Hyoid Movement and Laryngeal Penetration During Sequential Swallowing

This study examined hyoid movementduring sequential swallowing and evaluatedthe relationship among trajectory patterns,swallowing types based on laryngeal movementand laryngeal penetration. Twelve healthy adultsunderwent videofluorography during sequentialswallowing. Each swallow was classified intotwo types: opened laryngeal vestibule afterswallow (i-Segmental type) and closed laryngealvestibule after swallow (i-Continuous type). Eachparticipant’s swallowing type was classified bythe same method. We analyzed two-dimensionalmovements of the hyoid, and the trajectorieswere classified into three patterns: hyoidmoved in the anterosuperior direction after theonset of swallow (pattern L); hyoid moved inthe anterosuperior direction after the onset ofswallow, beyond the mandibular plane (patternX); and the hyoid was above the mandibular planeat the onset of swallow, and then it moved in theinferior direction (pattern U). Two-way ANOVArevealed that there was a significant interactionbetween the swallowing type and trajectorypattern, and laryngeal penetration was thehighest for the combination of individual swallowof i-Continuous type and pattern L. In sequentialswallowing, the existence of a penetration-proneswallowing pattern combination was an interestingphenomenon relevant to eating management fordysphagic patients; however further study inpatient groups is required.