减阻牵张快速牙移动不同加力方式下骨改建效果观察

Observation on the effect of rapid tooth movement through reducing resistance and distraction method on bone remolding

目的:观察不同牵张力下减阻牵张快速移动牙牙周组织骨改建情况。方法:Beagle犬12只,随机分为加力5天、15天、加力15天固定保持10天、90天组共四组,拔除犬双侧下颌第二前磨牙,选择下颌第一前磨牙为移动牙。将每组6颗牙齿随机分配为减阻-牵张方法组、减阻-常规方法组和常规方法组,每组2颗牙。按相应分组定期取材并制作切片,行HE、MASSON三色染色并观察。结果:减阻牵张方法组第一前磨牙远中移动量远大于减阻常规方法组和常规方法组(P<0.05),且3组支抗牙前移量无显著差异(P>0.05);组织学观察减阻牵张组张力侧成骨最为活跃,且未见牙周膜结构破坏,而压力侧少见透明样变组织。MASSON染色观察减阻牵张组新生骨较其余两组更为明显,长期保持后骨质良好。结论:减阻牵张方法能有效激发正畸移动牙牙周组织骨改建,且无不良反应,适宜强牵张力是实现牙齿快速移动的必要条件。

Objective To observe the bone remodeling of periodontal tissue under different distracting force during rapid tooth movement through reducing resistance and distracting method. Methods Twelve Beagle dogs were randomly divided into four groups as follows：group of distraction 5 days, group of distraction 15days,group of distraction 15days and retaining 10days,and group of distraction 15days and retaining 90days. The second premolar of mandibular on both sides of each dog was extracted,and then the first premolar was distalized. Six teeth in each group were randomly assigned to group using resistance and distracting method,group using resistance and conventional method and group using conventional method,and there were two teeth in each group.Moving teeth models were prepared regularly.HE staining and MASSON＇s 3-color staining were performed. Results The distal movement of the group using resistance and distracting method was significantly greater than that of the group using resistance and conventional method and the group using conventional method（P〈0.05 ）, and there was no significant difference in movement of anchorage among three groups （P〉0.05）. Active osteogenesis was found on the reducing resistance and distracting side. No pathological change was found in the periodontal tissues,and there was little hyaline tissue.MASSON staining showed that the new bone on the reducing resistance and distraction group was more evident than the other two groups,and sclerotin was good after long-term keeping. Conclusion Reducing resistance and distracting method can effectively stimulate bone tissue remolding during orthodontic tooth movement without adverse reaction. Suitable strong tension force is necessary for achieving rapid tooth movement.