Medialization of the vocal cord by the method of thyroplasty I is a possible surgical treatment of unilateral paresis of the larynx or inadequate closure of the true glottis during phonation. The authors implemented thyroplasty I as a phonosurgical operation in the modification of Harries and Morrison in a total of 31 patients. In 23 patients unilateral paresis of the recurrent nerve was involved (14 times after thyroidectomy ogoitrectomy, twice after surgery of a chemodec- toma of the glomus caroticum, once after surgery of neurinoma of the acoustic nerve; five times idiopathic paresis was involved, probably after a virosis and once paresis of obscure etiology in a female patient with breast cancer). In seven patients the voice was impaired due to atrophy of a movable vocal cord and in one patient due to ankylosis of the cricoarytenoid articulation. The most frequent preoperative complaints of the surgically treated group of patients were hoarse- ness, vocal fatigue and inadequate expectoration or the feeling of mucus in the airways. The complaint of dyspnoea when speaking was more frequent than dyspnoea during physical exertion. During the postoperative subjective evaluation 25 patients reported substantial regression of their complaints, four patients reported improvement of their condition and only two patients reported that their condition did not change. The subjective evaluation was in the majority of patients consistent with findings of laryngoscopy, the preoperative and postoperative phoniatric examina- tion. The evaluation was less consistent with the change in the length of the maximal phonation time before and after surgery. In one patient the authors observed a dislocation of the prosthesis from the window in the thyroid cartilage, one female patient complained about the postoperative scar on the neck. The postopera- tive oedema in the laryngeal area did not cause in any of the patients dyspnoea during inspiration. The authors consider thyroplasty I a phonosurgical method which gives great hope of substantial mitigation of complaints in patients with unilateral paresis or atrophy of the vocal cord, while complications and failure of treatment are minimal. Detailed pre- and postoperative phoniatric examination is an essential part of phonosurgical treatment.

        Key words: phonosurgery, thyroplasty I, medialization of the vocal cord.