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

• US 8,075,306 B2
• Filed: 06/08/2007
• Issued: 12/13/2011
• 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): Rodriguez, Cris L
• Assistant Examiner(s): ROSEN, ERIC J
• Application Number:
  US11/760,612
• Publication Number:
  US 20080305451A1
• Time in Patent Office: 1,649 Days
• Field of Search: 433/24, 433/213, 433/214, 382/128
• US Class Current: 433/24
• 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 method for detecting deviation during an orthodontic treatment plan, the method comprising 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 orthodontic treatment plan ends for the patient;

pre-processing the un-segmented current teeth image;

comparing the un-segmented current teeth image with a previously segmented teeth model for an initial match;

performing a surface matching step that matches the previously segmented teeth model to the un-segmented current teeth image, the surface matching step comprising;

creating a grid on the previously segmented teeth model,

selecting sampling points in the grid, and

overlaying the grid onto the un-segmented current teeth image; and

adjusting a position of a tooth in the previously segmented teeth model to a corrected stage if an error generated after the surface matching step is within a programmable threshold parameter value.

2. The method of claim 1, wherein if there is no initial match for a tooth, then the tooth is manually adjusted by a technician.

3. The method of claim 1, wherein during the pre-processing of the un-segmented current teeth image, each tooth in the un-segmented current teeth image is assigned a unique identifier which is compared to each tooth'"'"'s unique identifier in the previously segmented teeth model to determine if there is an initial match.

4. The method of claim 3, wherein the unique identifier comprises a mark added to a specific location on a tooth, an attachment on a tooth or a distinct characteristic of the tooth.

5. The method of claim 1, wherein a technician enters bite match setting values for the surface matching step.

6. The method of claim 5, wherein the bite match setting values are programmable parameters that include one or more of a matching tolerance, a maximum iteration, and a fluctuation count.

7. The method of claim 1, wherein a user interface displays any teeth with matching errors after executing the surface matching step.

8. The method of claim 7, wherein a matching error for a tooth occurs when an error is greater than a programmed threshold parameter.

9. The method of claim 7, further comprising selecting a matching error in the user interface which generates a report identifying the matching error, the distance from a good match and a suggestion on how to correct the error.

10. The method of claim 1, wherein the previously segmented teeth model is based on an initial segmented teeth model prior to starting the orthodontic treatment plan.

11. The method of claim 1, 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.

12. The method of claim 1, wherein the un-segmented current teeth image is a digital image created from one or more of a dental impression;

a two dimensional digital image and a bite registry;

a plurality of two-dimensional images; and

an intra-oral scan.

13. The method of claim 1, 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.

14. The method of claim 1 further including a step of tracking adjustments made to each tooth of the previously segmented tooth model to match the un-segmented current teeth image.

15. The method of claim 1 further includes creating corrective stages with the previously segmented teeth model from a tooth arrangement of the un-segmented current teeth image to a prescribed tooth arrangement.

16. The method of claim 1 further includes creating corrective stages with the previously segmented teeth model from a tooth arrangement of the un-segmented current teeth image to a tooth arrangement of the previously segmented teeth model.

17. The method of claim 1, wherein the surface matching step is performed by a computing system.

18. The method of claim 1, wherein the surface matching step further comprises:

finding sampling points on the un-segmented current teeth image that are closest to the selected sampling points.

19. The method of claim 1, wherein overlaying the grid onto the un-segmented current teeth image includes superimposing the selected sampling points onto the un-segmented current teeth image.

20. The method of claim 1, wherein the steps of 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.

21. A method for detecting and correcting deviation during an orthodontic treatment plan, the method comprising 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 orthodontic treatment plan ends for the patient;

matching 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 step of matching a surface comprising;

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

generating 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.

22. The method of claim 21, wherein the step of generating at least one corrective stage moves the teeth of the previously segmented teeth model from the un-segmented current teeth image to the prescribed tooth arrangement of the previously segmented teeth arrangement.

23. The method of claim 21, wherein the step of generating the at least one corrective stage moves the teeth of the previously segmented teeth model from the un-segmented current teeth image to a previously segmented teeth arrangement.

24. The method of claim 21, further including the step of pre-processing 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 each tooth'"'"'s unique identifier in the previously segmented teeth model to determine if there is an initial match.

25. The method of claim 21, wherein the step of matching further includes the step of comparing the tooth of the un-segmented current teeth image with the tooth of the previously segmented teeth model for an initial match.

26. The method of claim 25, wherein if there is no initial match for the tooth, then the tooth is adjusted.

27. The method of claim 21, wherein the matching further includes the step of adjusting a position of a tooth in the previously segmented teeth model to a corrected stage if there is a match after the surface matching step.

28. The method of claim 21, wherein a technician enters bite match setting values for the surface matching.

29. The method of claim 28, wherein the bite match setting values are programmable parameters that include one or more of a matching tolerance, a maximum iteration, and a fluctuation count.

30. The method of claim 21, wherein a user interface displays any teeth with matching errors after executing the surface matching.

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

33. The method of claim 21, wherein the previously segmented teeth model is based on an initial segmented teeth model prior to starting the orthodontic treatment plan.

34. The method of claim 21, 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.

35. The method of claim 21, wherein the un-segmented current teeth image is a digital image created from one or more of a dental impression;

a two dimensional digital image and a bite registry;

a plurality of two-dimensional images; and

an intra-oral scan.

36. The method of claim 21, 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.

37. The method of claim 21, wherein the surface matching is performed by a computing system.

38. The method of claim 21, wherein the step of matching a surface further comprises:

finding sampling points on the un-segmented current teeth image that are closest to the selected sampling points.

39. The method of claim 21, wherein overlaying the grid onto the un-segmented current teeth image includes superimposing the selected sampling points onto the un-segmented current teeth image.

40. The method of claim 21, wherein the steps of 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.

31. The method of further comprising selecting a matching error in the user interface which generates a report identifying the matching error, the distance from a good match and a suggestion on how to correct the error.