OBJECTIVES: Antiresorptive agents for bone pain were widely used to treat patients with advanced osteoporosis, multiple myeloma, and bone metastatic cancer. In recent years, however, bisphosphonate-related osteonecrosis of the jaw (BRONJ) has been a rare but major complication of this therapy. Most patients with BRONJ undergo dental procedures during treatment with antiresorptive agents. However, BRONJ may also occur spontaneously. This study reports 13 BRONJ patient cases at Kaohsiung Veterans General Hospital, Taiwan, and their related treatments. We also compare patients with cancer with patients with osteoporosis in treatment outcomes. METHODS: Thirteen symptomatic patients with BRONJ were reviewed between 1985 and 2018 at Kaohsiung Veterans General Hospital. We included patients at advanced stage who were hospitalized for infection control of osteonecrosis of the jaw and excluded asymptomatic patients at stage 0 and stage 1. Four multiple myeloma, 3 patients with bone metastatic breast cancer and 6 patients with advanced osteoporosis (average ages, 63.57 ± 14.54 years in cancer patients and 79.5 ± 9.31 years in osteoporosis patients; average drug durations, 25.86 ± 27.23 months in cancer patients and 58.33 ± 23.87 months in osteoporosis patients; average follow-up times, 22.71 ± 14.46 months in cancer patients and 28.08 ± 36.35 months in osteoporosis patients) were included. RESULTS: Seven patients were defined as having stage 3 (53.8%) and 6 as having stage 2 (46.2%) medication-related osteonecrosis of the jaw, according to the American Association of Oral and Maxillofacial Surgeons classification. The complete response rate with totally healed mucosa was 61.5%. Four cancer patients received free fibular flap (FFF) reconstruction with a high complete response rate (100%). All of them had a relatively better performance status, and the average age was also younger than osteoporosis patients. CONCLUSION: Free fibular flap with a high complete response rate may improve pain relief and infection control for patients with BRONJ. Younger age is seemed to be a great indicator for FFF, but poor self-care ability (Eastern Cooperative Oncology Group status >3) is not suitable for these surgical treatments.