Oral risk factors associated with medication-related osteonecrosis of the jaw in patients with cancer.

INTRODUCTION: Bone-modifying agents (BMAs) are indispensable to cancer therapy. However, the number of patients with medication-related osteonecrosis of the jaw (MRONJ) is increasing according to the BMA administration. Oral factors predisposing to development of MRONJ are receiving attention, and oral management is recommended for prevention of MRONJ; however, the strategy and criteria have not yet been established. Therefore, we investigated the oral risk factors associated with MRONJ development in this study. MATERIALS AND METHODS: A retrospective study was carried out on 398 cancer patients who had received oncological-dose BMAs between 2007 and 2018; general health factors, demographic, and dental factors were examined along with MRONJ development in all the patients. The cumulative occurrence rate of MRONJ was calculated using a Kaplan-Meier analysis. Clinical factors were analyzed using the Cox regression analysis. RESULTS: MRONJ occurred in 42 of the 398 patients. The cumulative MRONJ incidence rates were 4.5, 12.9, 17.7, and 21.6% at 1, 2, 3, and 4 years, respectively. Age (p = 0.038), male sex (p = 0.002), initiation of dental interventions before BMA administration (p = 0.020), alveolar bone loss involving more than half the root (p < 0.001), and torus mandibularis (p < 0.001) were significantly associated with MRONJ. CONCLUSIONS: Our findings suggest that patients with alveolar bone loss involving more than half the root on panoramic radiographs and torus mandibularis carry a high risk of MRONJ development. Early dental intervention before BMA administration and oral management during the treatment are important for preventing MRONJ.