Movement of the epiglottis during deglutition. A cineradiographic study.

The movements of epiglottis during swallowing of barium were studied by high-speed cineradiography in 150 volunteers who had no dysphagia. In 137 individuals the epiglottis tilted down in a two-step fashion during deglutition. The first movement from an upright to transverse position was accomplished by elevation of the larynx and approximation of the hyoid bone and thyroid cartilage. This first movement is evidently a passive one and induced by the muscles that lift the hyoid bone. The second movement of the epiglottis, from transverse to an inverted position, occurs later in swallowing and seems related to contraction of the thyroepiglottic muscle. The second epiglottic movement was absent in 7 individuals, and 6 others demonstrated obliquity of their epiglottis (30-90 degrees) when studied in AP projection.