The aryepiglotticus is an extension of the oblique arytenoid internus muscle, with fibers running anterosuperiorly from the arytenoid apex to the epiglottic margin within the aryepiglottic fold. Together with the oblique arytenoid, it constitutes the inlet sphincter of the larynx. The aryepiglottic folds form the lateral walls of the laryngeal aditus.
| Origin | Apex of the arytenoid cartilage, as a continuation of the oblique arytenoid muscle fibers |
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| Insertion | Lateral margin of the epiglottis and the aryepiglottic fold |
| Nerve Supply | Recurrent laryngeal nerve (CN X) |
| Blood Supply | Superior laryngeal artery |
| Actions | Narrows the laryngeal inlet by drawing the aryepiglottic folds toward the midline; assists in laryngeal closure during swallowing to prevent aspiration; contributes to the arytenoid-to-epiglottis closure mechanism |
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The aryepiglotticus and aryepiglottic folds are surgically addressed in supraglottoplasty for laryngomalacia, the most common cause of stridor in infants. In severe laryngomalacia, redundant aryepiglottic folds prolapse into the airway during inspiration; microlaryngoscopic division of the aryepiglottic folds (aryepiglottoplasty) widens the laryngeal inlet. The aryepiglottic fold is also the superolateral boundary of the piriform sinus, relevant in hypopharyngeal carcinoma staging.
Redundant aryepiglottic folds and omega-shaped epiglottis causing inspiratory stridor in infants are treated by endoscopic division of the aryepiglottic folds and trimming of the redundant supraglottic mucosa, widening the laryngeal inlet with resolution of stridor in over 90% of cases.
