正畸牙齿复发后牙周组织改建的实验研究

Study on Periodontal Tissue Remodeling after Rat Orthodontic Tooth Relapse Movement

目的:研究实验性大鼠牙齿移动后复发的基本规律,并探讨BMP-2、RANKL和OPG在复发前后牙周组织中的表达变化。方法:Wistar大白鼠10只,建立正畸牙齿移动的动物模型(双侧),加力21d时去除加力装置,在大鼠去除加力装置时及其后每周(连续4周),取模型,测量复发距离。4周后,取组织块,行HE染色及免疫组化染色,计算机图像分析的方法定量分析。结果:第一磨牙复发移动的程度以第1周最多,2、3周程度缓慢,第4周几乎完全复发。复发4周时,BMP-2、OPG、RANKL的表达,压力区和张力区均明显低于加力21d时(P<0.01和P<0.05);OPG/RANKL比值仍小于1。结论:加力装置去除后的第1周是牙齿复发移动的最活跃期。BMP-2、OPG、RANKL仍然参与复发能量作用下的骨改建,OPG/RANKL途径可能在复发过程中起着重要作用。

Objective：To investigate the basic relapse rule after the experimental rat tooth movement,and study the changes of BMP-2,RANKL and OPG expression in periodontal tissues.Methods：Firstly,the orthodontic models were established in 10Wistar rats（bilaterally）.After 21days,appliances were removed.We measured the interdental distance between the first and second maxillary molars separately,when appliances were removed and 1 week,2,3,4weeks after removal.After the rats were sacrificed,sections of first maxillary molar and periodontal tissue were stained.Then BMP-2,OPG and RANKL expression was examined by using S-P immunohistochemical staining.The results were analyzed by the computer image analyzing system and treated by statistics test.Results：In the 1st week,the extent of first molar distal movement was the fastest.After that it slowed,and nearly complete relapsed after 4weeks.After 4weeks,the quantities of BMP-2,RANKL and OPG expression were quite less than those at the orthodontic 21days（P0.01and P0.05）.OPG and RANKL ratio was still less than 1.Conclusion：The first week after orthodontic appliance removed was the most active phrase during tooth relapse.BMP-2,OPG and RANKL took part in bone remodeling controlled by relapse energy.OPG and RANKL might play an important role in relapse movement.