CN113208752A

CN113208752A - Shell-shaped appliance and manufacturing method thereof

Info

Publication number: CN113208752A
Application number: CN202010065758.9A
Authority: CN
Inventors: 曾鹏
Original assignee: Shanghai Kuohong Information Technology Co ltd
Current assignee: Jia Jun
Priority date: 2020-01-20
Filing date: 2020-01-20
Publication date: 2021-08-06

Abstract

One aspect of the present application provides a shell-shaped appliance manufacturing method, including: obtaining a first three-dimensional digital model representing a first shell-shaped appliance; modifying the thickness of a selected area of the occlusal surface of the posterior dental area of the first three-dimensional digital model according to the requirement of opening posterior occlusion, and forming a jaw pad for opening posterior occlusion in the selected area to obtain a second three-dimensional digital model representing a second shell-shaped appliance; and manufacturing the second shell-shaped appliance based on the second three-dimensional digital model by using a 3D printing technology.

Description

Shell-shaped appliance and manufacturing method thereof

Technical Field

The present application relates generally to shell appliances and methods of making the same, and more particularly to a shell appliance that can open the posterior bite while repositioning teeth and methods of making the same.

Background

Shell appliances based on polymeric materials are becoming more popular due to their advantages of aesthetics, convenience, and ease of cleaning.

At present, the shell-shaped appliance is generally manufactured by a hot-pressing film forming process, and due to the characteristics of the process, the thicknesses of all parts of the manufactured shell-shaped appliance are basically consistent. To open the posterior bite with such shell appliances, there are generally two approaches. For one, a material of a particular thickness is attached to selected areas of the occlusal surface of the shell-shaped appliance, for example, by an additive process or gluing, and the thickness of the attached material is used to open the occlusion. And secondly, forming a bulge with a certain thickness at a selected area of the occlusal surface of the dental cast for hot-pressing film forming, so that a raised empty bag is formed at the corresponding part of the shell-shaped appliance, and opening occlusion by utilizing the raised empty bag. However, in view of the snap-in force, the attached material may fall off due to the constant force, and the blank may also be flattened out and lose the effect of opening the snap.

In view of the above, there is a need to develop a new shell-shaped appliance and a method for making the same.

Disclosure of Invention

An aspect of this application provides a ware is rescued to shelly, and shelly as an organic whole forms the cavity that holds the tooth, and the geometry of this cavity makes the ware is rescued to shelly can utilize the resilience force that the deformation produced to relocate the tooth from first overall arrangement to second overall arrangement, wherein, the second overall arrangement is different from first overall arrangement, its characterized in that, the ware is rescued to shelly forms jaw pad on the zone occlusal surface of back tooth for open the back tooth interlock, jaw pad is solid, and with the continuous entity is formed to the main part of the ware is rescued to shelly.

In some embodiments, the thickness of the shell appliance at the jaw pad is greater than the average thickness of the shell appliance.

In some embodiments, the jaw pads on both sides of the shell-shaped appliance can cover at least two posterior teeth respectively.

In some embodiments, the jaw pad can have a snap feature formed thereon that cooperates with a snap feature formed on the jaw pad of the opposing jaw shell appliance to prevent slippage during occlusion.

In another aspect, the present application provides a shell-shaped appliance manufacturing method, including: obtaining a first three-dimensional digital model representing a first shell-shaped appliance; modifying the thickness of a selected area of the occlusal surface of the posterior dental area of the first three-dimensional digital model according to the requirement of opening posterior occlusion, and forming a jaw pad for opening posterior occlusion in the selected area to obtain a second three-dimensional digital model representing a second shell-shaped appliance; and manufacturing the second shell-shaped appliance based on the second three-dimensional digital model by using a 3D printing technology.

In some embodiments, the first three-dimensional digital model is uniform in thickness.

In some embodiments, the second shell appliance is a unitary shell forming a cavity for receiving the teeth, the geometry of the cavity being such that the second shell appliance is able to reposition the teeth from the first configuration to the second configuration using resilient forces generated by the deformation.

In some embodiments, the thickness of the second three-dimensional digital model at the jaw pad is greater than its average thickness.

In some embodiments, the first three-dimensional digital model and the second three-dimensional digital model may be parametric three-dimensional digital models.

In some embodiments, the parameterized three-dimensional digital model may be a parameterized shell element model.

In some embodiments, the parameterized three-dimensional digital model expresses geometry in both geometric data and a parametric description.

In some embodiments, the second three-dimensional digital model may be obtained by modifying a thickness parameter of the first three-dimensional digital model.

