上颌前牙埋伏阻生与矢状骨面型的关系

The relationship between maxillary anterior impacted teeth and sagittal facial type

目的:研究上颌前牙埋伏阻生与矢状骨面型之间的关系,探讨上颌埋伏阻生牙患者的牙颌面形态特征。方法 :经全口曲面体层片筛选出上颌1颗中切牙埋伏、1颗尖牙埋伏及2颗尖牙埋伏阻生患者各30例,进行头颅定位侧位片的定点、测量、分析。将所测项目值与正常值比较,并根据ANB角大小分为Ⅰ类骨面型、Ⅱ类骨面型、Ⅲ类骨面型,统计构成比。采用SPSS17.0软件包对数据进行t检验和χ2检验。结果:3组测量项目中,以2颗尖牙埋伏组的变化项目最多,变化幅度最大。其中,SNA、A’-Ptm’、L1-NB角在3组中均小于正常值;而在1颗或2颗尖牙阻生组,颌凸角、L1-MP角、ANB角、Wits值小于正常值,上、下牙槽座角、U1-NA角、U1-NA距大于正常值;而S’-Ptm’、L1-NB距小于正常值,上、下中切牙角大于正常值仅发生在2颗尖牙埋伏阻生组。3组的ANB角、Wits值以2颗尖牙埋伏组最小,上、下牙槽座角在2颗尖牙埋伏组中最大。90例患者的矢状骨面型总体构成比以I类骨面型为主,占50%;但在2颗尖牙埋伏组中,Ⅲ类骨面型明显增多,达到40%。结论:上颌前牙埋伏阻生使上颌基骨发育不足,长度变短;尖牙埋伏比中切牙埋伏对上、下颌骨矢状向位置关系影响大;2颗尖牙埋伏对矢状骨面型影响更大,Ⅲ类骨面型趋势更明显。

PURPOSE： To investigate the relationship between impaction of maxillary anterior teeth and sagittal facial type and evaluate the dentofacial morphological characteristics of patients with maxillary teeth impaction. METHODS： Totally 90 patients with maxillary anterior teeth impaction were divided into 3 groups （one incisor impaction, one canine impaction and two canines impaction）, and their cephalometric films were measured and analyzed. They were further divided into Class I , II and III facial types according to ANB and the constituent ratio were calculated. SPSS 17.0 software package was applied for Student＇s t test and ehi-square test. RESULTS： SNA, A＇-Ptm＇ and L1-NB were smaller than the normal value in the 3 groups. Convexity, L1-MP, ANB and Wits appraisal were smaller while AB plane angle, U1-NA and U1-NA were greater than the normal value in groups of one and two canines impaction; S＇-Ptm＇, L1- NB were smaller while U1-L1 was greater than normal value in group of two canines impaetion; Among the 3 groups, ANB and Wits appraisal were the smallest while AB plane angle was the greatest in group of two canines impaction. The sagittal facial type of 90 patients was mainly Class I （50%）, but Class III in group of two canines impaction increased to 40%. CONCLUSIONS： Impacted maxillary anterior teeth might result in short maxillary basal bone. One canine impaction has the greatest influence than one incisor impaction on sagittal position of jaws. Two canines impaetion has the greatest impact on sagittal facial type and tends to be Class III facial type.