Temporomandibular joint disorders in dental students - a systematic review of the literature

BACKGROUND: Temporomandibular disorders (TMD) are a group of musculoskeletal conditions that may affect quality of life and functional performance. Dental students represent a population potentially at increased risk due to academic demands, psychosocial stress, and occupational strain; however, reported prevalence estimates and associated factors vary across studies. OBJECTIVE: This systematic review aimed to synthesize evidence published between 2010 and 2024 on the prevalence of TMD among dental students and to examine reported associations with psychological stress, gender, and stage of dental education. METHODS: A systematic literature search was conducted in PubMed, Scopus, Web of Science, and Embase in accordance with PRISMA 2020 guidelines. The search strategy combined controlled vocabulary (MeSH and Emtree terms) and free-text terms. Original quantitative studies involving dental students were included. Data extraction included study characteristics, diagnostic methods, prevalence estimates (n/N, %), and reported associations. Methodological quality was assessed using an adapted Newcastle-Ottawa Scale, and the certainty of evidence was evaluated using the GRADE framework. Due to substantial heterogeneity in diagnostic criteria and outcome measures, a qualitative synthesis was performed, with studies grouped according to diagnostic approach. Missing data were coded as "NA", and non-reportable prevalence values were indicated as "NR". RESULTS: A total of 23 studies were included. Reported prevalence of TMD ranged from 15.0% to 82.3%, reflecting differences in diagnostic methods and study designs. Studies using standardized diagnostic criteria (RDC/TMD or DC/TMD) generally reported lower prevalence estimates compared to those using self-reported instruments. Psychological stress was assessed in 15 out of 23 studies; however, reported associations with TMD were not consistent. Associations with gender were also inconsistently reported. The overall certainty of evidence was rated as low. CONCLUSIONS: Temporomandibular disorders are frequently reported among dental students; however, prevalence estimates vary considerably due to methodological heterogeneity. Reported associations with psychological stress and gender are inconsistent, and the predominantly cross-sectional design of included studies precludes causal inference. Future research should prioritize standardized diagnostic criteria, validated assessment tools, and longitudinal designs to improve comparability and strengthen the evidence base.