Relationship between Maxillofacial Morphology and Mandibular Function

咀嚼肌、颌骨、颞下颌关节（TMJs）和牙齿之间平衡的生物力学关系是实现正常功能所必需的。本研究的目的是确定存在下颌功能障碍的患者的颌面形态是否导致TMJ功能障碍和疼痛。(1)日本成年人的头颅测量标准：面部骨骼凸出度高于美国白人。日本人的上颌骨位置稍靠前，下巴位置稍靠后。此外，上唇和下唇的变形也比美国白人大。日本人鼻唇角比美国白人小。(2)颌面形态与颞下颌关节功能障碍（TMD）的关系：不对称面部的功能障碍发生率较高，在各种功能障碍的构成中所占比例也较高。虽然混杂类型与TMD之间无统计学差异，但大多数TMD存在功能性咬合差异。由此可见，颞下颌关节功能障碍闭塞组表现为局限骨间状态，可能与颞下颌关节功能障碍有关。(3)髁突在关节盂窝的位置：用校正后的层状图评价对照组和经IVRO矫正的TMD患者的TMJs。结果显示，患者的症状和功能障碍的显著变化与肩关节窝的髁突位置有关。在没有TMJ成像或轴位成像研究的情况下，改变椎间盘-髁位置和/或髁位置的临床效果很难进行批判性分析。显然，进一步的累积研究是必要的。研究者希望将来能进一步开展这项研究。

A balanced biomechanical relationship between the masticatory muscles, jaws,temporomandibular joints(TMJs),and teeth is necessary to achieve normal function. The purpose of this study was to determine if maxillofacial morphology in patients with existing mandibular dysfunction result in the TMJ dysfunction and pain.(1)Cephalometric Norms in Japanese Adults: There was greater skeletal facial convexity than in white American. The Maxilla in Japanese was positioned slightly anteriorly,and the chin posteriorly. Additionally, upper and lower lip protorution were greater than white american. There was a smaller nasolabial angle in Japanese than in white american.(2)Relationship between maxillofacial morphology and temporomandibular joint dysfunction(TMD): Asymmetry faces showed higher incidence of dysfunction as well as percentage of composition of various dysfunctions. Though there was not statistically significant between the type of maocclusion and TMD, most of TMD had functional occlusal interdelferences. From these findings , the occlusion of TMJ dysfunction group was characterized to be in the restricted interpospal condition, which might relate to the TMJ dysfunction.(3)Condylar position in the glenoid fossa: Evaluation of the TMJs of control group and TMD patients corrected by IVRO was made with corrected laminograms. The results showed that the dramatic change in the patient's symptoms and dysfunction concern with the condylar position in the glenoid fossa. The clinical effect of altering the disk-condyle position and / or condylar position was difficult to analyze critically without TMJ imaging or axiografic study. Obviously, further cumulative study is necessary. The investigator wishes to developdel this study in future.