An Experimental Study of Bone Distraction in Rabbit Skull

Tak, Min Sung; Shin, Ho Sung; Kang, Sang Gue; Kim, Yong Bae; Lee, Young Mann; Sim, Sang Bak; Kim, Jong Whan

Abstract

The epiopathogenesis of craniosynostosis remains obscure. According to the studies involved, the conditions observed at birth are very different. In case that a deformity is obvious or the risk of brain compression is possible, strip craniectomy, frontal bone advancement and cranial vault remodeling methods are used. These direct reshaping or remodeling methods are time consuming and require greater use of physical resources and still are not uniformly successful in making skull shape to normal. Distraction of the cranial bone has been studied to solve this problem. This study subsequently included 30 white rabbits aged about 25 weeks. The rabbits were divided in three groups. In group I, a 0.25mm distraction was done every other day after 3 day latency period. In group II, there was a 7 day latency period with the same rate of distraction as in group I. There was a 3 day latency period with a 0.5mm distraction every other day in group III. The contralateral side underwent a sham operation as a control group. During distraction and after consolidation periods, histologic and ultrastructural studies were carried out. And a serial radiologic study was done. As a result, group I and group II showed successful distraction osteogenesis, and we demonstrated the biological and mechanical factor associated with distraction osteogenesis. In group I, despite the short latency period, there was successful bone regeneration. Group III, it also showed successful ossification. During the distraction period, there was a remarkable increase of TGF-beta1 in both groups, especially in periosteum osteoid and newly developed connective tissue. In conclusion, we have demonstrated a useful model of distraction osteogenesis in rabbit skulls, and attempted to evaluate associated biological and mechanical factors.