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US-12616557-B2 - Systems and methods for determining an edge of orthodontic appliances

US12616557B2US 12616557 B2US12616557 B2US 12616557B2US-12616557-B2

Abstract

A method and a system for determining a configuration of an open edge for a set of orthodontic appliances are provided. The method comprises: receiving a 3D digital model representative of a surface of a subject's arch form including teeth and a gingiva; obtaining, in the 3D digital model, along a surface of the gingiva, a respective position for a given control point of a plurality of control points, the plurality of control points defining the open edge for a given one of the set of orthodontic appliances; determining, based on the positions of the plurality of control points, a respective vector of positioning values for each of the plurality of control points; storing the respective vector of positioning values for each of the plurality of control points for further use in determining a respective configuration of the open edge for each other one of the set of orthodontic appliances.

Inventors

  • Islam Khasanovich Raslambekov

Assignees

  • OXILIO LTD

Dates

Publication Date
20260505
Application Date
20230619

Claims (20)

  1. 1 . A computer-implementable method for determining a configuration of an open edge for an orthodontic appliance of a set of orthodontic appliances, the set of orthodontic appliances configured to be applied to a subject during an orthodontic treatment, the method comprising: receiving image data associated with the subject, the image data including: a current 3D digital model representative of a current configuration of a surface of a subject's arch form including teeth and a gingiva; and data representative of segmentation contours between the teeth and the gingiva; obtaining, in the current 3D digital model, along a surface of the gingiva, coordinates for a respective position for a given control point of a plurality of control points, the plurality of control points defining the open edge for the given orthodontic appliance of the set of orthodontic appliances, the respective position for the given control point being determined such that: the respective position corresponds to a position on the gingiva undergoing a predetermined change of a profile of the gingiva during the orthodontic treatment, and the respective position corresponds to a position on the gingiva which is within a predetermined distance from a closest segmentation contour to the given control point; determining, based on the obtained respective positions of each one of the plurality of control points within the current 3D digital model, a respective vector of positioning values for each one of the plurality of control points, a given positioning value of the respective vector of positioning value being based on a distance value from the given control point to the closest segmentation contour; and causing manufacturing of at least one orthodontic appliance of the set of orthodontic appliances using the respective vector of positioning values for each one of the plurality of control points using a manufacturing apparatus.
  2. 2 . The method of claim 1 , wherein determining the respective vector of positioning values for the given control point of the plurality of control points comprises: identifying, along each segmentation contour, at least one anchor point of a plurality of anchor points; identifying, by the processor, in the plurality of anchor points, a closest anchor point to the given control point; and determining, by the processor, a distance from the given control point to the closest anchor point.
  3. 3 . The method of claim 2 , wherein the determining the respective vector of positioning values for the given control points in the current 3D digital model further comprises: determining a ratio value indicative of a ratio between (1) a first distance value from the given control point to a first neighboring anchor point to the closest one; and (2) and a second distance value from the given control point to a second neighboring anchor point to the closest one.
  4. 4 . The method of claim 3 , wherein the ratio value is determined according to an equation: d 1 d 1 + d 2 , where d 1 is the first distance value, and d 2 is the second distance value.
  5. 5 . The method of claim 2 , wherein the identifying the at least one anchor point comprises: determining, along a given segmentation contour, a lingual and buccal portions thereof; and identifying the at least one anchor point as being representative of a point of maximum curvature of each one of the lingual and the buccal portion of the given segmentation contour.
  6. 6 . The method of claim 2 , wherein determining the distance from the given control point to the closest anchor point is executed using a distance field determined, in the current 3D digital model, along the surface of the gingiva.
  7. 7 . The method of claim 6 , wherein the current 3D digital model comprises a plurality of vertices representative of the current configuration of the surface of the subject's arch form, and the method further comprises determining the distance field along the surface of the gingiva in the current 3D digital model, by: determining for a given gingiva vertex representative of the surface of the gingiva, a respective gingiva shortest distance value therefrom, along the surface of the gingiva, to each one of the segmentation contours; assigning a positive sign to the respective gingiva shortest distance value; determining for a given tooth vertex representative of a surface of a given tooth of the subject, a respective tooth shortest distance value therefrom, along the surface of the given tooth, to a respective segmentation contour associated with the given tooth; and assigning a negative sign to the respective tooth shortest distance.
  8. 8 . The method of claim 7 , wherein determining any one of the respective gingiva shortest distance value and the respective tooth shortest distance comprises applying a Dijkstra's algorithm.
