FR3039982A1 - MANUFACTURING AN ORTHODONTIC DEVICE - Google Patents

Abstract

A method of manufacturing an orthodontic device for modifying a dental disposition, characterized in that it comprises the following steps: obtaining (E1) initial digital data relating to at least a part of a dentition in a dental disposition initial ; - Production (E4) of a digital data file representing an orthodontic appliance adapted to said dentition and adapted to exert a displacement force on at least one tooth; - manufacture (E5) of the orthodontic appliance directly from the digital product file.

Description

Fabrication of an orthodontic appliance

TECHNICAL FIELD OF THE INVENTION The invention is in the orthodontic field and relates to a method of manufacturing an orthodontic appliance, as well as to a device for manufacturing an orthodontic appliance as such. State of the art

A known solution for correcting dental malpositions in a patient is to secure a ring on each tooth and then to fix a wire on each ring. By its tension, this wire then exerts a force on each tooth, through the rings, to reposition them gradually. This solution has the disadvantage of requiring regular appointments with an orthodontist to readjust the position of the device, including the wire, as and when the movement of teeth. On the other hand, this orthodontic device is uncomfortable, unattractive, difficult to maintain and inconvenient for brushing teeth and oral hygiene in general.

To overcome these drawbacks, documents EP0989828 and EP2263599 describe another solution which is based on a series of orthodontic appliances to be worn successively. These devices are in the form of gutters of transparent plastic material providing housing or cavities for receiving teeth. For the sake of simplicity, we will call later "gutter" or "dental gutter" such a type of orthodontic appliance. Dental gutters help move teeth gently. The orthodontic procedure described in these documents requires the knowledge of the initial dental disposition and the preliminary definition of the final disposition of the dentition, from a digitization of the initial dentition. From the initial disposition and the desired final disposition of the teeth, a series of gutters to be carried one after the other is manufactured. The teeth are moved gently by means of these gutters successively carried on the patient's support teeth until reaching the desired final disposition of the teeth.

The manufacture of a gutter is done by a step of manufacturing a model that reproduces the gingiva and its teeth at a definite moment (intermediate or final), followed by a step of molding the gutter of plastic material by thermoforming. This process is time consuming and expensive and requires the manufacture of several models of the dentition, which are then discarded.

Object of the invention

Because of the preceding remarks, the object of the present invention is to propose an orthodontic solution that does not include all or part of the above disadvantages. The invention consists in manufacturing an orthodontic appliance directly from a digital data file representing virtually the structure of the orthodontic appliance. This digital file is produced from initial digital data relating to all or part of the patient's dentition. The invention thus avoids making a hard model of the patient's dentition in order to manufacture the orthodontic appliance. To this end, the invention relates to a method for manufacturing an orthodontic device for modifying a dental disposition, characterized in that it comprises the following steps: obtaining initial digital data relating to at least a part of a dentition in an initial dental disposition; producing a digital data file representing an orthodontic appliance adapted to said dentition and able to exert a displacement force on at least one tooth; - manufacturing the orthodontic appliance directly from the digital product file.

The method may comprise a step of at least partial virtual representation of said dentition according to the initial dental layout, from the initial digital data, and a step of virtual movement of the teeth to obtain a virtual model MODn representing all or part of the dentition of the dentition. patient, in modified dental arrangements. The production step may include a sub-step of producing digital data representing the occlusal shape of the orthodontic appliance by constructing the negative form of the virtual model MODn representing all or part of the modified dentition of the patient. The production step may include a substep of producing digital data representing at least one gingival end of the orthodontic appliance. The step of producing a digital data file representing an orthodontic appliance adapted to said dentition may include a digital data meeting step representing the occlusal shape of the orthodontic appliance and digital data representing at least one gingival end of the appliance. orthodontic appliance. The orthodontic appliance may be manufactured by a material addition technique, in particular by three-dimensional printing. Alternatively, the orthodontic appliance may be manufactured by a material subtraction technique, in particular by machining a block of material or laser cutting or by water jet. The manufacturing step may use a biocompatible material.

