Histological and immunohistochemical evaluation of the effects of teriparatide on midpalatal suture that administered after maxillary expansion

Aim: After RME treatment protocol, 3-12 months long retention period is needed to maintain final width. This period is important for new bone formation in sutura palatina media in order to prevent from relapse. The aim of this research was to evaluate the effects of teriparatide on sutural bone formation after expasion of the interpremaxillary suture in Wistar rats. Materials and Method: Twenty male, 7-8 weeks old Wistar rats were randomly divided into two equal groups named control and experimental. 7-day expansion period was planned for both groups and expansion force were applied to maxillary incisors via helical spring. After expansion period, rats were kept for 7-day retention period and 60 µg/kg teriparatide was given to experimental group subcutaneously during that period. After the retention, all rats were sacrificed, Histological sections were prepared with hemotoxilen-eozin staining and anti-osteonection, anti-osteocalsin, anti-VEGF, anti-TGF-β stainings for immunohistochemical evaluations." Mann Whitney U test" was used for intergroup statistical assessment. Results: In histological examination, experimental group showed spreading areas of new bone tissue in maxillary suture comparing to control group. In addition, in evaluation of immunohistochemical staining performed with osteonectin, osteocalcin and VEGF showed statistically significant immunoreactivity in the experimental group (p<0,05). On the other hand, TGF-β antibody showed mild reaction in experimental group but it was found statistically insignificant. Conclusions: Subcutaneous systemic administration of teriparatide after orthodopedically expanded inter-premaxillary suture may stimulate bone formation and shorten retention period in rats.