In some embodiments, the method for manufacturing a shell-shaped appliance may further include: generating a 3D printed digital file based on the second three-dimensional digital model; and controlling a 3D printing device to manufacture the second shell-shaped appliance by using the 3D printing digital file.

In some embodiments, the 3D printed digital file may be an STL file.

In some embodiments, the method for manufacturing a shell-shaped appliance may further include: acquiring a three-dimensional digital model of a tooth; and obtaining the first three-dimensional digital model by performing a wrapping operation on the three-dimensional digital model of the teeth.

Drawings

The above-described and other features of the present disclosure will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. It is appreciated that these drawings depict only several embodiments of the disclosure and are therefore not to be considered limiting of its scope, for the disclosure will be described with additional specificity and detail through use of the accompanying drawings.

FIG. 1 is a schematic flow chart of a method of making a shell appliance in one embodiment of the present application;

FIG. 1A is a schematic flow chart of the generation of a parameterized three-dimensional digital model of a shell appliance based on a three-dimensional digital model of teeth in one embodiment of the present application; and

FIG. 2 schematically illustrates a cross-sectional profile of a shell appliance in one embodiment of the present application.

Detailed Description

In the following detailed description, reference is made to the accompanying drawings, which form a part hereof. In the drawings, like reference numerals generally refer to like parts throughout the various views unless the context dictates otherwise. The illustrative embodiments described in the detailed description, drawings, and claims are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter described herein. It should be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the figures, can be arranged, substituted, combined, designed in a wide variety of different configurations, all of which are explicitly contemplated and make part of this disclosure.

An aspect of the present application provides a shell appliance and a method of making the same, which can open the posterior bite while repositioning teeth.

The shell appliance is an integral shell forming a cavity for receiving the teeth, the geometry of the cavity being such that it can reposition the teeth from the first configuration to the second configuration using the resilience of the deformation.

For the condition that the anterior teeth are covered with a high covering degree or the posterior teeth lock the jaw, the upper and lower back teeth can be lifted to prevent the upper and lower back teeth from contacting (namely, the back occlusion is opened) so as to facilitate the subsequent orthodontic treatment, and a jaw cushion is a common auxiliary means for opening the back occlusion.

Fig. 1 is a schematic flow chart of a method 100 for manufacturing a shell-shaped appliance based on 3D printing technology according to an embodiment of the present disclosure.

In 101, a parameterized three-dimensional digital model of the shell appliance is generated based on the three-dimensional digital model of the teeth.

In one embodiment, the three-dimensional digital model of the tooth is a non-parametric three-dimensional digital model.

The non-parametric three-dimensional digital model expresses geometry only in geometric data and has no parametric description of geometric features. For example, the non-parametric three-dimensional digital model generally expresses geometric data such as vertices, patches, normal vectors, etc., and takes an stl (stereo) file as an example, the geometric data includes vertices of each triangle patch and coordinate values of all the vertices in the world coordinate system.

The parameterized three-dimensional digital model expresses geometry in both geometry data and a parametric description. The geometric parameters in the parameterized three-dimensional digital model may include variable parameters and invariant parameters. Examples of geometric parameters include thickness, curvature, radius, positional relationship, and the like.

The modification of the geometry of the non-parametric three-dimensional digital model can only be achieved by directly modifying the geometry data, and the geometric features (e.g., thickness, curvature, radius, etc.) cannot be controlled intuitively and accurately, which makes it very difficult to modify the geometry of the three-dimensional digital model in a targeted manner (e.g., to obtain a specific thickness, curvature, radius, etc.). In contrast, since the parameterized three-dimensional digital model not only contains geometric data but also contains parameters describing geometric features, the target geometric form can be intuitively and accurately obtained by modifying the corresponding parameters for modifying the parameterized three-dimensional digital model, so that the control on the geometric form of the three-dimensional digital model is very convenient, intuitive and accurate.

Please refer to fig. 1A, which is a schematic flowchart of an embodiment 101 of the present application.

At 1011, a three-dimensional digital model of the tooth is acquired.

In one embodiment, the three-dimensional digital model of the teeth may be a three-dimensional digital model of a dentition (e.g., maxillary or mandibular dentition) in a target layout corresponding to the step of correction. Since the shell appliances reposition the teeth using the elastic force generated by the deformation, there is usually a slight gap between the tooth placement actually achieved by the repositioning and the target placement.

The shell-shaped appliance is generally required to be divided into a plurality of successive correction steps (for example, 20 to 40 successive correction steps) for performing orthodontic treatment by using the shell-shaped appliance, and each correction step corresponds to one shell-shaped appliance and is used for repositioning teeth from an initial layout of the correction step to a target layout of the correction step.

