This review looks at osteonecrosis in the stomatognathic system (mainly the jaws). Osteonecrosis of the jaw (ONJ) is a rare but serious clinical condition. It affects patients treated with bisphosphonates, and also with denosumab, mainly in oncological doses. In osteoporosis, it is a problem of relatively small significance. Article presents a thorough review of this phenomenon, including its definition, pathogenesis, risk factors, prevention and treatment methods, and its incidence rate.