Structural displacements in normal swallowing: A videofluoroscopic study

Dynamic videofluoroscopic swallow studies were performed on 60 normal adult volunteers to establish normative data for displacement of upper aerodiges tive tract structures during deglutition. Variables evaluated included hyoi d bone displacement, larynx-to-hyoid bone approximation, pharyngeal constri ction, and the extent of pharyngoesophageal sphincter (PES) opening during liquid swallows of 1, 3, and 20 cc. Results showed direct relationships bet ween bolus size and hyoid displacement, between bolus size and PES opening, and between bolus size and pharyngeal constriction. Only hyoid-to-larynx a pproximation remained unchanged across bolus sizes. Sex differences were no ted for all variables except PES opening. Reliability for most measurement variables was excellent. To our knowledge, normative data for pharyngeal co nstriction and larynx-to-hyoid approximation have not previously been descr ibed.