In one embodiment, the shell appliance may be fabricated based on a three-dimensional digital model of the dentition under the target layout corresponding to the corrective step.

In one embodiment, a target layout for a series of successive corrective steps can be generated based on a three-dimensional digital model of the dentition under the original layout prior to orthodontic treatment.

In one embodiment, a three-dimensional digital model of the dentition in the original layout may be obtained by directly scanning the patient's dental jaws. In yet another embodiment, a three-dimensional digital model of the dentition in the original layout may be obtained by scanning a solid model, such as a plaster model, of the patient's dental jaw. In yet another embodiment, a three-dimensional digital model of the dentition in the original layout may be obtained by scanning the bites of the patient's jaws.

In one embodiment, after the three-dimensional digital model of the dentition in the original layout is obtained, it may be segmented such that the teeth in the three-dimensional digital model are independent of each other, thereby enabling individual movement of each tooth.

In one embodiment, a series of successive intermediate layouts, i.e., a series of successive orthodontic step target layouts, may be generated based on the original layout and the desired layout.

In one embodiment, a three-dimensional digital model of the dentition in the desired layout may be obtained based on the segmented three-dimensional digital model of the dentition in the original layout. In one embodiment, the three-dimensional digital model of the dentition in the segmented original layout may be manually manipulated to move each tooth to a desired position to obtain the three-dimensional digital model of the dentition in the desired layout. In yet another embodiment, a three-dimensional digital model of the dentition in the desired layout may be obtained using a computer by automatically moving each tooth to the desired position based on the three-dimensional digital model of the dentition in the segmented original layout.

In one embodiment, after obtaining the original layout and the desired layout, interpolation may be performed based on both to obtain a series of successive targeted layouts for the correction step.

In yet another embodiment, a three-dimensional digital model of the dentition under the original layout can be manually manipulated to directly obtain a target layout for a series of successive corrective steps.

In yet another embodiment, a computer may be used to automatically generate a series of successive orthodontic step target layouts based on a three-dimensional digital model of the dentition under the original layout using a particular method (e.g., a spatial search method).

A more common format for a three-dimensional digital model of teeth is an STL model (or STL file), and the following describes embodiments of the present application with reference to a three-dimensional digital model of teeth in the STL format. The STL file format is an interface protocol established by 3D SYSTEMS in 1988, and is a three-dimensional graphics file format that serves rapid prototyping technology. The STL file is comprised of a plurality of definitions of triangle patches, each of which includes three-dimensional coordinates of each vertex of the triangle and a normal vector of the triangle patch. The STL model is essentially a three-dimensional body bounded by closed surfaces, which has no thickness definition.

At 1013, an unparameterized three-dimensional digital model of the shell appliance is generated based on the three-dimensional digital model of the teeth.

In one embodiment, the three-dimensional digital model of the teeth may be a three-dimensional digital model of the jaws that retains only the crown portion after removal of the gum portion.

In one embodiment, the three-dimensional digital model of the tooth may be subjected to a wrapping operation to generate a first three-dimensional digital model of the wrapped three-dimensional digital model of the tooth, and a portion of a surface of the first three-dimensional digital model corresponding to the crown may be used as an inner surface of the three-dimensional digital model of the shell-shaped appliance. Then, a second three-dimensional digital model is obtained based on the first three-dimensional digital model being outwardly expanded by a predetermined distance (i.e., the set thickness of the shell-shaped appliance) in the normal direction. Then, the surfaces of the first three-dimensional digital model and the second three-dimensional digital model are combined to generate a third three-dimensional digital model which is used as a shell-shaped appliance three-dimensional digital model. In one embodiment, the shell-shaped appliance three-dimensional digital model may be an STL model.

In 1015, the non-parametric three-dimensional digital model of the shell appliance is converted to a parametric three-dimensional digital model.

In one embodiment, the parameterized three-dimensional numerical Model may be in IGES (initiative Graphics Exchange Specification) or STEP (Standard for the Exchange of Product Model data) format.

In one embodiment, the parameterized model of the shell appliance may be a parameterized shell element model.

In finite element analysis, there are two common models, one is a solid element model and the other is a shell element model. For finite element analysis of thin-walled structures, it is relatively easy to converge to a stable solution using the shell element model. Because the shell-shaped appliance is also of a thin-wall structure, when a parameterized model of the shell-shaped appliance is generated, a shell unit model in finite element analysis can be used for reference, and meanwhile, thickness parameters can be given to the shell unit model, so that the thickness of each part of the shell-shaped appliance can be conveniently controlled.

In one embodiment, a parameterized shell element model with thickness parameters in IGES or STEP format may be generated based on the STL model of the shell appliance using Geomagic, HyperMesh, 3-matic, etc. software.

