Incidence and severity of medication-related osteonecrosis of the jaw

Medication-related osteonecrosis of the jaw (MRONJ) is an area of exposed bone in the jaw persisting for more than 8 weeks in a patient currently or previously treated with an antiresorptive drug, an antiangiogenic drug or romosozumab, who has not received radiation therapy to the craniofacial region. Antiresorptive drugs include bisphosphonates and denosumab. Antiangiogenic drugs (eg bevacizumab, cabozantinib, lenvatinib, sunitinib) interfere with the formation of new blood vessels, and are used in the treatment of some malignancies. Romosozumab, a sclerostin antibody inhibitor, increases bone formation and bone mineral density.

For information on osteonecrosis occurring in a patient who has received radiation therapy (osteoradionecrosis), see Head and neck radiotherapy: dental considerations.

Stages of osteonecrosis of the jaw outlines the stages of osteonecrosis of the jaw.

Osteonecrosis of the jaw is an uncommon adverse effect of antiresorptive drugs. Severe cases have mainly occurred in patients who had dental surgery during treatment with a high-dose intravenous bisphosphonate for multiple myeloma or metastatic cancer. Current data in oncology populations suggests that the incidence of medication-related osteonecrosis of the jaw is up to 12 222 per 100 000 patient-years for bisphosphonates, and up to 2316 per 100 000 patient-years for denosumab¹ . The incidence of medication-related osteonecrosis of the jaw in patients treated with antiresorptive drugs for osteoporosis is significantly lower than oncology populations. Based on limited data, the incidence of medication-related osteonecrosis of the jaw in patients taking antiresorptive drugs for osteoporosis may be up to 150 per 100 000 patient-years, which is only slightly higher than in the general population.

The frequency of osteonecrosis of the jaw with romosozumab is unclear but, at the time of writing, only a few cases have been reported in the literature.

Although medication-related osteonecrosis of the jaw has significant consequences for the patient and can be difficult to treat, the benefits of antiresorptive therapy and romosozumab outweigh the risk of harm in most patients.