  9. 9 . The method of claim 1 , wherein the obtaining the data representative of the segmentation contours between the teeth and the gingiva comprises determining the segmentation contours based on the current 3D digital model, determining of a given segmentation contour, associated with a respective tooth of the teeth, being based on analyzing, in the current 3D digital model, curvature of at least one of the respective tooth and a portion of the gingiva therearound.
  10. 10 . The method of claim 1 , wherein the position on the gingiva undergoing the predetermined change of the profile of the gingiva during the orthodontic treatment is determined based on gingiva deformation values of gingivae of other subjects having received the orthodontic treatment.
  11. 11 . The method of claim 1 , wherein the position on the gingiva undergoing the predetermined change of the profile of the gingiva during the orthodontic treatment is obtained from an orthodontic practitioner.
  12. 12 . The method of claim 1 , wherein the predetermined change of the profile of the gingiva comprises a minimum change thereof during the orthodontic treatment.
  13. 13 . The method of claim 2 , further comprising: obtaining an other 3D digital model representative of an other configuration of the subject's arch form during the orthodontic treatment and for which an other orthodontic appliance of the set of orthodontic appliances, different from the given orthodontic appliance, will be used; determining, in the other 3D digital model, new positions of the plurality of anchor points; applying based on the new positions of the plurality of anchor points, each one of the plurality of control points to the other 3D digital model according to the respective vector of positioning values; determining in the other 3D digital model, the respective configuration of the open edge for the other orthodontic appliance as a line extending through the plurality of control points; and using the other 3D digital model with the respective configuration of the open edge determined thereon for manufacturing the other orthodontic appliance.
  14. 14 . The method of claim 13 , wherein the determining the respective configuration of the open edge comprises sequentially joining, in the other 3D digital model, the plurality of control points applying a Dijkstra's algorithm.
  15. 15 . The method of claim 13 , wherein the determining the respective configuration of the open edge comprises sequentially joining, in the other 3D digital model, the plurality of control points comprises applying a spline function.
  16. 16 . The method of claim 13 , wherein the using comprises: generating based on the other 3D digital model with the respective configuration of the open edge determined thereon, an orthodontic appliance 3D digital model of the other orthodontic appliance; and causing 3D-printing of the other orthodontic appliance according to the orthodontic appliance 3D digital model.
  17. 17 . The method of claim 13 , wherein the using comprises: causing based on the other 3D digital model, manufacture of an orthodontic appliance mold for the other orthodontic appliance; causing thermoforming of an unfinished orthodontic appliance onto the orthodontic appliance mold; causing application of the line extending through the plurality of control points and defining the respective configuration of the open edge to the unfinished orthodontic appliance; and causing cutting the unfinished orthodontic appliance along the line, thereby manufacturing the other orthodontic appliance.
  18. 18 . The method of claim 1 , further comprising causing display of the other 3D digital model with the respective configuration of the open edge for the other orthodontic appliance determined thereon.
  19. 19 . The method of claim 1 , wherein the given orthodontic appliance of the set of orthodontic appliances is an orthodontic aligner.
  20. 20 . A computer system for determining an open edge for an orthodontic appliance of a set of orthodontic appliances, the set of orthodontic appliances configured to be applied to a subject during an orthodontic treatment, the computer system including: at least one processor and at least one non-transitory computer-readable medium comprising executable instructions that, when executed by the processor, cause the computer system to: receive image data associated with the subject, the image data including: a current 3D digital model representative of a current configuration of a surface of a subject's arch form including teeth and a gingiva; and data representative of segmentation contours between the teeth and the gingiva; obtain in the current 3D digital model, along a surface of the gingiva, coordinates for a respective position for a given control point of a plurality of control points, the plurality of control points defining the open edge for the given orthodontic appliance of the set of orthodontic appliances, the respective position for the given control point being determined such that: the respective position corresponds to a position on the gingiva undergoing a predetermined change of a profile of the gingiva during the orthodontic treatment, and the respective position corresponds to a position on the gingiva which is within a predetermined distance from a closest segmentation contour to the given control point; determine, based on the obtained respective positions of each one of the plurality of control points within the current 3D digital model, a respective vector of positioning values for each one of the plurality of control points, a given positioning value of the respective vector of positioning value being based on a distance value from the given control point to the closest segmentation contour; and cause manufacturing of at least one orthodontic appliance of the set of orthodontic appliances using the respective vector of positioning values for each one of the plurality of control points using a manufacturing apparatus.