In another embodiment, the STL model of the shell appliance may be directly edited by CAE software such as HyperMesh, LSTC, Abaqus, or Ansys, and the like, and the parameterized shell element model may be obtained by changing the data structure and assigning parameters including the thickness to the STL model.

In yet another embodiment, a parameterized shell cell model of a shell appliance may be generated directly based on point cloud data of the STL model of the shell appliance.

It will be appreciated in the light of the present application that other suitable parameterized three-dimensional digital models may be used in addition to the above-mentioned shell element parameterized model and are not exhaustive herein.

At 103, the parameterized three-dimensional digital model of the shell appliance is modified to form a jaw pad in a selected area of the occlusal surface of the posterior area thereof, as required to open the posterior bite.

In one embodiment, the thickness of the jaw pad may be determined as needed to open the posterior bite.

In one embodiment, when changing the local thickness of the parameterized three-dimensional digital model of the shell appliance, the surface geometry of the local area can be kept substantially unchanged, i.e., simply increased in thickness. In yet another embodiment, when changing the local thickness of the parameterized three-dimensional digital model of the shell appliance, the geometric features of the surface of the local area may be smoothed out.

To distribute the occlusal force and prevent excessive concentrations of the occlusal force that may lead to tooth depression, the number of bite sites where the jaw pad covers the occlusal surface may be increased, e.g., the jaw pad on each side of a shell appliance may cover at least two posterior teeth.

Referring to FIG. 2, a cross-sectional profile of a shell appliance in one embodiment of the present application is schematically illustrated. To open the posterior occlusion, the thickness of the maxillary shell appliance 201 at the area of the occlusal surface corresponding to the posterior teeth 203 is increased to form the jaw pad 205 thereat, while the thickness of the mandibular shell appliance 211 at the area of the occlusal surface corresponding to the posterior teeth 213 is increased to form the jaw pad 215 thereat. Upon occlusion, the

jaw pads

205 and 215 abut, causing the

posterior teeth

203 and 213 to move away from each other, thereby opening the posterior occlusion. In one embodiment, the bolsters 205 and 215 may be shaped to match each other to reduce the chance of slippage of the occlusion.

In one embodiment, the thickness of the occlusal selected area of the posterior zone may be increased by modifying the thickness parameter of the parameterized three-dimensional digital model of the shell appliance.

In 105, a 3D printed digital file is generated based on the modified parameterized three-dimensional digital model of the shell appliance.

Currently, the more common 3D printed digital files are STL and STP format files. Although some 3D printing apparatuses of manufacturers support format files such as OBJ, BREP, MAX, 3DM, 3DS, X _ T, SKP, SLDPRT, PRT, ASM, F3D, FBX, RVT, WIRE, and the like, it is rare. The following embodiment will be described by taking a case unit model to STL file as an example.

In one embodiment, if the shell element is a triangle, the conversion of the shell element model to the STL file can be realized by importing, converting and exporting through preprocessing software of CAE business software such as HyperMesh, LSTC, Abaqus and Ansys.

After the parameterized model is converted to an STL file, the surfaces and curves are replaced and transformed into a mesh, forming a series of triangular patches and point cloud data that represent the exact geometric meaning of the prototype.

In one embodiment, the 3D printing device may be detected and repaired before controlling it to perform 3D printing using the STL file to ensure that the triangular patches form a fully enclosed surface.

In light of the present application, it is understood that in addition to the modification of the local thickness of the shell appliance by modifying the local thickness of the parameterized three-dimensional digital model of the shell appliance, the modification of the local thickness of the shell appliance may also be achieved by modifying the local thickness of the unparameterized three-dimensional digital model of the shell appliance.

For example, in the Geomagic Studio software environment, the surface of the STL model of the shell appliance can be expanded, eroded, and smoothed. The expansion operation serves to bulge the surface of the selected area outwardly a set distance (i.e. to increase the thickness of the selected area) and may provide a gradual degree of transition between the bulged area and the edge. The etching operation serves to recess the surface of the selected area a set distance (i.e. to reduce the thickness of the selected area), and the smoothness of the transition between the recessed area and the edge can likewise be set. The smoothing operation is used to smooth the surface of the selected area to be more gradual.

In 107, the 3D printing device is controlled to fabricate a shell appliance using the 3D printed digital file.

Currently, 3D printing devices suitable for making shell appliances include Stereolithography (SLA) devices (such as those provided by 3D Systems), Digital Light Processing (DLP) devices (such as those provided by Envision TEC), and polymer jet (PolyJet) devices (such as those provided by Stratasys), among others.

