Yamaguchi K, Morimoto Y, Nanda R S, Ghosh J, Tanne K
Orthodontic Department, School of Dentistry, University of Hiroshima, Japan.
J Oral Rehabil. 2000 Oct;27(10):893-901. doi: 10.1046/j.1365-2842.2000.00596.x.
The study group consisted of 19 subjects with positive overjet and overbite, and 17 subjects with skeletal open bite. Two bipolar surface electrodes were attached to the skin of the upper and lower lips. The mean integrated amplitude of the electromyographic (EMG) activity was obtained at the mandibular rest position with the lips in contact and with the lips apart. Subjects were divided into two groups based on positive or negative values of the difference in integrated EMG activity of the mentalis muscle between the two lip positions. Subjects displaying a negative value were classified as having competent lips and those displaying a positive value were classified as having incompetent lips. The EMG activity of the mentalis muscle was found to be more indicative of lip sealing as compared with the EMG activity of the depressor of the lower and the upper lips. The activities of the mentalis muscle at the mandibular rest position with the lips in contact and with the lips apart appear to offer an objective criterion for the evaluation of lip incompetence. In addition, the vertical dimension of the face, as well as the proclination of the incisors, appear to affect lower lip function.
研究组由19名伴有前牙覆盖和覆牙合阳性的受试者以及17名伴有骨性开牙合的受试者组成。将两个双极表面电极附着于上下唇的皮肤。在下颌休息位，分别在双唇闭合和分开时获取肌电图（EMG）活动的平均积分幅度。根据两个唇位之间颏肌EMG活动积分差异的正值或负值，将受试者分为两组。显示负值的受试者被归类为唇部功能正常，显示正值的受试者被归类为唇部功能不全。与下唇降肌和上唇降肌的EMG活动相比，发现颏肌的EMG活动更能指示唇部闭合情况。在下颌休息位，双唇闭合和分开时颏肌的活动似乎为评估唇部功能不全提供了一个客观标准。此外，面部垂直维度以及切牙的倾斜度似乎会影响下唇功能。
