Longitudinal analysis and visualization under limited accuracy system

Patent metadata

Field	Value
Publication number	US-10499793-B2
Application number	US-201715858940-A
Country	US
Kind code	B2
Filing date	Dec 29, 2017
Priority date	Feb 17, 2017
Publication date	Dec 10, 2019
Grant date	Dec 10, 2019

Abstract

Processing logic makes a comparison between first image data and second image data of a dental arch and determines a plurality of spatial differences between a first representation of the dental arch in the first image data and a second representation of the dental arch in the second image data. The processing logic determines that a first spatial difference is attributable to scanner inaccuracy and that a second spatial difference is attributable to a clinical change to the dental arch. The processing logic generates a third representation of the dental arch that is a modified version of the second representation, wherein the first spatial difference is removed in the third representation, and wherein the third representation comprises a visual enhancement that accentuates the second spatial difference.

First claim

The invention claimed is:

1. A method comprising:
making a comparison between first image data of a dental arch and second image data of the dental arch;
determining, by a processing device, a plurality of spatial differences between a first representation of the dental arch in the first image data and a second representation of the dental arch in the second image data;
determining, by the processing device, that a first spatial difference of the plurality of spatial differences is attributable to scanner inaccuracy;
determining, by the processing device, that a second spatial difference of the plurality of spatial differences is attributable to a clinical change to the dental arch; and
generating, by the processing device, a third representation of the dental arch that is a modified version of the second representation, wherein the first spatial difference is removed in the third representation, and wherein the third representation comprises a visual enhancement that accentuates the second spatial difference.

2. The method of claim 1 , further comprising:
determining a classification for the second spatial difference that is attributable to the clinical change, wherein the visual enhancement is based at least in part on the classification.

3. The method of claim 2 , wherein the classification for the second spatial difference is one of a tooth movement classification, a tooth wear classification, a gum recession classification, or a gum swelling classification.

4. The method of claim 2 , wherein determining the classification comprises:
applying a plurality of detection rules to the second spatial difference, wherein each of the plurality of detection rules identifies a specific type of clinical change.

5. The method of claim 1 , wherein:
the first image data was generated based on a first intraoral scan of the dental arch performed at a first time by a first intraoral scanner and the second image data was generated based on a second intraoral scan of the dental arch performed at a second time by the first intraoral scanner or a second intraoral scanner; and
an error comprises the scanner inaccuracy of at least one of the first intraoral scanner or the second intraoral scanner.

6. The method of claim 1 , wherein determining that the first spatial difference is attributable to scanner inaccuracy and that the second spatial difference is attributable to the clinical change to the dental arch comprises:
applying a low pass filter that identifies low frequency spatial differences, wherein the first spatial difference is a low frequency spatial difference having a first value that is below a frequency threshold of the low pass filter and the second spatial difference is a higher frequency spatial difference having a second value that is above the frequency threshold.

7. The method of claim 1 , wherein the first spatial difference is a difference in arch length between the first representation of the dental arch and the second representation of the dental arch.

8. The method of claim 1 , wherein the visual enhancement comprises a color overlay for the third representation of the dental arch, wherein the color overlay comprises a first color for a region of the dental arch associated with the second spatial difference and a second color for one or more additional regions of the dental arch for which no clinical differences were identified between the first representation and the second representation of the dental arch.

9. The method of claim 1 , further comprising:
determining a magnitude of the second spatial difference; and
comparing the magnitude of the second spatial difference to one or more difference thresholds to determine a severity of the clinical change, wherein the visual enhancement is based at least in part on the severity of the clinical change.

10. The method of claim 9 , further comprising:
receiving an input defining the one or more difference thresholds, wherein the one or more difference thresholds comprise an upper threshold and a lower threshold.

11. The method of claim 1 , further comprising:
making an additional comparison between the first representation and the third representation;
determining a plurality of appearance differences between the first representation and the third representation, wherein an appearance difference comprises a difference in at least one of color, translucency, transparency, hue or intensity between a region in the first representation and a corresponding region in the second representation; and
adding an additional visual enhancement that accentuates one or more of the plurality of appearance differences.

12. The method of claim 11 , further comprising:
determining that a first appearance difference of the plurality of appearance differences is attributable to scanner inaccuracy of a scanner;
determining that a second appearance difference of the plurality of appearance differences is attributable to a clinical change to the dental arch; and
updating an appearance of the third representation to remove the first appearance difference, wherein the additional visual enhancement accentuates the second appearance difference.

13. The method of claim 1 , further comprising:
generating the visual enhancement that accentuates the second spatial difference by extrapolating the second spatial difference to a future time, wherein the clinical change is more extensive after extrapolation.

14. The method of claim 1 , wherein the first representation is a first virtual three-dimensional (3D) model of the dental arch, the second representation is a second virtual 3D model of the dental arch, and the third representation is a third virtual 3D model of the dental arch.

15. The method of claim 1 , wherein the second spatial difference comprises an actual tooth movement for a tooth, the method further comprising:
making a comparison of the actual tooth movement for the tooth to a planned tooth movement for the tooth;
determining, based on the comparison of the actual tooth movement for the tooth to the planned tooth movement for the tooth, whether the actual tooth movement deviates from the planned tooth movement by more than a threshold amount; and
generating a visual indicator that indicates whether the actual tooth movement deviates from the planned tooth movement by more than the threshold amount.

16. A system comprising:
a memory; and
a processing device operatively coupled to the memory, the processing device to:
make a comparison between first image data of a dental arch and second image data of the dental arch;
determine a plurality of spatial differences between a first representation of the dental arch in the first image data and a second representation of the dental arch in the second image data;
determine that a first spatial difference of the plurality of spatial differences is attributable to scanner inaccuracy;
determine that a second spatial difference of the plurality of spatial differences is attributable to a clinical change to the dental arch; and
generate a third representation of the dental arch that is a modified version of the second representation, wherein the first spatial difference is removed in the third representation, and wherein the third representation comprises a visual enhancement that accentuates the second spatial difference.

17. The system of claim 16 , wherein the processing device is further to:
determine a classification for the second spatial difference that is attributable to the clinical change, wherein the visual enhancement is based at least in part on the cla

Assignees

• Align Technology Inc

Inventors

• Ozerov Sergei
• Saphier Ofer
• Kopelman Avi
• Levin Adi
• Razumovskiy Pavel
• Sabina Michael
• Dyachenko Mikhail
• Sterental Rene M
• Dey Partha
• Roschin Roman A
• Gavrilov Anton
• Grechishnikov Leonid Vyacheslavovich

Classifications

• A61B1/0638

  providing two or more wavelengths · CPC title

• A61B1/043 Primary

  for fluorescence imaging · CPC title

• A61C7/002

  Orthodontic computer assisted systems · CPC title

• G16H50/50

  for simulation or modelling of medical disorders · CPC title

• G16H30/40

  for processing medical images, e.g. editing · CPC title