Chen H-M, Liu M-Q, Yap A U-J, Fu K-Y
Center for TMD & Orofacial Pain, Peking University School & Hospital of Stomatology, Beijing, China.
Department of General Dentistry II, Peking University School & Hospital of Stomatology, Beijing, China.
J Oral Rehabil. 2017 Sep;44(9):664-672. doi: 10.1111/joor.12532. Epub 2017 Jul 2.
Anterior repositioning splints (ARS) are used primarily for the management of temporomandibular joint (TMJ) anterior disc displacement with reduction (ADDwR). However, the exact physiological effects of ARS are still unclear. This study investigated the short and long-term effects of ARS on disc and condyle angles/positions by metric analysis. Twenty-two subjects diagnosed with ADDwR were recruited. Maxillary full-coverage ARS were fabricated, and MRI of TMJs was obtained before splint treatment, immediate post-insertion and 6 months after splint treatment. Disc-condyle relationship was determined by disc-condyle angle measurement. Disc and condyle positions were described as X-Y coordinates with the summit of glenoid fossa as the origin of the coordinates. Thirty-two TMJs were classified as ADDwR and 12 were normal. Upon ARS insertion, all TMJs with ADDwR got normal disc-condyle relationships. The condyles moved significantly forward and downward, while the discs moved significantly backward and upward. MRI at 6 months after treatment (without ARS insertion) indicated that only 40·6% (13/32) of the joints were maintained in the normal disc-condyle relationship. The majority of condyles returned to their pre-treatment positions, while the discs generally moved anteriorly again. The use of ARS resulted in forward and downward condyle movement, and a concurrent backward movement of the disc resulting in ideal spatial disc-condyle relationship. The stability of this relationship, however, could not be maintained in the majority of TMJs upon ARS removal. Findings explain the good short-term clinical outcomes with ARS and their relatively lower efficacy in the long term.
前复位夹板（ARS）主要用于治疗可复性颞下颌关节（TMJ）前盘移位。然而，ARS的确切生理效应仍不清楚。本研究通过测量分析调查了ARS对盘和髁突角度/位置的短期和长期影响。招募了22名被诊断为可复性前盘移位的受试者。制作了上颌全覆盖ARS，并在夹板治疗前、插入后即刻和夹板治疗后6个月获取TMJ的MRI。通过盘-髁突角度测量确定盘-髁突关系。盘和髁突的位置用X-Y坐标描述，以关节窝顶点为坐标原点。32个TMJ被分类为可复性前盘移位，12个正常。插入ARS后，所有可复性前盘移位的TMJ均获得了正常的盘-髁突关系。髁突显著向前和向下移动，而盘显著向后和向上移动。治疗后6个月（未插入ARS）的MRI显示，只有40.6%（13/32）的关节保持正常的盘-髁突关系。大多数髁突回到治疗前的位置，而盘通常再次向前移动。ARS的使用导致髁突向前和向下移动，同时盘向后移动，从而形成理想的盘-髁突空间关系。然而，在大多数TMJ中，去除ARS后这种关系的稳定性无法维持。研究结果解释了ARS良好的短期临床效果及其相对较低的长期疗效。
