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Updated: Dec 13, 2025
Adapting Human Videofluoroscopic Swallow Study Methods to Detect and Characterize Dysphagia in Murine Disease Models
Published on: March 1, 2015
The effect of bolus consistency on pharyngeal volume during swallowing: Kinematic analysis in three dimensions using
Yuriko Ito1, Yoko Inamoto2, Eiichi Saitoh1
1Department of Rehabilitation Medicine I, School of Medicine, Fujita Health University, Toyoake, Japan.
Objective:
This study investigated the effects of bolus consistency on pharyngeal volume during swallowing using three-dimensional kinematic analysis.
Methods:
Eight subjects (2 males and 6 females, mean ± SD 44 ± 10 years old) underwent a 320-row area detector scan during swallows of 10 mL of honey-thick liquid and thin liquid. Critical event timing (hyoid, soft palate, UES) and volume of pharyngeal cavity and bolus were measured and compared between two swallows.
Results:
The pharynx is almost completely obliterated by pharyngeal constriction against the tongue base for both consistencies. There were no significant differences in maximum volume, minimum volume and pharyngeal volume constriction ratio values between thick and thin liquids. However, the pattern of pharyngeal volume change (decrease) was different. For thick liquids, the air volume started to decrease before the onset of hyoid anterosuperior movement and decreased rapidly after onset of hyoid anterosuperior movement. During thin liquid swallowing, air volume remained relatively large throughout the swallow and started to decrease later when compared to swallowing thick liquids. At onset of UES opening, the bolus volume was not significantly different between thin and thick liquids; however, air volume was significantly larger when swallowing thin liquids, which made the total volume of the pharyngeal cavity larger.
Conclusion:
This difference between the two consistencies is associated with differences in tongue motion to propel the bolus and clear the pharynx from possible residue.
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