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.