Mandibular torus as known OnJ risk factor: a case report of osteonecrosis of the jaw

introduction. Osteonecrosis of the jaw (ONJ) is a rare but serious complication linked to exposure to antiresorptive and antiangenic drugs, especially aminobisphosphonates. Up to date, many drug-related, systemic and local risk factors are known, even if many researches are in progress in order to identify and define pathogenesis. ONJ is often associated to oncological patients (one of the systemic known risk factors), to intravenous administration (one of the drug-related risk factors) and to dental extraction (the most frequent local risk factor). Methods and results. In May 2015, a 78-year-old female patient was referred to our department because she could no longer worn her prosthesis for swelling of anterior mandible. She referred to be surgered for a breast cancer in 2003, and no chemotherapy was added. From 2008, she has been treated with weekly alendronate for osteoporosis. No other known local and systemic risk factors for ONJ were reported. During intraoral examination, two mandibular pronounced tori were present. The right one showed bone exposure. No signs of local inflammation were detected and no symptom was referred. After CBCT scans, the bone necrosis was classified as stage II A, according to Bedogni et al.1 Systemic antibiotic (amoxicillin/clavulanic acid orally twice daily for 8 days and metronidazole 250 mg per os twice daily for 8 days), local antiseptics (chlorhexidine 0.2% mouth rinses and 0.5% chlorhexidine gel) were administered. The patient was referred to Oral and Maxillofacial surgery for surgical management. Conclusion. ONJ pathogenesis still remains not fully understood. Although dentoalveolar surgery is the most com- mon local ONJ risk factor, more attention should be given to concomitant presence of other local features (i.e. torus and prosthesis): protruding cortical bone is coverage with thin mucosal favoring a greater risk for necrosis especially if a local additional trauma (e.g. ill-fitting dentures) is detected