving physical tooth models, comprising: receiving position information for the physical tooth models on the physical base; and machining first features on a base plate in accordance with the position information to produce the physical base, wherein the first features are configured to receive the physical tooth models.
1 14. The method of claim 1 13, wherein the physical tooth models include second features that are complimentary to the first features.
115. The method of claim 114, wherein the first features in the physical base and the second features in the physical tooth models can join together to enable the reception of physical tooth models by the physical base.
116. The method of claim 1 14, wherein the first features or the second features include one or more of registration slots, a socket, a pin, a notch, a protrusion, a hole, an interlocking mechanism, a jig, and a pluggable or an attachable feature.
117. The method of claim 114, wherein the first features in the physical base are labeled by a predetermined sequence that define the positions of the physical tooth models on the base.
1 18. The method of claim 113, wherein machining first features on the base plate comprises milling and/or drilling the base plate in accordance with the position information.
1 19. The method of claim 1 13, wherein machining first features on the base plate comprises machining the base plate using Computer Numerical Control (CNC) based manufacturing in accordance with the position information.
120. The method of claim 1 13, wherein the position information comprises data specifying the locations and orientations of a patient's teeth or the desired locations and orientations of a patient's teeth in a orthodontic treatment.
121. The method of claim 1 13, wherein the physical base comprises a material selected from the group consisting of plastics, polymers, urethane, epoxy, plaster, stone, clay, acrylic, metals, wood, paper, ceramics, and porcelain.
122. A method for producing a physical base having first features for receiving physical tooth models having second features, comprising: receiving position information for the physical tooth models on the physical base; and machining first features on a base plate in accordance with the position information to produce the physical base, wherein the first features are complimentary to the second features.
123. The method of claim 122, wherein the first features in the physical base and the second features in the physical tooth models can join together to enable the reception of physical tooth models by the physical base.
124. The method of claim 122, wherein the first features or the second features include one or more of registration slots, a socket, a pin, a notch, a protrusion, a hole, an interlocking mechanism, a jig, and a pluggable or an attachable feature.
125. The method of claim 122, further comprising acquiring the position information from a patient's arch.
126. The method of claim 122, wherein the physical base comprises a material selected from the group consisting of plastics, polymers, urethane, epoxy, plaster, stone, clay, acrylic, metals, wood, paper, ceramics, and porcelain.
127. The method of claim 122, wherein the first features are labeled by a predetermined sequence that defines the positions of the physical tooth models on the physical base.
128. A system for producing a physical base having first features: a computer configured to store position information for physical tooth models comprising second features complimentary to the first features; and apparatus under the control of the computer, wherein the device is configured to fabricate the first features on a base plate in response to the position information thereby to produce the physical base for receiving the physical tooth models.
129. The system of claim 128, wherein the apparatus fabricates the first features on the base plate by milling and/or drilling .
130. The system of claim 128, wherein the first features in the physical base and the second features in the physical tooth models can join together to enable the reception of physical tooth models by the physical base.
131. The system of claim 128, wherein the first features or the second features include one or more of registration slots, a socket, a pin, a notch, a protrusion, a hole, an interlocking mechanism, a jig, and a pluggable or an attachable feature.
132. The system of claim 128, further comprising acquiring the position information from a patient's arch.
133. A method for producing a dental base having sockets for receiving physical tooth models, comprising: receiving positional information of the sockets on the base; determining a relative movement between a laser and a base plate; emitting a laser beam from the laser to the base plate; and producing a socket in the base plate by the emitted laser beam to form a dental base configured to receive the physical tooth models.
134. The method of claim 133, wherein the base plate comprises a material selected from one of the following: polymers, thermal elastic materials, urethane, epoxy, plaster, clay, acrylic, latex, dental PVS, resin, metal, aluminum, ice, wax, sand, and stone.
135. The method of claim 133, further comprising: labeling the physical tooth models and their associated sockets on the base in a predetermined sequence to define the positions of the physical tooth models on the base.
136. The method of claim 133, further comprising: generating positional information of the sockets on the base in accordance with a digital arch models that is acquired from a patient's arch.
137. The method of claim 133, wherein determining a relative movement between the laser and the base plate includes moving the base plate by a motorized stage in X and Y directions.
138. The method of claim 133, wherein determining relative movement between the laser and the base plate includes moving the base plate in a first direction and moving the laser beam in a second direction.
139. The method of claim 133, further comprising focusing the emitted laser beam to a location on the base plate to produce the socket.
140. The method of claim 133, further comprising guiding the emitted laser beam by an optical fiber to a location on the base plate to cut the socket.
141. The method of claim 133, wherein the material around the location on the base plate is removed by heating, melting, ablation, or evaporation by the emitted laser beam.
142. The method of claim 133, wherein the physical tooth models comprise features to assist the reception of the physical tooth models by the base.
143. The method of claim 142, wherein the features comprise one or more of a pin, a registration slot, a notch, a protrusion, a hole, an interlocking mechanism, a jig, and a pluggable or attachable feature.
144. The method of claim 142, wherein the features in the physical tooth models are shaped in accordance with the profile of the emitted laser beam that produces the socket in the base plate.
145. The method of claim 133, further comprising producing a plurality of sockets in the base plate by the emitted laser beam to form a base to receive a plurality of physical tooth models to form a physical dental arch model.
146. The method of claim 143, wherein the base comprises a plurality of configurations of sockets, wherein each of the configurations is adapted to receive physical tooth models to form a different arrangement of a tooth arch model.
147. The method of claim 146, further comprising: inserting the physical tooth models into the sockets in a first configuration; and inserting the physical tooth models into the sockets in a second configuration.
148. A method for producing a dental base having sockets for receiving physical tooth models, comprising: producing the physical tooth models having one or more of a pin, a protrusion, and a pluggable feature at the bottom portion; determining a relative movement between a laser and a base plate; emitting a laser beam from the laser to the base plate; producing a socket in the base plate by the emitted laser beam; and inserting the pin, the protrusion, or the pluggable feature at the bottom portion of the physical tooth models to the sockets in the base to form a physical dental arch model.
149. A system for producing a base for receiving physical tooth models, comprising: a computer adapted to store positional information of the sockets to be formed on a base plate; a transport system configured to move the base under the control of the computer; and a laser configured to emit a laser beam onto the base plate to form a socket in the base plate after the base plate is moved to a position in accordance to the positional information stored in the computer.
150. The system of claim 149, wherein the positional information of the sockets are derived from a digital arch model.
151. The system of claim 149, wherein the transport system includes a motorized stage that can move the base plate in two dimensions.
152. The system of claim 149, wherein the physical models comprise one or more of a pin, a registration a notch, a protrusion, and a pluggable or attachable feature that can be received by the sockets in the base.
153. A method for producing a base configured to receive physical models of teeth, comprising: acquiring coordinates of the physical models in a physical dental arch model using a mechanical location device; determining one or more configurations of one or more first features affixed to the physical models; and determining one or more locations of one or more second features in the base in accordance with the coordinates of the physical models in the physical dental arch model and the configurations of the first features, wherein the second features are configured to receive the first features affixed to the physical tooth models.
154. The method of claim 153, further comprising fabricating a physical base using Computer Numerical Control (CNC), wherein the base comprises the second features at the locations in accordance with the coordinates of the physical tooth models in the physical dental arch model and the configurations of the first features affixed to the physical tooth models.
155. The method of claim 153, further comprising acquiring positions and orientations of the physical models from an impression of a patient's dental arch using a mechanical location device having one or more degrees of freedom.
156. The method of claim 155, wherein the mechanical location device comprises a stylus configured to touch one or more points on the surface of the impression; and a digital device configured to retrieve coordinates of the points touched by the stylus.
157. The method of claim 153, wherein acquiring the coordinates of the physical tooth models comprises acquiring a coordinate of a reference point using the mechanical location device; and acquiring one or more coordinates of one or more points of the physical model using the mechanical location device.
