A systematic review of trismus induced by cancer therapies in head and neck cancer patients

This systematic review represents a thorough evaluation of the literature to clarify the impact of cancer therapies on the prevalence, quality of life and economic impact, and management strategies for cancer-therapy-induced trismus.A systematic literature search was conducted with assistance from a research librarian in the databases MEDLINE/PubMed and EMBASE for articles published between January 1, 1990 and December 31, 2008. Each study was independently assessed by two reviewers. Taking into account predetermined quality measures, a weighted prevalence was calculated for the prevalence of trismus. The level of evidence, recommendation grade, and guideline (if possible) were given for published preventive and management strategies for trismus.We reviewed a total of 22 published studies between 1990 and 2008. Most of them assessed the prevalence of this complication, and few focused on management. The weighted prevalence for trismus was 25.4% in patients who received conventional radiotherapy and 5% for the few intensity-modulated radiation therapy studies. No clear guideline recommendations could be made for the prevention or management of trismus.Newer radiation modalities may decrease the prevalence of trismus compared to conventional radiotherapy. Few studies have addressed the quality of life impact of trismus, and no studies were identified to assess the economic impact of trismus. The few preventive and management trials identified in the literature showed some promise, although larger, well-designed studies are required to appropriately assess these therapies before recommendations can be provided.