基于特征映射的义齿表面三维变形设计方法

3D Deformation Design Method for Prosthetic Dental Surface Based on Feature Mapping

义齿表面设计是牙科计算机辅助设计和制造系统的一个重要环节,设计的义齿形状必须符合患者的口腔咬合环境并能保持牙齿的拓扑结构特征。针对这一问题,在此提出一种基于特征映射的义齿表面三维变形设计方法。该方法主要思想是首先识别预备体与同名标准牙的重要特征点,采用径向基函数建立两者的特征映射关系,再通过对应特征点的位置对齐和表面的插值变形,实现义齿表面的变形设计。下颌第一磨牙嵌体的设计案例结果表明,该方法设计程序简单,标准牙曲面变形合理,能有效地避免曲面失真,最终生成的嵌体与预备体匹配良好,为牙科计算机辅助设计和制造系统的临床应用提供一种新的方法。

The prosthetic tooth surface design is an important issue in dental computer aided design systems（CAD）.The designed tooth shape should fit to the patient＇s tooth articulation environment and keep the topological features of the generic teeth.Aiming at the problem,a 3D deformation approach for prosthetic dental surface design based on feature mapping is presented.The main idea is by identifying the corresponding feature points between the preparation tooth and the standard tooth firstly,using a suitable radial basis function to define the feature mapping relations in both teeth,then through the corresponding features alignment and the surface interpolation deformation,the prosthetic tooth surface deformation is realized.The result of case study of the first molar in lower jaw shows that the design process is simple,the standard tooth surface deformation is reasonable,the surface distortion can be avoided and the final inlay surface matches well with the preparation tooth.The feature mapping design method provides a new way for clinic application in dental CAD.