Comparison of the Surgical Results in Mutational Dysphonia between Unilateral Shortening of Thyroid Cartilage Method and Bilateral Shortening of Thyroid Cartilage Method in Type III Thyroplasty

변성발성장애의 제3형 갑상연골성형술시 갑상연골익의 편측절제술과 양측절제술과의 치료성적 비교

Failure to change from the higher pitched voice of preadolescence to the lower pitched voice of adolescence and adulthood is called "mutational dysphonia" The voice is weak, thin, breathy, hoarse, and mono-pitched. If the voice theraphy was failed, surgery to lower vocal pitch which is refered to thyroplasty type III, is indicated. We compared the post-op acoustic parameters with pre-op data in unilateral antero-posterior shortening of the thyroid cartilage method and bilateral antero-posterior shortening of the thyroid cartilage method each other. Bilateral antero-posterior shortening of the thyroid cartilage method shows significant drop of fundamental frequency and speaking fundamental frequency statistically than unilateral shortening method. There was no significant differences in Jitter, Shimmer, SNR, MFR and other psychoacoustic analysiss parameters between two groups. These data shows that unequal tension of the vocal cord in uilateral antero-posterior shortening of the thyroid cartilage method does not control the pitch effectively so bilatreal shortening method in Type III thyroplasty is recommandable procedure in surgery of the mutational dysphonia.