Diagnostic guideline of CBCT images to prevent complications while operating -classification of bone morphology of pterygomaxillary suture region

Le Forti截骨术是治疗上颌畸形的普通外科手术。然而，在分离翼上颌缝(PMS)时，有可能因腭动脉损伤而导致严重出血。术前诊断是避免此类并发症的重要措施。因此，提出了PMS及其周围结构的个体化解剖形态的影像诊断指南。从锥形束CT图像中可以看出，腭小管(LPC)从腭大管(GPC)发出的分支形态多种多样。肉眼观察到GPC、LPC和PMS内的神经、动脉和静脉有不同的分布。有限元分析表明，PMS分离过程中的应力分布受PMS、GPC和LPC的形态和位置的影响。综上所述，在Le FortI截骨术前诊断时应考虑GPC、LPC和PMS。

The Le FortI osteotomy is general surgical procedure for maxillary deformity. However, there is a possibility of severe bleeding caused by damage to the palatine artery during separation of pterygomaxillary suture (PMS). The preoperative diagnosis is important to avoid such complication. Therefore, the guideline of the imaging diagnosis for individual anatomical morphology of the PMS and surrounding structures was suggested. It was confirmed that the patterns of the branching of the lesser palatine canal (LPC) from the greater palatine canal (GPC) had a lot of variety from cone beam CT images. It was observed that the nerve, artery and vein in the GPC, LPC and PMS had a variety of distributions from macroscopic observation. From the FEM analysis, the stress distribution during the separation of the PMS is affected by the morphology and position of the PMS, GPC and LPC. In conclusion, it seems to be necessary to consider the GPC, LPC and PMSwhen diagnosing before Le FortIosteotomy.