158. The method of claim 153, wherein determining the configurations of the first features affixed to the physical tooth models includes acquiring the coordinates of the first features affixed to physical models using a mechanical location device
159. The method of claim 153, wherein determining the configurations of the first features affixed to the physical tooth models includes acquiring the coordinates of the first features affixed to physical tooth models using a digital dental model representing the physical tooth models.
160. The method of claim 153, further comprising fabricating a physical base comprising the second features at the locations in accordance with the coordinates of the physical models in the physical dental arch model and the configurations of the first features affixed to the physical models.
161. The method of claim 153, further comprising developing a digital dental arch model comprising a plurality of digital models in response to the coordinates of the physical tooth models acquired by the mechanical location device and the configurations of the first features affixed to the physical tooth models.
162. The method of claim 153, further comprising fabricating the physical tooth models affixed with the first features having the configurations in response to the digital dental arch model.
163. The method of claim 153, further comprising inserting the first features affixed to the physical tooth models into the corresponding second features in the base to form a physical dental arch model.
164. The method of claim 153, wherein the first features comprise one of a pin, a registration slot, a socket, a notch, a protrusion, a hole, an interlocking mechanism, a jig, and a pluggable feature and an attachable feature.
165. The method of claim 153, further comprising measuring the positions of the physical tooth models in the physical dental arch model using a mechanical location device to determine positions adjustment of the second features in the base.
166. A method for producing a base configured to receive one or more physical tooth models, comprising: acquiring one or more coordinates of the one or more physical tooth models in a physical dental arch model from an impression of a patient's arch using a mechanical location device; and determining one or more locations of the one or more physical tooth models in the base in accordance with the one or more coordinates of the one or more physical tooth models in the physical dental arch model.
167. The method of claim 166, wherein one of the physical tooth models is affixed with first features and the base includes one or more second features configured to receive the one or more first features affixed to the physical tooth the models.
168. The method of claim 167, wherein a location of each of the second features in the base is determined by coordinates of the physical tooth models.
169. The method of claim 166, wherein the mechanical location device comprises a stylus configured to touch a point in space; and a digital device for retrieving coordinates of the point touched by the stylus.
170. The method of claim 166, wherein acquiring the coordinates of the physical tooth models comprises acquiring coordinates of a reference point fixed to the impression of the patient's arch using the mechanical location device; and acquiring the coordinates of one or more of the physical tooth models from the impression of the patient's arch using the mechanical location device.
171. A physical dental arch model, comprising: one or two physical tooth models each comprising a tooth portion and two or more first features affixed to the bottom of the tooth portion; and a base comprising a plurality of second features configured to receive first features affixed to the physical tooth models, wherein the locations of the second features are determined by the coordinates acquired from the impression of a patient arch using a mechanical location device.
172. The physical dental arch model of claim 171, wherein the base comprises a plurality of pairs of receiving sockets, wherein each pair of receiving sockets are configured to receive a physical tooth model affixed with two pins.
173. A method for producing a base configured to receive physical tooth models, comprising: acquiring coordinates of the physical tooth models in the physical dental arch model using an optical location device; determining configurations of first features affixed to the physical tooth models; and determining locations of second features in the base in accordance with the coordinates of the physical tooth models in the physical dental arch model and the configurations of the first features, configuring one or more sockets to receive the first features affixed to the physical tooth models.
174. The method of claim 173, further comprising fabricating a physical base using Computer Numerical Control (CNC), wherein the base comprises the second features at the locations in accordance with the coordinates of the physical tooth models in the physical dental arch model and the configurations of the first features affixed to the physical tooth models.
175. The method of claim 173, further comprising acquiring the positions and orientations of the physical tooth models from an impression of a patient's dental arch using an optical location device.
176. The method of claim 173, wherein the optical location device comprises a stylus configured to touch points on the surface of the impression; a linking arm connected to the stylus, and an imaging system to determine the coordinates of the points touched by the stylus.
177. The method of claim 173, wherein determining the configurations of the first features affixed to the physical tooth models includes acquiring the coordinates of the first features affixed to physical tooth models using an optical location device
178. The method of claim 173, wherein determining the configurations of the first features affixed to the physical tooth models includes acquiring the coordinates of the first features affixed to physical tooth models using a digital dental model representing the physical tooth models.
179. The method of claim 173, further comprising fabricating a physical base comprising the second features at the locations in accordance with the coordinates of the physical tooth models in the physical dental arch model and the configurations of the first features affixed to the physical tooth models.
180. The method of claim 173, further comprising developing a digital dental arch model comprising a plurality of digital tooth models in response to the coordinates of the physical tooth models acquired by the optical location device and the configurations of the first features affixed to the physical tooth models.
181. The method of claim 173, further comprising fabricating the physical tooth models affixed with the first features having the configurations in response to the digital dental arch model.
182. The method of claim 173, further comprising inserting the first features affixed to the physical tooth models into the corresponding second features in the base to form a physical dental arch model.
183. The method of claim 173, wherein the first features comprise one or more of a pin, a registration slot, a socket, a notch, a protrusion, a hole, an interlocking mechanism, a jig, a pluggable feature and an attachable feature.
184. A method for acquiring the coordinates of a patient's dental arch, comprising: receiving an impression of the patient's arch; touching at least a point on the surface of the impression with a stylus connected to a location device, wherein the location device includes a plurality of rigidly connected marking objects; capturing an image of the plurality of rigidly connected marking objects; determining the coordinates of marking objects; and using the coordinates of marking objects to calculate the position of the stylus to obtain the coordinates of the point on the surface of the impression.
185. The method of claim 184, wherein determining the coordinates of marking objects comprises recognizing patterns of the marking objects; and calculating coordinates of centers of the marking objects.
186. The method of claim 184, further comprising: capturing a plurality of images of the rigidly connected marking objects from different directions using a plurality of cameras; and determining the coordinates of marking objects by correlating the plurality of images.
187. The method of claim 184, further comprising attaching reflective markers to the marking objects; capturing an image of the reflective markers; and determining the coordinates of marking objects using the image of the reflective markers.
188. The method of claim 184, further comprising attaching infrared reflective markers to the marking objects; irradiating infrared light on the infrared reflective markers; capturing an infrared image of the infrared reflective markers; and determining the coordinates of marking objects using the image of the infrared reflective markers.
189. The method of claim 184, further comprising attaching magnetic markers and magnetic sensors to the marking objects; capturing an image of the magnetic markers; and determining the coordinates of marking objects using the image of the magnetic markers.
190. A physical dental arch model, comprising: one or two physical tooth models each comprising a tooth portion and two or more first features affixed to the bottom of the tooth portion; and a base comprising a plurality of second features configured to receive first features affixed to the physical tooth models, wherein the locations of the second features determined by the coordinates acquired from the impression of a patient arch using an optical location device.
191. The physical dental arch model of claim 190, wherein the first features comprise one or more of a pin, a registration slot, a socket, a notch, a protrusion, a hole, an interlocking mechanism, a jig, and a pluggable or attachable feature.
192. The physical dental arch model of claim 190, wherein the base comprises a plurality of pairs of sockets, wherein each pair of sockets are configured to receive a physical tooth model affixed with two pins.
193. A method for producing a physical dental arch model having one or more physical tooth models, comprising: producing a digital base model compatible with the physical tooth models; producing a base having receiving features using CNC based manufacturing in accordance with the digital base model; and assembling the physical tooth models and adjustment jigs with the base at the receiving features to form the physical dental arch model.
194. The method of claim 193, wherein the adjustment jigs are capable of adjusting one or more of translational degrees of freedom and rotational degrees of freedom of the physical tooth models.
195. The method of claim 193, wherein at least one physical tooth model is associated with two or more jigs at the corresponding receiving feature of the base.
196. The method of claim 195, wherein two jigs at a receiving feature of the base can adjust a combination of translational and/or rotational degrees of freedoms of the physical tooth models.
197. The method of claim 193, wherein the physical dental arch model comprises a plurality of configurations each of which includes a specific set of jigs associated with respective physical tooth models at the corresponding receiving features of the base.
198. The method of claim 197, further comprising: assembling the physical tooth models and associated jigs with the base in a first configuration; and assembling the physical tooth models and associated jigs with the base in a second configuration.
