中位牵引前移面中份骨骼的可行性研究

The possibility of midface skeleton protraction:an experimental study in dogs

目的 探索缝牵引成骨修复面中部发育不全的新技术。方法 同窝 12周龄杂种犬 4只 ,随机分为空白对照组 1只 ,实验组 3只。分别在两组犬前颌缝、腭横缝、颧颌缝、颧颞缝的前后种植钛钉 ,作为骨标志。实验组安置特制外置式牵引支架和牵引钩 ,将牵引钩插入鼻腭孔 ,橡皮圈连接外置支架和牵引钩 ,向前持续弹性牵引 1个月 ,牵引力约为 6 0 0g ,牵引前后进行临床和X线检查及头影测量。于 16周龄时将两组犬均处死 ,进行组织学观察。结果 上颌逐渐前突 ,咬合关系呈现Ⅱ类错咬合。骨缝前后骨标志点间距离测量结果提示 ,前颌骨前移最明显 ,上颌骨次之 ,颧骨前移不多。对照组与实验组颅底角度变化幅度不明显 ,上颌未见旋转发生。实验组各犬的骨缝有大量新骨生成 ,大量的成骨细胞 ,成纤维细胞沿张力方向排列 ,前颌缝尤为明显。结论 本牵引装置可有效地平行前移上颌 ,作用力更直接 ,避免了上颌的旋转 ,牙移位。

Objective To probe the feasibility of a new technique of sutural distraction osteogenesis for midface hypoplasia repair. Methods A protraction system was developed, which consisted of three parts: a rigid external framework, a bone hook, and the elastic band. Four 12-week mongreal dogs were randomly assigned into two groups:the control( n =1) and the experimental groups ( n=3 ).Four pairs of titanium bone markers were fixed on either side of the bone sutures of all animals. The experimental group was fitted with a distraction device, through which a forward elastic force was exerted for 1 month. Clinical observations and X-ray examinations were performed at the beginning and the end of distraction.New bone specimens were examined histologically. Results All the animals in the experimental group showed progressively forward movement of the maxilla and manifested class Ⅱ occlusion at the end of the experiment.The distance increase between each pair of bone markers showed that premaxilla advancement was more than that of the maxilla.The next was zygoma.There was no obvious difference between the control and the experimental group in terms of the basilar-maxillary angle and counterclockwise rotation. Theer was active osteogenesis in the sutures, especially in premaxilla-maxillary sutures. The number of osteoblasts and fibroblasts increased dramatically and new bone formation was found at the edge of the suture. Conclusion This technique can create effective advancement of the maxilla.The direct force can avoid counterclockwise rotation of the maxilla during distraction.