牙槽骨缺损修复后牙齿移动的动物实验

Tooth movement in tissue-engineered bone

目的探讨用组织工程方法修复大鼠下颌骨缺损对牙齿移动的影响。方法选用40只SD大鼠,获取大鼠骨髓基质细胞,分离培养并诱导为成骨样细胞。将成骨样细胞与陶瓷化骨复合,种植到大鼠下颌骨的一侧全层骨缺损区。缺损修复8周后,在手术组和正常对照组大鼠下颌安装正畸矫治器,加力近中移动第一磨牙。观察牙齿移动距离和牙根长度的变化,t检验比较组间差异。结果加力初期,手术组大鼠的牙齿移动距离大于对照组,差异有统计学意义(P<0·05)。手术组牙根长度变化小于对照组,差异有统计学意义(P<0·05)。结论应用陶瓷化骨复合体外诱导的大鼠自体成骨样细胞,可修复大鼠的下颌骨缺损,修复手术不会对牙齿移动产生不良影响。

Objective To explore the effect and practical value of repairing the alveolar defects with tissue engineering technique and investigate the influence of the generated new bone on the orthodontic tooth movement. Methods The marrow stromal cells of rats were separated, cultured in vitro and induced to osteoblast-like cells. The osteoblast-like cells were implanted onto the ceramic bovine bone. Then the complex was implanted into the alveolar defect in one side of the rat＇ s mandible. The other side of the mandible served as control. Eight weeks later, the orthodontic appliances were placed between the first molar and incisors of SD rats to move the first molar forward. The tooth movement and root resorption of the molar were observed. Results We found that the tooth movement in the experimental area was faster than that in the normal alveolar bone （ P 〈 0. 05 ）. The root resorption and the alveolar bone height loss were less than that in the control area （P 〈 0. 05 ）. Conclusions The tissue-engineered bone did not have negative influences on tooth movement. The repair of alveolar bone defect by tissue engineering approach may be used in craniofacial surgery and orthodontics.