199. The method of claim 193, further comprising fabricating the physical tooth based on input digital tooth models; and producing the digital base model compatible with the digital tooth models.
200. The method of claim 193, further comprising acquiring digital tooth models by scanning and digitizing the physical tooth models; and producing the digital base model compatible with the digital tooth models.
201. The method of claim 193, wherein the receiving features comprise one or more of a pin, a registration slot, a notch, a protrusion, a hole, an interlocking mechanism, a jig, and a pluggable or attachable feature.
202. The method of claim 193, wherein the physical tooth models comprise one or more features to assist the physical tooth models to be received by the base.
203. The method of claim 202, wherein the features comprise one or more of a pin, a registration slot, a notch,- a protrusion, a hole, an interlocking mechanism, a jig, and a pluggable or attachable feature.
204. The method of claim 193, wherein the physical tooth models are labeled by a predetermined sequence that define the positions of the physical tooth models on the base.
205. The method of claim 193, wherein the receiving features in the base are labeled by a predetermined sequence that define the relation to the corresponding physical tooth models.
206. The method of claim 193, wherein the jigs are labeled in accordance with the degrees of freedom and the extent of the adjustment they can make associated with physical tooth models.
207. The method of claim 193, wherein the CNC based manufacturing includes milling, stereolithography, laser machining, molding, and casting.
208. The method of claim 193, further comprising automatically assembling the physical tooth models and adjustment jigs with the receiving features of the base using a programmable robot.
209. A system for producing a physical dental arch model having one or more physical tooth models, comprising: a computer storage device adapted to store digital tooth models for the physical tooth models; a computer processor that is capable of generating a digital base model compatible with the digital tooth models; and an apparatus that can fabricate the base having receiving features using CNC based manufacturing in accordance with the digital base model, wherein the physical tooth models can be assembled with adjustment jigs at the receiving features of the base to form the physical dental arch model.
210. The system of claim 209, wherein the adjustment jigs are capable of adjusting the translational or rotational degrees of freedom of the physical tooth models over the base.
21 1. The system of claim 209, further comprising a device that is capable of fabricating the adjustment jigs to be assembled with the physical tooth models at the receiving features of the base.
212. A physical dental arch model, comprising: a base having receiving features; and the physical tooth models associated with the receiving features on the base; and adjustment jigs adapted to be assembled with the physical tooth models at the receiving features of the base.
213. A physical dental arch model, comprising: an adjustment jig configured to receive a physical tooth model and to enable the rotations of the physical tooth model around at least two separate axes; a base configured to receive the adjustment jig such that the physical tooth model can rotate relative to the base around at least the two separate axes.
214. The physical dental arch model of claim 213, wherein the adjustment jig comprises a universal joint that includes an inner rotative joint member and an outer joint member housing the inner rotative joint member, wherein one of the inner rotative joint member and the outer joint member is attached to the physical tooth model.
215. The physical dental arch model of claim 214, wherein a different one of the inner rotative joint member and the outer joint member is attached to the base.
216. The physical dental arch model of claim 214, wherein the inner rotative joint member comprises a spherical outer surface and the outer joint member comprises a spherical inner surface that is adapted to be contact with the spherical outer surface of the inner rotative joint member.
217. The physical dental arch model of claim 214, wherein the universal joint further comprises a clamp mechanism that is capable of stopping the relative rotary movement between the inner rotative joint member and the outer joint member.
218. The physical dental arch model of claim 213, wherein the physical tooth model can rotate relative to the base around at least three separate axes.
219. The physical dental arch model of claim 213, wherein the adjustment jig further comprises a translational adjustment device that enables the physical tooth model to move along one or more directions.
220. The physical dental arch model of claim 213, wherein the base comprises one or more receiving features configured to receive the adjustment jig, wherein the receiving features include one or more of a pin, a registration slot, a notch, a protrusion, a hole, an interlocking mechanism, a jig, and a pluggable or attachable feature.
221. The physical dental arch model of claim 213, wherein the physical tooth model comprises one or more features to assist the physical tooth model to be mounted on the adjustment jig, wherein the features include one or more of a pin, a registration slot, a notch, a protrusion, a hole, an interlocking mechanism, a jig, and a pluggable or attachable feature.
222. A physical dental arch model, comprising: a universal joint including an inner rotative joint member and an outer joint member housing the inner rotative joint member; a base configured to receive one of the inner rotative joint member and the outer joint member; and a physical tooth model to be fixed to another one of the inner rotative joint member and the outer joint member such that the physical tooth model can rotate relative to the base.
223. The physical dental arch model of claim 222, wherein the inner rotative joint member comprises a spherical outer surface and the outer joint member comprises a spherical inner surface that can be in contact with the spherical outer surface of the inner rotative joint member.
224. The physical dental arch model of claim 222, wherein the universal joint further comprises a clamp mechanism that is capable of stopping the relative rotary movement between the inner rotative joint member and the outer joint member.
225. The physical dental arch model of claim 222, wherein the adjustment jig further comprises a translational adjustment device that enables the physical tooth model to translate along one or more directions.
226. A method for producing a physical dental arch model having one or more adjustable physical tooth models, comprising: providing a universal joint including an inner rotative joint member and an outer joint member housing the inner rotative joint member; attaching one of the inner rotative joint member and the outer joint member to a receiving feature on a base; attaching a physical tooth model to another one of the inner rotative joint member and the outer joint member of the universal joint; and rotating the physical tooth model relative to the base.
227. The method of claim 226, further comprising: rotating the physical tooth model relative to the base around the two or more separate axes.
228. The method of claim 226, further comprising: stopping the relative rotary movement between the inner rotative joint member and the outer joint member using a clamp mechanism.
229. The method of claim 226, further comprising: translating the physical tooth model relative to the base along one or more directions.
230. The method of claim 226, further comprising: labeling the physical tooth model, the universal joint, and the receiving feature on the base in accordance with a predetermined configuration of physical tooth models in the physical dental arch model.
231. The method of claim 230, further comprising: assembling the physical tooth model to the universal joint and the universal joint to the receiving feature on the base in accordance with a first predetermined configuration of physical tooth models in the physical dental arch model; and assembling the physical tooth model to the universal joint and the universal joint to the receiving feature on the base in accordance with a second predetermined configuration of physical tooth models in the physical dental arch model.
232. The method of claim 226, further comprising: automatically assembling the physical tooth model to the universal joint and the universal joint to the receiving feature on the base using a programmable robot.
233. A method for producing a physical dental arch model having at least two adjacent physical tooth models and a base configured to receive the physical tooth models, comprising: determining positions and orientations of the two adjacent physical tooth models in the physical dental arch model; and selecting a configuration of a first feature to be produced at the bottoms of the two adjacent physical tooth models to prevent interference between the two adjacent physical tooth models when mounted to the base using the first feature.
234. The method of claim 233, wherein the first feature comprises one or more of a pin, a registration slot, a socket, a notch, a protrusion, a hole, an interlocking mechanism, a jig, and a pluggable or attachable feature.
235. The method of claim 233, wherein the first feature includes at least one pin and the base comprises at least one socket configured to receive the pin.
236. The method of claim 235, wherein the pins affixed to at least one tooth model have different lengths to prevent interference between the two adjacent physical tooth models when inserted into the sockets on the base and wherein the pins are retractable.
237. The method of claim 233, wherein the base includes one or more through-holes, further comprising a second feature in the base, wherein the second feature is compatible with the first feature and is configured to receive the first feature with the through-holes.
238. The method of claim 233, further comprising fabricating the physical tooth models having the first feature with the selected configurations.
239. The method of claim 238, further comprising fabricating the base that is configured to receive with the physical tooth models including the first feature having the selected configurations.
240. The method of claim 233, further comprising two first features having different sizes affixed to at least one of the physical tooth models to prevent the interference between the two adjacent physical tooth models when they are mounted to the base using the first feature.
