Systems and methods for removing gingiva from computer tooth models

• US 7,826,646 B2
• Filed: 07/31/2003
• Issued: 11/02/2010
• Est. Priority Date: 08/16/2000
• Status: Expired due to Fees

• Current Assignee: Align Technology Incorporated
• Original Assignee: Align Technology Incorporated
• Inventors: Cheang, Carmen, Sarva, Venkata S., Pavlovskaia, Elena
• Primary Examiner(s): Rodriguez; Cris L
• Assistant Examiner(s): PATEL, YOGESH P
• Application Number:
  US10/633,015
• Publication Number:
  US 20040023188A1
• Time in Patent Office: 2,651 Days
• Field of Search: 433/24, 433213-215, 382/128, 382/154, 434/263, 700/90
• US Class Current: 382/128
• CPC Class Codes: A61C 2007/004 Automatic construction of a set of axes for a tooth or a plurality of teeth
• CPC Class Codes: A61C 5/77 Methods or devices for making crowns
• CPC Class Codes: A61C 7/002 Orthodontic computer assisted systems
• CPC Class Codes: A61C 9/00 Impression cups, i.e. impression trays; Impression methods computer-assisted sizing A61C13/0004; instruments for determining occlusion A61C19/05
• CPC Class Codes: A61C 9/0046 Data acquisition means or methods
• CPC Class Codes: B33Y 80/00 Products made by additive manufacturing
• CPC Class Codes: G16H 20/40 relating to mechanical, radiation or invasive therapies, e.g. surgery, laser therapy, dialysis or acupuncture

Abstract

A computer-implemented method separates gingiva from a model of a tooth by defining a cutting surface along the gingiva; and applying the cutting surface to the tooth to separate the gingiva from the tooth.

Claims

1. A computer-implemented method for separating gingiva from a tooth on a computer model of the gingiva and the tooth, the method comprising:

defining a three dimensional closed cutting surface passing through a line between the gingiva and a crown of the tooth of the computer model, the crown defining a volume, wherein the closed cutting surface comprises a crown portion surrounding the crown of the tooth and a root portion approximating the shape of the root of the tooth, and wherein the crown portion of the closed cutting surface comprises a volume greater than the volume of the crown of the tooth; and

applying the cutting surface to the tooth to separate the gingiva from the tooth of the computer model.

2. The method of claim 1, wherein the cutting surface is curved.

3. The method of claim 1, wherein the cutting surface is expressed as a function.

4. The method of claim 1, wherein the cutting surface is expressed as a spline function and a quadratic function.

5. The method of claim 1, wherein the cutting surface is expressed as a spline function and a parabolic function.

6. The method of claim 1, wherein the cutting surface is interactively adjusted.

7. The method of claim 4, wherein the interactive adjustment of the cutting surface modifies a function defining the cutting surface.

8. The method of claim 4, further comprising interactively highlighting the separated gingiva.

9. The method of claim 8, further comprising interactively highlighting a border of the separated gingiva.

10. The method of claim 1, wherein the cutting surface is defined by specifying a basis for the tooth.

11. The method of claim 1, further comprising finding a gingival line separating a tooth surface and a gingiva.

12. The method of claim 11, further comprising finding the high curvature location on the tooth surface.

13. The method of claim 11, further comprising fitting a spline to the gingival line.

14. The method of claim 1, wherein the cutting surface further comprises a plurality of surfaces.

15. The method of claim 14, wherein the root of the tooth is modeled as a parabolic surface below a gingival line.

16. The method of claim 14, further comprising defining an enclosing surface to enclose the crown of the tooth.

17. The method of claim 14, further comprising:

displaying the cutting surface specified with a plurality of nodes;

adjusting one or more nodes to modify the surface; and

applying the surface to separate the gingiva from the tooth.

18. The method of claim 17, further comprising providing a handle to adjust an orientation-of the cutting shape.

19. The method of claim 17, wherein adjusting one or more nodes further comprises moving one or more nodes.

20. The method of claim 17, wherein the cutting surface is formed using a function in a cylindrical coordinate system.

21. The method of claim 1, further comprising:

visually displaying the cutting surface to a user as two surfaces representing opposed sides of the separation between the gingival and the tooth; and

allowing the user to determine whether to separate the gingival from the tooth.

