正畸力作用下垂直型骨吸收牙周炎大鼠牙槽骨改建的实验研究

Periodontitis with vertical bone resorption under orthodontic force bone remodeling in rats

目的:观察正畸力作用下牙周炎大鼠垂直吸收的牙槽骨改建,为牙周炎的临床正畸治疗提供依据。方法:将75只10周龄雄性SD大鼠,随机分为3组,正常加力对照组(A)、牙周炎垂直骨吸收对照组(B)、牙周炎垂直骨吸收加力实验组(C),每组各25只,各组动物分别于加力后8 h,1、7、14、21 d处死,取动物模型上颌左侧第一磨牙近中牙槽骨进行组织学及免疫学检测,所得结果进行对比研究。结果:正畸加力至7 d时,实验组大鼠垂直吸收侧牙周膜纤维排列紊乱,出现无细胞结构,结缔组织可见少量炎症细胞,牙槽骨表面还可见功能活跃的多核破骨细胞,与对照组相比较无显著差异,实验组大鼠牙周组织中IGF-1表达达到峰值,光密度值最高,与对照组比较有显著差异(P<0.05);加力至14 d时,实验组大鼠垂直吸收侧牙周组织中RUNX2的表达达到峰值,其光密度值最高,明显高于正常加力对照组,其变化有统计学意义(P<0.05)。结论:控制牙周炎症和消除咬合创伤后,正畸力能刺激牙周炎大鼠垂直缺损牙槽骨区域的RUNX2和IGF-1的表达增强,合成骨胶原和骨基质的能力增强,从而促进牙槽骨的改建。

Objective ： To observe the remodeling of alveolar bone in rats with the vertical absorption alter loading orthodontic force, and to provide evidence for clinical orthodontic treatment. Methods： 75 SD rats （ 10-week-old , male）were randomly divided into three groups（25 in each group） ：loading force control group （A）,control group of periodontitis with vertical bone absorption （B）,loading force group to periodontitis with vertical bone absorption （C）. With loading force on for 8 hours, 1d, 7d, 14d and 21d, the alveolar bone of the first molar of left maxillary were taken to do the histological and immunological detection. Results： On the 7^th day,the derange of the periodontal ligament fibers, non-cellular structure,a small amount of inflammatory cells, and active multinucleated osteo-clasts were observed. There was no significant difference between the control groups and experimental group in histological detect. But the IGF-1 expression peak was detected on the 7^th day in experimental group（C）,much higher than that in the control groups（ P 〈 0.05）. On the 14^th day,the RUNX2 expression peak was detected in the experimental group（ C）,and much higher than that in the control groups（P〈0.05）. Conclusions： After controlling periodontal disease and eliminating occlusal trauma,loading orthodontic force which could enhancethe expression of RUNX2 and IGF-1 in alveolar bone defect region,and also the capacity of remodeling of bone matrix and collagen, contribute to tooth alveolar bone remodeling.