在牙齿矫正中，传统的金属矫正不仅具有易磨损口腔、难清洁、不易摘取、影响美观等缺点，而且很难预测矫正效果。开发具有过程模拟与结果预测的虚拟牙齿矫正系统，可以预先计划每个阶段牙齿移动的先后次序、位置、幅度及力度，因此具有重要的实际应用价值。 首先，本文在分析STL文件特性的基础上，提出了层次环状数据结构拓扑重建的方法，既节省了存储空间、降低了冗余数据，又为后续的查找和数据处理提供了方便；在分析三维网格分割方法的基础上，提出了一种矢量逼近寻找边界点的组织分割方法，并利用快速成型技术中的实体切割方法对单个牙齿进行了分离。 其次，针对软组织物理变形的特点，通过对几种常用变形模型的分析，建立了简化质点－弹簧模型，并对其进行了动力学分析，给出了拉格朗日方程的数值解法。 最后，本文在分析正畸加力与牙齿移动关系的基础上，利用层次包围盒思想对牙齿移动中的碰撞检测算法进行了研究，解决了牙齿移动中的碰撞检测实时处理问题 本项目以 VC++6.0 和 OpenGL 为开发工具。在开发中贯彻了面向对象的编程思想，把系统分为若干模块，介绍了各模块的功能及实现方法并给出了模拟结果，并对文中不足之处进行了分析，对未来的工作提出了要求。

Traditional metal orthodontics not only has disadvantages such as abrading nonnasality, cleansing and taking off difficulty as well as influencing appearance, but also hardly forecast orthodontic effect in the process of orthodontics. Developing virtual orthodontic system which have process simulation and effect forecast can preplan order, position, range, and force of each stage in tooth movement, accordingly it is have important value in practice use. Firstly, on the basis of analyzing the properties of the STL file, the topological reconstruction method of hierarchy and circularity of data structure are presented. Therefore, the efficiency of following lookup, the space of memory and data processing are greatly improved; A sort of vector approximation searching boundary point method of tissue segmentation is present by analyzing 3D mesh segmentation, and single tooth is divided by citing solid incision method in Rapid Protoyping technique. Secondly, based on the properties of the physical deformation, a simplified mass-spring model is established by analyzing deformed model in common use, then its dynamics characteristic is analyzed, finally, numerical solution of the Lagrange equation is presented. Finally, according to the relationship of orthodontic force and tooth movement, the collision detection algorithm of the tooth movement is investigated by using hierarchy bounding boxes thinking. The real-time processing problem of the collision detection is settled in tooth movement. The subject is developed with VC++6.0 and OpenGL. The system is divided into several modules by using object-oriented programming ideas. The function and implement approach of every module are introduced, and the simulation results are presented. Finally, the shortcomings of the paper are analyzed, and some requests are put forward in the future.