ABSTRACT
OBJECTIVE: To investigate the effect of Selective Alveolar Decortication (SADc) facilitated orthodontic tooth movement (OTM) on bisphosphonate burdened alveolar bone in a rodent model. DESIGN: OTM was accomplished by protraction of the maxillary right first molars. Four groups were included of which two groups were pre-treated for three months with alendronate sodium (BP+TM+SADc and BP+TM group) and two groups were given saline (TM+SADc and TM group). Selective alveolar decortication surgery was performed on day 1 of appliance insertion. OTM measurements were obtained at 0, 4, and 8 weeks using in-vivo µCT. Tissues were analysed by histology and EPMA. RESULTS: Tooth movement of 0.39 mm and 0.75 mm in the BP+TM+SADc group at 4 and 8 weeks respectively was achieved with 113% increase in tooth movement compared to BP+TM group at 4 weeks. In comparison, SADc+TM group showed 0.63 mm and 2.1 mm of tooth movement at 4 weeks and 8 weeks respectively with only 6% increase at 4 weeks and 2% increase at 8 weeks compared to TM group. Severe interproximal and buccal bone loss around the first permanent molar in the BP+TM+SADc group was seen with µCT imaging and histology. Animals in BP+TM+SADc group histologically showed signs of osteonecrotic bone with irregular borders, loss of osteocytes and absence of osteocytic lacunae. CONCLUSION: This study demonstrated selective alveolar decortication accelerates tooth movement in a bisphosphonate burdened alveolar bone in the short term but the potential of such an invasive injury can have adverse effects.
