羊下颌骨牵张骨形成实验

目的 观察山羊下颌骨牵拉后的新骨形成情况。方法 将8只山羊下颌骨单侧皮质骨切开后，每日2次，每天牵拉1mm，共8天，后继续以牵开器固定，行组织学、放射学观察。结果 牵拉术后颌骨成骨明显牵拉后2周，X线示骨间隙内新生骨已基本连接骨缺损，4周时骨化明显，组织学见大量新骨形成，随稳固期延长而渐成熟，部分形成板层骨。结论 山羊为一良好的下颌牵张模型动物。新骨形成以膜内成骨为主。

Experimental study of mandibular distraction osteogenesis in the goat

Objective To establish an animal model in goats and observe the development of bone at different times during the period of mandibular distraction.Methods Eight goats were used for this experiment.Extraoral distractors were activated 7 days after mandibular corticotomy at a rate of 1mm per day,twice a day,for 8 days.Radiographic and histologic examinations were performed on the harvested mandibles.Results Radiographic evaluation suggested definite ossification.Mineralized tissue was seen bridging the defect as early as 2 weeks after.Histologic observation of the distraction site showed a gradual change from fibrous matix to osseous like tissue and finally,more matural bone tissue.Conclusion The goat is a good animal model for the experiment of distraction.New bone is formed predominatly by intramembranous ossification.