Commentary

Treatment of bone loss in cancer and non-cancer patients has improved over the years because of the use of ARD. The first cases of jaw osteonecrosis in patients taking these medications were reported in 2003. Since then multiple approaches have been developed following the evolving understanding of the condition and risk factors. Numerous studies helped us learn of the incidence and prevalence also indicate that patients are at higher risk of developing MRONJ when using IV or oral ARD for more than five years. Some patients go on to develop MRONJ without dental treatment while some will it develop after a surgical procedure.

This review focused on MRONJ as one of the complications of the use of bisphosphonates in oncologic and osteoporotic patients after dental extractions. The main question of the study was clearly described and targeted the occurrence rate and the risk indicators of MRONJ in patients treated with Antiresorptive Drugs - ARD.

The systematic review was well organised and guided by PRISMA guidelines. The authors searched potential papers in three online databases followed by hand searching of the references. All steps of the review were clearly described. Two investigators independently screened and assessed for inclusion. Ultimately, 13 studies were included in the review: two RCTs, nine case series and two cohorts. Quality of the included studies was evaluated with a checklist that, according to the authors, is designed for each study design. A score of ≥7/11 was required from inclusion.

The authors separately performed a meta-analysis on the proportion of MRONJ for oncologic patients treated intravenously, and for osteoporotic patients treated orally. In addition, they compared the surgical techniques and protocols for preventing MRONJ.

The review included 6331 surgical procedures in 2662 patients. Of those patients, 80% were treated for osteoporosis, using alendronate in 72.2% of the cases. Regarding the type of extraction eight studies reported surgical and four performed simple extractions. The proportion of MRONJ cases among oncologic patients and osteoporotic patients was 2.9% and 0.15% respectively. Regarding the relation of surgical procedure and MRONJ it seems that alveolectomy performed after extraction reduces the chance of osteonecrosis in patients treated with ARD for cancer by 6%. Additionally, the use of a biological membrane (PRGF) combined with alveolectomy causes a modest reduction of the cases of MRONJ compared to alveolectomy alone.

Caution should be used when looking at the results because different study designs were combined and a tool with unclear ability to determine the quality of observational studies besides cohorts was employed.

There is insufficient evidence to conclude the optimal surgical protocol for patients under ARD to prevent MRONJ. It seems reasonable to continue reinforcing the importance of preventive care for this target group of patients from the very beginning of treatment with ARD. The latest position finds that papers from national and international organisations are useful tools for case evaluation and treatment together with the University of Connecticut Osteonecrosis Numerical Scale1 for risk evaluation.