Type III Thyroplasty for Patients With High-Pitched Voice Disorders: A Systematic Review and Meta-analysis

Abstract

Objective: High-pitched voice disorders can present notable social and professional obstacles for cisgender and transgender men. Our study aims to conduct a comprehensive meta-analysis assessing the efficacy of type III thyroplasty, also known as relaxation thyroplasty, for different populations with high-pitched voice disorders.

Data sources: A systematic literature review was conducted following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, searching Medline/Pubmed, Embase, Cochrane, Science Direct, Scielo, LILACS, and Google Scholar databases from inception to April 2024.

Review methods: Studies included patients undergoing type III thyroplasty for high-pitched voice disorders. The primary outcome was the change in fundamental frequency postintervention. Subgroup analyses compared the following: (1) cisgender versus transgender populations, (2) primary versus secondary causes of high-pitched voice disorders, and (3) unilateral versus bilateral vertical stripe resection techniques.

Results: The initial search yielded 284 articles, 9 studies, including 69 unique patients, were included in the analysis. All studies provided level 4 evidence. Most patients were cisgender men with primary mutational dysphonia (66.7%, n = 46). The meta-analysis showed a significant reduction in fundamental frequency after surgery, with a mean difference of -75.9 Hz (95% confidence interval [CI]: -91.5 to -60.3). Cisgender men and patients submitted to unilateral resection had higher preoperative fundamental frequency and showed a more pronounced reduction in fundamental frequency. There were no significant differences between primary and secondary mutational dysphonia.

Conclusion: Type III thyroplasty effectively lowers vocal pitch in patients with high-pitched voice disorders. The procedure is viable for both cisgender and transgender men, as well as for primary and secondary voice disorders.

Keywords: framework surgery; mutational falsetto; puberphonia; relaxation thyroplasty; transgender persons; type III thyroplasty.