Medication-related osteonecrosis of the jaws – a retrospective study

Abstract

Introduction: Medication-related osteonecrosis of the jaws (MRONJ) is a multifactorial disease whose pathophysiology is not completely understood. Actinomyces spp. (AS) have regularly been found in MRONJ patients suggesting a role in pathogenesis and prognosis [1]. Objective(s): (a) Describe the prevalence of AS in MRONJ patients sample; (b) identify differences in antibiotherapy length, healing time and treatment outcome according to presence of AS; (c) describe differences in AS positivity according to time of collection of sample. Material(s) and Method(s): A retrospective study was conducted including all patients with MRONJ submitted to sequestrectomy or marginal resection during treatment in an Oral Surgery Clinic between 2004 and 2016. Exclusion criteria was follow-up inferior to 3 months. All bone samples were evaluated for the presence of AS by histopathological analysis. Treatment outcome was defined as healed/improved versus. Stable/Worse. Chi-square, Student t-test, Mann-Whithney U test and Kaplan-Meier analysis were used as appropriate. All analyses were performed using IBM SPSS version 23. Result(s): Fifty patients were included in the sample, 34 female and 16 male, with a mean age at diagnosis of 68.08 +/- 11.38 years. The MRONJ lesion was located in the mandible in 32 patients and in the maxilla in 18 patients. AS was identified in 35 patients (70%), 15 in maxilla and 20 in mandible. Median healing time was longer in patients with AS (360 +/- 89.87 days) than their counterparts (150 +/- 36.66 days) (p