Long-term changes in vocal quality following Isshiki thyroplasty type I.

Long-term changes in vocal quality, pre-Isshiki thyroplasty type I and up to 4 years 4 months post-thyroplasty, were determined in a group of five subjects exhibiting unilateral vocal fold paralysis. Thyroplasty type I medializes the paralyzed fold by using a Silastic implant for external compression of the paralyzed vocal fold. No periphonosurgical or post-phonosurgical complications were noted. Longitudinal evaluation resulted in significantly higher vocal fundamental frequency, significant moderation of habitual vocal intensity, and significantly longer maximum phonation time. The thyroplasty group exhibited significantly more breath groups than control subjects both prethyroplasty and post-thyroplasty; within the thyroplasty group, a reduction in breath groups was exhibited prethyroplasty as compared to post-thyroplasty. The long-term positive changes observed in fundamental frequency, intensity, maximum phonation time, and breath groups were attributed to medialization of the paralyzed vocal fold.