THE LIP SEALING FUNCTION CORRELATES WITH INCREASED FACIAL HEIGHT

在第一年的研究中，研究了通过下颌顺时针旋转增加前面部高度的个体的封唇功能。选取7名切牙关系正常、无严重前挤现象的17岁成年志愿者，根据静息时下唇接触和分开时的肌电图活动，将其分为9名称职和8名不称职的唇部受试者。用咬合夹板增加切间距离，同时记录下唇肌电图活动。两组下唇接触时的肌电图活动与面部高度高度相关。当面部高度增加到2.0 mm以上时，大部分胜任唇组的嘴唇能力都出现了断裂。当面部高度增加6.0 mm时，所有被试均表现为嘴唇功能不全。结果表明，下颌顺时针旋转增加面部高度对正常唇部受试者的封唇功能有显著影响。在此基础上，在第二年，研究了正颌手术患者咀嚼功能相关的封唇功能的变化。经正颌手术治疗后，唇部功能不全及牙面畸形均得到改善。

In study of the first year, the lip sealing function was investigated in individuals with increased anterior facial height by mandibular clockwise rotation. Seven-teen adult volunteers with normal incisor relationship and without severe anterior crowding were divided into 9 competent and 8 incompetent lip subjects based on EMG activities of lower lip at rest with the lips in contact and apart. The inter-incisal distance was increased with a occlusal splint, while EMG activities of the lower lip were recorded. EMG activity of the lower lip with the lips in contact highly correlated with the facial height in two groups. The lip competence in the most of the competent lip group was broken when increasing facial height over 2.0 mm. With increase of the facial height by 6.0 mm, all subjects showed lip incompetence. The results suggest that increased facial height by clockwise rotation of the mandible has significant effect on the lip sealing function in the competent lip subjects.Based on the results, in the second year, the changes of the lip sealing function associated with chewing function were studied in patients underwent orthognathic surgical treatment. The lip incompetence was improved after orthognathic surgical treatment as well as dentofacial deformities.