Nicol P, Loncle T, Pasquet G, Vacher C
Anatomy, Université de Paris, Paris, France.
Department of Maxillofacial Surgery, Hôpital Beaujon, APHP, 100 Boulevard du Général Leclerc, 92110, Clichy, France.
Surg Radiol Anat. 2020 May;42(5):509-514. doi: 10.1007/s00276-019-02379-5. Epub 2019 Nov 11.
In bilateral sagittal split osteotomy (BSSO), the risk of lesion of the inferior alveolar nerve (IAN) is important. The aim of this study was to investigate the situation of the IAN in the area of the BSSO in preoperative 158 CBCT.
The situation of the mandibular canal (MC) has been studied in six coronal sections (one section each 4 mm) from the proximal root of the second mandibular molar. The height of the MC related to the height of the mandible, and the horizontal distance between the MC and the lateral cortical plate related to the mandibular width have been determined in each section. The cancellous bone width has been measured allowing to determine a cancellous bone ratio.
The variability of the MC was high, depending mainly on the cancellous bone ratio which was higher when the IAN was deep. When a third molar was present, the MC was lower in the area of the third molar.
To decrease the risk of injuring the IAN in BSSO, the evaluation of the cancellous bone ratio by a preoperative CBCT may be proposed to adapt the surgical technique to the anatomy.
在双侧矢状劈开截骨术（BSSO）中，下牙槽神经（IAN）损伤的风险很重要。本研究的目的是通过术前158例锥形束计算机断层扫描（CBCT）来研究BSSO区域内IAN的情况。
从下颌第二磨牙近中根开始，在六个冠状面（每个层面间隔4毫米）上研究下颌管（MC）的情况。在每个层面上，确定MC相对于下颌骨高度的高度，以及MC与外侧皮质板之间相对于下颌骨宽度的水平距离。测量松质骨宽度以确定松质骨比例。
MC的变异性很高，主要取决于松质骨比例，当IAN较深时松质骨比例更高。当存在第三磨牙时，第三磨牙区域的MC较低。
为降低BSSO中IAN损伤的风险，建议通过术前CBCT评估松质骨比例，以便根据解剖结构调整手术技术。
