Application Of 3D Model Processing Algorithms In Orthopedics And Dentistry

Computer-aided technology has been widely used in the medical field, especially in orthopedics and dentistry. In this work, some three-dimensional model processing algorithms will be applied into orthopedics and dentistry in order to solve problems met in invisible dental appliances and orthopedic knee surgery.In orthopedics, this work studies the X-ray diagram edge extraction and three-dimensional motion state of the knee bones. There are two steps. First the motion of the knee on a two-dimensional plane is portrayed by using the closest point iterative algorithm. Then the registration of the two-dimensional grayscale image and the three-dimensional X-ray image is discussed, we will find the most suitable match point by doing X-ray projection of the 3D models.The most important data base in invisible dental appliance technology is dental reconstruction. Dental reconstruction method is to use a grid division to separate each tooth. There have been much mature research on mesh segmentation approach, such as watershed algorithm, feature extraction method and skeleton extraction method, but these algorithms cannot be applied directly to the teeth model segmentation, therefore we use a method based on the outline of the tooth base to do the mess segmentation. First get the boundary of the teeth contour, and then use the region growing method to do the teeth mesh segmentation.In the entire design of tooth invisible appliance, reconstruction dental occlusion is an indispensable step. Unfortunately, this task is time-consuming and often inaccurate. In this work, a new approach is used to automatically and efficiently reestablish dental occlusion. It has two steps. The first step is to initial the tooth position according to dental curves and a point matching technique. The second step is to reposition the models to the final desired occlusion based on iterative technique with minimum distance collision constraints.