Glucocorticoids reduce alveolar and trabecular bone in mice

Glucocorticoid (GC) treatment is the main cause of secondary osteoporosis. There are some controversies about the relationships between alveolar bone loss and bone loss at the appendicular and axial skeleton. Objective To assess, in parallel, the effects of GCs on alveolar bone and on the tibia in a mice model. Methods Five-month-old male Swiss-Webster mice were randomized into two groups. Pellets releasing 5 mg/kg/day of prednisolone or control pellets were subcutaneously implanted for 28 days. After euthanasia, the right tibia and the right hemimandible of each mouse were analyzed by histomorphometry and microcomputed tomography. Alveolar bone consists of a thin slab between the incisor and the molar roots connected with the alveolar processes. A 2D-frontal section was done through the pulp chamber of the first molar and was used to measure the thickness of the alveolar bone slab. A 2D-sagittal section was done through the pulp chamber of the three molars and was used to measure bone volume in the alveolar processes. Results At day 28, thickness and bone volume of alveolar bone were significantly decreased in the GC group (P < 0.05). At the tibia, GCs decreased bone formation with a reduced mineral apposition rate and bone formation rate and a significant decrease in BV/TV and Tb.Th (P < 0.05). Conclusion Although the amount of alveolar bone is very low in the mouse, this study shows that GCs can induce an alveolar bone loss in long-term treated animals