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Introduction Maxillary surgery alone can be proposed for the surgical management of class III malocclusion, but anticipating outcomes for the labiomental muscle complex is challenging due to the mandibular autorotation phenomenon. The objective of this study was to quantify the mandibular and labiomental movements induced by maxillary osteotomy alone in the management of class III malocclusion according to different clinical and surgical variables. Methods The post-operative changes in mandibular and labiomental shapes were studied by geometric morphometry from the pre- and post-operative lateral cephalometric radiograph of 25 patients. The explanatory variables tested were maxillary advancement, maxillary rotation, and divergence. Results Soft tissues repositioning are different from postoperative mandibular repositioning after maxillary osteotomy. Neuromuscular adjustments of mandible depend on divergence and the maxillary rotation. Labiomental response only depends on divergence. Conclusion The surgical procedure does not have the same bone-related and musculocutaneous effects on patients with the same class III malocclusion. It is therefore essential for surgeons to understand the effects of their procedure on musculocutaneous tissues in order to best anticipate post-operative outcomes.引言 仅采用上颌手术即可用于安氏三类错颌畸形（class III malocclusion）的外科矫治，但受下颌自主旋转（mandibular autorotation）现象影响，精准预测唇颏肌复合体（labiomental muscle complex）的术后效果极具挑战。本研究旨在量化不同临床与手术变量下，仅行上颌骨截骨术（maxillary osteotomy）矫治安氏三类错颌畸形时，下颌及唇颏部的运动变化。 方法 本研究通过几何形态测量法（geometric morphometry），对25例患者的术前与术后头颅侧位X线片（lateral cephalometric radiograph）的下颌及唇颏部形态的术后变化进行分析。本次研究所纳入的解释变量包括上颌前移量、上颌旋转角度及颌骨分角度（divergence）。 结果 上颌骨截骨术后，软组织移位模式与下颌骨术后复位模式存在差异。下颌骨的神经肌肉适应性调节取决于颌骨分角度与上颌旋转角度。而唇颏部的术后反应仅与颌骨分角度相关。 结论 对于罹患同类安氏三类错颌畸形的患者，同一手术方案对其骨组织与肌皮组织的影响并不一致。因此，外科医师需充分了解手术方案对肌皮组织的作用效果，方能更精准地预测术后结局。