BMP-2在减阻牵张快速牙移动不同加力方式下的表达及对牙移动的影响

目的：观察不同牵张力下减阻牵张快速牙移动中 BMP-2的表达。方法：Beagle 犬12只，随机均分为加力5、15 d、加力15 d 保持固定10、90 d 4组。以44为移动牙，每个组3只犬的6颗移动牙随机采用减阻-牵张方法、减阻-常规方法和常规方法各2颗。各组犬按预定时间处死并获取移动牙牙周组织块，免疫组化法染色并观察 BMP-2表达。结果：各加力方式下 BMP-2阳性表达分布区域相似，均在加力结束时达峰值，其中减阻牵张组峰值最大（P ＜0．05）；牙移动距离最大（P ＜0．01）。加力各时间点，减阻常规组 BMP-2阳性表达均强于常规方法组但不及减阻牵张组显著；保持固定90 d，3组无差异（P ＞0．05）。结论：减阻措施配合持续强牵张力可显著提高移动牙牵张新骨区 BMP-2阳性表达，加速牙周组织新骨形成。

The effects of BMP-2 expression in the related periodontal tissue on bone remolding of rapid tooth movement by resistance reduction and distration method

Objective:To investigate the effects of bone morphogenetic protein 2(BMP-2)expression in the related periodontal tissue on bone remodeling under different distracting force during rapid tooth movement by resistance reduction and distraction. Methods:1 2 Beagle dogs were randomly divided into 4 groups as follows:5 d distraction,1 5 d distraction,1 5 d distraction and 1 0 d retaining and 1 5 d distraction and 90 d retaining.4 4 were distalized.6 teeth in each group were randomly assigned to re-sistance and distracting method,resistance and conventional method and conventional method,and there were 2 teeth in each group.Moving teeth models were prepared regularly.BMP-2 expression was examined by immunohistochemistry.Results:The BMP-2 positive expression of the 3 groups of different distraction schedule showed similar distribution area,and it reached peak at the end of 1 5-day distration,but the group of resistance and distracting method showed the maximum peak(P <0.05)and maximum tooth movement(P <0.01 ).In different stages of distraction,the positive expression in the group of resistance reduc-tion and conventional method was higher than in the group of conventional method but lower than the group of resistance reduction and extraction method(P <0.05).There was no significant difference in BMP-2 positive expression among 3 groups when retai-ning was 90 d(P >0.05).Conclusion:Resistance reduction with sustained strong distracting force can significantly increased the positive expression of BMP-2 and effectively accelerate new bone formation in periodontal tissue.