【摘 要】
：
目的:探讨前牙龈下断根轴向快速牵引后,牙及牙周组织的变化.方法:选择18例前牙断根的患者,其断面位于龈下距龈缘2-5 mm,经过完善根管治疗2周后,利用方丝弓矫治器沿牙长轴方向
【机 构】
：
南京大学医学院口腔医院正畸科,江苏,南京,210008;南京大学医学院口腔医院修复科
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目的:探讨前牙龈下断根轴向快速牵引后,牙及牙周组织的变化.方法:选择18例前牙断根的患者,其断面位于龈下距龈缘2-5 mm,经过完善根管治疗2周后,利用方丝弓矫治器沿牙长轴方向快速牵引断根,使断面升至龈上并固定保持6个月.用长焦距X线平行投照技术,Digora数字成像系统拍摄前牙数字牙片.比较牵引前、保持6个月时,牙龈、牙槽骨高度及牙根长度的变化.结果:牙槽嵴顶和牙龈缘位置随着断根的轴向牵出而(牙合)向移动.近远中牙槽嵴高度的增加约为牵引距离的33%,唇侧牙龈宽度的增加约为牵引距离的36%.牙根长度的变化无统计学意义.结论:在持续、适度牙体轴向牵引力作用下,前牙断根快速移动,牙齿移动的距离大于牙周组织.配合牙冠延长术,可以获得良好的“生物学宽度”及和邻牙相协调的龈缘弧线.
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