The method may comprise producing a series of digital data files respectively representing a series of orthodontic appliances adapted to said dentition and corresponding to a succession of dental arrangements modified with respect to the initial dental layout to achieve a dental disposition. final from the initial disposition by at least one intermediate dental arrangement, and the manufacture of a series of orthodontic appliances respectively from the series of digital data files produced. The invention also relates to a device for controlling the manufacture of an orthodontic appliance for modifying a dental disposition, characterized in that it comprises: a module for obtaining initial digital data relating to at least a part a dentition in an initial dental disposition; a production module capable of producing a digital data file representing an orthodontic appliance adapted to said dentition and able to exert a displacement force on at least one tooth; a module for controlling a device for manufacturing the orthodontic appliance, from the digital data file produced. The invention also relates to a system for manufacturing an orthodontic device for modifying a dental disposition, comprising the control device described above and a device for manufacturing the orthodontic appliance.

The system may include an image capture device. The invention also relates to a computer program comprising program code instructions for performing the steps of the method described above when said program is executed by a processing unit.

Brief description of the drawings

These objects, features and advantages of the present invention will be set forth in detail in the following description of a particular embodiment made in a non-limiting manner in relation to the appended figures among which:

Figure 1 shows a diagram of the manufacturing system of an orthodontic appliance, according to an exemplary embodiment of the invention.

FIG. 2 represents a flow diagram of the steps of the method of manufacturing an orthodontic appliance, according to a particular embodiment of the invention.

Description of preferred modes of the invention

The method of the invention allows the manufacture of an orthodontic appliance for modifying a dental disposition. The method is implemented by a system comprising here the following elements: - an image capture device 1, - a control device 2 and - a manufacturing device 3.

The manufacturing method comprises a first step E1 of obtaining initial digital data relating to all or part of a dentition of a patient, the dentition having an initial dental disposition (in other words, initial positions of the teeth). The step E1 comprises an image capture sub-step E10 during which the image-capture device 1 takes digital images IMi (with i = 1, 2, ... N) of all or part of the dentition, the teeth being in their initial positions. The image capture device 1 may be an intraoral camera for taking images directly inside the patient's mouth. Alternatively, a three-dimensional model of all or part of the patient's dentition can be manufactured beforehand in a suitable material, for example in plaster, in a known manner, by molding made from an impression of the dentition, and then taking digital images of the model made using the image capture device. The image data IM, (with i = 1, 2, ...) represent all or part of the patient's dentition in its initial disposition and associated gingiva. They are transmitted to the control device 2 and received by the control device 2 during a transmission substep E11. The step E1 for digitizing the dentition and for transmitting initial digital data IM, is followed by a step E2 of virtual 3D representation of all or part of said dentition of the patient, from the initial digital data received (that is i.e. IM image data,). A component of the controller 2 processes the received image data IM, and generates an initial digital data set, denoted DATA0, representing an initial virtual three-dimensional model MOD0. This MOD0 model represents virtually all or part of the patient's teeth in their initial positions, that is, according to the initial dental disposition of the patient. It is represented virtually, here by display on a screen of the control device 2, to allow an operator to view and manipulate it virtually. The representation step E2 is followed by a virtual modification step E3 of the modeled dentition (in whole or in part). The modification comprises a virtual displacement of the modeled teeth (by translation and / or rotation in 3D) to produce one or more modified dental arrangement (s). These modified dental arrangements include: - at least one final dental arrangement, wherein the patient's teeth are in desired positions; possibly an intermediate dental disposition or several successive intermediate dental arrangements, between the initial dental disposition and the final dental disposition.

During step E3, a series of virtual models MODn, representing all or part of the patient's dentition, is created in modified and successive dental layouts comprising the intermediate dispositions and the final disposition. Each virtual teething model thus created is defined by a set of digital data DATAn, with 1 <n <N. It is represented virtually by display on the screen of the control device 2.

The steps E2 and E3 are executed by a software component of the control device 2. The modified dental arrangements are obtained here by a manipulation of the modeled teeth performed by an operator using man-machine interface means 25 of the device. control 2. Alternatively, the control device 2 could integrate a software component capable of automatically determining the intermediate provisions of the dentition from the initial layout and the final disposition, or all of the intermediate arrangements (s) and final from the original layout.

