The effect of Strontium ranelate on sutural bone formation

Rapid maxillary expansion is performed to correct skeletal transversal deficiency of the upper jaw, which are frequently encountered in orthodontic anomalies. With this application, the sutura palatina media opens and increase in the width of the posterior dentition is obtained. Then, active bone formation occurs on the midpalatal sutura. After the expansion, retention is needed to maintain the achieved results. The long retention period waited for the new bone formation lenghtens the treatment time and makes the patients get bored of the treatment. The aim of this study was to evaluate the effects of systemically applied Strontium ranelate in osteoblastic bone formation on midpalatal sutures of rats after the expansion using histological and immunohistochemical tests. In this study, 24 Wistar rats were used. Rats were randomly divided into two equal groups, 5-day expansion in both groups was applied, and the rats were kept for 7-day retention period.625mg/kg/day Strontium ranelat diluted with saline solution was given to the experimental group orally during the retention period. After the retention, all rats were sacrificed for histological and immunohistochemical assessments. According to the histological findings, the osteoblastic activity and the width of the blood vessels were found to be statistically increased in the Strontium ranelate group compared to the control group (p<0,05). The ossification was also observed better in the experimental group. In the evaluation of immunohistochemical staining performed with osteonectin, osteocalcin, VEGF and TGF-β antibodies, more statistically significant immunoreactivity was observed in the experimental group (p<0,05). As a result of our study, it may be concluded that Strontium ranelate contributed faster osteogenesis in the expansion region by stimulating bone formation. In this way, the retention period can be shortened and the relaps can be reduced by applying Strontium ranelat after the expansion. Key Words: Expansion, retention, relapse, Strontium ranelat.