THE LIP SEALING FUNCTION CORRELATES WITH INCREASED FACIAL HEIGHT

在第一年的研究中，研究了下颌顺时针旋转增加了前面部高度的个体的嘴唇封闭功能。7名切牙关系正常、前牙无严重拥挤的成年志愿者，根据下唇静止、接触和分开时的肌电活动，将受试者分为9个正常唇部和8个不能唇部受试者。咬合夹板固定后切牙间距增加，同时记录下唇肌电活动。两组患者下唇与嘴唇接触部位的肌电活动与面部高度高度呈高度正相关。当面部高度增加到2.0 mm以上时，大多数适口组的唇力都被破坏了。面部高度每增加6.0 mm，所有受试者均表现为唇功能不全。结果表明，下颌顺时针旋转增加的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，第二年对正颌外科手术患者封唇功能与咀嚼功能的变化进行了研究。正颌外科治疗和口腔颌面畸形后，唇功能不全均得到改善。

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.