241. The method of claim 233, wherein the two first features comprise different lengths of the first features.
242. The method of claim 233, wherein the base is configured to receive a whole or a portion of a dental arch.
243. The method of claim 233, further comprising receiving a digital dental arch model that defines the positions and orientations of the two adjacent physical tooth models in the physical dental arch model; using digital tooth models to simulate the interference between two adjacent physical tooth models mounted on the base to assist the selection of first feature configurations; and fabricating physical tooth models affixed with the first feature having the selected configurations in accordance with the digital tooth models.
244. The method of claim 233, further comprising fabricating physical tooth models in response to a digital dental arch model comprising at least two digital tooth models corresponding to the two adjacent physical tooth models in the physical dental arch model.
245. The method of claim 244, further comprising determining an interference between adjacent digital tooth models by affixing first features to the digital tooth models.
246. A method for producing a physical dental arch model having at least two adjacent physical tooth models and a base configured to receive the physical tooth models, comprising: determining positions and orientations of the two adjacent physical tooth models in the physical dental arch model; and selecting configurations of a first feature to be produced at the bottom of the two adjacent physical tooth models to prevent interference between the two adjacent physical tooth models when mounted to the base using the first feature, wherein the first feature comprises one or more of a pin, a registration slot, a socket, a notch, a protrusion, a hole, an interlocking mechanism, a jig, and a pluggable or attachable feature.
247. A physical dental arch model, comprising: a base comprising a plurality of second features configured to receive physical tooth models; and at least two physical tooth models each comprising a tooth portion and one or more first features affixed to the bottom of the tooth portion, wherein the first features of the two physical tooth models are configured to prevent interference between the two physical tooth models when inserted in the base.
248. The physical dental arch model of claim 247, wherein the base comprises one ore more second features configured to receive a physical tooth model affixed with the first features.
249. The physical dental arch model of claim 247, wherein at least one of the physical tooth models are affixed with two first features having different sizes to prevent interference between the two adjacent physical tooth models.
250. The physical dental arch model of claim 247, wherein the first features affixed to the two physical tooth models include pins having different lengths.
251. The physical dental arch model of claim 247, wherein the first feature comprises one or more of a pin, a registration slot, a notch, a protrusion, a hole, an interlocking mechanism, a jig, and a pluggable or attachable feature.
252. The physical dental arch model of claim 247, wherein the first feature includes at least one pin and the base comprises at least one socket configured to receive the pin.
253. A method for producing a physical dental arch model having at least two physical tooth models, comprising: determining the positions and orientations of a first physical tooth model; determining the positions and orientations of a second physical tooth model that is adjacent to the first physical tooth model; detecting the interference between the first physical tooth model and the second physical tooth model; if interference is detected between the first physical tooth model and the second physical tooth model, modifying the positions and orientations of at least one of the first physical tooth model and the second physical tooth model to prevent interference between the first physical tooth model and the second physical tooth model; and fabricating the first physical tooth model and the second physical tooth model in accordance with the modified positions and orientations of the first physical tooth model and/or the second physical tooth model.
254. The method of claim 253, wherein the first physical tooth model includes a first feature affixed to the bottom portion of the first physical tooth model to allow the first physical tooth model to be mounted to a base and the second physical tooth model includes a second feature affixed to the bottom portion of the second physical tooth model to allow the first physical tooth model to be mounted to the base.
255. The method of claim 254, further comprising modifying the first feature or the second feature to prevent interference between the first physical tooth model and the second physical tooth model.
256. The method of claim 254, wherein the first feature comprises one or more of a pin, a registration slot, a socket, a notch, a protrusion, a hole, an interlocking mechanism, a jig, and a pluggable or attachable feature.
257. The method of claim 254, wherein the first feature comprises at least one pin affixed to the bottom portion of the first tooth model and the base comprises at least one socket configured to receive the pin.
258. The method of claim 257, further comprising: modifying the length and/or the orientations of the pin relative to the bottom portion of the pin to prevent interference between the first physical tooth model and the second physical tooth model.
259. The method of claim 254, further comprising fabricating the first physical tooth model having the first feature; and fabricating the second physical tooth model having the second feature.
260. The method of claim 254, wherein the first feature affixed to the bottom portion of the first physical tooth model includes a spring loaded pin mechanism.
261. The method of claim 260, wherein the first feature affixed to the bottom portion of the first physical tooth model having the spring loaded pin mechanism comprises two pins of different lengths or pins tilted to the bottom portion of the first physical tooth model.
262. A method for producing a physical dental arch model having at least two physical tooth models, comprising: producing a digital dental arch model that simulates the positions and orientations of a first physical tooth model and the positions and orientations of a second physical tooth model that is adjacent to the first physical tooth model; detecting the interference between the first physical tooth model and the second physical tooth model; if interference is detected between the first physical tooth model and the second physical tooth model, modifying the positions and orientations of at least one of the first physical tooth model and the second physical tooth model to produce a modified digital dental arch model to prevent interference between the first physical tooth model and the second physical tooth model; and fabricating the first physical tooth model and the second physical tooth model in accordance with the modified digital arch model.
263. The method of claim 262, wherein the first physical tooth model includes a first feature affixed to the bottom portion of the first physical tooth model to allow the first physical tooth model to be mounted to a base and the second physical tooth model includes a second feature affixed to the bottom portion of the second physical tooth model to allow the first physical tooth model to be mounted to the base.
264. The method of claim 263, further comprising: modifying the first feature or the second feature to produce the modified digital dental arch model to prevent interference between the first physical tooth model and the second physical tooth model.
265. The method of claim 263, wherein the first feature comprises one or more of a pin, a registration slot, a socket, a notch, a protrusion, a hole, an interlocking mechanism, a jig, and a pluggable or attachable feature.
266. The method of claim 263, wherein the first feature comprises at least one pin affixed to the bottom portion of the first tooth model and the base comprises at least one socket configured to receive the pin.
267. The method of claim 266, further comprising modifying the length and/or the orientations of the pin relative to the bottom portion of the pin to prevent interference between the first physical tooth model and the second physical tooth model.
268. The method of claim 263, wherein the first feature affixed to the bottom portion of the first physical tooth model includes a spring loaded pin mechanism.
269. The method of claim 263, further comprising: fabricating the first physical tooth model having the first feature; fabricating the second physical tooth model having the second feature; and fabricating the base that is configured to receive with the first physical tooth model and the second physical tooth model.
270. A method for producing a physical dental arch model having at least two physical tooth models, comprising: producing a digital dental arch model that simulates the positions and orientations of a first physical tooth model and the positions and orientations of a second physical tooth model that is adjacent to the first physical tooth model, wherein the first physical tooth model includes a first feature affixed to the bottom portion of the first physical tooth model to allow the first physical tooth model to be mounted to a base and the second physical tooth model includes a second feature affixed to the bottom portion of the second physical tooth model to allow the first physical tooth model to be mounted to the base. detecting the interference between the first physical tooth model and the second physical tooth model; if interference is detected between the first physical tooth model and the second physical tooth model, modifying the configurations of the first feature and/or the second feature to produce a modified digital dental arch model to prevent interference between the first physical tooth model and the second physical tooth model; and fabricating the first physical tooth model having the first feature and the second physical tooth model having the second feature in accordance with the modified digital arch model.
271. The method of claim 270, wherein the first feature comprises at least one pin affixed to the bottom portion of the first tooth model and the base comprises at least one socket configured to receive the pin.
272. The method of claim 271, further comprising modifying the length and/or the orientations of the pin to prevent interference between the first physical tooth model and the second physical tooth model.
273. A casting chamber to cast a physical tooth model representing a patient's tooth, comprising: a chamber body having a cavity adapted to hold a negative impression of the patient's tooth and to receive a cast material, wherein the negative impression and the chamber body are registered by a registration unit; and a chamber lid configured to seal the cast material in the casting chamber to permit the casting material to solidify in the casting chamber and to form a physical tooth model representing the patient's tooth.
274. The casting chamber of claim 273, wherein the chamber lid and the chamber body are registered by the registration unit.
275. The casting chamber of claim 274, wherein the registration unit includes one or more of a registration pin, a locating pin, an alignment hole, and a liner.
