Bisphosphonate related osteonecrosis of the jaws: Clinico-pathological investigation and histomorphometric analysis

Objectives: Clinico-pathological evaluation of bisphosphonate (BP)-related osteonecrosis of jaws, comparison between oral (PO) and intravenous (IV) BPs and histomorphometric analysis of associated actinomyces. Study design: Retrospective clinical and histomorphometric analysis. Data on background, clinical, treatment and follow-up were analyzed. Actinomyces colonies were identified by typical filamentous colony morphology, Gram, and PAS stains. Colony density and relative colony surface area were measured. Results: Fifty-two patients were included, 37 (71.2%) IV, 15 (28.8%) PO BPs. with a mean duration of 2.33 and, 4.33 years respectively. One hundred percent of cases exhibited actinomyces colonization. The relative colony surface area was significantly higher in PO treatment (P = .024), with no differences in density, healing time or antibiotic treatment periods. High frequency of diabetes mellitus (60% PO cases) and corticosteroid treatment (25% of cases) were recorded. Conclusion: Infection with actinomyces is a common denominator in BP-related osteonecrosis of the jaws (BRONJ), regardless of administration route. Diabetes and corticosteroid treatment seem to be important contributing factors for BRONJ.