System and method for detecting deviations during the course of an orthodontic treatment to gradually reposition teeth

• US 9,364,297 B2
• Filed: 01/10/2014
• Issued: 06/14/2016
• Est. Priority Date: 06/08/2007
• Status: Active Grant

• Current Assignee: Align Technology Incorporated
• Original Assignee: Align Technology Incorporated
• Inventors: Kitching, Ian, Cheang, Ka M.
• Primary Examiner(s): Lewis, Ralph
• Application Number:
  US14/152,776
• Publication Number:
  US 20140193765A1
• Time in Patent Office: 886 Days
• Field of Search: 433/24
• US Class Current: 1/1
• CPC Class Codes: A61C 7/00 Orthodontics, i.e. obtaining or maintaining the desired position of teeth, e.g. by straightening, evening, regulating, separating, or by correcting malocclusions
• CPC Class Codes: A61C 7/002 Orthodontic computer assisted systems
• CPC Class Codes: G16H 50/50 for simulation or modelling of medical disorders
• CPC Class Codes: G16Z 99/00 Subject matter not provided for in other main groups of this subclass

Abstract

Method and system for detecting and correcting deviation during an orthodontic treatment plan is provided. The method includes the steps of receiving an un-segmented current teeth image representing a patient'"'"'s teeth after an orthodontic treatment plan has begun and before the plan ends for the patient; matching a previously segmented teeth model with the current teeth image; and generating at least one corrective stage to define an intermediate tooth arrangement, wherein the at least one corrective stage repositions a digital teeth image so that a prescribed tooth arrangement of the previously segmented teeth model can be used.

Claims

1. A system for detecting deviation in a patient'"'"'s teeth during a planned orthodontic treatment for the patient, the system comprising:

a computer comprising a display, processor, and storage media comprising instructions that, when executed, cause the computer to;

receive an un-segmented current teeth image representing a patient'"'"'s teeth after the planned orthodontic treatment has begun and before the planned orthodontic treatment ends;

pre-process the un-segmented current teeth image so as to assign each of a plurality of teeth in the un-segmented current teeth image with a unique current teeth image identifier selected based on an anatomical feature of the respective tooth;

perform an initial comparison of the un-segmented current teeth image with a previously segmented teeth model by aligning each unique current teeth image identifier of the un-segmented current teeth image with a corresponding unique previously segmented model identifier assigned to a tooth of the previously segmented teeth model;

after performing the initial comparison of the un-segmented current teeth image with the previously segmented teeth model, determine a positional deviation between the un-segmented current teeth image and the previously segmented teeth model for each of one or more teeth in the previously segmented teeth model; and

generate a corrected stage model by using the determined one or more positional deviations to modify the previously segmented teeth model to reposition each of the one or more teeth in the previously segmented teeth model to match the un-segmented current teeth image.

2. The system of claim 1, wherein the determination of the one or more positional deviations includes creating a grid on the previously segmented teeth model, selecting sampling points on the previously segmented teeth model, and overlaying the grid on the un-segmented current teeth image.

3. The system of claim 2, wherein the determination of the one or more positional deviations includes finding sampling points on the un-segmented current teeth image that are closest to the selected sampling points on the previously segmented teeth model.

4. The system of claim 2, wherein the overlaying of the grid on the un-segmented current teeth image includes superimposing the selected sampling points of the previously segmented teeth model onto the un-segmented current teeth image.

5. The system of claim 2, wherein creating the grid, selecting sampling points in the grid, and overlaying the grid on the un-segmented current teeth image are repeated until the previously segmented teeth model is within a preset tolerance from the un-segmented current teeth image.

6. The system of claim 1, wherein each tooth in the un-segmented current teeth image is individually assigned with the unique current teeth image identifier.

7. The system of claim 1, wherein the unique current teeth image identifier is a Facial Axis of a Clinical Crown (FACC) identifier, corresponds to an abnormality in a tooth in the un-segmented current teeth image, or corresponds to an attachment or marker on a tooth in the un-segmented current teeth image.

8. The system of claim 1, wherein the unique previously segmented model identifier is a Facial Axis of a Clinical Crown (FACC) identifier, corresponds to an abnormality in a tooth in the previously segmented teeth model, or corresponds to an attachment or marker on a tooth in the previously segmented teeth model.