Description

CROSS-REFERENCE The present application is a Continuation of a U.S. patent application Ser. No. 17/980,868, filed on Nov. 4, 2022, the content of which is incorporated herein by reference in its entirety. FIELD The present technology relates to systems and methods for manufacturing an orthodontic appliance; and more specifically, although not exclusively, to determining a configuration of an open edge of the orthodontic appliance. BACKGROUND In orthodontics, treatments for achieving alignment of malposed teeth in a subject include applying orthodontic appliances, such as orthodontic aligners, to the subject's teeth. Orthodontic aligners are typically worn over teeth of an arch form in order to exert a force to the subject's teeth to cause movements thereof to their respective target positions, typically associated with their alignment within the arch form. In another example, the orthodontic aligners can be used to retain the subject's teeth in an already achieved desired position. The orthodontic aligners are typically custom-made to the subject's teeth, and a shape of the orthodontic aligners, among other factors, defines the effective forces to be exerted to the teeth, and the effective correction that may be attained. Certain methods of designing such an aligner may comprise obtaining a 3D representation of the arch form, and based thereon, determining the required treatment plan for the teeth requiring alignment. The treatment plan may comprise multiple sequential treatment steps, each treatment step comprising a different aligner to be worn by the subject. The aligners can be made by a thermoforming process, in which a preform is shaped using a mold to produce an unfinished aligner. The unfinished aligner is further processed, such as by trimming excess material along a predetermined cut line to form an open edge, the idea being that the cut line more closely follows the gum line of the subject for a more comfortable wear. However, if the predetermined cut line does not follow the tooth-gingiva boundary accurately, the open edge may cause discomfort to the subject, such as rubbing and/or scratches of the gingiva. Also, as the teeth move during the orthodontic treatment, the configuration of the tooth-gingiva boundary and hence the open edge for each consecutive aligner in a set of aligners applied during the treatment may need to be re-determined, which may be computationally expensive. Certain approaches for determining the cut line for forming the aligner have been proposed in the prior art. U.S. Patent Application Publication No. 2021/0271,225-A1 published on Sep. 2, 2021, assigned to Ormco Corp., and entitled “SYSTEMS AND METHODS FOR DESIGNING AND MANUFACTURING AN ORTHODONTIC APPLIANCE” discloses systems and methods of defining a trimline in relation to modeled teeth including modeled gingiva. The trimline is for use to manufacture an aligner. A margin point is placed proximate a gingival margin at each tooth on at least one jaw in the model. A trimline connects the plurality of margin points from which machine code is generated. The aligner manufactured includes an edge that correlates with the trimline according to the machine code. A margin point may be proximate a gingival zenith. At least one tooth cooperates with the modeled gingiva to define a line around the tooth. The trimline includes at least one tooth curve and at least one connector curve connected to the tooth curve at a transition point. At least one control point is on the trimline between two margin points. The trimline is defined by a spline that may be a Bezier curve. U.S. Pat. No. 11,116,606-B1, issued on Sep. 14, 2021, assigned to Arkimos Ltd., and entitled “SYSTEMS AND METHODS FOR DETERMINING A JAW CURVE”, discloses a method for determining a jaw curve for orthodontic treatment planning for a patient, the method being executable by a processor. The method includes obtaining a tooth and gingiva mesh from image data associated with teeth and surrounding gingiva of the patient, the mesh being representative of a surface of the teeth and the surrounding gingiva; obtaining a tooth contour of each tooth, the tooth contour being defined by a border between a visible portion of each tooth and the surrounding gingiva; determining a tooth contour center of each tooth, the tooth contour center of a given tooth being an average point of the tooth contour of the given tooth; projecting the tooth contour center of each tooth onto a jaw plane; and fitting the tooth contour center of each tooth to a curve to determine the jaw curve. U.S. Pat. No. 10,842,594-B2, issued on Nov. 24, 2020, assigned to Clearcorrect Operating LLC, and entitled “VIRTUAL MODELING OF GINGIVA ADAPTATIONS TO PROGRESSIVE ORTHODONTIC CORRECTION AND ASSOCIATED METHODOLOGY OF APPLIANCE MANUFACTURE”, discloses a system and associated methodology for the generation of digital models that account for the adaptation of the shape of the patient's gingiva. The exemplary system u