Osteonecrosis of the Jaw Associated with Bisphosphonates. A Histopathological Study of 24 Cases

The aim of this work is to report the histopathological features of jaw bone in 24 cases of bisphoshonate-related osteonecrosis of the jaw. In all cases, lamellar bone trabeculae were thicker (bone sclerosis), had no osteocytes in the lacunae (bone necrosis), and exhibited a Pagetlike structure with marked signs of bone remodeling and formation of multiple trabecular compartments that were not connected to the trabecular surface. The Paget-like trabecular structure would result in a loss of trabecular vitality and in the onset of an inflammatory process due to microbial invasion. Bisphosphonate-related osteonecrosis of the jaw would initially be an aseptic process and osteomyelitis would develop after microbial infection. The results obtained from this series of cases would seem to confirm that bisphosphonates cause Paget-like bone regeneration, which would explain the likely aetiopathogenic mechanism and the association between bisphosphonate administration and the development of necrosis with secondary infection.