9. The system of claim 1, wherein the corrected stage model is used to create corrective stages from a tooth arrangement of the un-segmented current teeth image to a prescribed tooth arrangement.

10. A system for detecting and correcting deviation during an orthodontic treatment plan, the system comprising:

a computer comprising a display, processor, and storage media comprising instructions that, when executed, cause the computer to;

receive an un-segmented current teeth image representing a patient'"'"'s teeth after an orthodontic treatment plan has begun and before the orthodontic treatment plan ends for the patient;

match a surface of a tooth of a previously segmented teeth model to a surface of a tooth of the un-segmented current teeth image, the surface matching including;

creating a grid on the surface of the tooth of the previously segmented teeth model, selecting sampling points in the grid, and overlaying the grid onto the un-segmented current teeth image; and

generate at least one corrective stage to define an intermediate tooth arrangement, wherein the at least one corrective stage repositions the previously segmented teeth model so that a prescribed tooth arrangement of the previously segmented teeth model can be used.

11. The system of claim 10, wherein the generation of the at least one corrective stage includes moving one or more teeth of the previously segmented teeth model from an arrangement of the un-segmented current teeth image to the prescribed tooth arrangement of the previously segmented teeth model.

12. The system of claim 10, wherein the generation of the at least one corrective stage includes moving one or more teeth of the previously segmented teeth model from an arrangement of the un-segmented current teeth image to a previously segmented teeth arrangement.

13. The system of claim 10, wherein the instructions further cause the computer to pre-process the un-segmented current teeth image, wherein each tooth of the un-segmented current teeth image is assigned a unique identifier which is compared to a unique identifier for each tooth in the previously segmented teeth model to determine if there is an initial match.

14. The system of claim 10, wherein the matching of the surfaces includes a comparison of the tooth of the un-segmented current teeth image with the tooth of the previously segmented teeth model for an initial match.

15. The system of claim 14, wherein if there is no initial match for the tooth, then the tooth of the previously segmented teeth model is adjusted.

16. The system of claim 10, wherein the instructions, when executed, cause the computer to adjust a position of a tooth in the previously segmented teeth model to a corrected stage if there is a match after the matching of the surfaces.

17. The system of claim 10, wherein the computer is configured to receive bite match setting values for the surface matching.

18. The system of claim 17, wherein the bite match setting values are programmable parameters that include one or more of a matching tolerance, a maximum iteration, or a fluctuation count.

19. The system of claim 10, wherein the computer is configured to display any teeth with matching errors after the matching of the surfaces.

20. The system of claim 19, wherein when a matching error is selected, the instructions further cause the computer to generate a report identifying the matching error, the distance from a good match, and a suggestion on how to correct the matching error.

21. The system of claim 10, wherein a matching error for a tooth occurs when an error is greater than a programmed threshold parameter.

22. The system of claim 10, wherein the previously segmented teeth model is based on an initial segmented teeth model prior to starting the orthodontic treatment plan.

23. The system of claim 10, wherein the previously segmented teeth model is based on an intermediate stage between a beginning of the orthodontic treatment plan and an end of the orthodontic treatment plan.

24. The system of claim 10, wherein the un-segmented current teeth image is a digital image created from one or more of:

(a) a dental impression, (b) a two-dimensional digital image and a bite registry, (c) a plurality of two-dimensional images, or (d) an intra-oral scan.

25. The system of claim 10, wherein the previously segmented teeth model is a segmented teeth model created from a digital data set that represents a patient'"'"'s teeth arrangement and each tooth is represented as an individual digital object.

26. The system of claim 10, wherein the matching of the surfaces includes finding sampling points on the un-segmented current teeth image that are closest to the selected sampling points.

27. The system of claim 10, wherein the overlaying of the grid onto the un-segmented current teeth image includes superimposing the selected sampling points onto the un-segmented current teeth image.

28. The system of claim 10, wherein creating a grid, selecting sampling points in the grid, and overlaying the grid are repeated until the previously segmented teeth model is within a preset tolerance from the un-segmented current teeth image.