A Study on the Mechanism of the Neck Muscle Pain originated from Occlusal Disharmony.

颞下颌关节咬合干扰患者常主诉咀嚼肌疼痛，颈部肌肉也有疼痛。颈肌痛的治疗方法和发病机制至今仍有许多未解之谜。因此，我们做了一些研究集中在疼痛的胸锁乳突肌（SCM：最大的外侧颈部肌肉）。因此，我们取得了显著的成就。所取得的成果概述如下。对颞下颌关节患者的治疗给予指导，通过正确的前路引导重建，对临床病例中颞下颌关节疼痛的SCM患者进行了治疗.结果表明，SCM的疼痛主要发生在肌止点（SCM-I），而非肌中部（SCM-M）。因此，我们通过解剖学和肌电图实验，探讨了在咬合功能过程中，SCM-I和SCM-M的功能分化，从解剖学观察中证实了SCM腹的数量在个体之间存在一定的差异。肌电图分析表明，SCM-I和SCM-M的肌电图存在定性和定量的差异。肌电功率谱在12-13 Hz处有一个低频峰，表明肌电活动受牵张反射的调节。另一方面，来自SCM-M的EMG不好的较高频带。SCM-I组肌电功率值随咬合力的增加而增加，SCM-M组肌电功率值随咬合力的增加而增加。这些结果表明，SCM-Ⅰ在咬合功能过程中是活跃的，SCM在咬合功能过程中在插入部和中间部似乎存在功能分化。

TMJ patients with occlusal interferences often complain of pains not only in masticatory muscles but also in neck muscles. There are still unclarified points regarding the treatment and the causative mechanism of the pain in neck muscles. Therefore we made some studies focused on the pain in the Sternocleidomastoid Muscle ( SCM : the largest lateral neck muscle). As a result, we have made a remarkable achievements.The outline of the results obtained will be described below.1. We gave a guidance for the treatment of TMJ patients.W had trported on clinical cases of TMJ patients with pain in SCM treated errectively by the reconstruction of proper anterior guidance.2. We clarified the function of SCM during occlusal functions.The pain in SCM occurs mainly in the insertion of the muscle (SCM-I) reather than in the middle part of the muscle (SCM-M). Therefore we made anatomical and electromyographical experiments to investigate the functional differentiation between the SCM-I and the SCM-M during occlusal functions.From the anatomical observation, it was confirmed there are some variations between individuals in the number of belly of SCM. From the electromyographic analysis, it was revealed there are qualitative and guantitative differences between the EMG of SCM-I and that of SCM-M. The powerspectrum of the EMG from the SCM-I had low frequency band with a peak(12-13 Hz).This peak shows that the activity of the SCM-I during occlusal function can be regulated by stretch reflex of the muscle. On the other hand the EMG from the SCM-M bad higher frequency band. The power value of EMG of SCM-I was more increased than that of SCM-M in proportion to the increase of occlusal force. From these results,it reveals that SCM-I is active during occlusal functions and SCM seems to have a functional differentiation between insertion and middle part during occlusal function.