Tooth segmentation using tooth registration

A method for segmenting a 3-Dimensional (3D) model image of a patient's dentition comprising:

• a) obtaining a first 3D model image of the patient dentition using an intraoral scanner and generating a segmentation of the first 3D model image, wherein the segmentation provides at least a tooth surface contour and a tooth label for a plurality of teeth of the first 3D model;
• b) obtaining a second 3D model image of the patient dentition, the second 3D model image having a surface;
• c) registering each segmented tooth surface contour of the first 3D model image to the surface of the second 3D model image;
• d) obtaining a second segmentation of the second 3D model image according to the registered tooth surface contour, wherein the second segmentation similarly provides at least a tooth surface contour and a tooth label for a plurality of teeth of the second 3D model image;
• e) identifying a tooth feature for at least one tooth of the first 3D model image and identifying a corresponding tooth feature of the second 3D model image based on the identified at least one tooth feature of the first 3D model image;
• and f) storing the segmented second 3D model image.

An apparatus for generating a 3-Diniensional (3D) model image of a patient's dentition comprising:

• a) an intraoral scanner that is configured to acquire multiple images of patient dentition;
• b) a processor in signal communication with the intraoral scanner and configurable to execute programmed instructions for:
• (i) obtaining a first 3D model image of the patient dentition and obtaining a segmentation of the first 3D model image, wherein the segmentation provides at least a tooth surface contour and a tooth label for at least one tooth of the first 3D model image;
• (ii) obtaining a second 3D model image of the patient dentition, the second 3D model image having a surface;
• (iii) registering each segmented tooth surface contour of the first 3D model image to the surface of the second 3D model image;
• (iv) obtaining a second segmentation of the second 3D model image according to the registered tooth surface contour, wherein the second segmentation similarly provides at least tooth surface contour and tooth labeling for at least one tooth of the second 3D model image;
• and c) a display that is in signal communication with the processor for displaying the segmented second 3D model image.