After the 3D printing digital file is obtained, the shell-shaped appliance can be manufactured by controlling a 3D printing device through the digital file.

It will be appreciated that, in the context of the present application, the posterior occlusion may be opened by increasing the local thickness of the occlusal surface of either the upper or lower shell appliances, or both.

Because the jaw pad of the shell-shaped appliance is solid and forms a continuous entity with the shell-shaped appliance main body, namely, no boundary exists between the jaw pad and the shell-shaped appliance main body, the problem that the jaw pad of the existing shell-shaped appliance drops or is sunken is solved.

While various aspects and embodiments of the disclosure are disclosed herein, other aspects and embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification. The various aspects and embodiments disclosed herein are for purposes of illustration only and are not intended to be limiting. The scope and spirit of the application are to be determined only by the claims appended hereto.

Likewise, the various diagrams may illustrate an exemplary architecture or other configuration of the disclosed methods and systems that is useful for understanding the features and functionality that may be included in the disclosed methods and systems. The claimed subject matter is not limited to the exemplary architectures or configurations shown, but rather, the desired features can be implemented using a variety of alternative architectures and configurations. In addition, to the extent that flow diagrams, functional descriptions, and method claims do not follow, the order in which the blocks are presented should not be limited to the various embodiments which perform the recited functions in the same order, unless the context clearly dictates otherwise.

Unless otherwise expressly stated, the terms and phrases used herein, and variations thereof, are to be construed as open-ended as opposed to limiting. In some instances, the presence of an extensible term or phrases such as "one or more," "at least," "but not limited to," or other similar terms should not be construed as intended or required to imply a narrowing in instances where such extensible terms may not be present.

Claims

1. A shell-shaped appliance, which is in an integral shell shape and forms a cavity for accommodating teeth, the geometric shape of the cavity enables the shell-shaped appliance to reposition the teeth from a first layout to a second layout by using resilience force generated by deformation, wherein the second layout is different from the first layout, and the shell-shaped appliance is characterized in that a jaw pad is formed on the occlusal surface of a posterior dental area for opening posterior occlusion, and the jaw pad is solid and forms a continuous entity with a main body of the shell-shaped appliance.

2. The shell appliance of claim 1, wherein the thickness of the shell appliance at the jaw pad is greater than the average thickness of the shell appliance.

3. The shell appliance of claim 1, wherein the pads on each side of the shell appliance cover at least two posterior teeth.

4. The shell appliance of claim 1, wherein the jaw pads have a snap feature that cooperates with a snap feature formed on the jaw pad of the shell appliance to prevent slippage during occlusion.

5. A method for manufacturing a shell-shaped appliance comprises the following steps:

obtaining a first three-dimensional digital model representing a first shell-shaped appliance;

modifying the thickness of a selected area of the occlusal surface of the posterior dental area of the first three-dimensional digital model according to the requirement of opening posterior occlusion, and forming a jaw pad for opening posterior occlusion in the selected area to obtain a second three-dimensional digital model representing a second shell-shaped appliance; and

and manufacturing the second shell-shaped appliance based on the second three-dimensional digital model by using a 3D printing technology.

6. The method of claim 5, wherein the first three-dimensional digital model is of uniform thickness.

7. The method of claim 5, wherein the second shell appliance is one-piece shell shaped to define a cavity for receiving the teeth, the cavity having a geometry such that the second shell appliance is capable of repositioning the teeth from the first configuration to the second configuration using a resilient force generated by the deformation.

8. The method of making a shell appliance of claim 5 wherein the second three dimensional digital model has a thickness at the jaw pad that is greater than its average thickness.

9. The method of making a shell appliance of claim 5, wherein the first three-dimensional digital model and the second three-dimensional digital model are parameterized three-dimensional digital models.

10. The method of making a shell appliance of claim 9, wherein the parameterized three dimensional digital model is a parameterized shell element model.

11. The method of claim 9, wherein the parameterized three dimensional digital model expresses geometry in both geometric data and parametric description.

12. The method of claim 9, wherein the second three-dimensional digital model is obtained by modifying a thickness parameter of the first three-dimensional digital model.

13. The method of making a shell appliance of claim 9, further comprising:

generating a 3D printed digital file based on the second three-dimensional digital model; and

and controlling a 3D printing device to manufacture the second shell-shaped appliance by using the 3D printing digital file.

14. The method of making a shell appliance of claim 13, wherein the 3D printed digital file is an STL file.

15. The method of making a shell appliance of claim 5, further comprising:

acquiring a three-dimensional digital model of a tooth; and

and obtaining the first three-dimensional digital model by performing a wrapping operation on the three-dimensional digital model of the teeth.