下颌切牙先天缺失女性患儿的牙颌面形态分析

目的研究下颌切牙先天缺失女性患儿的牙颌面形态特征,探讨下颌切牙先天缺失对其颌面部生长发育的影响。方法选取47例12～15岁的下颌切牙先天缺失女性患儿(实验组)进行X线头影测量分析,与21例不缺牙的个别正常同龄女性儿童(对照组)比较。结果缺失一颗下前牙与两颗下前牙者,X线头影测量无显著差异;将两者合并,与对照组比较,缺牙组UI-NA(mm)、IMPA显著减小,ANB、NA-PA、MP-SN、N-ME、ANS-ME、下颌长显著增加。结论下颌切牙先天缺失可以引起女性患儿Ⅱ类错,上前牙舌侧移位、下前牙舌倾,下颌骨的顺时针旋转,全面高、下面高以及下颌骨长度增加。

Dento-facial morphology study of female children with congenital absence of mandibular incisor

Objective To examine the dento-facial morphology of the female children with congenital absence of mandibular incisor.Methods Cephalometric analyses for 47 girls aged 12～15 with congenital absence of mandibular incisor(the test group)were conducted and compared with the cephalometric standards from 21 age-matched female subjects without hypodontia or malocclusion(the control group).Results There was no significant difference in all cephalometric measurements between the female children who lacked one mandibular incisor and those who lacked two.The hypodontia group showed smaller UI-NA(mm),IMPA and increased ANB,NA-PA,MP-SN,N-ME,ANS-ME and mandibular length,compared with the control group.Conclusion Female children with congenital absence of mandibular incisor might have a skeletal classⅡappearance,greater retroclination of the anterior teeth,a more clockwise-rotated mandibular plane,an increased vertical facial dimensions,lower vertical facial dimensions and mandibular length.