牙周膜牵张成骨快速移动牙齿的组织学观察

目的 观察牙周膜牵张成骨快速移动牙齿的牙周组织学变化。方法 将6只杂种犬随机分为2w，4w，6w三组（每组二只）。拔除两侧第二前磨牙，并随机选择其中一侧为实验侧，另一侧为常规橡皮圈加力方法对照侧。动物基牙预备：拔牙凿骨减阻；粘结自制牵张装置；实验组以2次／天的频率、0．15fnm／次的速率加力，2w后固定保持。对照组以传统橡皮链对移动牙施加100g力值，加力2w后，固定保持。测量支抗牙、移动牙移动距离：分别于第2、4、6w各宰杀二只动物，观察实验侧与对照侧的组织学变化。结果 ①实验侧移动牙加力2w平均向远中移动3．78mm，对照侧移动牙平均向远中移动1．09mm（P〈0．01），实验侧支抗牙平均向近中移动0．42mm，对照侧支抗牙平均向近中移动0．40mm（P〉0．01）。②组织学观察得出：2w组，实验侧与对照侧相比，实验侧牙周膜显著增宽，牙周膜内成纤维细胞增殖，新生板层状牙槽骨明显增多，与牵张作用力方向一致；4w组，旧间隔骨已改建完成，牙周膜宽度基本恢复正常；6如组两种方法作用下移动牙牙周组织己无明显差异。结论 牙周膜牵张成骨可以快速移动牙齿；牙周组织不会出现不可复性损害。

Histo logical examination of rapid orthodontic tooth movement through distraction of the periodontal ligament

Objective To observe the histological changes of rapid orthodontic tooth movement through distraction of the periodental ligament.Methods Six dogs were divided into 3 groups randomly as follows:six-week group,four-week group and two-week group(2 in each group).The second premolars were extracted in both sides.One side served as experimental side and the other side as control.The experimental side was activated 0.3mm/day,twice a day for 2 weeks and followed by retention.A hundred grams of force were applied to the control side for 2 weeks and followed by retention.The anchorage loss,regular X-ray and pulp vitality were evaluated.Results On the experimental side,two-week activation created 3.78mm distal movement compared with 1.09 mm distal movement on the control side(P<0.001).The anchorage loss on the experimental side was 0.42mm on averagely compared with 0.40mm on the control side(P>0.05).Root resorption and alveolar bone loss were not found on both sides.Conclusion The rapid orthodontic tooth movement was feasible.This method could accelerate orthodontic tooth movement.