牙周膜牵张成骨正畸牙快速移动规律与牙根组织变化的光镜观察

目的　观察正畸牙快速移动时移动牙支抗牙的移动规律及移动牙根的组织学变化。方法　杂种犬 8只 ,随机分为 7、14、2 1、44d四组。拔除下颌两侧第二前磨牙 ,实验侧实施减阻 牵张措施 ,加力 14d ,停止加力固定 30d ;对照侧仅行拔牙术。于 1、7、14、2 1、44d时测量移动牙支抗牙移动距离 ,观察移动规律 ;7、14、2 1、44d时取材 ,常规石蜡包埋、切片 ,HE染色光镜观察移动牙根的组织学变化。结果　加力 14d ,移动牙移动呈直线上升趋势 ,支抗牙移动呈前 7d的直线上升和后 7d的平台趋势 ;加力期间 ,移动牙牙根牙骨质无明显吸收 ,根部牙槽骨稍有吸收 ,固定 30d后 ,牙根组织结构基本恢复正常。结论　牙周膜牵张成骨快速牙移动过程中 ,移动牙移动规律与常规方法不同 ,支抗牙移动规律与之相同 ;移动牙的快速移动不会造成牙根的广泛吸收。

The orthodontic rapid tooth movement through distracting osteogenesis of the periodontal ligament and the observation of tooth root changes under light microscope

Objective To observe the moved anchorage tooth movement and histological changes of moved tooth apical on orthodontic rapid tooth movement through distraction osteogenesis of periodental ligament. Methods Eight native-healthy-hybrid dogs were used. The animals were randomly divided into four groups according to experimental times: 7, 14, 21 and 44 days groups. Resistance-distracted step was only on experiment side. Groups were activated for 14 days and device was fixed for 30 days by ligature wire. During the experiment, the movement distances of the moved and anchorage tooth were measured; mandible was cut on 7, 14, 21 and 44 days, respectively, and histological changes of moved tooth apical were observed by light microscope.Results The distracted tooth moved more slowly in the first week than that of the second. The anchor tooth moved faster than that of the second week. The movement and anchor tooth in the first week was significantly different from the second. In the activated period, moved tooth apical had no obvious absorption, alveolar bone had a little absorption. After fixed for 30 days, the periodontal tissue structure of moved tooth apical recovered.Conclusion The movement tooth accompany activated to accelerate, but anchor tooth follow activated to lower speed. The distracted tooth movement regularity is different from traditional methods, but anchor movement is similar. No abnormality of moved tooth apical had been seen when it moves rapidly