Temporomandibular Disorders as a Risk Factor for Suicidal Behavior: A Systematic Review

Background: Temporomandibular disorders (TMD) are a group of common musculoskeletal dysfunctions that affect the temporomandibular joint or masticatory muscles and related structures or are expressed as a clinical combination of these two factors. The etiology of TMD is multifactorial and features related to anxiety, depression and mental disorders can contribute to the predisposition, onset and progression of TMD. The ability to adapt and develop coping attitudes was reduced in patients presenting with chronic pain, while suicidal behavior (suicidal ideation, suicide attempts, and suicide completion) was increased. The objective of this review was therefore to investigate suicidal behavior in relation to TMD. Methods: The review was performed according to the PRISMA 2020 guidelines. Six databases (PubMed, MEDLINE, EMBASE, Scopus, Ovid, and Google Scholar) were consulted through the use of keywords related to the review topic. The study is registered on PROSPERO (CRD42022320828). Results: The preliminary systematic search of the literature yielded 267 records. Excluding duplicates, 15 were considered potentially relevant and kept for title and abstract analysis. Only six articles were considered admissible reporting a single exposure factor, TMD and a single outcome, suicidal behavior, although these were evaluated through different assessment tools. We found a low association of TMD with suicidal behavior in observational studies, with estimates partly provided [prevalence ratio (PR) from 1.26 to 1.35, 95% confidence intervals (CI) from 1.15 to 1.19 (lower) and from 1.37 to 1.54 (higher); and odds ratios (OR) from 1.54 to 2.56, 95% CI from 1.014 to 1.157 (lower) and 2.051 to 6.484 (higher)], a relevant sample size (n = 44,645), but a few studies included (n = 6). Conclusions: The results of the included studies showed that the prevalence data of suicidal behavior were more present in young adults with TMD, with a controversial association with gender. Suicidal behavior was also correlated and aggravated by the intensity of pain.