## 2 Materials and Methods  
This umbrella review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines [38]. The protocol of this review was registered in the International Platform of Registered Systematic Review and Meta-analysis Protocols (INPLASY) under the number INPLASY202160061. The following four databases were explored: PubMed, MEDLINE, EMBASE and CINAHL. A three-stage screening approach was used to ensure precision and safeguard the quality of the search. The screening of titles and abstracts was carried out independently by five authors ([PERSON], [PERSON], [PERSON], [PERSON] and OA) to eliminate any irrelevant materials (i.e., reviews, animal studies, non-clinical studies). Disagreements were resolved by discussion until a consensus was reached. A data screening and abstraction form was used to:  
* Verify the study eligibility derived from the inclusion/exclusion criteria. Carry out the methodological quality assessment. * Extract data on study characteristics and outcomes for the included studies (Figure 1). \begin{table}
\begin{tabular}{c c c} \hline \hline
**Guideline/Position Paper/Recommendation** & **Country** & **Year** \\ \hline Canadian Consensus of Practice Guidelines for Bisphosphonate Associated Osteonecrosis of the Jaw [26] & Canada & 2008 \\ \hline Osteonecrosis of the Jaw Complicating Bisphosphonate Treatment for Bone Disease in Multiple Myeloma: An Overview with Recommendations for Prevention and Treatment [27] & Australia & 2009 \\ \hline The Use of Bisphosphonates in Multiple Myeloma: Recommendations of an Expert Panel on & Europe & 2009 \\ \hline Management of Patients at Risk of Bisphosphonate Osteonecrosis in Maxillofacial Surgery Units in the UK [29] & UK & 2009 \\ \hline Managing the Care of Patients Receiving Antiresorptive Therapy for Prevention and Treatment of Osteonecrosis. Executive Summary of Recommendations from the American Dental Association Council on Scientific Affairs [30] & USA & 2011 \\ \hline Guidelines for Supportive Care in Multiple Myeloma 2011 [31] & UK & 2011 \\ \hline Medication-Related Osteonecrosis of the Jaw-2014 Update [8] & USA & 2014 \\ \hline Diagnosis and Management of Osteonecrosis of the Jaw: A Systematic Review and International Consensus [32] & Canada & 2014 \\ \hline Medication Related Osteonecrosis of the Jaw: 2015 Position Statement of the Korean Society for Bone and Mineral Research and the Korean Association of Oral and Maxillofacial Surgeons [33] & Korea & 2015 \\ \hline “Position paper on medication-related osteonecrosis of the jaw (MRONJ)” [34] & Germany & 2016 \\ \hline Antiresorptive Agent-Related Osteonecrosis of the Jaw: Position Paper 2017 of the Japanese Allied Committee on Osteonecrosis of the Jaw [35] & Japan & 2016 \\ \hline Case-Based Review of Osteonecrosis of the jaw (ONJ) and Application of the International Recommendations for Management from the International Task Force on ONJ [1] & Canada & 2017 \\ \hline Oral Health Management of Patients at Risk of Medication-Related Osteonecrosis of the Jaw [36] & Scotland & 2017 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Chronologic summary of the most common published guidelines/position papers/recommendations. The authors of any studies eligible for inclusion in the review with insufficient information were contacted directly to provide further information. The inclusion criteria was based on a PICO(S) strategy [39]. Focused question and PICO strategy  
What is the current state of evidence related to MRONJ after 18 years of study? - Population (P): any (no limits of age) patients with MRONJ;  
- Interventions (I): any types;  
- Comparison (C): any types;  
- Outcome (O): state of knowledge based on the type of studies included in the reviews;  
- Study (S): systematic review (SR) or meta-analysis (MA). A search strategy for all databases was developed as follows:  
1.