Videofluoroscopic analysis of different volumes of liquid bolus swallowing in healthy individuals: comparison between height and sex

OBJECTIVE The volume of swallowed bolus affects the pharyngeal transit duration. The sex and corporal height of individuals may likely influence this effect. The aim of this investigation was to determine the influence of sex and corporal height on the pharyngeal transit modification produced by the swallowed bolus volume. METHODS Forty healthy volunteers, 20 men and 20 women, including tall (10 men and 10 women, corporal height: 1.71--2.07m) and short (10 men and 10 women, corporal height: 1.52--1.70m) persons, ranging in age between 20 and 50 years, were included in the study. Videofluoroscopic evaluation of swallowing was performed with the subjects in the sitting position. Each individual swallowed three 5 mL and three 10 mL boluses of liquid barium in a random sequence. The durations of oral transit, pharyngeal transit, pharyngeal clearance, hyoid movement, upper esophageal sphincter opening and oral-pharyngeal transit were evaluated. RESULTS In men and women, and in taller and shorter individuals, the increase of the swallowed liquid bolus volume from 5 mL to 10 mL causes a faster transit of the bolus tail from the oral-pharyngeal transition to the upper esophageal sphincter and an increase in the duration of the upper esophageal sphincter opening, with similar alteration in men and women and in taller and shorter individuals. CONCLUSION An increase in the swallowed liquid bolus volume from 5 mL to 10 mL causes a faster pharyngeal bolus transit and a longer bolus transit through the upper esophageal sphincter, with similar alterations in men and women and in shorter and taller individuals.