A case of bisphosphonate-related osteonecrosis of the maxilla with orbital cellulitis.

Bisphosphonates are used for the treatment of bone metastases of cancer and prevention of osteoporosis. Bisphosphonate-related osteonecrosis of the jaw (BRONJ) has unclear mechanisms, but its elucidation, prevention, and treatment are essential to improve patient outcomes.An 88-year-old woman who was taking oral bisphosphonates for 4 years presented with a 5-day history of gradual orbital pain. Computed tomography (CT) revealed bilateral maxillary sinusitis and bony destruction at the base of the right maxillary sinus and inferior orbital wall. We diagnosed her with bisphosphonate-related osteonecrosis of the maxilla. In addition to intravenous antibiotic treatment, an endoscopic sinus surgery was performed. The patient's postoperative course was uneventful.To the best of our knowledge, this is the first case report of BRONJ with orbital cellulitis. This condition should be considered among patients taking bisphosphonates, who manifest with symptoms of orbital cellulitis and bone destruction on imaging.