276. The casting chamber of claim 273, further comprising a chamber base coupled to the chamber body.
277. The casting chamber of claim 276, wherein the chamber base and the chamber body are registered by a registration unit including one or more of a registration pin, a locating pin, an alignment hole, and a liner.
278. The casting chamber of claim 273, wherein the chamber body comprises one or more chamber walls surrounding the cavity.
279. The casting chamber of claim 278, wherein the chamber walls include one or more through-holes to enable the de-molding of the physical tooth model.
280. The casting chamber of claim 273, further comprising a unit that is configured to assist the solidification of the casting material within the casting chamber.
281. The casting chamber of claim 280, wherein the unit provides one or more of • cooling, heating, emitting UV light, emitting IR light, and radiating microwave.
282. The casting chamber of claim 273, further comprising a window in the chamber lid to permit the irradiation of UV light or IR light through the window to the casting material.
283. A casting chamber for casting a physical tooth model representing a patient's tooth, comprising: a chamber body having chamber walls surrounding a cavity, wherein the cavity is adapted to hold a negative impression of the patient's tooth and to receive a cast material and the negative impression and the chamber body are registered by a registration unit; and a chamber lid configured to seal the cast material in the casting chamber to permit the casting material to solidify in the casting chamber thereby forming a physical tooth model representing the patient's tooth.
284. The casting chamber of claim 283, wherein the chamber lid and the chamber body are registered by the registration unit comprising one or more of a registration pin, a locating pin, an alignment hole, and a liner.
285. The casting chamber of claim 273, further comprising a chamber base adapted to be held to the chamber body.
286. The casting chamber of claim 283, wherein the chamber base and the chamber body are registered by the registration unit including one or more of a registration pin, a locating pin, an alignment hole, and a liner.
287. A method for producing a physical tooth model, comprising: receiving a negative impression of a patient's tooth in a casting chamber; pouring a cast material over the negative impression of the patient's tooth; and solidifying the cast material to produce the physical tooth model.
288. The method of claim 287, wherein the registration unit includes one or more of a registration pin, a locating pin, an alignment hole, and a liner.
289. The method of claim 287, further comprising sealing the casting chamber by a chamber lid to permit the solidification of the casting material.
290. The method of claim 287, wherein the casting a material is selected from the group consisting of polymers, thermal elastic material, urethane, epoxy, plaster, clay, acrylic, latex, dental PVS, resin, metal, aluminum, ice, wax, and one or more crosslinking agents for polymerization.
291. The method of claim 287, further comprising cooling or heating the cast material to cause the solidification of the cast material to produce the physical tooth model.
292. The method of claim 287, further comprising irradiating the cast material with UV light or IR light to cause the solidification of the cast material to produce the physical tooth model.
293. A method for producing a physical tooth model, comprising: receiving a negative impression of a patient's tooth in a casting chamber; pouring a casting material over the negative impression of the patient's tooth; solidifying the casting material wherein the casting material is attached to a lid of the casting chamber; and cutting a tooth portion from the solidified casting material to produce a reference base of the casting material attached to the lid of the casting chamber, wherein the reference base is configured to mold the physical tooth model.
294. The method of claim 293, wherein the negative impression is held to the casting chamber by a registration unit.
295. The method of claim 294, wherein the registration unit includes one or more of a registration pin, a locating pin, an alignment hole, and a liner.
296. The method of claim 293, further comprising sealing the casting chamber by a chamber lid to permit the solidification of the casting material.
297. The method of claim 293, further comprising removing air bubbles from the casting material to permit the solidification of the casting material.
298. The method of claim 293, wherein the casting a material is selected one of: polymers, thermal elastic material, urethane, epoxy, plaster, clay, acrylic, latex, dental PVS, resin, metal, aluminum, ice, wax, and one or more crosslinking agents for polymerization.
299. The method of claim 293, further comprising cooling or heating the casting material to cause the solidification of the casting material to produce the physical tooth model.
300. The method of claim 293, further comprising irradiating the casting material with UV light or IR light to cause the solidification of the casting material to produce the physical tooth model.
301. The method of claim 293, further comprising applying microwave radiation to cause the solidification of the casting materials having the impressions.
302. The method of claim 293, further comprising producing first features in the reference base to assist the molding of the physical tooth model having second features complimentary to the first features using the reference base.
303. The method of claim 302, wherein the second features of the physical tooth models are configured to enable the reception of the physical tooth models by the base.
304. The method of claim 302, wherein the first features comprise one or more of a pin, a registration slot, a notch, a protrusion, a hole, an interlocking mechanism, a jig, and a pluggable or attachable feature.
305. The method of claim 302, wherein the producing first features in the reference base comprises machining the reference base at positions as defined by the lid of the casting chamber.
306. A method for producing a physical tooth model, comprising: receiving a negative impression of a patient's tooth in a casting chamber; pouring a casting material over the negative impression of the patient's tooth; solidifying the casting material wherein the casting material is attached to a lid of the casting chamber; cutting a tooth portion from the solidified casting material to produce a reference base attached to the lid of the casting chamber, and producing one or more first features in the reference base to assist the molding of the physical tooth model having second features complimentary to the first features using the reference base.
307. The method of claim 306, wherein the second features of the physical tooth models are configured to enable the reception of the physical tooth models by the base.
308. The method of claim 306, wherein the first features comprise one or more of a pin, a registration slot, a notch, a protrusion, a hole, an interlocking mechanism, a jig, and a pluggable or attachable feature.
309. The method of claim 306, wherein the producing first features in the reference base comprises machining the reference base at locations as defined by one or more reference points on the lid of the casting chamber.
310. The method of claim 306, further comprising removing the solidified casting material from the casting chamber by lifting the lid of the chamber on which the solidified casting material is attached to.
31 1. A casting system for producing a physical tooth model, comprising: a casting chamber configured to hold a negative impression of a patient's tooth and to receive casting material capable of being solidified in the casting chamber; a chamber lid configured to hold solidified casting material and to produce a reference base by removing the tooth portion, wherein the reference base is adapted to mold the physical tooth model.
312. The casting system of claim 293, wherein the reference base is adapted to mold the physical tooth model in the casting chamber.
313. A method for producing a base to receive physical models of one or more teeth, comprising: providing a cast material in a container; pressing undersides of the physical tooth models into the cast material to produce an impression of the undersides in the cast materials; and solidifying the cast material with the impressions to produce the base configured to receive the physical tooth models.
314. The method of claim 313, wherein the cast material comprising one of: polymers, thermal elastic materials, urethane, epoxy, plaster, clay, acrylic, latex, dental PVS, resin, metal, aluminum, ice, wax, sand, and stone.
315. The method of claim 313, comprising: labeling the physical tooth models in a predetermined sequence that defines the positions of the physical tooth models on the base.
316. The method of claim 313, wherein the base comprises an impression for receiving the physical tooth models to form a whole or a portion of a dental arch model.
317. The method of claim 316, comprising: defining the positions of the impressions on the base in accordance with a patient's arch.
318. The method of claim 313, comprising heating or cooling the cast materials to cause the solidification of the cast materials having the impressions.
319. The method of claim 313, comprising applying microwave radiation to cause the solidification of the cast materials having the impression.
320. The method of claim 313, further comprising illuminating UV or IR irradiation on the cast materials to cause the solidification of the cast materials having the impression.
321. The method of claim 313, further comprising applying crosslinking agents to the cast materials to cause the polymerization and solidification of the cast materials having the impressions.
322. The method of claim 313, wherein the physical tooth models comprise first features to assist the reception of the physical tooth models by the base.
323. The method of claim 322, wherein the features comprise one or more of a pin, a registration slot, a notch, a protrusion, a hole, an interlocking mechanism, a jig, and a pluggable or attachable feature.
324. The method of claim 322, wherein the impression in the base comprise second features complementary to the first features to assist the reception of the physical tooth models by the base.
325. A method for producing a base for physical tooth models, comprising: placing the physical tooth models in a container; pouring a cast material over the underside of the physical tooth models in the container; and solidifying the cast material having the impression to produce the base that is adapted to receive the physical tooth models.
