Purpose: The purpose of this study was to evaluate voice quality before and after thyroplasty type 1 in patients with symptomatic unilateral vocal cord paralysis.
Methods: Fifteen consecutive cases of unilateral symptomatic vocal cord paralysis of a known or idiopathic etiology with the duration of 6 months who have failed conventional speech therapy. The voice quality was assessed by perceptual evaluation, acoustic measures, and aerodynamic measures. The position of the cord was assessed by using fiberoptic laryngoscope. The procedure was done under local anesthesia.
Results: Among 15 patients, on the first postoperative day, 7 patients were changed to moderate dysphonia and 8 patients had a near-normal voice. On the 30th postoperative day, 3 patients had persistent moderate dysphonia, nine patients had near-normal voice, and 3 patients had normal voice.
Conclusion: Thyroplasty type 1 successfully reduces glottic gap and improves voice quality in patients with unilateral vocal cord paralysis. Improved maximum phonation time, signal-to-noise ratio, shimmer, jitter, fundamental frequency, and intensity of voice appear to be directly related to medialization of the paralyzed vocal cord.