Effect of radiotherapy on temporomandibular disorders and mandibular function in head and neck cancer patients: A systematic review

OBJECTIVE: To evaluate the effect of radiotherapy on temporomandibular disorders and mandibular function in adults with head and neck cancer. METHODS: A systematic review was conducted according to PRISMA 2020. MEDLINE/PubMed, Scopus, and Epistemonikos were searched, and eligible studies were qualitatively synthesized. RESULTS: Twenty-seven eligible reports/studies were included. Trismus and reduced mouth opening were the most frequently reported functional outcomes, whereas TMD-specific diagnoses were assessed less consistently. Evidence regarding dose-response relationships was heterogeneous, and interventions varied substantially across studies. CONCLUSION: Radiotherapy may adversely affect mandibular function in patients with head and neck cancer, particularly through restricted mouth opening. Further prospective studies using standardized TMD diagnostic criteria, dosimetric parameters, and longitudinal functional outcomes are needed.