Detecting and monitoring development of a dental condition

1. A computer program product comprising program code means for causing a data processing system to perform method for detecting and monitoring movement of a patient's teeth between a first and a second point in time, wherein the method comprises:

obtaining a first digital 3D representation of the teeth and, optionally, including a patient's rugae, recorded at the first point in time and segmenting the first digital 3D representation such that a first 3D tooth model is formed for at least one tooth;

obtaining a second digital 3D representation of the teeth and, optionally, including a patient's rugae, recorded at the second point in time and segmenting the second digital 3D representation such that a second 3D tooth model is formed for the least one tooth;

locally aligning the first and second 3D tooth models;

selecting one or more anatomically corresponding regions on the locally aligned first and second 3D tooth models;

arranging the first and second digital 3D representations or the first and second 3D tooth models according to a global alignment of the patient's set of teeth, wherein the global alignment is based on at least one at least one of the patient's rugae or parts of the first and second digital 3D representations corresponding to parts of the set of teeth that have not moved during the time elapsed between the first and second digital 3D representations, and deriving anatomically correct distances between the selected corresponding regions; and

determining the tooth movement for the at least one tooth between the first and second point in time based on the derived distances.

2. The computer program product according to claim 1 , wherein the global alignment is based on at least two teeth in the digital 3D representation, such as the neighboring teeth.

3. The computer program product according to claim 1 , wherein the global alignment is based on more the teeth of one or more quadrants in the patient's set of teeth.

4. The computer program product according to claim 1 , wherein the global alignment is based on the patient's rugae.

5. The computer program product according to claim 1 , wherein locally aligning the first and second 3D tooth models comprises determining a transformation matrix which provides the local alignment, and where the distances are derived from the transformation matrix.

6. The computer program product according to claim 1 , wherein selecting one or more corresponding regions on the locally aligned first and second 3D tooth models comprises selecting the entire surface of the first and/or second 3D tooth model.

7. The computer program product according to claim 6 , wherein the method comprises deriving a distance map from the globally aligned first and second 3D tooth models or from the globally aligned first and second digital 3D representations expressing the variation in the distance over the tooth.

8. A method for detecting and monitoring movement of a patient's teeth between a first and a second point in time, wherein the method comprises:

obtaining a first digital 3D representation of the teeth and, optionally, including a patient's rugae, recorded at the first point in time and segmenting the first digital 3D representation such that a first 3D tooth model is formed for at least one tooth;

obtaining a second digital 3D representation of the teeth and, optionally, including the patient's rugae, recorded at the second point in time and segmenting the second digital 3D representation such that a second 3D tooth model is formed for the least one tooth;

locally aligning the first and second 3D tooth models;

selecting one or more anatomically corresponding regions on the locally aligned first and second 3D tooth models;

arranging the first and second digital 3D representations or the first and second 3D tooth models according to a global alignment of the patient's set of teeth, wherein the global alignment is based on at least one at least one of the patient's rugae or parts of the first and second digital 3D representations corresponding to parts of the set of teeth that have not moved during the time elapsed between the first and second digital 3D representations, and deriving anatomically correct distances between the selected corresponding regions; and

determining the tooth movement for the at least one tooth between the first and second point in time based on the derived distances.

9. The method according to claim 8 , wherein the global alignment is based on at least two teeth in the digital 3D representation, such as the neighboring teeth.

10. The method according to claim 8 , wherein the global alignment is based on more the teeth of one or more quadrants in the patient's set of teeth.

11. The method according to claim 8 , wherein the global alignment is based on the patient's rugae.

12. The method according to claim 8 , wherein locally aligning the first and second 3D tooth models comprises determining a transformation matrix which provides the local alignment, and where the distances are derived from the transformation matrix.

13. The method according to claim 8 , wherein selecting one or more corresponding regions on the locally aligned first and second 3D tooth models comprises selecting the entire surface of the first and/or second 3D tooth model.

14. The method according to claim 13 , wherein the method comprises deriving a distance map from the globally aligned first and second 3D tooth models or from the globally aligned first and second digital 3D representations expressing the variation in the distance over the tooth.

15. A method for detecting development in gingival recession at a tooth between a first and a second point in time, wherein the method comprises:

obtaining a first digital 3D representation of the patient's set of teeth recorded at the first point in time;

obtaining a second digital 3D representation of the patient's set of teeth recorded at the second point in time;

generating a first and a second 3D model of the tooth by segmentation of the corresponding parts of the first and second digital 3D representations, respectively;

determining a local transformation which aligns first and second 3D tooth models;

arranging the digital 3D representations according to the determined local transformation such that the tooth portions of the sections are aligned;

detecting an anatomically correct development in the gingival recession between the first and the second point in time by comparing the gingival boundaries in the first and second digital 3D representations arranged according to the determined local transformation.

16. A computer program product comprising program code means for causing a data processing system to perform method for detecting development in gingival recession at a tooth between a first and a second point in time, wherein the method comprises

obtaining a first digital 3D representation of the patient's set of teeth recorded at the first point in time;

obtaining a second digital 3D representation of the patient's set of teeth recorded at the second point in time;

generating a first and a second 3D model of the tooth by segmentation of the corresponding parts of the first and second digital 3D representations, respectively;

determining a local transformation which aligns first and second 3D tooth models;

arranging the digital 3D representations according to the determined local transformation such that the tooth portions of the sections are aligned;

detecting an anatomically correct development in the gingival recession between the first and the second point in time by comparing the gingival boundaries in the first and second digital 3D representations arranged according to the determined local transformation.

17. A method for detecting development of tooth wear for a patient's set of teeth between a first and a second point in time, wherein the method comprises:

obtaining a first digital 3D representation of the teeth recorded at the first point in time;

obtaining a second digital 3D representation of the teeth recorded at the second point in time;

segmentation of the teeth in the first and second digital 3D representations;

locally aligning segmented teeth of the first and second digital 3D representations;

comparing the locally aligned segmented teeth of the first and second digital 3D representations; and

detecting based on the comparison an anatomically correct change in the shape and/or size of at least one tooth.

18. The method of claim 17 , the method further comprising correlating a detected change in the tooth size with a threshold value relating to an expected depth of the patient's enamel.

19. A computer program product comprising program code means for causing a data processing system to perform method for detecting development of tooth wear for a patient's set of teeth between a first and a second point in time, wherein the method comprises:

obtaining a first digital 3D representation of the teeth recorded at the first point in time;

obtaining a second digital 3D representation of the teeth recorded at the second point in time;

segmentation of the teeth in the first and second digital 3D representations;

locally aligning segmented teeth of the first and second digital 3D representations;

comparing the locally aligned segmented teeth of the first and second digital 3D representations; and

detecting based on the comparison an anatomically correct change in the shape and/or size of at least one tooth.

20. The computer program product of claim 19 , the method further comprising correlating a detected change in the tooth size with a threshold value relating to an expected depth of the patient's enamel.