Effect of Jaw Exercise on Mouth Opening and Trismus in Head and Neck Cancer Patients Undergoing Radiotherapy: A Randomised Controlled Trial
In brief
Wooden tongue depressors add no measurable benefit to jaw exercises during radiotherapy
In this 38-patient trial, adding wooden tongue depressors to basic jaw exercises did not significantly improve mouth opening compared with basic exercises alone. Mouth opening did not worsen from baseline through 20 weeks after radiotherapy began, but the small study leaves uncertainty about effects in larger groups or over longer follow-up.
- Journal
- Cancers (Q1)
- Published
- 5 October 2026
- Study design
- Randomized controlled trial
- Evidence level
- Level 1, High (CEBM 1b)
- Authors
- Tharmentheran Pitchaimuthu, Mohamad Yunus Mohd Razif, Khairiyiah Sidek, Syed Nabil
- PMID
- 42882909
- DOI
- 10.3390/cancers18193215
Why clinicians should know about it
- Picked for Radiation Oncology (top studies of the week, 18 October 2026): Randomised controlled trial, jaw exercise during radiotherapy
Abstract
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. Results: A total of 38 subjects were recruited, comprising 19 (50.0%) in the control group and 19 (50.0%) in the intervention group. There were 22 (57.9%) males and 16 (42.1%) females. Overall, the mean age of the patients was 52.5 years (22 to 74 years). Our clinical assessment showed no statistically significant differences (p = 0.835) in mouth opening among the groups, with an overall median of 0mm (IQR 7.0). Conclusions: Mouth opening did not worsen from baseline to 20 weeks after initiation of radiotherapy, and the addition of wooden tongue depressors did not confer a statistically significant benefit over basic jaw exercise alone. Trial Registration: ISRCTN96737564, registered on 26 August 2026, retrospectively registered.
Abstract as published, via PubMed.
For healthcare professionals. The summary is generated by AI from the published abstract, and the evidence level is assigned automatically from the study design on the Oxford CEBM hierarchy. Neither is medical advice. Read the full paper before changing practice.