Abstract: Objective    To evaluate the effect of the height of crown and the depth of undercut on the retention of flexible denture in maxillary incisor region. Methods    Totally 212 patients who needed the flexible denture in the maxillary incisor region were involved. All patients were assessed by the same examiner at the moment of denture insertion，3 and 6 months later，respectively. The following items were verified in each assessment：retention，crown height and undercut depth of abutment teeth. Patients were divided into two groups by retention：good retention group and bad retention group. Results         There was significant difference of crown height and undercut depth of abutment teeth between the two groups at each assessment（P < 0.05）. Conclusion    Retention of flexible dentures in the maxillary incisor region was affected by the crown height and undercut depth of abutment teeth. It’s necessary to make a comprehensive evaluation of the height of crown and the depth of undercut of bilateral abutments before restoration.

Key words: the height of crown, the depth of undercut, flexible denture, retention

摘要： 探讨上颌切牙区基牙牙冠高度和唇侧倒凹深度对弹性义齿固位的影响。方法    选择2009年1月至2011年5月来佛山禅城区口腔医院修复科就诊的212例上颌单颗中切牙缺失患者进行弹性义齿修复。在弹性义齿戴用的当天及3、6个月后测量各基牙的牙冠高度和唇侧倒凹深度，并检查义齿固位情况。结果    弹性义齿在固位良好和固位不良两种情况下的基牙牙冠高度及唇侧倒凹深度的差异均有统计学意义（P < 0.05）。结论    弹性义齿修复前应对两侧基牙的牙冠高度和唇侧倒凹深度进行综合评价。

关键词: 牙冠高度, 倒凹深度, 弹性义齿, 固位