The study is to provide further understanding of the posterior maxillary anatomy in relation to the bonecut design of Le fort I osteotomy and to create clinical safety guidelines in order to avoid damaging the descending palatine vessels.

• 本研究结果可为临床医师进行上颌后部截骨术提供观测资料，并对避免损伤腭降动脉等结构具有指导意义。