326. The method of claim 325, wherein the cast material comprises one of a polymer, a thermal elastic material, a urethane, an epoxy, a plaster, a clay, an acrylic, a latex, a dental PVS, a resin, a metal, an aluminum material, an ice materiak, and a wax material.
327. The method of claim 325, wherein the physical tooth models comprise one or more features to assist the reception of the physical tooth models by the base.
328. A method for producing a base for a dental arch model, comprising: transferring a cast material in a container; placing the underside of a physical tooth model in the container such that the underside of the physical tooth model produces an impression in the cast material; solidifying the cast material having the impression to produce a base component; and assembling a plurality of base components to form the base configured to receive the dental arch model.
329. The method of claim 328, wherein the base components comprise features to assist the assembly of the base components to form the base for the dental arch model.
330. The method of claim 329, wherein the features comprise one or more of a pin, a registration slot, a socket, a notch, a protrusion, a hole, an interlocking mechanism, a jig, and a pluggable or attachable feature.
331. The method of claim 328, wherein the physical tooth models comprise one or more features to assist the reception of the physical tooth model by the base component.
332. A method for digitizing a patient's arch, comprising: producing a physical arch model for the patient's arch; separating the physical arch model into a plurality of arch model components; mounting the arch model components on a scan plate; capturing one or more images of the arch model components; and developing digital representations of the arch model components using the captured one or more images.
333. The method of claim 332, further comprising: transforming the digital representations for the arch model components into a common coordinate.
334. The method of claim 333, further comprising: combining the digital representations for the arch model components into a digital arch model.
335. The method of claim 1, further comprising: producing registration features on the arch model components to define relative positions of the arch model components; and producing receiving features on the scan table to receive the registration features on the arch model components when the arch model components are mounted on the scan table.
336. The method of claim 335, further comprising: combining the digital representations for the arch model components into the digital arch model using the coordinates of registration features and the positions of the receiver features on the scan plate.
337. The method of claim 332, further comprising: selecting a direction for the image capturing of the arch model components; and determining the distribution of the arch model components on the scan plate.
338. The method of claim 332, wherein the one or more images of the arch model components are captured at 45 degrees relative to the surface of the scan plate.
339. The method of claim 332, wherein developing digital representations of the arch model components using the captured one or more images comprises: computing the coordinates of a plurality of surface points on the arch model components by triangulation; and interpolating the coordinates of the plurality of surface points to construct the surfaces of the arch model components.
340. The method of claim 332, further comprising: capturing a first image of the arch model components when the scan plate is at a first orientation; rotating the scan plate to a second orientation; and capturing a second image of the arch model components when the scan plate is at the second orientation.
341. A method for digitizing a patient's arch, comprising: producing a physical arch model for the patient's arch; separating the physical arch model into a plurality of arch model components; mounting the arch model components on a scan plate; capturing one or more images of the arch model components; developing digital representations of the arch model components using the captured one or more images; and combining the digital representations for the arch model components into a digital arch model.
342. The method of claim 341, further comprising: producing registration features on the arch model components wherein the registration features can define relative positions of the arch model components; and producing receiving features on the scan table, the receiving features being configured to receive the registration features on the arch model components when the arch model components are mounted on the scan table.
343. The method of claim 342, further comprising: combining the digital representations for the arch model components into a digital arch model using the coordinates of registration features and the positions of the receiver features on the scan plate.
344. The method of claim 341, wherein constructing surfaces of the arch model components comprising: computing the coordinates of a plurality of surface points on the arch model components by triangulation; and interpolating the coordinates of the plurality of surface points to construct the surfaces of the arch model components.
345. The method of claim 341, further comprising: capturing a first image of the arch model components when the scan plate is at a first orientation; rotating the scan plate to a second orientation; and capturing a second image of the arch model components when the scan plate is at the second orientation.
346. A system for digitizing a patient's arch, comprising: a scan plate configured to be mounted with a plurality of arch model components that are separated from a physical arch model corresponding to the patient's arch; an image capturing device configured to capture at least one image of the arch model components; and a computer configured to develop digital representations of the arch model components using the captured one or more image.
347. The system of claim 346, wherein the computer is configured to combine the digital representations for the arch model components into a digital arch model.
348. The system of claim 346, further comprising: a rotation mechanism coupled to the scan plate, configured to rotate the scan plate under control of the computer to allow a plurality of images of the arch model components to be captured in a plurality of directions.
349. The system of claim 346, wherein the arch model components comprise registration features that define relative positions of the arch model components.
350. The system of claim 349, wherein the scan table comprises receiving features configured to receive the registration features on the arch model components.
351. The system of claim 346, further comprising: a plurality of image capture devices configured to capture images at different directions relative to the arch model components.
352. A method for digitizing a patient's arch, comprising: producing a physical tooth arch model for the patient's tooth arch; separating the physical tooth arch model into a plurality of tooth arch model components; scanning the tooth arch model component capture data representing the tooth arch model component; and developing digital representations of the tooth arch model components using the data representing the tooth arch model component.
353. The method according to claim 352 wherein the scanning step comprises scanning the plurality of tooth arch model components one at a time.
354. The method according to claim 352 wherein the scanning step comprises scanning two or more tooth arch model components at a time.
355. A scanning platform comprising: a scanner; a rotating scan plate; a plurality individual tooth models of a patient's teeth being positioned on the rotating scan plate in a configuration to allow all the tooth models to be scanned by rotating the rotating scan plate.
356. A method for mounting at least two physical tooth models on a physical dental arch model, comprising: acquiring coordinates of a plurality of points on the surfaces of each of the two physical tooth models; digitally representing the surfaces of each of the two physical tooth models as a mesh of points in three dimensions using the acquired coordinates, wherein the meshes representing the surfaces of the two physical tooth models intersect at least at one point to form an overlapping portion; and calculating the depth of the overlapping portion between the two meshes to quantify the interference of the two physical tooth models.
357. The method of claim 356, wherein acquiring the coordinates of a plurality of points on the surfaces of each of the two physical tooth models includes measuring the positions of points on the surfaces of an impression representing a patient's teeth.
358. The method of claim 356, further comprising digitally representing the surfaces of each of the two physical tooth models by a triangular mesh in three dimensions.
359. The method of claim 356, wherein at least one of the meshes comprises at least one mesh opening having three, four or five nodes.
360. The method of claim 356, further comprising adjusting the positions or the orientations of at least one of the two physical tooth models in accordance with the depth of the overlapping portion between the two physical tooth models to prevent the interference between the physical tooth models.
361. The method of claim 356, further comprising selecting the configurations of a first feature to be affixed to the undersides of the two physical tooth models in accordance with the depth of the overlapping portion between the two physical tooth models to prevent interference between the two physical tooth models when they are mounted to a base with the assistance of the first feature.
362. The method of claim 361, wherein the second feature comprises one or more of a pin, a registration slot, a socket, a notch, a protrusion, a hole, an interlocking mechanism, a jig, and a pluggable or. an attachable feature.
363. The method of claim 361, further comprising fabricating the physical tooth models having the first features having the selected configurations.
364. The method of claim 356, further comprising selecting the positions and orientations of second features on a base to prevent interference between the two physical tooth models when they are mounted to a base with the assistance of the second features.
365. The method of claim 364, wherein the second feature comprises one or more of a pin, a registration slot, a socket, a notch, a protrusion, a hole, an interlocking mechanism, a jig, and a pluggable or attachable feature.
366. The method of claim 364, further comprising fabricating the base having the second features having the selected positions and orientations.
367. The method of claim 356, wherein the mesh is interpolated to produce one or more surfaces to represent the boundaries of one of the two physical tooth models.
368. A method for preventing interference between two physical tooth models in a physical dental arch model, comprising: acquiring the coordinates of a plurality of points on the surfaces of each of the two physical tooth models; digitally representing the surfaces of each of the two physical tooth models by a mesh of points in three dimensions using the acquired coordinates, wherein the meshes representing the surfaces of the two physical tooth models intersect at least at one point to form an overlapping portion; calculating the depth of the overlapping portion between the two meshes; and adjusting the positions or the orientations of at least one of the two physical tooth models in accordance with the depth of the overlapping portion between the two physical tooth models to prevent the interference between the physical tooth models.
