A study on establishment of the normal range in clinical examination of the masticatory system

本研究旨在建立颞下颌关节紊乱病(TMD)患者几项临床检查的正常范围。结果如下：1.诱发肌电和肌纤维传导速度(MFCV)研究了肌肉疲劳和咬合垂直尺寸对健康人咬肌和颞肌的肌纤维传导速度(MFCV)的影响。结论：1.随着肌肉疲劳和咬合垂直度的增加，MFCV降低。健康人咀嚼单侧口香糖时咀嚼肌(Mm)、前颞肌(Ta)和二腹肌前腹(Da)的肌电图谱呈现稳定的模式，每咀嚼一次Mm和Ta的肌电峰值约为咀嚼一次的30%，而一次咀嚼约80%的二腹肌的肌电图谱为Da。牙合检查T-SCAN系统获得100名健康人的时间和力分析的正常范围。4.咀嚼肌压力痛阈值(PPT)观察10名正常人和4名TMD患者在夹板治疗过程中PPT的日变化。正常人的PPT无明显差异。但夹板治疗前疼痛侧PPT明显低于对侧。牙尖间隙位置的咬合接触与正常受试者相比，TMD患者的咬合接触失衡。咀嚼肌深层温度正常受试者左右两侧咀嚼肌深层温度无差异。然而，在TMD患者中发现了两侧之间的差异。

The purpose of this study was established the normal range on several clinical examinations in patients with temporomandibular disorders (TMD).The results obtained were as follows :1. Evoked electromyography and muscle fiber conduction velocity (MFCV)The influence of muscle fatigue and occlusal vertical dimension in the muscle fiber conduction velocity (MFCV) was studied in the healty human masseter and temporal muscle. MFCV was decreased with muscle fatigue and increment of the occlusal vertical dimension.2. EMG profiles of the masticatory musclesEMG profiles of the healthy human masseter (Mm), anterior temporal (Ta) and anterior belly of the digastric muscles (Da) during deliberate unilateral gum chewing showed stable patterns Each peak of EMG profiles of Mm and Ta was observed about 30% of one chewing stroke, but Da was observed about 80% of one chewing stroke.3. T-Scan system for occlusal examinationNormal ranges of the time and force analyzes were obtained from 100 healthy human.4.Pressure pain threshhold (PPT) in masticatory musclesThe daily change of PPT was observed in 10 normal subjects and 4 TMD patients with muscle palpation during splint therapy. No difference of PPT between sides was observed in normal subjects. However, PPT of the painful side was significantly lower than that of the other side before the splint therapy.5. Occlusal contacts in the intercuspal positionOcclusal contacts of the TMD patient were unbalanced in comparison with the normal subject.6. Deep temperature of masticatory musclesNo difference was identified in the deep temperature between the right and left masseter muscles in normal subjects. However, the difference between sides was identified in TMD patients.