The Effects of Bolus Consistency in Pharyngeal Transit Duration during Normal Swallowing

OBJECTIVE: To examine the effects of age, gender and bolus consistency in normal populations using the temporal measurement of Pharyngeal Transit Duration (PTD), which reflects the duration of bolus flow from the ramus of the mandible to the upper esophageal sphincter. METHOD: 40 normal and healthy subjects had Videofluoroscopic Swallowing Examinations (VFSEs) of 5 ml thin and nectar thick liquids, and puree consistencies. A slow motion and frame by frame analysis was performed. Three-way analysis of variance (ANOVA) was performed to examine the main effect and interactions, and paired t-tests for the three consistency comparisons. RESULTS: Older subjects had a significantly longer PTD than younger subjects (p<0.01). In addition, men had significantly shorter PTDs than women (p<0.01). Puree showed a significantly longer PTD than the other two consistencies, regardless of age and gender (p<0.05). CONCLUSION: PTD is an indicative of motor weakness in pharyngeal swallowing secondary to aging. In addition, the results supported the assumption that there is a functional difference in pharyngeal swallowing between men and women. It is expected that the results of this study will be used for further investigation of patients with dysphagia.