Trismus in patients with head and neck cancer and 5-year overall survival.

Trismus is a common complication of radiotherapy for head and neck cancer but its impact on survival is unknown.This prospective study evaluates the incidence of trismus in patients with head and neck cancer receiving radiotherapy and the impact of trismus on 5-year overall survival.Two hundred forty-four patients with head and neck cancer were included. All patients received instructions on jaw exercises and were evaluated before initiation of radiotherapy and at 2, 6, and 12 months after termination of radiotherapy.One year after treatment 25% had a reduced maximum interincisal opening (MIO) of 13 mm or more as compared to the pretreatment MIO. Trismus was most prevalent in patients with oral and oropharyngeal cancer. A trend towards worse 5-year overall survival was seen among patients with trismus.The trismus rate was approximately 30% at 12 months. Jaw exercises should primarily be offered to patients with oral and oropharyngeal cancer who are most likely to benefit. Further studies are required to investigate the effect of trismus on survival.This study identifies patients likely to benefit from jaw exercises and provides basis for further research on trismus and survival.