Dental note Osteoporosis treatment and medication-related osteonecrosis of the jaws

摘要

Antiresorptive drugs are used widely for the prevention and management of primary and secondary osteoporosis. The bisphosphonates and newer drugs such as denosumab have been associated with osteonecrosis of the jaws. This condition is characterised by the presence of exposed, non-healing bone for more than eight weeks in the absence of radiotherapy or other pathology in the jaws. Extraction of teeth has been identified as the trigger factor in 60-87% of cases. Dentoalveolar surgery has also been identified as a trigger and is considered a major risk factor for osteonecrosis. When osteonecrosis occurs with antiresorptive therapy, it is termed medication-related osteonecrosis of the jaws (MRONJ). There has been much debate over the incidence of MRONJ associated with bisphosphonate use. A widely quoted paper by the American Society for Bone and Mineral Research said it was rare, at between 1 in 10 000 and less than 1 in 100 000 patient-treatment years. Detailed independent studies that take into account dental extractions have reported a much higher incidence at around 1 in 1000 patients.38 When the duration of oral bisphosphonate therapy is taken into account, the incidence has been found to double to 2.1 in 1000 patients for those with four or more years of drug exposure. A recent UK national survey over a two-year period estimated that the incidence in a population of postmenopausal women with osteoporosis was between 1 in 1262 and 1 in 4419.