A method for segmenting a 3D model image of a patient's dentition obtains a first 3D model image of the patient dentition and obtains a first segmentation of the first 3D model image, wherein the first segmentation provides at least a tooth surface contour and a tooth label for one or more teeth of the first 3D model. A second 3D model image of the patient dentition is obtained. Each segmented tooth surface contour of the first 3D model is registered to corresponding tooth surface contour of the second 3D model. A second segmentation of the second 3D model image is obtained according to the registered tooth surface contour, wherein the second segmentation similarly provides at least tooth surface contour and a tooth labeling for one or more teeth of the second 3D model image. The segmented second 3D model image is displayed, transmitted, or stored.