369. The method of claim 368, further comprising selecting the configurations of a first feature to be affixed to the undersides of the two physical tooth models in accordance with the depth of the overlapping portion between the two physical tooth models to prevent interference between the two physical tooth models when they are mounted to a base with the assistance of the first feature.
370. The method of claim 369, wherein the second feature comprises one or more of a pin, a registration slot, a socket, a notch, a protrusion, a hole, an interlocking mechanism, a jig, and a pluggable or an attachable feature.
371. The method of claim 369, further comprising fabricating the physical tooth models having the first features having the selected configurations.
372. A method for preventing interference between two physical tooth models in a physical dental arch model, comprising: acquiring the coordinates of a plurality of points on the surfaces of each of the two physical tooth models; digitally representing the surfaces of each of the two physical tooth models by a mesh of points in three dimensions using the acquired coordinates; interpolating each of the two meshes to produce one or more surfaces to represent the boundaries of one of the two physical tooth models, wherein the interpolated surfaces intersect at least at one point to form an overlapping portion; and calculating the depth of the overlapping portion between the two interpolated surfaces to quantify the interference of the two physical tooth models.
373. The method of claim 372, adjusting the positions or the orientations of at least one of the two physical tooth models in accordance with the quantified interference between the two physical tooth models to prevent the interference between the physical tooth models.
374. The method of claim 373, further comprising selecting the configurations of a first feature to be affixed to the undersides of the two physical tooth models in accordance with the quantified interference between the two physical tooth models to prevent interference between the two physical tooth models when they are mounted to a base with the assistance of the first feature.
375. A method for preventing interference between two physical tooth models in a physical dental arch model, comprising: digitally representing the surfaces of each of the two physical tooth models by a mesh of points in three dimensions; interpolating the meshes of points to produce interpolated surfaces to represent the boundaries of the two physical tooth models, wherein the interpolated surfaces representing the boundaries of the two physical tooth models intersect at least at one point to form an overlapping portion; specifying a straight line running through the overlapping portion and intersecting the two interpolated surfaces representing the boundaries of the two physical tooth models; and calculating the length of the straight line in the overlapping portion to quantify the interference between the two physical tooth models.
376. The method of claim 375, further comprising acquiring the coordinates of a plurality of points on the surfaces of each of the two physical tooth models; and digitally representing the surfaces of each of the two physical tooth models by a mesh of points in three dimensions using the acquired coordinates.
377. The method of claim 376, further comprising measuring the positions of points on the surfaces of an impression representing a patient's teeth.
378. The method of claim 375, further comprising developing aligned coordinate systems or a common coordinate system for the two interpolated surfaces representing the boundaries of the two physical tooth models wherein the straight line can be quantitative defined.
379. The method of claim 375, further comprising calculating the lengths of three orthogonally oriented straight lines in the overlapping portion; defining three vectors along the three orthogonally oriented straight lines, each of the vectors having a magnitude of the inverse of the length in the overlapping portion; and calculating a vector sum of the three vectors to determine the direction and the distance required for the interpolated surfaces representing the two physical tooth models to move apart to avoid interference between the two physical tooth models.
380. The method of claim 379, further comprising moving apart the interpolated surfaces representing the boundaries of the two physical tooth models in accordance to the vector sum to avoid interference between the two physical tooth models.
381. The method of claim 375, further comprising adjusting the positions or the orientations of at least one of the two physical tooth models to prevent the interference between the physical tooth models.
382. The method of claim 375, wherein at least one of the meshes comprises at least one mesh opening having three, four or five nodes.
383. The method of claim 375, further comprising selecting the configurations of a first feature to be affixed to the undersides of the two physical tooth models to prevent interference between the two physical tooth models when they are mounted to a base with the assistance of the first feature.
384. The method of claim 383, wherein the second feature comprises one or more of a pin, a registration slot, a socket, a notch, a protrusion, a hole, an interlocking mechanism, a jig, and a pluggable or an attachable feature.
385. The method of claim 384, further comprising fabricating the physical tooth models having the first features having the selected configurations.
386. The method of claim 375, further comprising selecting the positions and orientations of second features on a base to prevent interference between the two physical tooth models when they are mounted to a base with the assistance of the second features.
387. The method of claim 386, wherein the second feature comprises one or more of a pin, a registration slot, a socket, a notch, a protrusion, a hole, an interlocking mechanism, a jig, and a pluggable or attachable feature.
388. The method of claim 386, further comprising fabricating the base having the second features having the selected positions and orientations.
389. A method for preventing interference between two physical tooth models in a physical dental arch model, comprising: digitally representing the surfaces of each of the two physical tooth models by a mesh of points in three dimensions; interpolating the meshes of points to produce interpolated surfaces to represent the boundaries of the two physical tooth models, wherein the interpolated surfaces representing the two physical tooth models intersect at least at one point to form an overlapping portion; developing aligned coordinate systems or a common coordinate system for the two interpolated surfaces representing the two physical tooth models; specifying a straight line running through the overlapping portion and intersecting the two interpolated surfaces representing the boundaries of the two physical tooth models; and calculating the length of the straight line in the overlapping portion to quantify the interference between the two physical tooth models.
390. The method of claim 389, further comprising calculating the lengths of three orthogonally oriented straight lines in the overlapping portion; defining three vectors along the three orthogonally oriented straight lines, each of the vectors having a magnitude of the inverse of the length in the overlapping portion; and calculating a vector sum of the three vectors to determine the direction and the distance required for the interpolated surfaces representing the boundaries of the two physical tooth models to move apart to avoid interference between the two physical tooth models.
391. The method of claim 390, further comprising moving apart the interpolated surfaces representing the boundaries of the two physical tooth models in accordance to the vector sum to avoid interference between the two physical tooth models.
392. The method of claim 389, further comprising selecting the configurations of a first feature to be affixed to the undersides of the two physical tooth models to prevent interference between the two physical tooth models when they are mounted to a base with the assistance of the first feature.
393. The method of claim 392, wherein the second feature comprises one or more of a pin, a registration slot, a socket, a notch, a protrusion, a hole, an interlocking mechanism, a jig, and a pluggable or an attachable feature.
394. A method for preventing interference between two physical tooth models in a physical dental arch model, comprising: digitally representing the surfaces of each of the two physical tooth models by a mesh of points in three dimensions; interpolating the meshes of points to produce interpolated surfaces to represent the boundaries of the two physical tooth models, wherein the interpolated surfaces representing the boundaries of two physical tooth models intersect at least at one point to form an overlapping portion; specifying three orthogonally oriented straight lines each running through the overlapping portion and intersecting the two interpolated surfaces representing the boundaries of the two physical tooth models; calculating the lengths of three orthogonally oriented straight lines in the overlapping portion; defining three vectors along the three orthogonally oriented straight lines, each of the vectors having a magnitude of the inverse of the corresponding length of the overlapping portion; calculating a vector sum of the three vectors to determine the direction and the distance required for the interpolated surfaces representing the boundaries of the two physical tooth models to move apart to avoid interference between the two physical tooth models; and moving apart the interpolated surfaces representing the boundaries of the two physical tooth models in accordance to the vector sum to avoid interference between the two physical tooth models.
395. A method for producing a physical dental arch model based on a three-dimensional (3D) digital dental arch model, comprising: smoothening the digital dental arch model to make the digital dental arch model suitable for CNC based manufacturing; segmenting the digital dental arch model into at least two manufacturable digital components; producing manufacturable physical components using Computer Numerical Control (CNC) based manufacturing in accordance with the manufacturable digital components; and assembling the manufacturable physical components to form the physical dental arch model.
396. The method of claim 395, further comprising: determining if the smoothened digital dental arch model satisfies one or more predetermine criteria for CNC based manufacturing.
397. The method of claim 396, further comprising running a CNC simulator to determine if the smoothened digital dental arch model satisfies one or more predetermine criteria for CNC based manufacturing.
