口腔固定义齿数字化设计技术研究

发布时间：2018-06-27 01:40

本文选题：固定义齿 + 网格拓扑重建　；参考：《哈尔滨工业大学》2014年硕士论文

【摘要】：随着人民生活水平的提高，口腔健康越来越受到人们的关注，我国口腔疾病患病率达到97.6%，约有50%的龋齿需要进行固定义齿修复。由于传统义齿制作方法工序复杂、周期长、而且无法保证精度，计算机辅助设计制造技术开始渗透到口腔医学领域。国外市场上陆续出现了口腔修复系统，但其昂贵的价格导致了口腔治疗费用的增加，影响临床上的推广和应用。相比之下，国内尚无商品化的系统，所以本文对口腔固定义齿的数字化设计关键技术进行了研究，致力于开发具有自主知识产权的义齿设计系统。研究了三角网格模型拓扑重建技术，对现有方法进行了对比分析，采用平衡二叉树辅助结构去除冗余顶点，提取了模型顶点和三角形信息；分别求取顶点、边和三角面的邻接关系，建立了网格拓扑关系图；在网格优化算子中引入曲率约束，实现了网格拓扑形状优化，建立了基于三角网格曲面的义齿三维模型数据结构。研究了预备牙模型颈缘线提取技术，提出了一种基于改进蚁群算法的颈缘线提取方法，本文在标准蚁群算法基础上，以平均曲率作为颈缘线特征点的度量，辅以距离函数作为方向引导，对标准蚁群算法启发函数进行了改进，并针对蚁群算法局部最优问题，引入了随机动态权值，最终实现了颈缘线的交互自适应提取，并通过实例验证了算法的有效性。研究了三角网格曲面等距技术，提出了一种基于离散隐式曲面的三角网格等距方法，以预备牙颈缘线作为边界线，采用种子三角形区域增长的方法提取了预备牙等距基面，建立了包围盒空间符号距离场，应用改进的MT算法从符号距离场中提取出了等距面，实现了三角网格曲面等距，避免了现有等距方法的自交问题。基于Qt4软件开发环境及OpenGL图形库，开发了一套固定义齿数字化设计系统，融入了本文义齿数字化设计技术的研究理论，建立了系统数据存储结构，设计了系统总体框架，实现了三维牙模的输入和输出、用户信息的交互存储，模型的自由显示，，固定义齿的设计等功能。
[Abstract]:With the improvement of people's living standard, people pay more and more attention to oral health. The prevalence rate of oral diseases in China is 97.6. about 50% of dental caries need to be repaired with fixed dentures. Because the traditional denture manufacturing process is complicated, the period is long, and the precision can not be guaranteed, the computer-aided design and manufacture technology has begun to infiltrate into the field of stomatology. Oral repair systems have appeared in foreign markets, but their high prices have led to the increase of oral treatment costs, affecting the clinical promotion and application. In contrast, there is no commercial system in China, so this paper studies the key technology of digital design of fixed denture in oral cavity, and devotes to the development of denture design system with independent intellectual property rights. The topology reconstruction technology of triangular mesh model is studied, and the existing methods are compared and analyzed. The redundant vertices are removed by using balanced binary tree auxiliary structure, and the information of model vertices and triangles are extracted, and the vertices are obtained respectively. The topological graph of mesh is established by the contiguous relation between edges and triangles, and the mesh topology shape optimization is realized by introducing curvature constraint into the mesh optimization operator, and the data structure of denture 3D model based on triangular mesh surface is established. In this paper, the technique of neck edge line extraction of the prep tooth model is studied, and a new method based on improved ant colony algorithm is proposed. Based on the standard ant colony algorithm, the mean curvature is taken as the measure of the characteristic point of the neck edge line. Guided by distance function, the heuristic function of standard ant colony algorithm is improved, and random dynamic weights are introduced to solve the local optimal problem of ant colony algorithm. Finally, interactive adaptive extraction of neck edge line is realized. The effectiveness of the algorithm is verified by an example. A triangular mesh isometric method based on discrete-time implicit surface is proposed in this paper. The edge line of the prepared tooth is taken as the boundary line, and the equidistant base surface is extracted by using the method of seed triangle region growth. The symbolic distance field in the bounding box space is established and the equidistant surface is extracted from the symbol distance field by using the improved MT algorithm. The triangular mesh surface isometry is realized and the self-intersection problem of the existing isometric methods is avoided. Based on Qt4 software development environment and OpenGL graphics library, a set of fixed denture digital design system is developed, which integrates the research theory of digital denture design technology in this paper, establishes the data storage structure of the system, and designs the overall framework of the system. The functions of input and output of 3D tooth die, interactive storage of user information, free display of model and design of fixed denture are realized.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TP391.7

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