加速成骨正畸(AOO)过程中破骨细胞的形成情况

Differentiation of Osteoclasts in the Process of Accelerated Osteogenic Orthodontic

目的：加速成骨正畸能增加骨改建及牙移动的速率,但仅仅只有部分关于加速成骨正畸的机制被获知。本实验进一步探讨骨改建过程中破骨细胞的分化形成情况,以更好地了解加速成骨正畸的机制。方法：40只新西兰大白兔随机分成5组,每组8只。下颌左侧作为加速成骨正畸实验侧,右边作为常规正畸对照侧。左右两侧均用4盎司的力值。在1、3、5、7、14d将实验动物处死。每个时间点上的3只动物用作形态学观察,另外5只用作分子生物研究。结果：形态学观察显示,加速成骨实验组压力侧破骨细胞计数及骨改建活跃程度均较对照组高,而且有2次连续明显的增长。在加速成骨正畸（AOO）中,可观察到破骨细胞不同的分化因子在同一时期表达趋势不同：在第5天,实验组,CTSK,TRAP的mRNA显著上调并达到高峰;CTR的mRNA表达量在1~7d较平缓;JDP2、NFATC1的mRNA的表达量趋势相一致,在第7天达到高峰;Fra2的mRNA在第5天开始增加,之后持续升高。结论：提示在AOO过程中,破骨细胞可能有2次明显的连续分化,继而能持续的加速牙齿移动。

Objective.. To optimize alveolar decortications--facilitated orthodontic and to study the mechanism un- derlying . Methods： In this study, 40 rabbits were randomly divided into 5 groups of 8 rabbits each. The left side of the mandible served as the experimental side, which was treated by alveolar deeortication--facilitated orthodontic and the right side served as the control side. 4 oz force was applied to the mandibular first molar. The measure- ments on 8 rabbits were done on days 1, 3, 5, 7 and 14. Three of the animals at each time point were used for his- tological Observation. The other five animals were used for molecular studies. Results： Histological observation demonstrated a higher count of osteoclasts and bone remodeling activity and two consecutive obvious growth in the experimental group. In addition, different cytokines of the osteoclast had different expression trend at the same time： the mRNA expression of CTSK and TRAP was markedly upregulated and reached its highest on the 5th day; the CTR mRNA was expressed evenly on day 1 through day 7, and the trend of JDP2 and NFATC1 expression was consistent, reaching its highest on the 7th day; the Fra2 expression increased on the 5th day and was significantly higher on days 5, 7, and 14 days. Conclusion： It suggests that among this procedure osteoclast may differentiate twice to accelerate roots movement.