中文摘要：

目的分析和评价计算机辅助正颌外科模拟和预测系统（CASSOS2001）的准确性。方法将25例颌面畸形患者术前x线侧位定位片及彩色软组织侧面照输入CASSOS2001系统进行头影测量分析，并通过骨段移动来模拟正颌手术，预测术后咬合关系及软组织侧貌；再将术后x线侧位定位片输入该系统进行头影测量分析，选取10项测量参数，将术后实际结果和术前预测结果进行配对t检验。结果硬组织相关的4个测量项目（SNA角、SNB角、ANB角、MP—SN角），其术前模拟结果和术后真实结果比较均无统计学意义（P〉0．05）。软组织相关的6个测量项目中，仅上唇长一项有统计学意义（P〈0．05），其余5项包括sn（鼻下点）到零子午线的距离、Pog（软组织颏前点）到零子午线的距离、面突度、鼻唇角及唇颏比均无统计学意义（P〉0．05）。此外，软组织相关项目的均差及标准差普遍大于硬组织相关项目。结论CASSOS2001系统对于正颌术后硬组织变化的预测是准确的，对软组织变化的预测略有不足，尤其是唇部。标志点的定位误差，软硬组织移动比例的差异等均会对预测结果产生影响，因而CASSOS2001系统尚有较大的改善空间。

英文摘要：

Objective To assess the accuracy of computer aided stimulation systerm （ SASSOS 2001 ） for orthognathic surgery. Methods The study consisted of 25 patients with maxillofacial deformity treated with orthognathic surgery. Their lateral cephalograms and color lateral photos of soft tissue before surgery were input to the CASSOS 2001 system. Carry out cephalometric analysis and simulative orthognathic surgery by bone movement and predict occlusal relationship and lateral features of soft tissue. Then input the lateral cephalograms after surgery into the CASSOS 2001 system, and carry out cephalometric analysis. Choose ten parameters and compare predicted surgical parameters with actual postsurgical parameters. Results Results of four parameters of hard tissue and five parameters of soft tissue in this study were similar（ P 〉 0.05 ）. There were statistical differences in only one parameter of soft tissue, the labral length （ P 〈 0.05 ）. Conclusions CASSOS 2001 system is precise for the prediction simulation of changes of hard tissue in orthognathic surgery. It has a little shortcoming in the prediction of soft tissue, especially in the prediction of lips. The positioning error of the marking points, and the soft to hard tissue movement proportion have a large influence in the prediction. CASSOS 2001 system still has great room for improvement.