A retrospective study on the predictive factors in chronic trismus

Abstract Objectives Trismus is one of the most debilitating and treatment-resistant complications resulting from head and neck oncologic treatments. The objective of this study was to assess how primary tumour variables could assist in predicting chronic trismus. Materials and Methods From a (retrospective) oncologic database (department of Oral and Maxillofacial Surgery, University Hospitals Leuven), tumour-related, surgical and oral functional variables were reviewed. Contributing factors for chronic trismus, defined as a mouth opening of less than 35 mm, at least one year after treatment for oral squamous cell cancer were assessed via logistic regression. A mediational analysis was conducted on the significant predictive variables. Results Thirteen out of 52 patients were observed to have chronic trismus. A significantly higher prevalence of trismus was found for increasing clinical T classification (p  Conclusion Although radiotherapy and clinical T classification are well-established risk factors for postoperative trismus, masticatory muscle invasion should be considered as one of the main predictive factors.