Motions of the posterior pharyngeal wall in human swallowing: A quantitative videofluorographic study

Objective: To quantify segmental motions of the posterior pharyngeal wall during swallowing. Design: Prospective study. Setting: Hospital radiology suite. Participants: Six healthy adult volunteers. Interventions: Videofluorography of the pharynx in posteroanterior and lateral projections during water swallows by 6 able-bodied adults. Radiopaque suction markers, inserted through the nose, were attached by suction to the midline of the posterior pharyngeal wall of the upper and lower oropharynx, pharyngoesophageal segment (PES), or cervical esophagus. Main Outcome Measures: Displacement of the larynx, hyoid bone, and markers. Results: Marker pathways were ovoid in the oropharynx but linear in the PES and esophagus. Marker displacement was greatest in the vertical dimension, intermediate in posteroanterior dimension, and smallest in mediolateral dimension. Vertical displacement was greater for the PES marker than for larynx, hyoid bone, or oropharynx markers (p < .001), so that the pharynx shortened significantly during each swallow. Marker displacement was unaffected by bolus volume. Conclusions: The pharyngeal wall shortened during swallowing. The mechanism for PES elevation may differ from that of laryngeal elevation. Shortening of the pharynx may be produced by contraction of the pharyngeal suspensory muscles and traction on the larynx by suprahyoid muscles.