According to another variant embodiment, the step E3 comprises a substep of determining the forces to be applied on each tooth in order to obtain a desired displacement, this force being determined by a direction of displacement, for example a translation and / or a rotation. , and an intensity, depending on the amplitude of the desired displacement. A software component will then allow step E4 described below to automatically calculate the position of the wall of the gutter with respect to each tooth, to be able to exercise the calculated force, from rules that can be predefined and stored in a electronic memory. In this case, the digital data MODn no longer correspond to a virtual model representing the modified dentition of a patient, but to a set of rules for modifying the gutter that would be obtained from the initial virtual model MOD0.

The method therefore continues with a step E4 of producing a series of digital data files Fn respectively representing a series of orthodontic appliances, in this case dental gutters, adapted to the dentition of the patient and corresponding to the modified dental arrangements. successive, including here the intermediate and the final disposition. Alternatively, a single digital data file Fn representing a single orthodontic appliance can be generated. By "adapted (s) to the dentition of the patient" is meant that the or gutters are shaped to conform to the shape of at least a portion of the patient's dentition when they are carried on the support teeth, while applying the calculated forces on the teeth to move. More specifically, it is the inner walls of the gutter that are adapted by their shape to marry that of the support teeth. Step E4 comprises several substeps for automatically determining the contours of at least one gutter, among which: in a substep E41, the digital data Fni representing the occlusal shape of the gutter, that is to say say at the teeth, are obtained by constructing the negative of a virtual model MODn, representing all or part of the modified dentition of the patient, set in step E3. As a variant, these digital data Fni are constructed from the digital data obtained from the determined forces, according to the variant of step E3 described above; in another substep E42, the digital data Fn2 representing one or both gingival extremities, vestibular and / or lingual sides, are obtained. A first approach considers the digital data of a virtual model MODn, representing all or part of the modified dentition of the patient, established in step E3, and the gingival ends are established from the ends given by the virtual model. A second approach is to fix average pre-stored tooth heights in an electronic memory for certain categories of teeth, and to base the calculation of the gingival extremities on these average values and the knowledge of the type of tooth considered. Advantageously, the gingival ends of the orthodontic appliance are calculated to correspond to the actual boundary between the actual dentition and the actual gingiva. Alternatively, these ends are calculated to slightly cover the actual gingiva. Step E4 therefore generates a digital file Fn virtually representing an orthodontic appliance (or a gutter), containing a set of digital data defining the structure and construction of the appliance, bringing together the digital data Fn-ι and Fn2 established. It is determined from a virtual model MODn of all or part of the dentition of the patient in a modified arrangement, as created in step E3, in other words from the set of digital data DATAn defining a disposition modified tooth compared to the initial dentition. The digital file Fn of a gutter of index n can also contain in particular instruction data for controlling the manufacture of the nth orthodontic appliance by a manufacturing device.

The method then proceeds to a step E5 of manufacturing an orthodontic appliance or a series of orthodontic appliances, or dental gutters Gn with 1 <n <N, corresponding for example to the intermediate dental arrangements and the final dental arrangement, or in any case exerting forces on at least one tooth to move it in a predefined manner. The manufacture is carried out by the manufacturing device 3. It can use a manufacturing technique by adding material, for example by three-dimensional printing. Alternatively, it can use a manufacturing technique by subtraction of material. In this case, the orthodontic appliance is for example manufactured by machining a block of material, or laser cutting or water jet.

During the manufacturing step E5, the manufacturing device 3 is controlled by commands obtained from the digital file corresponding to the orthodontic appliance to be manufactured. In this case, the control device 2 transmits to the manufacturing device 3 manufacturing control instructions (for example 3D printing control instructions or machining control instructions, depending on the technique used). Alternatively, the controller 2 could transmit the file Fn to the manufacturing device and the manufacturing control instructions would be generated from the file Fn by the manufacturing device itself. In any case, each dental gutter Gn is manufactured directly from the digital file Fn, without going through the manufacture of a hard model. In addition, a gutter is entirely manufactured by this device, there is no need for a manual cutting step as a manual cutting of the lower boundary (gingival ends), as is the case during manufacture by thermoforming on models in the state of the art recalled in the preamble.

