Type 3 thyroplasty for vocal masculinization in transgender men: a systematic review

ABSTRACT Voice masculinization surgery, particularly Type 3 thyroplasty (TP3), plays an important role for transgender men who do not achieve a satisfactory male vocal pitch with hormone therapy alone. Approximately 20% of transgender men fail to reach cisgender male vocal frequencies following gender-affirming hormone therapy (GAHT). This systematic review evaluates the effectiveness and safety of TP3 in lowering vocal pitch for transgender men. Comprehensive literature searches were conducted across multiple databases, including Cochrane Library, CINAHL Complete, MEDLINE Complete, EMBASE, Scopus, Web of Science, PubMed, AMED, and SpeechBite. Study selection was managed using Rayyan software, and methodological quality was assessed using the ROBINS-I tool. Inclusion criteria focused on studies reporting pre- and postoperative fundamental frequency (F0) in transgender men undergoing TP3. The quality of evidence was assessed using the GRADE approach, and the protocol adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Two studies involving a total of 21 transgender men (aged 20–54 years) met the inclusion criteria. Both studies reported significant reductions in F0 (ranging from 47.23 to 49.24 Hz; P < 0.001) and high levels of patient satisfaction. No major postoperative complications were reported. TP3 appears to be an effective surgical option for lowering vocal pitch in transgender men who are dissatisfied with the outcomes of hormone therapy. The observed decrease in F0 and favorable patient-reported outcomes suggest clinical benefit. Nonetheless, the limited number of studies and small sample size underscore the need for further research with larger cohorts and long-term follow-up to better assess the durability and safety of the procedure.