正畸治疗中磨牙的拔除和保留(四十二)——下颌第三磨牙获得性间隙对其生长发育的意义  

The effect of acquired space on the root formation of mandibular third molar

作　　者：邓凯雄[1] 刘进[1] 郭鑫[1] 

机构地区：[1]深圳市儿童医院口腔正畸科,广东深圳518026

出　　处：《临床口腔医学杂志》2009年第5期317-319,共3页Journal of Clinical Stomatology

摘　　要：目的:揭示第三磨牙在牙根发育完成前受正畸治疗干预而获得充足的发育空间,其牙根生长发育的特征及意义。方法:随访21例第三磨牙牙根未发育完成前接受拔除第一或第二磨牙进行正畸治疗的青少年,调查其下颌第三磨牙牙根发育完成后的牙根融合率、根分叉程度及根长,并与下颌第二磨牙对应数值进行比较。结果:下颌第三磨牙在牙根生长完成发育前获得充足的生长空间后其牙根的分叉率、分叉程度均高于下颌第二磨牙,其牙根长度与下颌第二磨牙相仿。结论:下颌第三磨牙牙根融合可能是因空间不足受挤压所致,利用第三磨牙代替第二磨牙的正畸治疗应尽量选择在第三磨牙牙根未发育完成前进行。Objective：To demonstrate the characteristic of the root formation of the mandibular third molars with acquired space by orthodontic treatment. Method：21 orthodontic cases by extraction of first or second molars prior to the completeness of the root formation of mandibular third molars were followed up. After the completeness of root formation,the ratio and degree of separate root of mandibular third molars were compared with the second molars. Result：With abundant space, the ratio and degree of separate root of mandibular third molars were higher than the mandibular second molars,while the length of roots were similar. Conclusion：The fused root of mandibular third molar might be caused by being impacted in the insufficient space, and the relative orthodontic treatment should be carried out prior to the completeness of root formation of third molar.

关 键 词：口腔正畸 拔除磨牙 第三磨牙 形态学 

分 类 号：R783.5[医药卫生—口腔医学]