Supplementary Material for: Treatment effects of combined transoral injection laryngoplasty with short voice therapy in patients with unilateral vocal fold immobility – a pilot study

Introduction: Injection laryngoplasty (IL) in combination with short voice therapy (SVT) has been recommended in unilateral vocal fold immobility (UVFI). This pilot study investigated functional voice changes, age, and time-to-treatment effects in UVFI after transoral IL with hyaluronic acid (HA) and SVT.
Methods: 17 adults with UVFI (mean age: 61 years) were retrospectively analyzed. Outcome measures were the Voice Handicap Index 9i (VHI-9i), perceptual Grading-Roughness-Breathiness-Asthenia-Strain (GRBAS) Scale, voice range profiles (VRP) of the speaking, calling, and singing voice, maximum phonation time (MPT), jitter, and the Dysphonia Severity Index (DSI). T-tests and Wilcoxon tests evaluated treatment effects; age and time-to-treatment effects on the magnitude of change were assessed by Spearman’s correlation.
Results: There were significant improvements in VHI-9i and GRBAS scale overall G, R, B, and A. Mean speaking and mean calling sound pressure level (SPL), maximum singing SPL, and mean calling fundamental frequency (f0) increased, while the DSI and jitter improved. Time-to-treatment significantly affected the magnitude of change in mean speaking and maximum singing SPL, singing SPL range, jitter, and DSI; age influenced minimum speaking f0 only.
Conclusion: Transoral IL with SVT significantly improves subjective, perceptual, and instrumental acoustic voice outcomes in UVFI. Improvement of speaking and calling VRP after IL have not been previously documented. Our findings suggest that early treatment is beneficial for mean speaking loudness, maximum singing SPL, singing SPL range, jitter, and the DSI. More research is needed to examine the influence of time-to-treatment and age, and also to what extent SVT contributes to treatment effects.