Ferrario V F, Sforza C, Colombo A, Ciusa V
Functional Anatomy Research Center (FARC), Laboratorio di Anatomia Funzionale dell'Apparato Stomatognatico (LAFAS), Istituto di Anatomia Umana Normale, Facoltà di Medicina e Chirurgia, Università degli Studi, Milano, Italy.
J Oral Rehabil. 2000 Jan;27(1):33-40. doi: 10.1046/j.1365-2842.2000.00490.x.
The influence of occlusal conditions on stomatognathic function can be assessed by electromyography. Electromyographic activity of left and right temporal and masseter muscles was recorded in 30 young healthy adults with a normal occlusion during: (1) a 3-s maximum voluntary clench on cotton rolls positioned on the posterior teeth (standardization recording); (2) a 3-s maximum voluntary clench in intercuspal position; and (3) a 3-s alternate 'maximum' voluntary contraction and relaxation with a 1 Hz frequency. All potentials were standardized as a percentage of the maximum potential of test 1. Waveforms of paired muscles were compared by computing a percentage overlapping coefficient (ratio between each 50-ms overlapped areas and the total areas, up to 100% for symmetric muscles). Waveforms were also analysed for a laterodeviating effect on the mandible given by unbalanced muscular couples, and a torque coefficient (up to 100% for a significant laterodeviating couple on the mandible) was computed. In all subjects, both tests were performed with symmetric muscular patterns (more than 88%) and with negligible laterodeviating couples on the mandible (lower than 10%). The two coefficients allow an assessment of muscular asymmetry during static and dynamic clenching tests, and, together with the standardization of the potentials, could be a useful tool to detect functionally altered occlusal conditions, i.e. conditions where an apparent good morphological situation is not related to a correct neuromuscular status.
咬合状况对口颌系统功能的影响可通过肌电图进行评估。在30名咬合正常的年轻健康成年人中，记录了左右颞肌和咬肌在以下情况下的肌电活动：（1）在置于后牙上的棉卷上进行3秒最大自主紧咬（标准化记录）；（2）在牙尖交错位进行3秒最大自主紧咬；（3）以1赫兹频率进行3秒交替“最大”自主收缩和放松。所有电位均以测试1最大电位的百分比进行标准化。通过计算百分比重叠系数（每50毫秒重叠区域与总面积的比值，对称肌肉最高可达100%）比较配对肌肉的波形。还分析了肌肉力偶不平衡对下颌骨产生的侧向偏移效应，并计算了扭矩系数（下颌骨明显侧向偏移力偶时最高可达100%）。在所有受试者中，两项测试均呈现对称的肌肉模式（超过88%），且下颌骨的侧向偏移力偶可忽略不计（低于10%）。这两个系数可用于评估静态和动态紧咬测试期间的肌肉不对称性，并且与电位标准化一起，可能是检测功能改变的咬合状况的有用工具，即表面形态良好但与正确神经肌肉状态不相关的状况。
