The type of antiresorptive treatment influences the time to onset and the surgical outcome of medication-related osteonecrosis of the jaw

ABSTRACT Objectives Few data exist focusing on differences in the time to disease onset and the success rates in patients suffering from medication-related osteonecrosis of the jaw (MRONJ) dependent on their different antiresorptive treatment. The purpose of this study was to analyse and compare these variables for patients treated with bisphosphonates (BP) or denosumab (DNO), and for patients who switched the antiresorptive drug (BP/DNO). Patients and Methods A retrospective single-center cohort study with patients suffering from MRONJ was conducted. The predictor variable was the antiresorptive treatment, the outcome variables were I) time to onset of MRONJ (time of antiresorptive treatment to MRONJ diagnosis) and II) treatment success (mucosal integrity 12 months postoperatively). The other variables include data on demographic, underlying disease, MRONJ stage, and trigger events. Cox and logistic regression, Phi-coefficient, Cramer’s V, and Kruskal-Wallis tests were applied. Results One hundred thirty two patients were included and divided into three groups: group I (BP) n=45 patients, n=59 lesions; group II (BP/DNO) n=42 patients, n=71 lesions; group III (DNO) n=45 patients, n=62 MRONJ lesions. Treatment success and time to onset differed significantly between the groups: success rates in group I (84.7%) were significantly lower (p=0.04) than in group II (91.5%, (p=0.12), and group III (90.3%, p=0.35). The onset was significantly earlier in group III DNO (median 2.0 years, Q0.25: 1.49, Q0.75: 2.98; CI95: 1.93 – 2.83) compared with group II BP/DNO (median 4.07 years, Q0.25: 1.64, Q0.75: 6.70; CI95: 3.55 – 5.68) and group I BP (median 3.86 years, Q0.25: 1.69, Q0.75: 6.46; CI95: 3.43 – 5.87). Conclusion The different antiresorptive drugs show distinctive characteristics of time to onset and treatment success with the lowest success rates in the bisphosphonates group and the earliest onset in the denosumab group. The switch of the antiresorptive therapy (bisphosphonate to denosumab) did not influence the outcome variables negatively.