Combined type IIIB with bilateral type I thyroplasty for pitch lowering with maintenance of vocal fold tension

Abstract

Objective To evaluate type IIIB thyroplasty using the excised larynx bench apparatus and determine how altering vocal fold contour by performing bilateral medialization of the inferior vocal fold affects phonation. This procedure could be performed in patients for whom pitch lowering is desirable, such as female-to-male transsexuals or male patients with mutational falsetto in whom intensive voice therapy was insufficient. Methods Aerodynamic, acoustic, and high-speed videokymographic data were collected for nine larynges at three subglottal pressure inputs for each of three conditions: normal; type IIIB thyroplasty; and combined type IIIB with modified bilateral type I thyroplasty intended to create a more rectangular glottal configuration. Each larynx served as its own control. Results Phonation threshold flow (p=0.005), phonation threshold power (p=0.031), and airflow varied across conditions with highest values for type IIIB thyroplasty and lowest for the combined procedure. Fundamental frequency was significantly different (p<0.001), decreasing by approximately 100 Hz from control to type IIIB trials, and then by approximately 15 Hz from IIIB to combined procedure trials. Vibratory amplitudes and intrafold phase difference were highest for type IIIB trials. Conclusions Addition of bilateral inferior medialization to type IIIB thyroplasty provided some further decrease in frequency, but mostly served to increase tension, reduce airflow, and produce a vibratory pattern which more closely mirrored control trials. Exploration of this combined procedure in patients may be warranted if not completely satisfied with the results from type IIIB thyroplasty alone.

Bilateral In-Office Injection Laryngoplasty as an Adjunctive Treatment for Recalcitrant Puberphonia: A Case Report and Review of the Literature

“…Less invasive modifications were proposed by Kocak et al and Tucker. 5, 6 Hoffman et al 14 proposed the combination of thyroplasties, for example, shortening thyroplasty with bilateral medialization thyroplasty. Kocak et al 5 reported 21 patients undergoing a window anterior commissure relaxation laryngoplasty, including one patient with mutational falsetto.…”

Development of Excised Larynx

“…57 In a subsequent study, an excised canine larynx was used to evaluate type IIIB thyroplasty combined with bilateral type I thyroplasty for lowering pitch while maintaining the tension of the vocal folds. 58 Thompson et al modified the approach of medialization thyroplasty by performing medialization thyroplasty via the subthyroid cartilage approach on an excised canine larynx, showing that it is possible to improve acoustic and aerodynamic parameters without requiring to make a window on thyroid cartilage. 59 Lagier et al used ImageJ to measure the mean glottal area of 21 excised human larynges in the situations of no adduction, arytenoid adduction, membranous vocal fold adduction, and both arytenoid and membranous adduction.…”