RESUMO
OBJECTIVE: The aim of the study was to evaluate the effect of 4 µg/kg teriparatide administered at intermittent and continuous frequencies on bone formation in the expanded midpalatal suture region using histomorphometric and micro-computed tomography (micro-Ct) analysis. Settings and sample population: In this study, 24 Sprague Dawley male rats were used. METHODS: The experimental animals were divided into 3 groups as follows: Group 1: only maxillary expansion, Group 2: maxillary expansion with continuous teriparatide administration (2 µg in the morning and 2 µg in the evening) and Group 3: maxillary expansion with intermittent teriparatide administration (daily 4 µg/kg). The expansion appliance was fixed to maxillary incisors of all animals within the 5-day expansion period, followed by a 12-day retention phase. Animals were sacrificed at the end of the retention period, and specimens were evaluated by micro-Ct and histomorphometric analysis respectively. RESULTS: The results of the histomorphometric analysis showed that Group 3 had the highest number of osteoblasts (1042 ± 90.76) (P < .01). In addition, the results of micro-Ct analysis revealed that Group 3 had the highest bone volume/total volume (16% ± 0), bone mineral density (173.82 ± 2.6 mgHA/cm3 ) and least midpalatal suture width (0.13 ± 0.001 mm) (P < .01). Osteoblasts number and micro-Ct analysis values of Group 2 were higher than those of Group 1 but no significant differences between them (P > .01). CONCLUSION: Intermittently administered TP (4 µg/kg once a day) was seen to enhance bone formation and mineralization. In the future, it can be used in drug studies that will increase or stimulate bone formation as well as in the midpalatal suture area.