US-12622773-B2 - Detecting and monitoring development of a dental condition

US12622773B2US 12622773 B2US12622773 B2US 12622773B2US-12622773-B2

Abstract

A method, user interface and system for detecting and monitoring development of a dental condition. In particular, detecting and monitoring such a development by comparing digital 3D representations of the patient's set of teeth recorded at a first and a second point in time. For example, determining tooth movement for at least one tooth between the first and second point in time based on derived distances.

Inventors

Rune Fisker
Henrik John Brandt
Alen BOGDANIC

Assignees

3SHAPE A/S

Dates

Publication Date: 20260512
Application Date: 20220601
Priority Date: 20160224

Claims (20)

1 . A non-transitory computer readable medium encoded with a computer program for causing a processor to perform a method for detecting or monitoring a dental condition of a patient's teeth, wherein the method comprises: obtaining a first digital 3D representation of the teeth recorded at a 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 recorded at a 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; aligning the first and second 3D tooth models; comparing one or more corresponding regions on the aligned first and second 3D tooth models; and subsequently detecting a change in a parameter representing a dental condition based on the comparison, wherein, when a detected change exceeds a set threshold, an operator is prompted through a graphical user interface; wherein the user interface is configured to visualize the change in the parameter by aligning the digital 3D representations and then controlling a transparency of the different digital 3D representations based on an order in which the digital 3D representations are obtained; wherein the dental condition is caries, and wherein the detecting comprises: detecting a change in color in the digital 3D tooth models between the one or more corresponding regions on the aligned first and second digital 3D tooth models, wherein a detected change in color is correlated with an expected change in the color in response to the development of caries.
2 . The non-transitory computer readable medium of claim 1 , wherein the operator is prompted with a notification on the graphical user interface.
3 . The non-transitory computer readable medium of claim 1 , wherein when the detected change reaches a set threshold value defined by a darkening color change, the detected change triggers prompting the operator.
4 . The non-transitory computer readable medium of claim 1 , wherein the detecting comprises determining a color difference map for the one or more corresponding regions by comparing the color data of the one or more corresponding regions.
5 . The non-transitory computer readable medium of claim 1 , wherein the detecting comprises selecting a region of interest as the one or more corresponding regions, wherein the detecting comprises determining a color value for at least said region of interest in the first and second digital 3D tooth models and determining the change in the color value between the first and second digital 3D tooth models.
6 . The non-transitory computer readable medium of claim 1 , wherein the alignment is based on at least two teeth in the digital 3D representation, such as the neighboring teeth.
7 . The non-transitory computer readable medium of claim 1 , wherein aligning is based on the patient's rugae.
8 . The non-transitory computer readable medium of claim 1 , wherein aligning the first and second 3D tooth models comprises determining a transformation matrix which provides the alignment, and where distances are derived from the transformation matrix.
9 . A system comprising a non-transitory computer readable medium encoded with a computer program for causing a processor to perform a method for visualize a change in a dental condition of a patient's set of teeth and a graphical user interface, wherein the graphical user interface is configured to visualize the change in a dental condition of a patient's set of teeth by the method, the method comprising: obtaining a first digital 3D representation of the teeth recorded at a first point in time; obtaining a second digital 3D representation of the teeth recorded at a second point in time; comparing at least parts of the first and second digital 3D representations; and detecting, based on the comparison, a change in a parameter relating to the dental condition, wherein, when a change exceeding a set threshold is detected, an operator is prompted through the graphical user interface; wherein the graphical user interface is configured to visualize a development of a dental condition by aligning the digital 3D representations and then controlling transparency of the digital 3D representations based on an order in which the digital 3D representations are obtained wherein the dental condition is caries, and wherein the detecting comprises: detecting a change in color in the digital 3D tooth models between the one or more corresponding regions on the aligned first and second digital 3D tooth models, wherein a detected change in color is correlated with an expected change in the color in response to the development of caries.
10 . The system of claim 9 , wherein the graphical user interface is configured to visualize a change in color over different parts of the patient's teeth by displaying a difference map.
11 . A method for detecting or monitoring a dental condition of a patient's teeth, the method comprising: obtaining a first digital 3D representation of the teeth recorded at a 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 recorded at a 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; aligning the first and second 3D tooth models; comparing one or more corresponding regions on the aligned first and second 3D tooth models; subsequently detecting a change in a parameter representing a dental condition based on the comparison; and prompting an operator through a graphical user interface when a detected change exceeds a set threshold; wherein the user interface is configured to visualize the change in the parameter by aligning the digital 3D representations and then controlling a transparency of the different digital 3D representations based on an order in which the digital 3D representations are obtained; wherein the dental condition is caries, and wherein the detecting comprises: detecting a change in color in the digital 3D tooth models between the one or more corresponding regions on the aligned first and second digital 3D tooth models, wherein a detected change in color is correlated with an expected change in the color in response to the development of caries.
12 . The method of claim 11 , wherein the operator is prompted with a notification on the graphical user interface.
13 . The method of claim 11 , wherein when the detected change reaches a set threshold value defined by a darkening color change, the detected change triggers prompting the operator.
14 . The method of claim 11 , wherein the detecting comprises determining a color difference map for the one or more corresponding regions by comparing the color data of the one or more corresponding regions.
15 . The method of claim 11 , wherein the detecting comprises selecting a region of interest as the one or more corresponding regions, wherein the detecting comprises determining a color value for at least said region of interest in the first and second digital 3D tooth models and determining the change in the color value between the first and second digital 3D tooth models.
16 . The method of claim 11 , wherein the alignment is based on at least two teeth in the digital 3D representation, such as the neighboring teeth.
17 . The method of claim 11 , wherein aligning is based on the patient's rugae.
18 . The method of claim 11 , wherein aligning the first and second 3D tooth models comprises determining a transformation matrix which provides the alignment, and where distances are derived from the transformation matrix.
19 . A system comprising: a non-transitory computer readable medium encoded with a computer program for causing a processor to perform a method for visualize a change in a dental condition of a patient's set of teeth; and a graphical user interface, wherein the method comprises: obtaining a first digital 3D representation of the teeth recorded at a 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 recorded at a 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; aligning the first and second 3D tooth models; comparing one or more corresponding regions on the aligned first and second 3D tooth models; and subsequently detecting a change in a parameter representing a dental condition based on the comparison, wherein, when a detected change exceeds a set threshold, an operator is prompted through the graphical user interface; wherein the user interface is configured to visualize the change in the parameter by aligning the digital 3D representations and then controlling a transparency of the different digital 3D representations based on an order in which the digital 3D representations are obtained; wherein the dental condition is caries, and wherein the detecting comprises: detecting a change in color in the digital 3D tooth models between the one or more corresponding regions on the aligned first and second digital 3D tooth models, wherein a detected change in color is correlated with an expected change in the color in response to the development of caries.
20 . The system of claim 19 , wherein the operator is prompted with a notification on the graphical user interface.

