Histopathological Features of Bisphosphonate-associated Osteonecrosis: Findings in Patients Treated with Partial Mandibulectomies

The present study investigated the histopathologic and radiographic features of stage 3 bisphosphonate-associated osteonecrosis of the jaw (BAONJ) in patients who were treated with partial mandibulectomies. Bisphosphonates had been orally administered to 10 patients with osteoporosis and intravenously administered to 1 patient with metastatic carcinoma. On radiographic images, massive osteolysis and periosteal bone formations were conspicuous, and a thin mandibular cortical width was observed in 5 of 10 osteoporosis patients despite the previous use of bisphosphonate. Microscopically, the mandibulectomy specimens of the patients could be divided into 4 distinct layers. Although there were few differences in overall histologic features between BAONJ and chronic suppurative osteomyelitis, a notable number of osteoclasts were found detached from the bony trabeculae in BAONJ.