System and method for determining a corrective stage in orthodontic treatment

Patent metadata

Field	Value
Publication number	US-12558192-B2
Application number	US-202016852251-A
Country	US
Kind code	B2
Filing date	Apr 17, 2020
Priority date	Jun 8, 2007
Publication date	Feb 24, 2026
Grant date	Feb 24, 2026

Abstract

Methods and systems for determining a corrective stage in orthodontic treatment. Methods may include presenting a menu for a user to enter a pre-determined tolerance or a maximum number of iterations for performing a surface matching algorithm. Methods may include matching one or more teeth of a previously segmented teeth model to one or more corresponding teeth of a current teeth image. The matching may include executing the surface matching algorithm. The methods may include iteratively finding closes sample points, determining whether distances between closest sample points exceed a predetermined tolerance, and adjusting the distances. A current teeth model may be generated based on the adjusted previously segmented teeth model. A current teeth model using the corrective stage may be generated.

First claim

What is claimed is:

1 . A method for determining a corrective stage in orthodontic treatment of a patient's teeth, the method comprising:
imaging the patient's teeth using an imaging device to obtain a current teeth image of the patient's teeth representing the patient's teeth after beginning the orthodontic treatment; receiving, at a receive module of an analysis module, a previously segmented teeth model of the patient's teeth; receiving, at the receive module, the current teeth image of the patient's teeth; presenting, on a user interface, a menu for a user to enter a pre-determined tolerance or a maximum number of iterations for performing a surface matching algorithm; matching, by a compare module of the analysis module, one or more teeth of the previously segmented teeth model to one or more corresponding teeth of the current teeth image, wherein the compare module is in communication with the receive module and wherein the matching step comprises executing the surface matching algorithm, which includes:
(a) finding a plurality of closest sample points between a tooth in the current teeth image and a corresponding tooth in the previously segmented teeth model;
(b) determining whether distances between the plurality of closest sample points between the tooth in the current teeth image and the corresponding tooth in the previously segmented teeth model exceed the pre-determined tolerance;
(c) adjusting, in response to determining that the distances exceed the pre-determined tolerance at (b), the corresponding tooth in the previously segmented teeth model with respect to the tooth in the current teeth image; and
(d) iteratively repeating (a)-(c) for each tooth of the patient's teeth until the distances between the plurality of closest sample points between each tooth in the current teeth image and each corresponding tooth in the previously segmented teeth model are within the pre-determined tolerance;
generating a current teeth model based on the adjusted previously segmented teeth model; and using the current teeth model to generate the corrective stage, wherein the corrective stage is generated by repositioning at least one tooth in the current teeth model based on a location of a corresponding at least one tooth in a previously prescribed stage of the orthodontic treatment, wherein the corrective stage is configured to move the at least one tooth in the current teeth model toward the location of the corresponding at least one tooth in the previously prescribed stage of the orthodontic treatment.

2 . The method of claim 1 , wherein the current teeth image comprises a camera picture.

3 . The method of claim 1 , wherein the previously segmented teeth model comprises scan data.

4 . The method of claim 1 , wherein the matching step comprises overlaying the current teeth image and the previously segmented teeth model onto each other.

5 . The method of claim 1 , wherein the matching step comprises rotating, scaling, and translating the previously segmented teeth model to represent the current teeth image.

6 . The method of claim 1 , wherein the surface matching algorithm comprises:
creating a grid on the previously segmented teeth model; and overlaying the grid onto the current teeth image.

7 . The method of claim 1 , wherein the surface matching algorithm comprises:
selecting one or more sampling points from a tooth in the previously segmented teeth model; and identifying one or more corresponding sampling points on the current teeth image.

8 . The method of claim 1 , further comprising pre-processing the current teeth image by assigning a unique identifier to each tooth in the current teeth image.

9 . The method of claim 1 , wherein determining that the distances exceed the pre-determined tolerance comprises determining that the tooth has a matching error, the method further comprising:
graphically representing, on the user interface, the previously segmented teeth model of the patient's teeth with a mark on the tooth indicating the matching error and a guidance box over the tooth, wherein the guidance box guides repositioning of the tooth in orthogonal directions with respect to a centerline through the tooth.

10 . The method of claim 9 , further comprising:
adjusting, based on user input, the previously segmented teeth model by adjusting a position of the tooth in the previously segmented teeth model to the location of the tooth in the current teeth image in one or more orthogonal directions according to the guidance box; and generating at least one corrective stage for repositioning at least one tooth in the adjusted previously segmented teeth model to a corresponding position of at least one tooth in a prescribed tooth arrangement.

11 . The method of claim 1 , further comprising transmitting a three-dimensional model corresponding to the corrective stage to a computer device for manufacturing a new orthodontic appliance.

12 . The method of claim 11 , further comprising manufacturing the new orthodontic appliance based on the three-dimensional model.

13 . A system for determining a corrective stage in orthodontic treatment of a patient's teeth, the system comprising:
a scanning system configured to image the patient's teeth using an imaging device to obtain a current teeth image of the patient's teeth representing the patient's teeth after beginning the orthodontic treatment; and a computing system comprising:
a processing unit; and
a memory storage device comprising code that, when executed by the processing unit, causes the computing system to:
receive, at a receive module of an analysis module, a previously segmented teeth model of the patient's teeth;
receive, at the receive module, the current teeth image;
present, on a user interface, a menu for a user to enter a pre-determined tolerance or a maximum number of iterations for performing a surface matching algorithm;
match, by a compare module of the analysis module, one or more teeth of the previously segmented teeth model to one or more corresponding teeth of the current teeth image wherein the match step comprises executing the surface matching algorithm, which includes:
(a) finding a plurality of closest sample points between a tooth in the current teeth image and a corresponding tooth in the previously segmented teeth model, by repositioning the corresponding tooth in the previously segmented teeth model to the tooth in the current teeth image;
(b) determining, whether distances between the plurality of closest sample points between the tooth in the current teeth image and the corresponding tooth in the previously segmented teeth model exceed the pre-determined tolerance;
(c) adjusting, in response to determining that the distances exceed the pre-determined tolerance at (b), the corresponding tooth in the previously segmented teeth model with respect to the tooth in the current teeth image; and
(d) iteratively repeating (a)-(c) for each tooth of the patient's teeth until the distances between the plurality of closest sample points between each tooth in the current teeth image and each corresponding tooth in the previously segmented teeth model are within the pre-determined tolerance;

generate a current teeth model based on the adjusted previously segmented teeth model; and
use the current teeth model to generate the corrective stage, wherein the corrective stage is generated by repositioning at least one tooth in the current teeth model based on a location of a corresponding at least one tooth in a previously prescribed stage of the orthodontic treatment, wherein the corrective stage is configured to move the at least one tooth in th

Assignees

• Align Technology Inc

Inventors

• Kitching Ian
• Cheang Ka M

Classifications

• G16Z99/00

  Subject matter not provided for in other main groups of this subclass · CPC title

• G16H50/50

  for simulation or modelling of medical disorders · CPC title

• A61C7/00

  Orthodontics, i.e. obtaining or maintaining the desired position of teeth, e.g. by straightening, evening, regulating, separating, or by correcting malocclusions · CPC title

• A61C7/002 Primary

  Orthodontic computer assisted systems · CPC title