Effects of the bolus volume on hyoid movements in normal individuals

Abstract

The hyoid bone moves during swallowing due to contraction of suprahyoid muscles, which are critical components of normal swallowing function. It has been reported that the muscle force and shortening velocity decline gradually with age. Reduced hyoid velocities may delay the sealing of the laryngeal vestibule and opening of the cricopharyngeal muscle. We hypothesised that the hyoid velocity could be a factor influencing aspiration. This study evaluated effects of bolus volume changes on the hyoid distance and velocity in normal swallowing. The subjects were 21 healthy young adults. Lateral projection videofluorography was recorded while each subject swallowed 2·5, 5·0, 10 and 20 mL of liquid barium. We evaluated the maximum hyoid distance (Max d), anterior and superior distance (Max ad, Max sd). And, we evaluated the maximum velocity (Max v), anterior and superior velocity (Max av, Max sv). Two-way anova test revealed that Max d, Max ad and Max sd for different bolus volumes are not significantly different. But, two-way anova test showed statistically significant difference in Max v, Max av and Max sv among different bolus volume (P < 0·01). Tukey's test showed that there are significant differences in Max v between 2·5 and 20 mL, 5·0 and 20 mL, 10 and 20 mL, and 2·5 and 10 mL swallowing. And, Tukey's test showed significant differences in Max av and Max sv between 2·5 and 20 mL, 5·0 and 20 mL, and 10 and 20 mL swallowing. It is possible that a larger bolus volume requires greater maximum hyoid velocity. We plan to study hyoid velocity in elderly subjects and in those with dysphagia.

Effects of Age and Bolus Volume on Velocity of Hyolaryngeal Excursion in Healthy Adults

“…Likewise, faster excursion velocity with increased bolus volume is consistent with prior reports [27,33]. Increased hyoid excursion magnitude and velocity with the larger bolus volume likely reflects the involuntary bolus accommodation process [21] in which the biomechanical aspects of swallowing system adapt to different bolus volumes to maintain optimal functional swallowing.…”

“…While some studies have found comparable excursion magnitudes between the hyoid and larynx during swallowing [14,15], other studies have reported different excursion magnitudes between these structures [16,17]. Hyolaryngeal excursion has been reported to be influenced by both age and bolus characteristics [17][18][19][20][21][22][23][24][25][26][27]. Studies of age-related changes in hyolaryngeal excursion have focused primarily on excursion duration and excursion magnitude.…”

“…Recent studies have incorporated excursion velocity to describe hyoid excursion kinematics during swallowing [27,33]. For example, Ueda et al [34] reported reduced hyoid excursion velocity in patients with dysphagia.…”

“…In another study, Sia et al [35] reported improved hyoid excursion velocity subsequent to successful intervention with the McNeill Dysphagia Therapy Program in patients with dysphagia. Moreover, recent studies have reported volume effects for hyoid excursion velocity in which hyoid excursion velocity increased with larger bolus volumes (faster movement) in young adults [27,33]. However, the effects of age and bolus volume on hyoid and laryngeal excursion velocities have not been systematically evaluated.…”

The Effect of Bolus Consistency on Hyoid Velocity in Healthy Swallowing

“…superior, anterior). Several recent studies suggest that hyoid velocity may differ between healthy and pathological swallows, with the latter having significantly reduced velocity [5, 8, 14–16]. Another parameter of potential clinical relevance is peak hyoid velocity, defined as the maximum rate of position change within a single plane of hyoid movement (Y: superior-inferior; or X: anterior-posterior).…”