Chen Hui-min, Fu Kai-yuan, Li You-wei, Zhang Zhen-kang
Center for Temporomandibular Disorders and Orofacial Pain, School and Hospital of Stomatology, Peking University, Beijing 100081, China.
Hua Xi Kou Qiang Yi Xue Za Zhi. 2009 Aug;27(4):408-12.
To measure the positional changes of temporomandibular joint (TMJ) disk and condyle with insertion of anterior repositioning splint (ARS) using magnetic resonance imaging (MRI) for further understanding of the splint therapy mechanisms.
Twenty-two patients with temporomandibular joint clicks were included. 31 TMJs were diagnosed as anterior disk displacement with reduction (disk-displaced group), and the other 13 TMJs were normal (normal group). All joints were scanned oblique-sagittally by MRI before splint treatment in three positions including closed-mouth position of centric occlusion (the position before insertion of ARS), incisors' edge to edge position, and mandibular least forward protrusion position (the position after insertion of ARS).
With insertion of the splint, the condyle moved anteriorly and inferiorly and the disk moved posteriorly, most of the anterior displaced disks could be reduced to normal positions in the joint fossa. The result indicated that the splint protruded condyle forward and prevented the backward reduced disk from displacing forward again during mouth closing.
使用磁共振成像（MRI）测量插入前牙再定位夹板（ARS）时颞下颌关节（TMJ）盘和髁突的位置变化，以进一步了解夹板治疗机制。
纳入22例有颞下颌关节弹响的患者。31个TMJ被诊断为可复性盘前移位（盘移位组），另外13个TMJ正常（正常组）。所有关节在夹板治疗前均通过MRI进行斜矢状面扫描，扫描三个位置，包括正中咬合闭口位（ARS插入前的位置）、切牙对刃位和下颌最小前伸位（ARS插入后的位置）。
1）盘 - 髁角：在闭口位时，盘移位组平均角度为54.23度，而正常组为9.80度；在切牙对刃位和下颌最小前伸位时，大多数盘移位病例的角度恢复正常。2）盘位置：从闭口位到切牙对刃位或下颌最小前伸位，向前移位的盘明显向后移动，而位置正常的盘在三个位置无明显变化。3）髁突位置：从闭口位到切牙对刃位或下颌最小前伸位，盘移位组和正常组的髁突均明显向前下方移动。
随着夹板的插入，髁突向前下方移动，盘向后移动，大多数前移位的盘可在关节窝内恢复到正常位置。结果表明，夹板使髁突向前突出，并防止闭口时向后复位的盘再次向前移位。