The material used for the manufacture of orthodontic appliances is advantageously a biocompatible material.

In the embodiment just described, the series of N digital files Fn is produced during step E4, and then the series of N gutters Gn is produced in step E5 with 1 <n <N. Alternatively, one could produce each file Fn and then directly manufacture the resulting gutter Gn, in two successive steps, and repeat the execution of these two successive steps N times for n varying from 1 to N to make the N orthodontic appliances, or dental gutters. The method has been described with a manufacture of a series of gutters, but alternatively, it can be implemented for the manufacture of a single gutter (N = 1).

Thanks to the production of orthodontic appliances digital files (or dental gutters), these can be manufactured directly, without intermediate step of realization of real three-dimensional models ("hard") of the dentition of the patient. As a remark, the method described above is advantageously implementable for manufacturing an orthodontic appliance of the "gutter" type. By gutter in the broadest sense, we mean any orthodontic appliance comprising housings for the total or partial positioning of at least one tooth of a patient, and which is fixed by clipping on at least one tooth of a patient. This gutter can have different shapes, include different materials and concern all or part of a patient's teeth. The housings may contain only a portion of the teeth, the walls of the gutter may have a reduced surface, or openwork areas. These walls are preferably thin, and comprise a front portion connected to a rear portion. There may be a single gutter for one of the upper or lower teeth, or more frequently two gutters for the upper and lower teeth, respectively. Alternatively, this method can be used for any other orthodontic appliance, not necessarily a gutter.

The device 2 for controlling the manufacture of an orthodontic appliance, shown in FIG. 1, comprises the following modules: a module 20 for obtaining initial digital data representing all or part of a dentition having an initial dental layout; a module 21 for creating virtual models representing all or part of the patient's dentition in an initial dental disposition and in at least one modified dental disposition with respect to the initial disposition and / or generation of modification rules from forces calculated; a production module 22 able to produce at least one digital data file representing an orthodontic appliance adapted to the dentition of the patient (that is to say capable of being fixed on his or her teeth by exerting the desired displacement forces) and corresponding at a modified dental disposition relative to the original dental disposition; an interface 23 of connection with the manufacturing device 3; a control module 24 able to control a device for manufacturing the orthodontic appliance, from the digital data file of the orthodontic appliance; man-machine interface means 25; a central processing and control unit 26.

The module 20 comprises a connection interface to the image capture device 1 and initial digital data reception means, containing image data captured and transmitted by the image capture device 1, and supplying these data elements. initial data to module 21 for creating virtual models. The received image data is obtained by capturing images of all or part of the patient's dentition using the image-capture device 1. The module 20 is intended to implement the step E11 (FIG. in reception).

The model creation module 21 integrates a software component making it possible to: create a first three-dimensional virtual model representing all or part of the patient's dentition in an initial dental layout; creating at least a second three-dimensional virtual model representing all or part of the patient's dentition in a modified dental arrangement by virtual displacement of the positions of the teeth; - manage the display of virtual models created or being created on a screen of the device 2.

The creation module 21 is thus adapted to create a series of virtual models representing all or part of the patient's dentition, in a succession of different dental arrangements comprising at least one initial and one final disposition and, where appropriate, one or several intermediate arrangement (s). More generally, this creation module 21 is adapted to implement the steps E2 and E3.

The production module 22 is intended to create a digital file or a series of digital file (s) relative (s) to one or more orthodontic device (s). Each digital file represents an orthodontic appliance adapted to said dentition. In the case where a series of files is produced, the different files respectively represent a series of orthodontic appliances corresponding to a succession of modified dental dispositions with respect to an initial dental layout making it possible to reach a final dental layout from the layout. initially by one or more intermediate dental arrangements. In the case where a single file is produced, it represents an orthodontic appliance corresponding to a final dental layout, modified with respect to an initial dental layout. The production module 22 is adapted to implement step E4. The connection interface 23 makes it possible to connect the control device 2 to an external device 3 for manufacturing an orthodontic appliance, for example a 3D printer.

The control module 24 is adapted to control the operation of the manufacturing device 3, from a digital file Fn produced by the module 22. It is intended to transmit control instructions to the manufacturing device 3 to control the production of the device. an orthodontic appliance. The control module 24 is intended to control the execution of the manufacturing step E5.

