计算机辅助下颌骨截骨的三维显微结构模型建立

3D measurement and analysis on 3D microstructure model for mandible osteotomy aided by computer

目的探索计算机重建下颌骨三维显微结构模型及下颌角截骨手术的三维仿真操作方法，以减少手术操作中的组织损伤。方法利用螺旋CTA数据重建包含血管神经束的下颌骨三维模型并进行测量分析，使用Freeform雕刻刀及其布尔运算的切割方法对模型进行保护血管的手术模拟。结果利用计算机辅助技术可以精确的重建包含下牙槽动脉的下颌骨三维模型：血管从下颌孔进入下颌支，依照下颌支外缘弧度走行，下颌孔距下颌支前缘距离为（19．13±0．66）mm，孔距下颌支后缘距离为（18．96±0．64）mm，下颌角的角度为（109．70±4．67）°，下颌支的安全截骨范围和角度是平行下颌支外缘（12．62±0．28）mm宽、与下颌底成角（22．30±4．67）°；根据模型与数据，Freeform可以模拟安全的下颌角截骨的手术操作。结论下颌骨显微结构的三维模型重建和测量分析技术，是增加手术安全性的一条新途径。

Objective To build a method of mandible 3D model to measure and analysis, then to finish the operation simulation, providing anatomic data to avoiding the complications of mandible osteotomy. Methods Using CT data to reconstruct 3D model of mandible with blood vessel and bone, then using Simpleware to measure and analysis, and using Freeform system and an incision method of Boolean to simulation mandible osteotomy safely. Results It was possible to use CT data to rebuild 3D model for 3D measure and analysis for operation simulation. The inferior alveolar artery and never were the main tissues which went through the madiblular. The length of mandibular foramen to anterior ramus was （19.13± 0.66） mm, and the ones to posterior ramus was （18.96 ± 0.64）mm. The angle of the mandible was （109.70 ±4.67）% The rages of the ramus for safe operation was （12.62 ± 0.2g）mm, and the safe rages about angle of the body and bottom of the mandible was （22.30 ± 4.67）°. There were obvious differences from children to the aged in the mandible physiological and anatomic study. We can use Freeform system to simulate the operation on 3D model. Conclusion It is a new method to build 3D model and use Freeform system to simulate operation and a new path to communion with patients for a good operation.