牙周膜牵张成骨快速牙移动动物模型的建立

目的　建立动物模型 ,探讨加快正畸牙移动速度的新方法。方法　杂种犬 8只 ,拔除下颌两侧第二前磨牙 ,实施减阻 牵张措施后 ,在移动牙、支抗牙上安装自制牵张装置 ,以 2次·d-1的频率、0 .5mm·d-1的速率加力 14d使移动牙向拔牙窝移动。停止加力、固定 31d ;对照侧仅行拔牙术。每周定期测量移动牙、支抗牙移动距离。实验开始、结束时 ,拍摄对照侧、实验侧X线片 ,取材行光镜观察。结果　①加力 14d ,移动牙平均向远中移动 4 .5 4mm ,支抗牙向近中平均移动 0 .4 5mm ,两者有显著性差异 (P <0 .0 1) ;②X线片显示未见牙根明显吸收 ,光镜下未见牙髓和压力侧组织坏死及牵张侧龈下骨质缺损等副作用。结论　实施减阻 牵张措施可大幅度提高牙齿移动速度 ,支抗牙支抗丧失少 ,无明显副作用。

Establishment of animal experimental model on orthodontic rapid tooth movement through distraction osteogenesis of periodontal ligament

Objective To explore method of re ducing resistance and distracting by setting up experimental model of rapid toot h movement. Methods Eight native healthy hybrid dogs were selected in t he study. The thickness of interseptal bone between the extracted tooth and move d tooth was groud by half to reduce the resistance when the first premolar was t o be pulled out, then the self-made distraction device was bound on the moved t ooth and anchor tooth immediately. It was activated 0.25 mm every 12 hours and twice a day. The groups were activated for 14 days, and the device was fixed by the ligature wire. During the experiment, the distance of the tooth movement was measured every week. Results ① The distracted tooth moved by the mean distance of 4.54 mm during 14 days, and the anchor tooth moved by 0.45 mm on average ( P<0.01). ②There was no loosening in tooth apical, and pulp and pressure-si de tissue necrosis and distraction-side bone defect were not found during the e xperiment. Conclusion The tooth movement can be increased through the reduction of bone resistance with grinding half interseptal bone and grooving so cket in extracted socket base.