Terminology and classification of medication-related osteonecrosis of the jaws (review)

Abstract

Over the past 20 years, key aspects of the terminology and classification of drug-associated osteonecrosis of the jaws have undergone major metamorphoses that have reflected a transformation in the understanding of the problem by researchers in various countries. To date, the most common and commonly used definition of this pathological process is the Medication-Related Osteonecrosis of the Jaw (MRONJ) proposed by the American Association of Oral and Maxillofacial Surgeons (AAOMS) in 2014. The criteria for establishing a diagnosis of drug-induced osteonecrosis of the jaws according to AAOMS (2014) are: 1) current or previous treatment with antiresorptive (osteomodifying) or antiangiogenic drugs; 2) exposed bone or bone that can be probed through an intraoral or extraoral fistula in the maxillofacial region that persists for more than 8 weeks; 3) there is no history of radiation therapy in the head and neck area or an obvious metastatic lesion of the jaws. The most well-known classification of drug-induced osteonecrosis of the jaws is the classification proposed by AAOMS in 2007, which includes 5 categories of patients (risk group, 0, 1, 2, 3 stages). A distinctive feature of the AAOMS classification is the emphasized role of the inflammatory process in MRONJ, which translates the disease into a more severe stage. There is also a fundamentally different classification of osteonecrosis of the jaws, proposed by the Italian Society of Oral Pathology and Medicine (SIPMO) together with the Italian Society of Maxillofacial Surgeons (SICMF) in 2013, in which 3 stages of the disease are distinguished. The SIPMO/SICMF classification considers osteonecrosis of the jaws not only as a destructive-necrotic, but also as a sclerotic process that occurs from limited to diffuse forms with the development of complications. The main controversial issues that exist today regarding the terminology and classification of drug-induced osteonecrosis of the jaws are: the possibility of combining drug-induced and toxic osteonecrosis of the jaws into one pathology, the place of the X-ray method in determining the case of the disease, the need for a biopsy in osteonecrosis of the jaws, a discussion about the so-called Stage 0 — unexposed variant of the disease (without exposing the bone), principles for constructing classifications depending on various signs. The data are presented in accordance with the position papers, as well as clinical guidelines for drug-induced osteonecrosis of the jaws of the world’s leading scientific and medical communities.