Isberg A, Widmalm S E, Ivarsson R
Am J Orthod. 1985 Dec;88(6):453-60. doi: 10.1016/s0002-9416(85)80044-0.
Fifteen patients with internal derangement of the temporomandibular joint (TMJ) were examined clinically, radiographically, and electromyographically. Electromyographic recordings were also obtained from 11 subjects without signs or symptoms associated with their TMJs or masticatory musculature. All the patients with internal derangement demonstrated interferences on the ipsilateral side. This was interpreted as the result of disc displacement producing a reduced joint space and, consequently, a decreased vertical dimension on the symptomatic side. Slow opening and closing mandibular movements without clenching could be performed by healthy persons without noticeable EMG activity in the temporalis and masseter muscles. In association with disc displacement, electromyographic activity of the temporalis and masseter muscles occurred when the condyle slid over the posterior band of the disc and could be interpreted as an arthrokinetic reflex caused by distraction. Continuous muscle activity could be provoked by TMJ disc displacement and ceased when the disc position was normalized on mouth opening, only to occur again every time the disc became displaced on mouth closure. Anterior disc displacement without reduction (closed lock) could cause spastic activity in the temporalis muscle on the affected side. Spastic activity of the masseter and temporalis muscles occurring on the same side as a joint with anterior disc displacement hinders or inhibits the condylar movement necessary to achieve reduction.
对15例颞下颌关节（TMJ）内紊乱患者进行了临床、影像学和肌电图检查。还从11名无TMJ或咀嚼肌相关体征或症状的受试者身上获取了肌电图记录。所有颞下颌关节内紊乱患者均表现出同侧干扰。这被解释为盘移位导致关节间隙减小，从而使患侧垂直维度降低的结果。健康人在不咬紧牙关的情况下进行缓慢的下颌开闭运动时，颞肌和咬肌没有明显的肌电图活动。与盘移位相关的是，当髁突滑过盘的后带时，颞肌和咬肌会出现肌电图活动，这可被解释为牵张引起的关节运动反射。TMJ盘移位可引发持续的肌肉活动，在张口时盘位置恢复正常时停止，而每次闭口盘移位时又会再次出现。不可复性前盘移位（闭锁）可导致患侧颞肌痉挛性活动。与前盘移位关节同侧出现的咬肌和颞肌痉挛性活动会阻碍或抑制实现复位所需的髁突运动。
