REPEATED BONE REPOSITIONING IN THE GROWING RABBIT CALVARIUM HAMPERS BONE SEGMENT INCORPORATION

There has been concern among surgeons that multiple extended craniofac ial procedures might be detrimental to the viability of the involved s keletal structures. This study aimed to explore the result of repeated bone reposition ings in the growing rabbit calvaria. Seven immature r abbits were subjected to a three-stage surgical procedure, implying th at four calvarial bone segments were originally harvested and repositi oned according to a rotational scheme: after 6 weeks only three of the bone segments were harvested and repositioned and, finally, after an additional period of 6 weeks, two segments were repositioned. The resu lts were evaluated by radiographic, histologic (with a special scoring system), and histomorphometric analysis. It was found that one or two cranioplasties did not markedly affect graft incorporation, but three procedures significantly reduced graft revascularization and integrat ion. The findings are discussed with special reference to syndromic cr aniofacial disorders.