Optical coherence tomography for orthodontic aligners

• US 10,517,482 B2
• Filed: 07/27/2018
• Issued: 12/31/2019
• Est. Priority Date: 07/27/2017
• Status: Active Grant

• Current Assignee: Align Technology Incorporated
• Original Assignee: Align Technology Incorporated
• Inventors: Sato, Jun, Boronkay, Allen, Shanjani, Yaser, Shirazi Aghjari, Reza, Kopelman, Avi, Jang, Andrew, Cheng, Jihua, Kuo, Eric, Shelbakh, Vladimir, Pesenti, Bastien
• Primary Examiner(s): Nguyen, Vu
• Application Number:
  US16/048,054
• Publication Number:
  US 20190029522A1
• Time in Patent Office: 522 Days
• Field of Search: None
• CPC Class Codes: A61B 2576/02 specially adapted for a particular organ or body part
• CPC Class Codes: A61B 5/0066 Optical coherence imaging
• CPC Class Codes: A61B 5/0088 for oral or dental tissue
• CPC Class Codes: A61B 5/4547 Evaluating teeth
• CPC Class Codes: A61B 5/4848 Monitoring or testing the effects of treatment, e.g. of medication
• CPC Class Codes: A61B 5/7257 using Fourier transforms
• CPC Class Codes: A61B 5/7425 Displaying combinations of multiple images regardless of image source, e.g. displaying a reference anatomical image with a live image geometric transforms for image registration G06T3/14; enhancement using image fusion G06T5/50; algorithms for registration of images G06T7/30
• CPC Class Codes: A61C 13/0004 Computer-assisted sizing or machining of dental prostheses
• CPC Class Codes: A61C 7/002 Orthodontic computer assisted systems
• CPC Class Codes: A61C 7/08 Mouthpiece-type retainers or positioners, e.g. for both the lower and upper arch arch-shaped medicament applicators for teeth or gums A61C19/063; mouthguards for protecting the teeth of sportsmen A63B71/085
• CPC Class Codes: A61C 7/10 Devices having means to apply outwardly directed force, e.g. expanders
• CPC Class Codes: A61C 9/0053 Optical means or methods, e.g. scanning the teeth by a laser or light beam
• CPC Class Codes: G06T 15/08 Volume rendering
• CPC Class Codes: G06T 2207/30036 Dental; Teeth
• CPC Class Codes: G06T 7/0014 using an image reference approach
• CPC Class Codes: G06T 7/75 involving models
• CPC Class Codes: G16H 30/40 for processing medical images, e.g. editing

Abstract

Methods and apparatuses for 3D imaging (including 3D optical coherence tomography imaging) to measure the shape of orthodontic aligners, teeth, and other oral structures simultaneously, in-vivo or in-vitro. These methods and apparatuses may be used to determine contact locations of aligners with teeth and/or teeth with other teeth with very high precision, including determining the size of gaps where they are not in contact. These measurements may be used design, modify or replace an aligner and/or to verify aligner fit. 3D models of the whole aligner and teeth may be generated.

Claims

1. A method of processing a dental aligner, the method comprising:

scanning, using an optical coherence tomography (OCT) scanner, a patient'"'"'s teeth while a dental aligner is worn on the teeth, wherein scanning comprises scanning both the dental aligner and the patient'"'"'s teeth together;

generating a three-dimensional (3D) model of the combined dental aligner and patient'"'"'s teeth;

detecting one or more regions of contact between the aligner and the patient'"'"'s teeth from the 3D model; and

displaying, storing and/or transmitting the 3D model.

2. The method of claim 1, wherein scanning comprises scanning a plurality of 3D volumes each comprising a set of voxels corresponding to the aligner and teeth.

3. The method of claim 2, wherein generating the 3D model comprises stitching the plurality of 3D volumes.

4. The method of claim 3, wherein generating the 3D model comprises filtering the 3D volume to remove noise prior to stitching the plurality of 3D volumes.

5. The method of claim 2, further comprising binarization of greyscale 3D volume intensity by identification of local intensity maximums for each Z-section.

6. The method of claim 2, further comprising parsing the plurality of 3D volumes to isolate an aligner outer surface, an aligner inner surface and a tooth surface.

7. The method of claim 6, further comprising smoothing each of the aligner outer surface, the aligner inner surface and the tooth surface.

8. The method of claim 6, further comprising correcting an optical path length of the plurality of 3D volumes after isolating the aligner outer surface, the aligner inner surface and the tooth surface.

9. The method of claim 6, further comprising displaying, on the 3D model, the detected one or more regions of contact.

10. The method of claim 6, further comprising estimating forces acting on the patient'"'"'s teeth by the aligner using the detected one or more regions of contact.

11. The method of claim 1, wherein scanning comprises scanning in a near-IR wavelength using the OCT scanner.

12. The method of claim 1, wherein displaying, storing and/or transmitting the 3D model comprises displaying the 3D model in real time.

13. The method of claim 1, further comprising detecting gaps between the aligner and the patient'"'"'s teeth from the 3D model.

14. The method of claim 13, further comprising displaying, on the 3D model, the detected gaps.

15. A system for imaging a dental aligner, the system comprising:

an optical coherence tomography (OCT) scanner;

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;

scanning, using the OCT scanner, a patient'"'"'s teeth while a dental aligner is worn on the teeth, wherein scanning comprises scanning both the dental aligner and the patient'"'"'s teeth together;

generating a three-dimensional (3D) model of the combined dental aligner and patient'"'"'s teeth;

identifying one or more regions of contact between the patient'"'"'s teeth and the dental aligner from the 3D model of the combined dental aligner and teeth; and

displaying the one or more regions of contact.

16. A method of processing a dental aligner, the method comprising:

scanning, using an optical coherence tomography (OCT) scanner, a patient'"'"'s teeth while a dental aligner is worn on the teeth, wherein scanning comprises scanning both the dental aligner and the patient'"'"'s teeth together;

generating a three-dimensional (3D) model of the combined dental aligner and patient'"'"'s teeth;

identifying regions of contact between the dental aligner and the patient'"'"'s teeth; and

displaying the regions of contact.

17. The method of claim 16, wherein displaying comprises interactively displaying, comprising allowing the user to rotate and/or zoom into the view.

18. The method of claim 16, wherein displaying comprises displaying a 3D model of the patient'"'"'s teeth with the regions of contact indicated thereon.

19. The method of claim 16, further comprising modifying an orthodontic treatment plan including the aligner based on the regions of contact.

20. The method of claim 16, wherein the patient'"'"'s teeth comprise one or more attachments, and further wherein identifying regions of contact between the dental aligner and the patient'"'"'s teeth comprises identifying regions of contact between the dental aligner and the one or more attachments.

21. The method of claim 16, wherein displaying comprises displaying in a user interface accessible to a dental practitioner.

22. A method of processing a dental aligner, the method comprising:

scanning, using penetrative scanning, a patient'"'"'s teeth while a dental aligner is worn on the teeth, wherein scanning comprises scanning both the dental aligner and the patient'"'"'s teeth together, wherein scanning comprises scanning a plurality of 3D volumes each comprising a set of voxels corresponding to one or more of the aligner and the patient'"'"'s teeth;

generating a three-dimensional (3D) model of the combined dental aligner and patient'"'"'s teeth; and

displaying, storing and/or transmitting the 3D model.

23. The method of claim 22, wherein the penetrative scanning comprises optical coherence tomography (OCT).

24. The method of claim 22, wherein the penetrative scanning comprises near-infrared light scanning.