Hellsing E, L'Estrange P
Am J Orthod Dentofacial Orthop. 1987 Apr;91(4):286-94. doi: 10.1016/0889-5406(87)90168-5.
The changes in upper and lower resting lip pressures following extension and flexion of the head and at changed mode of breathing were studied in a sample of 15 adults with Class I molar relationship. The lip pressure was measured with bonded strain gauge transducers on the upper and lower central incisors. The transducers could be calibrated directly in the subject's mouth. The upper and lower lip pressures during natural head posture had a mean value of 3.91 g/cm2 and 8.58 g/cm,2 respectively. The mean values of the differences between pressures obtained during natural head posture and during 5 degrees, 10 degrees, and 20 degrees of extension showed a continuously, highly significant increase in pressure. During 5 degrees, 10 degrees, and 20 degrees of flexion, the upper lip pressure continuously decreased with highly significant values. Changes in the lower lip pressure during flexion were difficult to measure because of intense muscle activity. A significant decrease was shown for the difference in upper and lower lip pressures between nose breathing and mouth breathing, whereas there was a significant increase in pressure when the subject extended the head 5 degrees during mouth breathing.
在15名I类磨牙关系的成年人样本中，研究了头部伸展和屈曲以及呼吸模式改变后上下静息唇压的变化。使用粘贴在上下中切牙上的应变片式传感器测量唇压。传感器可在受试者口腔内直接校准。自然头部姿势时的上下唇压平均值分别为3.91 g/cm²和8.58 g/cm²。自然头部姿势与头部伸展5度、10度和20度时所获压力差值的平均值显示压力持续、高度显著增加。在屈曲5度、10度和20度时，上唇压持续下降且差异高度显著。由于肌肉活动剧烈，屈曲时下唇压的变化难以测量。鼻呼吸和口呼吸时上下唇压差值显著降低，而在口呼吸时受试者头部伸展5度时压力显著增加。
