Geographical Location and Response to Trismus Rehabilitation Following Head and Neck Cancer Treatment: A Secondary Analysis of the Restorabite Trials

BACKGROUND: Trismus is a common and disabling complication following head and neck cancer (HNC) treatment, particularly after multimodal therapy. Survivors in regional areas face barriers to accessing specialist rehabilitation. This study explored whether a patient's geographical location of residence influenced their response to trismus therapy. METHODS: Secondary analysis of pooled data from three Restorabite trials (2021-2024) was performed. Adults with HNC-related trismus (maximal interincisal opening [MIO] ≤ 35 mm) completed a 10-week individualized rehabilitation program incorporating manual therapy, daily jaw exercises, and weekly speech pathology review delivered in person or via telehealth. Most participants (96.6%) received all or part of their intervention via telehealth. Outcomes included MIO and Gothenburg Trismus Questionnaire (GTQ) scores. Longitudinal change was modeled using generalized estimating equations. RESULTS: A total of 175 participants with a broad range of HNC subsites, tumor stage, and treatment modalities were included. MIO improved by an average of 1.2 mm/week and GTQ scores by -2.7 points/week after 10 weeks of trismus rehabilitation (both p < 0.001). While multimodal treatment had a negative effect on both MIO and GTQ, geographical residence was not associated with change in MIO or GTQ in adjusted models (p = 0.5 and p = 0.1, respectively). CONCLUSIONS: For geographically dispersed patients, geographical residence was not associated with poorer trismus outcomes within a predominantly telehealth-supported model of care, supporting the use of telehealth to facilitate access to specialist trismus rehabilitation.