The Research Of Tooth Segmentation Method In Virtual Orthodontics Treatment System

Lingual orthodontic device has the characteristics of safety, beautiful appearance and so on, and virtual orthodontics treatment system provides technical support for its extensive use.The method of tooth segmentation in the virtual orthodontics treatment system is the main content of this paper.This paper briefly introduces the STL file format of the dental jaw model and the method of triangular mesh segmentation. A method based on the quadric error metrics is used to simplified model, and it retains the original detail information of the triangular mesh model of dental. Calculating contour lines on the simplified model to improve the running efficiency,and separating the single tooth from the original dental and jaw model by the contour line keeps the real tooth data. This paper analyzes the manual sketching method and automatic segmentation algorithm in the mesh segmentation methods. This paper realized the tooth segmentation method based on sketching, users only need to have a simple sketch to mark and modify contours through the mouse on the triangular mesh model of dental. This method is tedious and time-consuming. Therefore, a tooth segmentation method based on the watershed is used to calculated the tooth contour lines, and it realizes the function of tooth segmentation.This article proposed a segmentation method based on cubic B-spline of watershed algorithm for contour problems after the watershed segmentation. At first, watershed algorithm is used to calculate regional contours of triangular mesh model of dental, followed by the use of cubic B-spline method to modify contours. This method achieves goals of local adjustment and smoothing. In order to have a further improve the separation efficiency of virtual orthodontics treatment system, this paper presents a tooth segmentation method based on the curvature feature of intersecting lines. This method established a custom mandibular plane to clip and abandon the meaningless part of dental base at first, and then calculating intersecting lines of teeth through cutting plane based on interaction selected points, andtraversing intersecting lines within the threshold value to calculate the extreme value of curvature. Finally, the teeth contours are generated by connected all extreme points.A method of tooth segmentation based on cubic B-spline is proposed is proposed in this paper,and experiment results show that this method can effectively and accurately adjust contours of the teeth. This paper put forward a method of tooth segmentation based on the curvature of intersecting lines for segmenting tooth, and experiments indicate that this method can meet the requirement of precise tooth contour.