Kossioni A E, Karkazis H C
Department of Removable Prosthodontics, Dental School, University of Athens, Greece.
J Prosthet Dent. 1993 Jun;69(6):605-10. doi: 10.1016/0022-3913(93)90290-5.
Although several studies have been conducted regarding the jaw-jerk reflex and its various modifying parameters, the effect of intercuspal clenching still remains poorly understood. Evidence of both excitatory and inhibitory influences of periodontal receptors on jaw muscle activity has been reported. It is also suggested that a level of background activity in the stimulated muscle facilitates the reflex response. It was therefore the purpose of this study to investigate the effect of simultaneously activated periodontal receptors on the various parameters of the masseteric jaw-jerk reflex during moderate masseter muscle activation. Electromyographic recordings were obtained from the masseter muscle of the preferred chewing side at rest and at intercuspal clenching in 10 men, by use of a computerized recording and analysis system. In the clenching trials the level of muscular activity was set at 40% of the maximum value obtained through visual feedback. The results showed that at 40% clenching the occurrence of the reflex was reduced as compared with that obtained at rest. Moreover, when present during clenching, its latency and duration were shorter, whereas its amplitude was higher. It was suggested that the simultaneous activation of periodontal receptors may occasionally inhibit the masseteric monosynaptic excitation.
尽管已经开展了多项关于下颌反射及其各种调节参数的研究，但牙尖交错位紧咬的影响仍知之甚少。有报道称，牙周感受器对颌面部肌肉活动既有兴奋性影响，也有抑制性影响。也有研究表明，受刺激肌肉的一定水平的背景活动有助于反射反应。因此，本研究的目的是探讨在咬肌适度激活期间，同时激活的牙周感受器对咬肌下颌反射各参数的影响。通过使用计算机记录和分析系统，在10名男性休息时和牙尖交错位紧咬时，从其优势咀嚼侧的咬肌获取肌电图记录。在紧咬试验中，肌肉活动水平设定为通过视觉反馈获得的最大值的40%。结果显示，与休息时相比，在40%紧咬时反射的发生率降低。此外，在紧咬时出现反射时，其潜伏期和持续时间较短，而振幅较高。研究表明，牙周感受器的同时激活可能偶尔会抑制咬肌的单突触兴奋。
