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

正畸牙齿的移动依赖于牙齿上的机械应力，但由于多托槽系统的存在，存在着牙根吸收、治疗周期长、疼痛、口腔卫生不良等问题。因此，应该建立牙齿移动和支抗控制的生物和生理控制，而不是仅仅依靠机械应力。为了抑制实验性牙齿移动后牙齿的复发，我们在牙槽骨压力侧局部注射1，25(OH)_2D_3或转化生长因子-β。1，25(OH)2D3注射组对复发无影响。24，25(OH)_2D_3或转化生长因子-β给药组抑制牙复发，破骨细胞少，成骨细胞成骨活跃。此外，各组受压侧的骨体积和骨形成面积增加，骨吸收面积和破骨细胞数量减少。HvJ脂质体是一种高效的…方法与腺病毒载体介导的基因传递相比，体内基因转移更无毒。(1)采用HVJ-脂质体方法将荧光素酶基因导入小鼠股骨骨髓间充质细胞。在大鼠实验性牙齿移动过程中，将β-Galactoeidase基因(LacZ)通过hvj-脂质体的方法转移到上颌骨。基因导入3天后，用X-Gal染色评价基因导入的效果。这些研究表明，利用HVJ-脂质体进行基因转移对实验性牙齿移动是有效的。用HVJ-脂质体将CTGF基因导入大鼠，进行实验性牙齿移动实验。在牙齿移动1、3、5、7、15天后，解剖上颌骨。采用原位杂交和免疫组织化学方法检测CTGF在牙周组织中的表达。较少

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