A Systematic Review on the Impact of Smartphone Usage on Temporomandibular Disorders.

Temporomandibular disorders (TMDs) are prevalent musculoskeletal conditions affecting the temporomandibular joint (TMJ), masticatory muscles, and associated structures. Excessive smartphone use has been associated with postural deviations, increased muscular strain, psychological distress, and parafunctional habits. However, the extent of these associations remains uncertain. This systematic review aimed to synthesize current evidence on the impact of smartphone use on TMD severity by evaluating its biomechanical, neuromuscular, and psychological implications. A systematic search following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines for Abstracts was conducted across PubMed, Embase, Scopus, Web of Science, Cochrane Library, PsycINFO, and Google Scholar from January 2000 to September 2025. Studies assessing smartphone use and TMD using validated diagnostic tools (DC/TMD, RDC/TMD, Fonseca Index) were included. Risk of bias was evaluated using the risk of bias tool for non-randomized studies (ROBINS-I) and AXIS tools. Seven studies (n = 3,568 participants) were included. Excessive smartphone use was significantly associated with higher TMD severity (OR = 1.9; 95% CI: 1.4-2.5; p < 0.05). Forward head posture and reduced craniovertebral angle correlated with increased muscular tension. Smartphone addiction was linked to parafunctional habits, such as bruxism (prevalence = 96.7%; p = 0.0005) and psychological distress (p < 0.01). Heterogeneity in diagnostic tools and exposure measures precluded meta-analysis. Excessive smartphone use is moderately associated with greater TMD severity, mediated by postural deviation, muscular strain, parafunctional behaviors, and psychological distress. Ergonomic posture correction, behavioral therapy, and stress-reduction interventions are essential preventive measures.