Osteonecrosis of the jaws in patients assuming oral bisphosphonates for osteoporosis: A retrospective multi-hospital-based study of 87 Italian cases

•Necessity of BRONJ prevention, also in non oncological patients in therapy with bisphosphonates.•Do not underestimate the spontaneous BRONJ, when known risk factors are absent.•Check oral cavity for all patients, oncological and osteoporotic one, before treatment with bisphosphonates.

BackgroundBisphosphonates (BPs) are currently the chief drugs for the prevention/treatment of osteoporosis; one of their adverse effects is the osteonecrosis of the jaw (BRONJ). The primary endpoints of this multi-center cross-sectional study are: i) an observation of the clinical features of BRONJ in 87 osteoporotic, non-cancer patients; and ii) an evaluation of their demographic variables and comorbidities.Methods87 BRONJ patients in therapy for osteoporosis with BPs from 8 participating clinical Italian centers were consecutively identified and studied. After BRONJ diagnosis and staging, comorbidities and data relating to local and drug-related risk factors for BRONJ were collected.Results77/87 (88.5%) patients in our sample used alendronate as a BP type; the duration of bisphosphonate therapy ranged from 2 to 200 months, and 51.7% of patients were in treatment for ≤ 38 months (median value). No comorbidities or local risk factors were observed in 17 (19.5%) patients, indicating the absence of cases belonging to BRONJ forms triggered by surgery. BRONJ localization was significantly associated with age: an increased risk of mandible localization (p = 0.002; OR = 6.36, 95%CI = [1.89; 21.54]) was observed for those over 72 yrs. At multivariate analysis, the increased risk of BRONJ in the mandible for people over 72 yrs (OR′ = 6.87, 95%CI = [2.13; 2.21]) was confirmed for a BP administration > 56 months (OR′ = 4.82, 95%CI = [2.13; 22.21]).ConclusionOur study confirms the fundamental necessity of applying protocols of prevention in order to reduce the incidence of BRONJ in osteoporotic, non-cancer patients in the presence of comorbidities and/or local risk factor as well as, less frequently, in their absence.