Description

CROSS REFERENT TO RELATED APPLICATIONS The present application is a continuation of U.S. application Ser. No. 17/066,068, filed on Oct. 8, 2020, which is a continuation of U.S. application Ser. No. 16/079,256, filed on Aug. 23, 2018, now U.S. Pat. No. 10,835,361, which is a U.S. National Stage of International Application No. PCT/EP2017/054296, filed on Feb. 24, 2017 which claims the benefit of Danish Application No. PA 2016-70103, filed on Feb. 24, 2016. The entire contents of each of U.S. application Ser. No. 16/079,256, International Application No. PCT/EP2017/054296, and Danish Application No. PA 2016-70103 are hereby incorporated herein by reference in their entirety. TECHNICAL FIELD This disclosure generally relates to methods, user interfaces, systems, and computer program products for detecting and monitoring development of a dental condition. In particular the disclosure relates to detecting and monitoring such a development by comparing digital 3D representations of the patient's set of teeth recorded at different points in time. SUMMARY Disclosed is 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 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 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 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 and deriving the distances between the selected corresponding regions; anddetermining the tooth movement for the at least one tooth between the first and second point in time based on the derived distances. Selecting corresponding regions on the locally aligned 3D tooth models provides the advantage that a true geometrical correspondence can be established. Determining tooth movement between different points in time based on the distance between anatomical corresponding regions on the tooth surface provides a more accurate measure than prior art methods which measure distance between closest parts of the tooth surfaces which not necessarily relate to the anatomically identical parts. The anatomical correct distance and movement can, e.g., be determined from a transformation matrix which locally aligns the first and second 3D tooth models. The detection of the development of, e.g., a tooth movement by comparing two digital 3D representations acquired at different points in time can be extended to comparing several digital 3D representations and to monitor the development of the patient's teeth over time. The monitoring may involve several other digital 3D representations recorded in between, before and/or after the first and second digital 3D representations such that a series of digital 3D representations is recorded. The comparison can then, e.g., be between two subsequently acquired digital 3D representations or between the latest acquired digital 3D representation and the first digital 3D representation acquired for the patient. In the first example the development since the last visit at the clinic can be detected. In the second example, an overall development since the beginning of the monitoring is detected. In some cases it may however also be advantageous to allow the operator to decide which of the previous digital 3D representations a given digital 3D representation should be compared with. In some embodiments, the user interface configured for implementing the disclosed method provides that the operator can decide which of several obtained digital 3D representations should be compared. When visualizing the development of the patient's set of teeth based on digital 3D representations recorded at two or more visits to the clinic, the user interface may be configured to visualize the development by aligning all the digital 3D representations and controlling the transparency of the different digital 3D representations based on a timeline indicator. The transparency of a given digital 3D representation then increases when the timeline indicator is positioned away from the corresponding point in time. In that case, preferably only the closest one or two digital 3D representations can be seen for any given indicator position on the timeline. The digital 3D representations may be obtained using different scanning techniques know to the skilled person, such as an intra oral scanner configured for recording the topography of the patient's set of teeth, i.e. the shape of the gingiva and/