Abstract
The adductory movement of the vocal fold is produced mainly by the lateral cricoarytenoid muscle and the abductory movement is produced by the posterior cricoarytenoid muscle. In recurrent laryngeal nerve paralysis, the position of the paralized vocal fold can be largely influenced by the balance of the tonus of these antagonistic muscles. Marked medialization of the paralyzed vocal fold was obtained by transection of the posterior cricoarytenoid muscle in a patient with left recurrent laryngeal nerve paralysis, resulting in a remarkable improvement of hoarse voice. Experimental studies proved that transection of the posterior cricoarytenoid muscle caused medial displacement of the vocal fold.
