This article provides a detailed explanation of the indications, sequence, and planning for type I thyroplasty and arytenoid adduction. Type I thyroplasty is indicated for all cases of vocal fold paralysis, in which the muscles are atrophied due to nerve paralysis. The indications for arytenoid adduction can be determined by a preoperative endoscopic examination. As the vocal fold swells with a short surgical procedure, arytenoid adduction is performed first. A cervical CT scan was used to evaluate and measure the following variables : 1) the shape and ossification state of the thyroid cartilage ; 2) the degree of vocal fold atrophy ; 3) the position of the anterior commissure attached to the thyroid cartilage ; 4) the angle of the vocal fold projected onto the affected thyroid cartilage ; and 5) the position of the arytenoid cartilage. Laryngeal electromyography is used to evaluate 1) based on the action potential during phonation, and 2) based on the difference in action potential between low-pitched and high-pitched phonation.
