The effect of bolus volume on laryngeal closure and UES opening in swallowing: Kinematic analysis using 320‐row area detector CT study

Summary This study investigated the effects of three different volumes of honey‐thick liquid on the temporal characteristics of swallowing. Twenty‐six healthy subjects (15 males, 11 females) underwent 320‐row area detector CT scan while swallowing 3, 10 and 20 mL of honey‐thick liquid barium. Three‐dimensional images were created at 10 images/s. Kinematic events involving six structures (velopharynx, hyoid bone, epiglottis, laryngeal vestibule (LV), true vocal cords (TVC), upper esophageal sphincter (UES)) and timing of bolus movement were timed using frame by frame analysis. The overall sequence of events did not differ across three volumes; however, increasing bolus volume significantly changed the onset and termination of events. The bolus head reached to pharynx and esophagus earlier and the duration of bolus passing through UES was significantly longer in 10 and 20 mL compared to 3 mL (P