The modules 21, 22 and 24 are software modules comprising software instructions for performing the corresponding process steps when the modules are executed by the processing unit 26. The man-machine interface 25 comprises a display screen and / or any other data retrieval means, a keyboard and / or any other means of data entry and / or control, and GUI GUI (Graphical User Interface).

Finally, the control device 2 comprises a central processing unit 26, here comprising a microprocessor, to which all the elements 20-25 of the device are connected, and intended to control its operation. The invention also relates to a system comprising the image capture device 1, the control device 2 and the manufacturing device 3. The three components 1, 2 and 3 of the system are here separated. The image capture device 1 and the manufacturing device 3 may be connected to the control device by wire or wireless connection. Alternatively, the image capture device 1 and / or the manufacturing device 3 may be integrated into the control device 2. The invention also relates to a computer program comprising program code instructions for the execution of the steps of the method previously described when said program is executed by a processing unit, in this case the unit 26.

Claims (13)

1. A method of manufacturing an orthodontic device for modifying a dental disposition, characterized in that it comprises the following steps: - obtaining (E1) initial digital data relating to at least a part of a dentition in a initial dental disposition; - Production (E4) of a digital data file representing an orthodontic appliance adapted to said dentition and adapted to exert a displacement force on at least one tooth; - manufacture (E5) of the orthodontic appliance directly from the digital product file. 2. Method according to claim 1, characterized in that it comprises a step (E2) of at least partial virtual representation of said dentition according to the initial dental layout, from the initial digital data, and a step (E3) of displacement. virtual teeth to obtain a virtual model MODn representing all or part of the dentition of the patient, in modified dental arrangements. 3. Method according to claim 2, characterized in that the production step (E4) comprises a substep (E41) for producing digital data representing the occlusal shape of the orthodontic appliance by constructing the negative form of the model. virtual MODn representing all or part of the modified dentition of the patient. 4. Method according to one of the preceding claims, characterized in that the production step (E4) comprises a substep (E42) for producing digital data representing at least one gingival end of the orthodontic appliance. 5. Method according to one of the preceding claims, characterized in that the step of producing (E4) a digital data file representing an orthodontic appliance adapted to said dentition comprises a digital data meeting step representing the occlusal shape. of the orthodontic appliance and digital data representing at least one gingival end of the orthodontic appliance. 6. Method according to one of the preceding claims, characterized in that the orthodontic appliance is manufactured (E5) by a material addition technique, in particular by three-dimensional printing. 7. Method according to one of claims 1 and 2, characterized in that the orthodontic appliance is manufactured (E5) by a material subtraction technique, in particular by machining a block of material or laser cutting or jet d 'water. 8. Method according to one of the preceding claims, characterized in that the manufacturing step (E5) uses a biocompatible material. 9. Method according to one of the preceding claims, characterized in that it comprises the production (E4) of a series of digital data files (Fn) respectively representing a series of orthodontic appliances adapted to said dentition and corresponding to a succession of modified dental arrangements in relation to the initial dental arrangement for achieving a final dental disposition from the initial disposition by at least one intermediate dental disposition, and the manufacture (E5) of a series of orthodontic appliances ( Gn) respectively from the series of produced digital data files (Fn). 10. A device for controlling the manufacture of an orthodontic appliance for modifying a dental arrangement, characterized in that it comprises: a module (20) for obtaining initial digital data relating to at least a portion of a dentition in an initial dental disposition; - A production module (22) capable of producing a digital data file (Fn) representing an orthodontic appliance adapted to said dentition and adapted to exert a displacement force on at least one tooth; a module (24) for controlling a device (3) for manufacturing the orthodontic appliance, from the digital data file produced. 11. A system for manufacturing an orthodontic appliance for modifying a dental arrangement, characterized in that it comprises the control device (2) according to the preceding claim and a device (3) for manufacturing the orthodontic appliance. 12. System according to the preceding claim, characterized in that it comprises a device (1) for capturing images. A computer program comprising program code instructions for executing the steps of the method according to any one of claims 1 to 6 when said program is executed by a processing unit (26).