下颌矢状劈开截骨术相关下颌管空间定位的三维CT研究

目的：应用三维CT影像测量下颌管解剖位置与骨皮质和磨牙的关系，为避免下颌矢状劈开截骨术中损伤下齿槽神经血管提供指导。方法：选择50名正常成人下颌骨三维CT扫描图像，应用AW4．4图像处理软件分别在第二前磨牙，第一、第二磨牙正中，下颌磨牙后区处测量下颌管的解剖位置。结果：通过获得的CT数据研究中国人下颌神经管的解剖位置与骨皮质和磨牙的联系，在第二磨牙区域下颌管距离颊侧骨皮质最远（平均7．82mm，最小4．9mm）。结论：在第二磨牙区域下颌体最厚，对于下颌矢状劈开截骨术的颊侧垂直切口须在下颌第二磨牙区域，这个区域骨质最厚并且下颌管距离颊侧骨皮质最远。对于下颌矢状劈开截骨术颊侧垂直切口的安全深度是4．9mm。

The study of the spatial location of the mandibular canal with 3-Dimensional Computed Tomography in relation to sagittal split ramus osteotomy

Objective： The aim of this study was to determine the anatomical position of the mandibular canal in relation to the cortical bone and molar teeth using 3-Dimensional computed tomographic imaging and to relate the findings to performing sagittal split ramus osteotomy. Method： Fifty adult human was selected for 3-Dimensional Computed Tomography measurement and AW4.4softweare analysis. These measurements were taken at the second premolar, mesial root of first and second molar, and the postzone of lower molar. Result： This study determined the anatomical position of the mandibular canal in relation to cortical bone and molar teeth in Chinese using archived CT records. The mandibular canal was the farthest from the buccal cortex at the second molar region （mean 7.82 mm： minimum distance 4.90 mm）. Conclusion： The mandible body was thickest in the region of the second molar. The vertical buccal cut for SSRO should be in the region of the mandibular second molar where the bone is thickest and the mandibular canal is furthest from the buccal cortex. The safe depth for the vertical buccal cut is 4.9 mm.