Shen Pei, Liu Xiaohan, Xie Qianyang, Zhang Shanyong, Yang Chi
Department of Oral Surgery, Ninth People's Hospital, College of Stomatology, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of Stomatology, Shanghai, China.
J Craniofac Surg. 2019 Jan;30(1):e15-e17. doi: 10.1097/SCS.0000000000004903.
Orthopedic functional appliances are usually used to correct patients with retrognathic mandible. However, a part of cases have a trend of relapse after splint treatment. The aim of this study was to explore the role of temporomandibular joint disc position in functional appliance treatment. This study included 8 patients who had 1 joint anterior disc displacement with reduction (ADDWR) and the other joint anterior disc displacement without reduction (ADDWoR) confirmed by magnetic resonance imaging (MRI). Only the ADDWR joint could return to its normal position after wearing the anterior repositioning appliances (ARAs). Condylar morphology, condylar height, and disc length were evaluated 6 months after ARA treatment. The MRI showed that new bone appeared on 7 joints with ADDWR and on 1 joint with ADDWoR. The condylar height has increased 1.4 mm in the ADDWR group, while 0.1 mm shorter in the ADDWoR group. Disc length has increased from 8.5 to 8.7 mm in the ADDWR group and 0.4 mm shorter in the ADDWoR group after wearing the ARA. Our results suggested that it is noneffective of functional appliance used for class II malocclusion adolescents with ADDWoR and only a normal disc-condyle relationship benefits condyle growth by functional appliance. Thus it is important to reposition the disc as soon as possible.
口腔正畸功能矫治器通常用于矫治下颌后缩患者。然而，部分病例在使用矫治器治疗后有复发趋势。本研究旨在探讨颞下颌关节盘位置在功能矫治器治疗中的作用。本研究纳入8例经磁共振成像（MRI）证实一侧关节为可复性盘前移位（ADDWR），另一侧关节为不可复性盘前移位（ADDWoR）的患者。佩戴前导矫治器（ARA）后，仅ADDWR关节可恢复至正常位置。在ARA治疗6个月后评估髁突形态、髁突高度和关节盘长度。MRI显示，7例ADDWR关节和1例ADDWoR关节有新骨形成。ADDWR组髁突高度增加1.4mm，而ADDWoR组缩短0.1mm。佩戴ARA后，ADDWR组关节盘长度从8.5mm增加至8.7mm，ADDWoR组缩短0.4mm。我们的研究结果表明，功能矫治器对患有ADDWoR的安氏II类错合青少年无效，只有正常的盘髁关系才能通过功能矫治器促进髁突生长。因此，尽早使关节盘复位很重要。
