Temporomandibular Disorders as Contributors to Primary Headaches: A Systematic Review.

AIMS: To systematically review the literature assessing associations between TMDs and primary headaches. METHODS: Using validated clinical criteria, studies on TMDs and primary headaches published up to January 10, 2023 were identified using six electronic databases. This review adhered to the PRISMA 2020 guidelines and 27-item checklist and is registered on PROSPERO (CRD42021256391). Risk of bias was evaluated using the National Institutes of Health Quality Assessment Toolkits for Observational Cohort and Cross-Sectional Studies. RESULTS: Two independent investigators rated 7,697 records against the primary endpoint and found 8 records meeting the eligibility requirements. Migraine was found to be the most common primary headache related to TMDs (61.5%), followed by episodic tension-type headache (ETTH; 38.5%). A moderate association was found for mixed TMDs with migraine and ETTH, with a large sample size and multiple studies included (n = 8). A very low-quality association was found for myalgia-related TMDs with migraine and ETTH (included studies, n = 2). CONCLUSION: The association between TMDs and primary headaches is of great interest given the possible effectiveness of TMD management in reducing headache intensity/frequency in patients with TMDs and headache comorbidity. A moderate association was found for mixed TMDs with primary headaches, in particular migraine and ETTH. However, owing to the overall moderate certainty of evidence of the present findings, further longitudinal studies with larger samples investigating possible associated factors and using accurate TMD and headache category assignment are needed.

Comparative in vitro study on biomechanical behavior of zirconia and polyetheretherketone biomaterials exposed to experimental loading conditions in a prototypal simulator.

Zirconia and polyetheretherketone (PEEK) are two biomaterials widely investigated as substitute for metals in oral prosthetic rehabilitation. To achieve a proper biomechanical behavior, the prosthetic biomaterials must ensure a good resistance to loads, as this is a crucial characteristic enabling their use in dental applications. The aim of this study was to investigate differences in the fracture resistance of different biomaterials in an experimental environment: fixed partial dentures (FPDs) screwed in a prototype of biomimetic mandible. 10 Samples of FPDs were allocated in 2 groups (A and B): Group A (n=5) involved FPDs in zirconia-ceramic, and Group B (n=5) involved FPDs in PEEK-composite. The samples were loaded by means of a three-point bending mechanical test, and the load to fracture has been evaluated generating a point-by-point graphics (speed/load and time/deformation). The samples were further analyzed by micro-computed tomography (micro-CT) and described under experimental loading conditions. Zirconia-ceramic FDPs were the samples reporting the worst results, showing a lower value of vertical displacement with respect to PEEK-based samples. The micro-CT results have further confirmed the preliminary results previously described. This in vitro study aims to give analytic data on the reliability of PEEK as a reliable and strong biomaterial for prosthetic treatments.

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.