Research On Teeth Orthodontic Movement Path Planning And Visual Development

Teeth movement path planning was an important step of the virtual orthodontic system which took advantage of computer-aided visualization technology to simulate treatment program provided in clinical practice. Accorded to the treatment program and clinical needs, based on the teeth movement path planning method, each stage of the invisible appliance for patients designed through the virtual orthodontic system, recorded the location of each tooth of each step, determined the amount of rotation and movement, and finally judged the reasonable treatment program for each step by doctors to determine the final treatment program, formulated the invisible appliance for patients by the data outputted through the virtual orthodontic system. However, the virtual orthodontic systems were mostly imported and more expensive, related research of invisible treatment technology in the domestic was also focused on the feasibility analysis or clinical effect introduced and few introduction to research and development about orthodontic. Therefore, the research of path planning method of teeth movement and visualization had important theoretical and practical value.In this paper, to achieve the clinical needs for develop virtual orthodontic system, took the path planning method of teeth movement design and visual development as the research priorities. It had been completed considering the clinical needs, treatment position determination and feasibility of clinical treatment control. Completed path planning method for teeth movement design and visual development based on the C++ language and OpenGL platform. The main works were as follows:This thesis firstly used Mimics 15.0 to reconstruct and segment the CT dates of dentition, got the STL files by threshold segmentation method and manual division method, set parameters to establish the initial window of OpenGL, completed dental STL file data display and achieved teeth rotation and movement operation.This paper used OBB method to detect collision of the teeth moving process, determined the center position coordinate, three-axis direction and the Side length of OBB bounding box that constituted important variables of OBB bounding box. Collision detection method was determined by the Separation Axis Theory which used C++ language and OpenGL platform to achieve the collision detection function.Established the coordinate systems of each tooth and respectively extracted feature points with different numbers of incisors, canines and molars. Used the β function and acquired feature points to fit the curve of the dental arch and obtained the displayed results. Respectively determined the amount of movement and rotation of each tooth that to determine the final position of the patient’s teeth.The process of teeth movement path planning and the methods of each tooth arrangement and the collision detection in the orthodontic process were designed. Proposed collision resolution methods and determined the termination condition of orthodontic path planning. Finally, the visualizing results of orthodontic path planning obtained by OpenGL platform.