Interventions for the treatment of Radiotherapy Induced Trismus: A Systematic Review of the Literature

OBJECTIVES: To systematically assess the outcome of interventions used to treat patients who have trismus as a result of radiotherapy to the head and neck region in the treatment of Head and Neck Cancer (HNC). METHODOLOGY: Searches were carried out on online databases (Medline, Embase and The Cochrane Central Library) on the 19th of June 2019 and then again using the same search terms on the 6th of June 2021. Randomized and Nonrandomized trials aimed at treating trismus as a side effect of head and neck radiotherapy (RT) were included for this systematic review. A total of 5 papers were reviewed for the purpose of this systematic review. RESULTS: Results show that there is limited evidence to support the use of any treatment modality other than structured jaw exercises to help treat trismus in patients with a history of HNC and RT induced fibrosis. There is no evidence to support the use of Botulinum toxin A, while further studies are needed to clarify the effectiveness of Pentoxifylline (with or without conjunction with Vitamin E) and Pregabalin in the treatment of postradiotherapy fibrosis. CONCLUSION: There is a need for more randomized control trials to identify treatment modalities for radiotherapy induced trismus. Rehabilitation exercises have been implemented across all papers involved in this study which indicates the need for analysis and identification of a pharmaceutical intervention. KEYWORDS: Head and neck cancer, trismus, lockjaw, radiotherapy, randomized controlled trial, placebo