Materials and methods
This study was performed according to The Joanna Briggs Institute Reviewers’ Manual 2014: Methodology for JBI Umbrella Reviews and Cochrane Handbook for Systematic Reviews of Interventions Version 6.2.13 The review protocol was registered at The Open Science Framework under osf.io/74cej.
An extensive literature search was performed among seven electronic databases for articles published up to February 5, 2022: MEDLINE/PubMed, Web of Science, Cochrane Library, Embase, Scopus, LILACS and BBO. Other sources were consulted through Google Scholar and System for Information on Grey Literature in Europe (SIGLE) through OpenGrey databases. The protocol registration databases included PROSPERO and Open Science Framework – OSF. Hand-searches were also performed in specialized periodicals (Step 1): Journal of Oral and Maxillofacial Surgery; International Journal of Oral and Maxillofacial Surgery; Journal of Cranio-Maxillo-Facial Surgery; British Journal of Oral and Maxillofacial Surgery; Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology; Journal of Dentistry, Medicine and Medical Sciences; and Journal of Oral Rehabilitation; and in reference lists of selected articles (Step 2). To keep the search strategy updated, alerts were established for each database.
This overview aimed to answer the focused question: “What is the quality of evidence of secondary studies on the treatment of DDwoR of the TMJ?” The terms and keywords of the search strategy (Table 1) were defined to identify SRs based on the elements of the PICO question:
We included SRs and meta-analyses on the comparison of different types of treatment for DDwoR of the TMJ. Systematic reviews based on animal studies and data from observational studies, and that did not report the eligibility criteria or quality assessment of the primary studies were excluded. Unavailability of the full paper was described in the PRISMA flow diagram. There was no restriction of studies by date and language of publication.
The selection process was conducted in two phases: Phase 1, two researchers (L.M.B. and D.S.B.) independently assessed all titles and abstracts, applying the including process (blind process); and Phase 2, the same two reviewers independently applied the exclusion criteria to the remaining studies, based on reading the full text. Inter-reviewer reliability in the study selection process was determined by the Cohen κ test, assuming an acceptable threshold value of 0.80.14 The disagreement at any stage was resolved by discussion, and a third reviewer (B.C.E.V.) will be consulted (consensus meeting). The final decision/selection was always based on the full text of the publication.
Data was independently extracted by two blinded reviewers (L.M.B. and D.S.B) using a standardized sheet, as recommended by the Cochrane Handbook for Systematic Reviews of Interventions Version 6.2,13 ordered in the PICO sequence: authors, year of publication, country where trials were performed, trial design, objectives, patient population characteristics, number of participants randomly assigned to each treatment group, clinical setting, detail of interventions in each group, details of comparators in each group, outcomes, measured outcomes (including assessment methods), results, duration of follow-up, number of withdrawals, and source of funding. When there were unclear or missed information, lack of data or when the full text was not available, weekly attempts were made for up to five weeks to contact the authors. The accuracy of extracted data was confirmed by another author (M.C.M.B.). The synthesis of qualitative results followed the SWiM reporting guideline.15
The quality of evidence and the possibility of biased results (bias) from the included systematic reviews and meta-analyses were independently assessed by two researchers (L.M.B. and D.S.B.) using the tools: ”A MeaSurement Tool to Assess systematic Reviews 2 (AMSTAR 2)”,16 ”Overview Quality Assessment Questionnaire (OQAQ)”17 and ”Critical Appraisal Skills Programme (CASP)”.18 The risk of bias in SRs was assessed using the “Risk of Bias in Systematic Reviews” (ROBIS) tool.19