A Study of Vocal Facilitating Techniques Compared to Manual Circumlaryngeal Therapy in Teachers With Muscle Tension Dysphonia

Abstract

There are several voice therapy techniques been suggested in patients with muscle tension dysphonia (MTD), however a few studies are compared between them. The purpose of present study was to compare the effect of vocal facilitating techniques (VFTs) and manual circumlaryngeal therapy (MCT) in teachers with MTD. This is a randomized clinical trial study. Sixteen teachers with MTD (female; mean age: 38.6 ± 4.6 years) participated in this study. The participants allocated to two treatment groups: the first group received VFTs (n: 8) and MCT was presented to the second one (n: 8). In each group, the voice therapy techniques were given for 10 individual sessions twice a week. The effect of both techniques was assessed using voice handicap index (VHI) and dysphonia severity index (DSI). Within group comparison, the VHI, DSI, and theirs components showed significantly better results after both treatment groups (P ≤ 0.05). Although, effect size was strong for all target features (η2 > 0.36); the greatest magnitude was obtained on the physical subscale of VHI following MCT and for the DSI after VFTs (η2 = 0.92 and 0.90, respectively). Moreover, the interactive effect of time and treatment groups indicated that there was significant main effect on the physical and functional subscales of VHI (P = 0.00 and 0.02, respectively) as well as I-low and DSI (P = 0.01 and 0.02, respectively). VFTs and MCT are two effective techniques in voice therapy of teachers with MTD. However, the greatest improvement obtained on the DSI following VFTs and for the physical aspect of VHI after MCT demonstrated voice therapist can use appropriate technique based on the voice complaints and results of voice assessments in MTD.