Systems and methods for selecting and marking a location on a dental aligner

1. A method for marking a dental aligner comprising:

receiving a digital model corresponding to a dental aligner, the digital model including a dental arch comprising a plurality of teeth;

determining whether a section of teeth on a right side or a left side of the dental arch includes flatter occlusal surfaces and selecting the section with the flatter occlusal surfaces;

identifying surfaces on the teeth of the selected section that are flat relative to other surfaces on the teeth of the selected section;

determining a line of best fit between the flat surfaces; and

marking the dental aligner with a marking based on the line of best fit.

2. The method of claim 1 , wherein the digital model comprises a plurality of polygons representing the occlusal surfaces of the teeth; and

wherein determining whether the section of teeth on the right side or the left side of the dental arch includes flatter occlusal surfaces comprises determining whether the section of teeth on the right side or the left side of the dental arch includes flatter occlusal surfaces based on face normal vectors of the plurality of polygons.

3. The method of claim 2 , wherein determining whether the section of teeth on the right side or the left side of the dental arch includes flatter occlusal surfaces and selecting the section with the flatter occlusal surfaces further comprises:

determining a face normal vector for each polygon representing the occlusal surfaces in the digital model;

determining a z-direction component for each face normal vector;

determining an average z-direction component for each section of teeth; and

selecting the section having the average z-direction component closer to 1.

4. The method of claim 1 , wherein the digital model comprises a plurality of polygons representing the occlusal surfaces of the teeth, and wherein identifying the surfaces on the teeth of the selected section that are flat relative to other surfaces on the teeth of the selected section comprises:

determining a face normal vector for each polygon representing the occlusal surfaces of the selected section in the digital model;

determining a z-direction component for each face normal vector; and

identifying each group of contiguous polygons having a face normal z-direction component greater than or equal to a threshold value as a flat surface.

5. The method of claim 4 , wherein the threshold value is 0.85.

6. The method of claim 1 , wherein determining the line of best fit between the flat surfaces comprises:

determining a centroid for each flat surface; and

determining the line of best fit between the centroids.

7. The method of claim 1 , wherein marking the dental aligner based on the line of best fit comprises etching the dental aligner with the marking using a laser.

8. The method of claim 1 , wherein the marking is a string of alphanumeric characters.

9. A system for marking a dental aligner comprising:

a processing circuit comprising at least one processor and a memory storing instructions that, when executed by the at least one processor, causes the processing circuit to:

receive a digital model corresponding to a dental aligner, the digital model including a dental arch comprising a plurality of teeth;

determine whether a section of teeth on a right side or a left side of the dental arch includes flatter occlusal surfaces and select the section with the flatter occlusal surfaces;

identify flat surfaces on the teeth of the selected section that are flat relative to other surfaces on the teeth of the selected section; and

determine a line of best fit between the flat surfaces; and

a marking system configured to mark the dental aligner with a marking based on the line of best fit.

10. The system of claim 9 , wherein the digital model comprises a plurality of polygons representing the occlusal surfaces of the teeth; and

wherein the instructions cause the processing circuit to determine whether the section of teeth on the right side or the left side of the dental arch includes flatter occlusal surfaces based on face normal vectors of the plurality of polygons.

11. The system of claim 10 , wherein the instructions further cause the processing circuit to determine whether the section of teeth on the right side or the left side of the dental arch includes flatter surfaces and select the section with the flatter occlusal surfaces by:

determining a face normal vector for each polygon representing the occlusal surfaces in the digital model;

determining a z-direction component for each face normal vector;

determining an average z-direction component for each section of teeth; and

selecting the section having the average z-direction component closer to 1.

12. The system of claim 9 , wherein the digital model comprises a plurality of polygons representing the occlusal surfaces of the teeth, and wherein the instructions further cause the processing circuit to identify the surfaces on the teeth of the selected section that are flat relative to other surfaces on the teeth of the selected section by:

determining a face normal vector for each polygon representing the occlusal surfaces of the selected section in the digital model;

determining a z-direction component for each face normal vector; and

identifying each group of contiguous polygons having a face normal z-direction component greater than or equal to a threshold value as a flat surface.

13. The system of claim 12 , wherein the threshold value is 0.85.

14. The system of claim 9 , wherein the instructions further cause the processing circuit to determine the line of best fit between the flat surfaces by:

determining a centroid for each flat surface; and

determining the line of best fit between the centroids.

15. The system of claim 9 , wherein the marking system is a laser etching system.

16. The system of claim 9 , wherein the marking is a string of alphanumeric characters.

17. A memory storing instructions that, when executed by a processor, cause a system to:

receive a digital model corresponding to a dental aligner, the digital model including a dental arch comprising a plurality of teeth;

determine whether a section of teeth on a right side or a left side of the dental arch includes flatter occlusal surfaces and select the section with the flatter occlusal surfaces;

identify surfaces on the teeth of the selected section that are flat relative to other surfaces on the teeth of the selected section;

determine a line of best fit between the flat surfaces; and

provide the line of best fit to a marking system configured to mark the dental aligner with a marking based on the line of best fit.

18. The memory of claim 17 , wherein the digital model comprises a plurality of polygons representing the occlusal surfaces of the teeth, and wherein the instructions further cause the system to determine whether the section of teeth on the right side or the left side of the dental arch includes flatter surfaces and select the section with the flatter occlusal surfaces by:

determining a face normal vector for each polygon representing the occlusal surfaces in the digital model;

determining a z-direction component for each face normal vector;

determining an average z-direction component for each section of teeth; and

selecting the section having the average z-direction component closer to 1.

19. The memory of claim 17 , wherein the digital model comprises a plurality of polygons representing the occlusal surfaces of the teeth, and wherein the instructions further cause the system to identify the surfaces on the teeth of the selected section by:

determining a face normal vector for each polygon forming the occlusal surfaces of the selected section in the digital model;

determining a z-direction component for each face normal vector; and

identifying each group of contiguous polygons having a face normal z-direction component greater than or equal to a threshold value as a flat surface.

20. The memory of claim 17 , wherein the instructions further cause the system to determine the line of best fit between the flat surfaces by:

determining a centroid for each flat surface; and

determining the line of best fit between the centroids.