Orthodontic appliances including at least partially un-erupted teeth and method of forming them

Patent metadata

Field	Value
Publication number	US-11714398-B2
Application number	US-202117454224-A
Country	US
Kind code	B2
Filing date	Nov 9, 2021
Priority date	Mar 31, 2017
Publication date	Aug 1, 2023
Grant date	Aug 1, 2023

Abstract

The example systems, methods, and/or computer-readable media described herein help with design of highly accurate models of un-erupted or partially erupted teeth and help fabricate of aligners for un-erupted or partially erupted teeth. Automated agents that use machine learning models to parametrically represent three-dimensional (3d) virtual representations of teeth as 3D descriptors in a 3D descriptor space are provided herein. In some implementations, the automated agents described herein provide instructions to fabricate aligners for at least partially un-erupted teeth using representative 3D descriptor(s) of a tooth type.

First claim

What is claimed is:

1. A non-transitory computer-implemented method for forming an orthodontic appliance, the method comprising:
using one or more three-dimensional (3D) descriptors to estimate a 3D shape in a 3D space for an at least partially un-erupted tooth of a patient's teeth based on data representing a plurality of teeth corresponding to a tooth type of the at least partially un-erupted tooth;
using the 3D shape to determine cavity attributes of a cavity to accommodate the at least partially un-erupted tooth as the at least partially un-erupted tooth erupts; and
providing instructions to form the orthodontic appliance including the cavity for the at least partially un-erupted tooth, wherein the instructions specify the cavity attributes of the cavity.

2. The method of claim 1 , further comprising determining a scaling factor for the 3D shape of the at least partially un-erupted tooth.

3. The method of claim 2 , wherein determining the scaling factor comprises matching an anticipated size of the at least partially un-erupted tooth.

4. The method of claim 1 , wherein the cavity attributes include a position and size of the cavity.

5. The method of claim 1 , wherein estimating the 3D shape comprises evaluating data from a plurality of samples of teeth according to determine a most average tooth shape.

6. The method of claim 1 , wherein estimating the 3D shape comprises using 2D Elliptic Fourier Descriptors (EFDs).

7. The method of claim 6 , wherein using EFDs comprises:
generating two-dimensional top, front, and side views from the data representing the plurality of teeth;
generating a characteristic, convex bounding shape for each two-dimensional top, front, and side views;
representing a convex bounding shape for each two-dimensional top, front, and side view using elliptic Fourier descriptors; and
normalizing the elliptic Fourier descriptors to provide rotation and size invariance.

8. The method of claim 1 , wherein determining the cavity attributes of the cavity comprises computing a principal component analysis to determine an optimal 3D shape for the cavity from the data representing the plurality of teeth.

9. The method of claim 1 , wherein estimating the 3D shape comprises determining a spherical harmonic signature of the at least partially un-erupted tooth.

10. The method of claim 9 , wherein determining the cavity attributes of the cavity comprises computing a Euclidean distance between the spherical harmonic signature of the at least partially un-erupted tooth and other of the patient's teeth.

11. The method of claim 1 , further comprising gathering an anatomical tooth identifier of the at least partially un-erupted tooth and identifying the tooth type using the anatomical tooth identifier.

12. The method of claim 1 , wherein estimating the 3D shape for the at least partially un-erupted tooth comprises identifying a representative 3D descriptor for the tooth type from the data representing the plurality of teeth.

13. The method of claim 12 , wherein the representative 3D descriptor has a minimum distance to other 3D descriptors of a plurality of 3D descriptors in a 3D descriptor space formed of the plurality of 3D descriptors.

14. The method of claim 1 , wherein the one or more 3D descriptors is associated with a 3D virtual representation of a plurality of teeth gathered from a plurality of subjects.

15. A system, comprising:
one or more processors;
memory coupled to the one or more processors, the memory configured to store computer-program instructions, that, when executed by the one or more processors, perform a computer-implemented method comprising:
using one or more three-dimensional (3D) descriptors to estimate a 3D shape in a 3D space for an at least partially un-erupted tooth of a patient's teeth based on data representing a plurality of teeth corresponding to a tooth type of the at least partially un-erupted tooth;
using the 3D shape to determine cavity attributes of a cavity to accommodate the at least partially un-erupted tooth as the at least partially un-erupted tooth erupts; and
providing instructions to form an orthodontic appliance including the cavity for the at least partially un-erupted tooth, wherein the instructions specify the cavity attributes of the cavity.

16. The system of claim 15 , wherein the computer-implemented method further comprises determining a scaling factor for the 3D shape of the at least partially un-erupted tooth.

17. The system of claim 15 , wherein the computer-implemented method further comprises estimating 3D shapes of multiple at least partially un-erupted teeth of the patient's teeth, and providing instructions to form the orthodontic appliance including multiple cavities for the multiple at least partially un-erupted teeth.

18. The system of claim 17 , wherein the 3D space includes a plurality of 3D descriptors parametrically representing virtual surface contours corresponding to the tooth type.

19. The system of claim 15 , wherein estimating the 3D shape comprises using 2D Elliptic Fourier Descriptors (EFDs).

20. The system of claim 15 , wherein estimating the 3D shape comprises determining a spherical harmonic signature of the at least partially un-erupted tooth.

21. A non-transitory computer-implemented method comprising:
estimating a 3D shape for an at least partially un-erupted tooth of a patient's teeth by associating a representative 3D descriptor in 3D descriptor space, the 3D descriptor space including a plurality of 3D descriptors parametrically representing virtual surface contours corresponding to a tooth type;
determining a position and size of a cavity to accommodate the at least partially un-erupted tooth as the at least partially un-erupted tooth erupts; and
providing instructions to form an orthodontic appliance including the cavity for the at least partially un-erupted tooth.

Assignees

• Align Technology Inc

Inventors

• Cramer Christopher Eric
• Choi Jeeyoung

Classifications

• G05B19/4099 Primary

  Surface or curve machining, making three-dimensional [3D] objects, e.g. desktop manufacturing · CPC title

• B29C64/393

  for controlling or regulating additive manufacturing processes · CPC title

• B33Y50/00

  Data acquisition or data processing for additive manufacturing · CPC title

• B33Y50/02

  for controlling or regulating additive manufacturing processes · CPC title

• B29L2031/7536

  Artificial teeth · CPC title