Bisphosphonate-related osteonecrosis of the jaw in malignant tumor patients with bone metastases: clinical analysis of six cases

Objective To analyze the clinical manifestation, imaging characteristics and prevention of medication-related osteonecrosis of the jaw (MRONJ) after intravenous bisphosphonate (BP) for cancer patients with bone metastases. Methods The clinical data and radiographic findings of 6 primary breast cancer patients with bone metastases diagnosed as MRONJ from January 2014 to April 2018 in Shanxi Dayi Hospital were retrospectively analyzed. Results All 6 patients were female, with the median age of 65.5 years old. All patients had no history of systemic application of hormone therapy, no history of diabetes, no history of radiation therapy, no history of metastasis of the jaw, and no history of infection. The average usage time of BP was 28 months. MRONJ occurred in 2 cases on maxilla and 4 cases on mandible. There were 2 patients with tooth extractions history in BP treatment. Clinical symptoms included maxillofacial pain, loosened teeth, fistula suppuration, and exposed sequestrum. Radiographic findings included osteolysis and bone sclerosis or the mixed manifestation of both, with or without periosteal reaction. In addition, nonhealing tooth sockets and sequestrum separation imaging were also included. Conclusions Tooth extraction is considered as an increased risk for MRONJ in patients with malignant bone metastases after BP therapy. MRONJ is more likely to appear in the mandible, but it can also appear in the maxilla. Early screening and initiation of appropriate dental care are necessary for the patients before using BP therapy. Key words: Neoplasm metastasis; Diphosphonates; Skeleton; Medication-related osteonecrosis of the jaw