不同牵引速率的牙周膜牵引成骨快速牙移动动物模型的建立

Establishment of an animal model on rapid tooth movement through distraction osteogenesis of periodontal ligament with different rates of distraction

目的建立固定牵引频率与不同牵引速率组合的牙周膜牵引成骨快速牙移动的动物实验模型,探讨在牵引频率一定情况下的最适牵引速率。方法将6只犬的下颌左右两侧随机分组,按每天牵引速率分为0.2、0.6、1.0 mm/d三组。拔除下颌第一前磨牙后行凿骨减阻,用自制牵引装置进行牵引,固定牵引频率1次/天,每组分别以不同的牵引速率(0.2、0.6、1.0mm/d)进行牵引,牵引1周后维持3 d。测量每组支抗牙、移动牙移动距离;取材行光镜观察。结果在固定牵引频率为1次/天的条件下,1.0 mm/d组移动牙移动距离最大,0.6 mm/d组次之,0.2 mm/d组最小。组织学结果显示:0.6 mm/d组、0.2mm/d组牙周膜改建活跃,1.0 mm/d组牙周纤维断裂,牙周组织水肿。结论牙周膜牵引成骨可以加快牙齿移动速度,且随着牵引速率的增大,牙齿移动速度也相应加快,但存在一定限度。

Objectives To establish an animal model of rapid tooth movement through distraction osteogenesis of the periodontal ligament with different rates of distraction. Methods The bilateral mandible of 6 male dogs were randomly divided into three groups ： 0. 2 mm/d,0. 6 mm/d and 1.0 nm/d groups. The self-made distractors were activated by 0. 2 mm,0. 6 mm,1.0 mm respectively once a day for one week. The movement of the second canine and anchor unit was measured. The histological change of PDL was observed with HE stain. Results The movement of the second canines with 1.0 mm once a day was the biggest ,the 0. 6 finn-once-a-day group was bigger,and the 0. 2 mm-once-aday group was small. The histological study revealed that the periodontal ligament on tension side remodeled more actively in 0. 2 mm and 0. 6 mm group than in 1.0 mm-once-a-day group. Conclusions Distraction osteogenesis of the periodontal ligament can accelerate the tooth movement ,within the maximum of the PDL. The higher rate of distraction was ,the more rapidly the tooth moved.