398. The method of claim 395, wherein smoothening the digital dental arch model includes removing sharp gaps and divots in the teeth arch in the digital dental arch model.
399. The method of claim 395, wherein the manufacturable digital components include a portion of a tooth, a whole tooth, a plurality of teeth, or a complete teeth arch.
400. The method of claim 395, wherein the manufacturable digital components and the manufacturable physical components include features that permit the manufacturable physical components to be assembled into the physical dental arch model.
401. The method of claim 395, wherein the features include one or more of a pin, a notch, a protrusion, a hole, an interlocking mechanism, a jig, and a pluggable or an attachable feature.
402. The method of claim 395, further comprising attaching or plugging the manufacturable physical components into each other to form the physical dental arch model.
403. The method of claim 395, wherein the CNC based manufacturing includes milling, stereolithography, laser machining, and molding.
404. The method of claim 395, wherein the physical dental arch model comprises a material selected from the group consisting of polymers, urethane, epoxy, plastics, plaster, stone, clay, acrylic, metals, wood, paper, ceramics, and porcelain.
405. The method of claim 395, further comprising: obtaining a cast for a teeth arch from a patient; and scanning the cast to obtain the digital data for the digital dental arch model.
406. The method of claim 395, further comprising: generating a digital model for a base compatible with the digital dental arch model; and producing the base that can be assembled with the manufacturable physical components.
407. The method of claim 406, wherein the base comprises one or more features to assist the assembling with the manufacturable physical components, said features comprising one or more of a pin, a notch, a protrusion, a hole, an interlocking mechanism, a jig, and a pluggable or attachable feature.
408. The method of claim 406, further comprising attaching or plugging the manufacturable physical components into the base to form the physical dental arch model over the base.
409. The method of claim 406, further comprising: producing the physical base using CNC based manufacturing.
410. A system for producing a physical dental arch model, comprising: a computer storage device that stores a three-dimensional (3D) digital dental arch model; a computer processor that can smoothen the digital data in the digital dental arch model and segment the digital dental arch model into at least two manufacturable digital components suitable for CNC based manufacturing; and an apparatus that can produce manufacturable physical components in accordance with the manufacturable digital components, wherein the manufacturable physical components can be assembled to form the physical dental arch model.
41 1. The system of claim 410, wherein the apparatus can produce manufacturable physical components in accordance with the manufacturable digital components using Computer Numerical Control (CNC) based manufacturing.
412. The system of claim 410, further comprising: an apparatus that can produce a physical base that is adapted to receive the manufacturable physical components form the physical dental arch model on the base.
413. A physical dental arch model assembled from a plurality of manufacturable physical components, comprising: two or more manufacturable physical components produced by Computer Numerical Control (CNC) based manufacturing in response to manufacturable digital components segmented from a three-dimensional (3D) digital dental arch model; and a base adapted to receive the manufacturable physical components.
414. The physical dental arch model of claim 413, wherein the base is produced by Computer Numerical Control manufacturing.
415. A method for producing a physical dental aligner, comprising: producing a digital dental aligner model suitable for CNC based manufacturing based on the digital dental arch model; segmenting the digital dental aligner model into a plurality manufactuable digital components; producing aligner components using Computer Numerical Control (CNC) based manufacturing in accordance with the digital aligner components; and assembling the aligner components to form the physical dental aligner.
416. The method of claim 415, wherein the physical dental aligner includes a shell that comprises an outer surface and at least inner surface that is capable of aligning one or more teeth.
417. The method of claim 416, wherein the shell comprises multiple layers.
418. The method of claim 416, wherein the shell comprises varying thicknesses in different areas that is capable of producing forces to render predetermined teeth movement.
419. The method of claim 416, further comprising smoothening the outer surface and the one or more inner surfaces in the digital dental aligner model to produce a smoothened digital dental aligner model.
420. The method of claim 415, further comprising: producing a digital dental aligner model based on a digital dental arch model.
421. The method of claim 415, further comprising automatically assembling the aligner components using a robot arm to form the physical dental aligner.
422. The method of claim 415, wherein the aligner components include features that permit the aligner components to be assembled into the physical dental aligner.
423. The method of claim 422, wherein the features include one or more of registration slots, a pin, a notch, a protrusion, a hole, an interlocking mechanism, a jig, and a pluggable or an attachable feature.
424. The method of claim 415, further comprising attaching or sealing the aligner components into each other to form the physical dental aligner.
425. The method of claim 415, further comprising assembling the aligner components in a predetermined sequence to form the physical dental aligner.
426. The method of claim 415, further comprising polishing or retouching the assembled aligner components to form the physical dental aligner.
427. The method of claim 415, wherein the CNC based manufacturing includes one or more of milling, stereo lithography, laser machining, molding, and casting.
428. The method of claim 415, wherein the physical dental aligner comprises a material selected from the group consisting of plastics, polymers, urethane, epoxy, plaster, stone, clay, acrylic, metals, wood, paper, ceramics, and porcelain.
429. The method of claim 415, wherein the physical dental aligner comprises surface textures that simulate the cosmetic appearance of teeth.
430. The method of claim 415, wherein the physical dental aligner comprises a multiple layers each comprising the same or different materials.
431. A system for producing a physical dental aligner, comprising: a computer processor capable of producing a digital dental aligner model and segmenting the digital dental aligner model into a plurality of digital aligner components suitable for CNC based manufacturing; and an apparatus capable of fabricating aligner components in accordance with the digital aligner components, wherein the aligner components can be assembled to form the physical dental aligner.
432. A physical dental aligner assembled from a plurality of aligner components, comprising: a plurality of aligner components produced by Computer Numerical Control (CNC) based manufacturing in response to digital aligner components segmented from a three-dimensional (3D) digital dental aligner model.
433. The physical dental aligner of claim 432, further comprising physical features associated with the aligner components that permit the aligner components to be assembled into the physical dental aligner.
434. The method of claim 433, wherein the features include one or more of a pin, a notch, a protrusion, a hole, an interlocking mechanism, a jig, and a pluggable or an attachable feature.
EP05825468A 2004-11-02 2005-11-02 Methods and apparatuses for manufacturing dental aligners Withdrawn EP1807015A2 (en)

Applications Claiming Priority (21)

Application Number Priority Date Filing Date Title
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US10/979,823 US7384266B2 (en) 2004-11-02 2004-11-02 Method and apparatus for manufacturing and constructing a physical dental arch model
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US10/979,504 US20060093987A1 (en) 2004-11-02 2004-11-02 Producing an adjustable physical dental arch model
US11/012,924 US20060127850A1 (en) 2004-12-14 2004-12-14 Accurately producing a base for physical dental arch model
US11/013,159 US20060127860A1 (en) 2004-12-14 2004-12-14 Producing a base for accurately receiving dental tooth models
US11/013,157 US20060127858A1 (en) 2004-12-14 2004-12-14 Producing accurate base for a dental arch model
US11/013,155 US7293988B2 (en) 2004-12-14 2004-12-14 Accurately predicting and preventing interference between tooth models
US11/013,154 US7309230B2 (en) 2004-12-14 2004-12-14 Preventing interference between tooth models
US11/013,160 US7435084B2 (en) 2004-12-14 2004-12-14 System and methods for casting physical tooth model
US11/013,158 US20060127859A1 (en) 2004-12-14 2004-12-14 Producing a physical toothmodel compatible with a physical dental arch model
US11/013,152 US7922490B2 (en) 2004-12-14 2004-12-14 Base for physical dental arch model
US11/013,156 US20060127857A1 (en) 2004-12-14 2004-12-14 Producing non-interfering tooth models on a base
US11/013,145 US8636513B2 (en) 2004-12-14 2004-12-14 Fabricating a base compatible with physical tooth models
US11/050,126 US7335024B2 (en) 2005-02-03 2005-02-03 Methods for producing non-interfering tooth models
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PCT/US2005/039715 WO2006050452A2 (en) 2004-11-02 2005-11-02 Methods and apparatuses for manufacturing dental aligners

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EP1807015A2 true EP1807015A2 (en) 2007-07-18

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WO (1) WO2006050452A2 (en)

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