Abstract: Computer-aided technique plays an important role in prediction and analysis of orthognathic surgery.However，the available methods cannot meet the diverse demand of virtual osteotomies.This paper presents a prism mesh cutting algorithm inspired by planar clipping.It regards the cutting track of virtual surgical knife as the cutting intersection of a polygon prism and a triangular mesh model.The results show that the proposed algorithms can handle effectively variant complex virtual osteotomies and provide further assistance with a preoperative guidance.

Key words: orthognathic surgery, craniofacial osteotomy, mesh cutting, prism

摘要： 计算机辅助虚拟手术技术对正颌外科手术方案的制定、手术效果的预测分析发挥着重要作用。然而，现有的计算机辅助正颌截骨术只能实现少量简单的截骨操作，不能满足虚拟截骨术多样性的需要。在平面切割地基础上，提出了一种基于凸柱体网格切割算法。该算法用凸柱体模拟虚拟手术刀对三维网格模型进行切割，根据截骨术的切口类型构造柱体，用此柱体进行切割实现骨块的分离。实验结果表明，该算法能有效地实现多种复杂虚拟截骨术，为手术方案的制订提供了辅助指导作用。

关键词: 正颌手术, 截骨术, 网格切割, 柱体