Biological control for the rate of orthodontic tooth movement and root resorption

点击翻译按钮获取中文摘要

Orthodontic tooth movement depends on the mechanical stress onto the tooth, but there are various problems, such as root resorption, long treatment period, pain, undesirable oral hygiene due to the multibracket system and others. Therefore, the biological and physiological control for the tooth movement and the anchorage control, not depending only on the mechanical stress should be established.1. Trying to suppress the relapse of the tooth after experimental tooth movement, we locally injected 1,25(OH)_2D_3 or TGF-β in the pressure side of the alveolar bone. 1,25(OH)_2D_3, injected group had no effect on the relapse. On the other hand, 24,25(OH)_2D_3 or TGF-β delivered group suppressed the tooth relapse showing few osteoclasts, but active bone formation by osteoblasts. Furthermore, in these groups the bone volume and bone formation surface in the pressure side increased, and resorption surface and the number of osteoclasts decreased.2. HVJ liposome method is developed an efficient and … More nontoxic in vivo gene transfer compared to adenoviral vector-mediated gene delivery. Following experiments were performed to examine the optimum conditions of HVJ lipoeome method for experimental tooth movement model in rats.(1) Luciferase gene was delivered to mesenchymal cells, isolated from bone marrow in mouse femur, by using HVJ-liposome method in vitro. Luciferase reporter assay was performed to evaluate delivery rate.(2) During experimental tooth movement in rats, β-galactoeidase gene (LacZ) was delivered to the maxillae by using HVJ-liposome method. Three days after gene introduction, X-gal staining was performed to evaluate the deliveryate. These studies indicated that the gene delivery by using HVJ-liposome was efficient to the experimental tooth movement.3. Experimental tooth movement was performed after CTGF gene was delivered by using HVJ-liposome in rat. After 1,3,5,7 and 15 days of tooth movement, the maxillary bones were dissected. In situ hybridization and immunohistochtemistry were performed to analyze the expression of CTGF in periodontal tissue. Less