Supraglottic web occurs when either the false folds or aryepiglottic folds adhere to each other. This narrows the laryngeal vestibule and distorts the normal contours of the larynx. This is an uncommon diagnosis, and is usually either a complication of cancer-treating radiation therapy or else is the result of trauma, such as from a gunshot wound or severe blunt trauma to the larynx that causes fracture and tears the mucosa.
See also: glottic web.