effect of dietary ascorbic acid on osteogenesis of expanding midpalatal suture in rats.

after maxillary expansion, a long period of retention is necessary to prevent early relapse. therefore, it is beneficial to accelerate bone formation in the expanding midpalatal suture to reduce relapse. this study was designed to evaluate the effect of dietary vitamin c on osteogenesis of rat midpalatal suture during expansion.fifty-four male wistar rats were randomly divided into three groups, each with a control and an experimental subgroup. an open-loop spring was bonded to maxillary incisors of each animal to expand the premaxillary suture. experimental groups received dietary vitamin c in their water. the rats in the three groups were sacrificed at three, nine or 17-day intervals after bonding the spring. then, the premaxilla was dissected and sections were made and stained with hematoxylin and eosin and osteopontin marker. osteoblasts and osteoclasts were counted in the suture. two-way anova and the mann-whitney-u test were used for analyzing the data.after three days, the number of osteoblasts was significantly higher in the vitamin c group but after nine days it was significantly higher in the control group and after seventeen days there were no significant differences between the groups. osteoclast counts were not significantly different between vitamin c and control groups.vitamin c had a positive effect on osteogenesis at the beginning of bone formation in the expanding suture, but after nine days it had a negative effect on suture osteogenesis in rats.