Impact of selective alveolar decortication on bisphosphonate burdened alveolar bone during orthodontic tooth movement

•We investigated acceleration of tooth movement in bisphosphonate burden alveolar bone.•We used Micro-CT for in-vivo monitoring of tooth movement.•EPMA was used to qualitatively assess bone remodelling.•Accelerated tooth movement effect of SADc in BP burden alveolar bone was short term.•Accelerated tooth movement was accompanied by histopathological signs of BRON.

ObjectiveTo investigate the effect of Selective Alveolar Decortication (SADc) facilitated orthodontic tooth movement (OTM) on bisphosphonate burdened alveolar bone in a rodent model.DesignOTM 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.ResultsTooth 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.ConclusionThis 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.