Effect of Jaw Exercise on Mouth Opening and Trismus in Head and Neck Cancer Patients Undergoing Radiotherapy: A Randomised Controlled Trial

Background/Objectives: We aimed to assess the efficacy of a simple intervention by comparing changes in mouth opening and trismus status among HNC patients during radiotherapy treatment. It also explored its effect on the patient’s mandibular function impairment.

Methods

This is a Randomised Controlled Trial in which subjects were divided into groups undergoing jaw exercise with a wooden tongue depressor versus a basic jaw exercise group. The primary outcome of this study was changes in maximal mouth opening (MMO)/maximal interincisal distance (MID) measured at baseline (before treatment), at the 10th and 20th week after initiation of radiotherapy. The secondary outcome included trismus prevalence and mandibular functionality, which were assessed in relation to trismus severity and the effectiveness of the intervention.