Incidence and risk factors associated to Medication-Related Osteo Necrosis of the Jaw (MRONJ) in patients with osteoporosis after tooth extractions. A 12-months observational cohort study.

OBJECTIVE

To evaluate the 12-months incidence of MRONJ after tooth extractions and possible related risk factors in patients with osteoporosis treated by means of oral bisphosphonates.

MATERIAL AND METHODS

Forty-five records of osteoporotic patients on therapy with oral bisphosphonates and treated with at least one dental extraction at the Department of Oral Surgery of University of Naples Federico II were selected. All patients were treated using a standardized surgical extraction protocol. At baseline and after 12-months follow-up, the following variables were recorded: "mucosal healing", "gender", "type of drug"; "duration of therapy"; "drug holiday". The collected data were analyzed and a linear regression analysis was performed to assess a possible correlation with onset MRONJ.

RESULTS

A total of 159 tooth extraction in 43 females (95.6%) and in 2 males (4.4%) with a mean age of 67.5 ± 3 years were available for the analysis. The majority part of patients was on therapy with alendronate (23; 51.2%), 11 patients (24.4%) were treated with risedronate and 11 (24.4%) with ibandronate. Before oral surgery, 84% of the patients showed a low-medium risk of MRONJ, while in 16% of the patients a medium-high risk was recorded. After 12-months follow-up, osteonecrosis was observed in 1 patient, with an overall incidence of MRONJ of 0.6%. The linear regression showed a significant correlation with MRONJ onset only for "gender" variable, with a R of 0.489.

CONCLUSIONS

Within their limitations, the outcomes of the study indicate that the risk of MRONJ after tooth extraction in osteoporotic patients taking bisphosphonates for OS is very low. A prolonged and specific antibiotic and antiseptic therapy, in addition to a surgical procedure as little traumatic as possible, will allow to perform oral surgery safely.