正畸微种植体植入早期骨改建中破骨细胞的观察

目的：观察微种植体植入早期破骨细胞的产生，探讨破骨细胞变化与骨改建的关系。方法：雄性新西兰兔20只随机分为4组，在胫骨近心端近骺板处植入微种植体1颗，分别于植入3、7、14、28 d后处死(每组5只)。HE染色观察微种植体周围骨组织的形态学变化，抗酒石酸酸性磷酸酶(TRAP)染色标记破骨细胞并作半定量分析。采用SPSS19.0软件包对数据进行统计学分析。结果：微种植体植入3 d后，种植体骨接触区可见大量红细胞、炎症细胞、间叶细胞和骨碎屑，无明显破骨细胞。7 d后，编织骨新生，呈颗粒状，破骨细胞位于骨陷窝中。14 d时，大量新生的编织骨呈网格状，破骨细胞增多，骨改建明显。28 d时，编织骨成片状，与层状骨相连，破骨细胞数目减少。TRAP染色半定量分析显示，破骨细胞数目在14 d时达到高峰，各时间点间均有显著差异(P<0.01)。结论：在正畸微种植体植入早期破骨细胞产生，在新骨生成的活跃阶段破骨细胞数目增多，提示破骨细胞参与微种植体周的骨改建过程。

Osteoclasts and early bone remodeling after orthodontic micro-implant placement

PURPOSE: To observe the incidence of osteoclasts during early bone remodeling after orthodontic micro-implant placement. METHODS：Twenty New Zealand rabbits were randomly allotted into 4 groups. One micro-implant was implanted proximal to the epiphyseal plate of the tibia. Animals were sacrificed on day 3, 7, 14 and 28 (n=5). The sequence of histological changes around the micro-implants were evaluated by hematoxylin and eosin (HE) staining. Osteoclasts were identified by TRAP staining. The differences of the number of the osteoclasts among each time point were analyzed by one way ANOVA with SPSS 19.0 software package. RESULTS: After 3 days of implantation, a large number of erythrocytes, inflammatory cells, mesenchymal cells and bone debris were seen at the implant bone interfaces. Few osteoclasts were observed. On day 7, granular woven bone was formed and some osteoclasts were found in the Howship’s lacunae. New bone formation and mineralization were apparent on day 14. Meanwhile, large amounts of osteoclasts were found in the latticed woven bone. On day 28，woven trabeculae with lamellate structures connected to lamellar bone and fewer osteoclasts were identified. Semi-quantitative analysis showed that the number of the osteoclasts was at peak on day 14. There were significant differences among each time point (P<0.01). CONCLUSIONS: Osteoclast activity is closely related to bone formation and remodeling after micro-implant insertion.