22. The method of claim 1, wherein the crown surface is modeled as a one or more functions.

23. The method of claim 22, wherein the crown surface is modeled as a quadratic function in polar coordinates.

24. The method of claim 1, further comprising allowing a user to change a shape of the crown surface.

25. The method of claim 24, wherein allowing the user to change the shape comprises allowing the user to move at least one of crown control points, top control points and a gingival line.

26. A computer program, residing on a tangible storage medium, for use in separating gingiva from a computer model of a tooth, the program comprising executable instructions operable to cause a computer to:

define a three dimensional closed cutting surface passing through a line between the gingiva and a crown of the tooth, wherein the closed cutting surface comprises a crown portion surrounding the crown of the tooth and a root portion approximating the shape of a root of the tooth, and wherein the crown portion of the closed cutting surface comprises a volume greater than the volume of the crown of the tooth; and

apply the cutting surface to the tooth to separate the gingiva from the tooth in a single cut.

27. A computer program, residing on a tangible storage medium, for use in separating gingiva from a computer model of a tooth, the program comprising executable instructions operable to cause a computer to:

define a three dimensional closed cutting surface passing through a line between the gingiva and a crown of the tooth, wherein the closed cutting surface comprises a crown portion surrounding the crown of the tooth and a root portion approximating the shape of a root of the tooth, and wherein the cutting surface is expressed as a spline function and a quadratic function, the crown portion of the closed cutting surface comprising a volume greater than the volume of the crown of the tooth; and

apply the cutting surface to the tooth to separate the gingiva from the tooth in a single cut.

28. A computer, comprising:

a processor;

a data storage device coupled to the processor, the data storage device containing a computer program for use in separating gingiva from a computer model of a tooth, the program comprising executable instructions operable to cause a computer to;

define a three dimensional closed cutting surface passing through a line between the gingiva and a crown of the tooth, wherein the closed cutting surface comprises a crown portion surrounding the crown of the tooth and a root portion approximating the shape of a root of the tooth, and wherein the cutting surface is expressed as a spline function and a quadratic function, and wherein the cutting surface further comprises a plurality of surfaces, and wherein a root of the tooth is modeled as a parabolic surface below a gingival line, the crown portion of the closed cutting surface comprising a volume greater than the volume of the crown of the tooth; and

apply the cutting surface to the tooth to separate the gingiva from the tooth.

29. The system of claim 28, further comprising instructions to define an enclosing surface to enclose the crown of the tooth.

30. A computer-implemented method for separating tooth from gingiva, comprising:

defining a three dimensional closed cutting surface passing through a line between the gingiva and a crown of the tooth of a computer model, wherein the closed cutting surface comprises a crown portion surrounding the crown of the tooth and a root portion approximating the shape of a root of the tooth, and wherein the crown portion of the closed cutting surface comprises a volume greater than the volume of the crown of the tooth; and

applying the cutting surface to the tooth to separate the gingiva of the computer model and reconstruct the root for the tooth.

31. A computer-implemented method for separating gingiva from a tooth on a computer model of the gingiva and the tooth, the method comprising:

defining a three dimensional closed cutting surface passing through a line between the gingiva and a crown of the tooth of the computer model, wherein the closed cutting surface comprises a crown portion surrounding the crown of the tooth, and wherein the crown portion of the closed cutting surface comprises a volume greater than the volume of the crown of the tooth; and

applying the cutting surface to the tooth to separate the gingiva from the tooth of the computer model.

32. A system for separating gingiva from a tooth on a computer model of the gingiva and the tooth, the system comprising:

a processor;

a data storage device coupled to the processor, the data storage device containing a computer program for use in separating gingiva from a computer model of a tooth, the program comprising executable instructions operable to cause a computer to;

define a three dimensional closed cutting surface passing through a line between the gingiva and a crown of the tooth, wherein the closed cutting surface comprises a crown portion surrounding the crown of the tooth, and wherein the crown portion of the closed cutting surface comprises a volume greater than the volume of the crown of the tooth; and

apply the cutting surface to the tooth to separate the gingiva from the tooth.

33. A computer program, residing on a tangible storage medium, for use in separating gingiva from a computer model of a tooth, the program comprising executable instructions operable to cause a computer to:

define a three dimensional closed cutting surface passing through a line between the gingiva and a crown of the tooth, wherein the closed cutting surface comprises a crown portion surrounding the crown of the tooth, and wherein the crown portion of the closed cutting surface comprises a volume greater than the volume of the crown of the tooth; and

apply the cutting surface to the tooth to separate the gingiva from the tooth in a single cut.