Oral bisphosphonate-induced osteonecrosis complications in patients undergoing tooth extraction: a systematic review and literature updates

Objective: Bisphosphonates, the most common anti-resorptive medications, are internalized by osteoclasts, where they inhibit the macrophage colony-stimulating factor (M-CSF) pathway, preventing their differentiation, inhibiting anchorage to the cell membrane, and inducing apoptosis. In patients undergoing oral bisphosphonate therapy, oral surgery involves a high risk of developing drug-related osteonecrosis of the jaws (BRONJ/MRONJ), among the possible complications. Materials and methods: A systematic search was carried out on the PubMed, Scopus and Cochrane Library search engines, using the keywords "oral bisphosphonates AND tooth extraction", "third molar extraction AND oral bisphosphonates". In addition, we manually evaluated the articles included in references from other sources and an analysis of the Gray Literature was performed. A secondary outcome was to evaluate the assessment of pharmacological (antibiotics) use in the BRONJ/MRONJ management. The revision protocol followed the indications of the Cochrane Handbook, and was registered in the INPLASY database, while the drafting of the manuscript was based on PRISMA. Results: The results of the systematic review, after the study identification and selection process, included a total of 7 studies: 4 retrospective studies, 2 prospective studies and 1 case report. The main complication was represented by osteonecrosis of the jaws, which appears to be related to the duration of treatment with bisphosphonates; in addition, data regarding the anatomical location of post-extraction sites, the sex and age of patients, comorbidities and various systemic risk factors were extrapolated. The most frequent post-extraction complication in patients treated with oral bisphosphonates is osteonecrosis of the jaws, with a significant prevalence in the posterior region of the mandible. In some cases, delayed healing of the surgical wound was also found; moreover, the duration of exposure to oral bisphosphonates influences the onset of complications. Conclusions: Ongoing studies continue to unravel the role of the oral environment response in alveolar bone homeostasis and how it might contribute to the induction of BRONJ/MRONJ. Approaching the problem from this perspective could provide new directions for the prevention of BRONJ/MRONJ and expand our understanding of the unique oral microenvironment.