Studies on effect of physical therapies and occlusal splints on temporomandibular disorders using blood flow analyses of masseter muscles

本研究旨在从血流状态的角度探讨物理治疗和咬合板对颞下颌关节紊乱病（TMD）患者肌肉疲劳是否有效。<Methods>采用三波长近红外光谱仪测量咬肌血流量，血流量参数为总血红蛋白量（THb）、氧合血红蛋白量（OXHb）、脱氧血红蛋白量（deOXHb）和血氧饱和度（StO2）。物理治疗的受试者是没有咀嚼系统肌肉疼痛史的健康受试者，而夹板治疗的受试者是使用稳定夹板的具有咀嚼肌症状的TMD患者。物理治疗采用20分钟热敷和30分钟肌电监测。<Results and discussion>1）热敷后THb、OXHb和StO2均显著高于静息时。deOXHb在热包应用前后的值之间没有显着差异。结果表明，热敷可以影响人体咬肌的血流状态，热敷治疗的效果是增加局部血容量，为有氧能量代谢创造有利条件。2）肌监测仪应用前后的各项血流参数值无显著差异。戴夹板组的StO 2均值显著大于不戴夹板组，戴夹板组的THb在紧咬牙合时和紧咬牙合后显著大于不戴夹板组。结果提示，短期内佩戴稳定夹板可影响咬肌血流。然而，长期使用夹板的效果仍然未知。对戴夹板后咀嚼肌血流状态的纵向变化还需进一步研究。

The purpose of this study was to clarify whether physical therapies and occlusal splints are effective against muscle fatigue of temporomandibular disorders (TMD) patients from the point of view of blood flow state.<Methods>Blood flow of masseter muscles were measured using 3-wave-length near-infrared spectroscopy, and the blood flow parameters were total hemoglobin volume (THb), oxygenated hemoglobin volume (OXHb), deoxygenated hemoglobin volume (deOXHb), and oxygen saturation level (StO2). Subjects for the physical therapies were healthy subjects with no history of muscle pain in the masticatory system, while subjects for the splint therapy were TMD patients with masticatory muscle symptoms who used stabilization splints. The physical therapies applied were 20-minite hot pack and 30-minite myo-monitor.<Results and discussion>1)THb,OXHb and StO2 after the hot pack application were significantly larger than those during resting. The deOXHb showed no significant difference between the values before and after the hot pack application. The results suggest that the blood flow state of human masseter muscles can be influenced by a hot pack, and that the effect of hot pack therapy is to increase regional blood volume and that it creates the advantageous conditions for aerobic energy metabolism.2)There was no no significant difference between the values before and after myo-monitor application in all parameters of blood flow.3)During resting, mean values of StO2 with the splint were significantly larger than those without the splint During and after clenching, THb with the splint was significantly larger than that without the splint. The results suggest that the blood flow of masseter muscles can be influenced by wearing stabilization splints in the short term. However, effect of longtime using of splints is still unknown. Further studies on longitudinal change in blood flow stale of masticatory muscles in wearing splints are needed.