Development of Square mandible model with Four-dimentional analysis system

方形下颌骨的特点是开口严重受限。本研究旨在通过“四维肌肉模型”阐明方形下颌骨的病因。我们将该系统应用于18例方形下颌骨患者。从结果来看，患者的颞肌扩张率低于对照组。此外，根据分析结果，所有病例均通过手术治疗明显改善了开口限制。张嘴受限的主要原因被认为是颞肌挛缩。所建立的“四维肌肉模型”将为方形下颌骨患者确定手术治疗的靶肌提供有价值的工具。

Square mandible is characterized by severe limitation of mouth opening. This study aimed to clarify the etiology of Square mandible with the "4-D Muscle Model". We applied this system to the 18 patients of Square mandible. From the results, the expansion rates of temporal muscles in the patient were less than those in the control. Moreover, in all cases, the limitation of mouth-opening was remarkably improved by surgical treatment according to the analysis result. The main cause of limitation of mouth-opening was suggested to be a contracture of the temporal muscle. The present "4-D muscle model" would be valuable tool to decide the target muscle of surgical treatment for patients with Square mandible.