Timing of Glottic Closure during Swallowing: A Combined Electromyographic and Endoscopic Analysis

Abstract

The initial medialization of the arytenoids is due to a decrease in motor tone of the posterior cricoarytenoid muscle. Full glottic closure typically occurs late in the process of swallowing, with activation of the thyroarytenoid muscle. Shifting of arytenoid medialization and glottic closure earlier in the super-supraglottic swallow indicates that glottic closure is under significant voluntary control.