Fig. 2

Latency of the swallowing reflex before and 3 months after treatment among the sites of head and neck cancer. Asterisks indicate significant differences between before and after treatment. The error bars indicate standard deviation. a Comparison of the latency time of the swallowing reflex between before and 3 months after treatment in cancers of the oral cavity (n = 28), pharynx (n = 25, p < 0.05, Wilcoxon rank-sum test), oropharynx (n = 17), and hypopharynx (n = 8, p < 0.05, Wilcoxon rank-sum test). b Comparison of the percentage of patients with a delayed swallowing reflex between before and 3 months after treatment in patients with cancers of the oral cavity, pharynx (p < 0.01, Fisher’s exact test), oropharynx, and hypopharynx. Time over 3 s was defined as a delayed swallowing reflex