Hamada Y, Kondoh T, Kamei K, Seto K
First Department of Oral and Maxillofacial Surgery, School of Dental Medicine, Tsurumi University, Tsurumi, Tsurumi-ku, Yokohama, Japan.
J Oral Maxillofac Surg. 2001 Sep;59(9):1002-5; discussion 1005-6. doi: 10.1053/joms.2001.25825.
The present study aimed to explore disc mobility and arthroscopically diagnosed morphologic changes in the temporomandibular joint (TMJ) associated with long-term mandibular discontinuity.
Twelve patients (24 TMJs) who had undergone mandibulectomy including the unilateral condyle or segmental mandibulectomy without mandibular reconstruction, more than 8 months before this study were examined. The 24 TMJs were classified into 3 groups as follows: group 1, TMJs with a major mandibular fragment including the mandibular body (n = 11); group 2, TMJs with a mandibular ramus including the coronoid process (n = 5); and group 3, TMJs with only a condylar process, a mandibular ramus not including the coronoid process, or without a condyle (n = 8). Disc mobility was evaluated by magnetic resonance imaging, and arthroscopic observation of the superior joint compartment (SJC) was performed in all TMJs. The relationship between disc mobility and the arthroscopic findings was also studied.
The frequency of immobile discs differed significantly among groups 1 (0%), 2 (40.0%), and 3 (100%). Arthroscopic findings were normal in all SJCs of group 1. Various types of fibrous adhesions were observed in 40.0% of group 2 and in 75.0% of group 3. The development of fibrous adhesions in the SJC was significantly related to the presence of an immobile disc.
Long-term immobilization of the TMJ in a nonfunctional state seems to promote the development of fibrous adhesions in the SJC. Preservation of the mandibular fragment including the coronoid process, during mandibulectomy appears to contribute to postoperative TMJ mobility. To ensure recovery of a physiologic TMJ after mandibulectomy, it seems important to re-establish TMJ mobility by establishing mandibular continuity as soon as possible.
本研究旨在探讨与长期下颌骨连续性中断相关的颞下颌关节（TMJ）盘的活动度及关节镜诊断的形态学变化。
对12例患者（24个TMJ）进行检查，这些患者在本研究前8个月以上接受了包括单侧髁突的下颌骨切除术或节段性下颌骨切除术且未进行下颌骨重建。将24个TMJ分为以下3组：第1组，具有包括下颌体的主要下颌骨碎片的TMJ（n = 11）；第2组，具有包括冠突的下颌支的TMJ（n = 5）；第3组，仅具有髁突、不包括冠突的下颌支或无髁突的TMJ（n = 8）。通过磁共振成像评估盘的活动度，并对所有TMJ进行上关节腔（SJC）的关节镜观察。还研究了盘活动度与关节镜检查结果之间的关系。
第1组（0%）、第2组（40.0%）和第3组（100%）之间静止盘的频率差异显著。第1组所有SJC的关节镜检查结果均正常。第2组40.0%和第3组75.0%观察到各种类型的纤维粘连。SJC中纤维粘连的形成与静止盘的存在显著相关。
TMJ长期处于非功能状态的固定似乎会促进SJC中纤维粘连的形成。下颌骨切除术中保留包括冠突的下颌骨碎片似乎有助于术后TMJ的活动度。为确保下颌骨切除术后TMJ的生理恢复，尽早通过建立下颌骨连续性来重建TMJ活动度似乎很重要。
