Experimental study of transport distraction osteogenesis.-Molecular basis of bone metabolism-

目的：运输牵张成骨技术是一种骨延长术，用于修复节段性畸形中缺失的骨和软组织。我们研究了这项技术在使用内牵引器的颞下颌关节(TMJ)关节成形术中的适用性。我们还观察了一氧化氮对骨形成的影响。材料和方法：1.兔运输盘前移0.9 mm/d，连续14天。结果1.延长完成后，每隔一段时间处死动物。在自由基供体、细胞因子或生长因子的刺激下，检测成骨细胞和破骨细胞的活性。结果：1.延长完成8周以上，成熟的皮质骨得到重建。在前缘上方形成了一种类似帽子的胶原状结构。这顶帽子可以代替关节盘。新骨已经重塑，类似于髁状突的头部。结论：骨转移技术在TMJ重建中具有良好的应用前景。NITO对骨重建系统具有调节作用。

Purpose :Transport distraction osteogenesis, a kind of bone lengthening, has been used to reconstruct missing bones and soft tissues in a segmental deformity. We investigated the applicability of this technique to the arthroplasty of temporomandibular joint (TMJ) with an internal distraction appliance.Nitric oxide is a principal regulator of bone remodeling systems. We also investigated the effects of nitric oxide on bone formation.Materials and Methods :1. The transport disc of the rabbits was advanced 0.9 mm per day for 14 days. After the completion of the lengthening, the rabbits were sacrificed at intervals.2. The osteoblastic and osteoclastic activities were measured after stimulation by free radical donors, cytokines or growth factors.Results :1. More than 8 weeks after the completion of lengthening, the mature cortical bone was reconstructed. A collagenous structure like a cap was formed over the leading edge. This cap may substitute for an articular disc. The new bone has remodeled and resembled the condylar head.2. Nitric oxide has the bone forming- and bone resorbing- effects.Conclusion : The bone transport technique is promising for the reconstruction of TMJ.Nitric oxide regulates the bone remodeling system.