Expression Of Bone Morphogenetic Protein -4 During Orthodontic Tooth Movement

Objective:Orthodontic treatment is some kind of process to use forces to move the teeth and approach the orthodontic treatment goal,when peridental membrane is forced,there will be various reaction and changes.During the orthodontic bone remodeling,there are many cytokine participated. One of the important cytokine is Bone Morphogenetic Protein (BMP). Our experiment is through the animal experiments to test the expression and distribution of bone morphogenetic protein-4 (BMP-4) in the peridental membrane of rabbit under orthodontic treatment, to analyze the role of BMP-4 in orthodontic tooth movement. As a result we could get the more message about the regularity of orthodontic teeth movement. In order to provide scientific support for clinical orthodontists.Methods:With 60 rabbit provided by Dalian Medical University, weight around 2.0-2.5 kg, divide the in to 12 groups with 5 rabbits. One group is comparison group other is experimental group. Orthodontic appliances was placed between the maxillary right first premolar and maxillary central incisors of adolescent rabbits in order to make the first premolar to move forward. Immunohistochemistry and image analyses were performed at 1,3,5,7,9,11,13,15,17,19,21 days after orthodontic force applied.Results:Through the immunohistochemical staining method, We found:â‘ in the comparison group, very weak positive staining was mainly distributed in the periodontal ligament cells and the surrounding cells, the package of osteoblasts have positive staining, the positive staining in osteoclast is relatively weaker.â‘¡in experimental group, positive staining in the tension side in stronger than the pressure side, especially the osteoblasts near alveolar has strongest staining, the osteoclasts of pressure side also have strong staining, but weaker compared to osteoblasts.â‘¢in the tension side,the expression of the BMP-4 reached a peak at the 5 day, then the expression level decreased. In the pressure side, the group of 7 days reached the peak and then decreased, to the 21 day group the staining reach the level of the comparison group.Conclusion:This experiment revealed the expression and distribution of BMP-4during orthodontic tooth movement. It testified that BMP-4 is concerned with the periodontium remodeling in orthodontic process and regulates the periodontium remodeling.