Methods:A total of 962 patients with malocclusion were selected from owtpatients, among this patients,27 cases with the congenitel hypodontia of mandibular incisor.

• 方法:从962名门诊正畸病人中选取下颌恒切牙缺失的病例27名,并测量下前牙牙冠的近远中径。