The issue with incidence: a scoping review of reported medication-related osteonecrosis of the jaws (MRONJ) incidence around the globe.

Background: Medication-related osteonecrosis of the jaws (MRONJ) can be a debilitating condition which is challenging to manage. While vast literature exists surrounding MRONJ, many studies have small participant numbers and are heterogeneous in design, leaving unanswered questions and making evidence-based practice challenging.

Objective: Provide an overview of recent MRONJ incidence data, over a 5-year period, identify potential issues in reporting MRONJ cases and propose changes for future reporting.

Eligibility criteria: Studies with original data regarding MRONJ incidence published from 2015 to 2020.

Sources of evidence: A search was conducted on MEDLINE Ovid, the National Library of Medicine's bibliographic database, using a combination of medical subject headings (MeSH) and free text terms and run on 29 April 2021.

Charting method: Each title was hand-screened, and the abstract/article in full was reviewed to establish suitability for inclusion by two authors. Data extraction by two reviewers included author, year of publication, study design, population-cancer/osteoporosis/both/other, description of population, sampling method, exclusion criteria, single centre Y/N, reported rate of MRONJ cases/number of participants, details of diagnosis and diagnostic criteria, duration of follow-up and location of study.

Results: The initial search returned 1186 titles, detailed screening and inclusion of additions resulted in 92 articles for data extraction. Mean incidence of MRONJ across all studies was 4.34% (median 2.42%, range 0% to 31.80%). The mean incidence based on patient group was oncology 6.22% (32 954 participants), osteoporosis 0.58% (498 443 participants), oncology and osteoporosis 7.21% (54 7651 participants) and other, including autoimmune, inflammatory and other bone conditions, 2.55% (4487 participants). Further analysis showed incidence influenced by study size (>500 participants), diagnostic criteria used, location of study and other factors.

Conclusion: Heterogeneity in studies reporting MRONJ incidence impacts results and conclusions. Standardised, contemporaneous reporting of MRONJ cases would eliminate this variation and provide valuable insight into the epidemiology, natural history and outcomes of these patients, supporting evidence-based management and service provision of patients affected.