Quantitative measures of laryngeal function following Teflon injection or thyroplasty type I

Laryngeal/voice function was evaluated in six patients with unilateral true vocal fold paralysis following treatment with Teflon injection (TEF) compared to six patients treated with thyroplasty type I (THY). Auditory perceptual, aerodynamic, and endoscopic assessments were conducted. Three judges rated nine voice characteristics. Aerodynamic measures included estimated subglottal pressure, airflow, and laryngeal resistance. Two judges rated laryngeal characteristics from flexible fiberoptic assessment. The THY group had significantly better voice quality and better quantitative aerodynamic findings compared to the TEF group. The TEF group also was more likely to have an irregular vocal fold edge, an irregular glottal closure pattern, a higher occurrence of hyperfunction and hypertrophy of the false vocal folds, edema, and erythema of the paralyzed folds. Results suggest that THY was associated with more favorable measures of laryngeal/voice function than TEF. It is likely that the poorer perceptual, aerodynamic, and endoscopic findings associated with TEF injection may be due to violation of the true vocal fold cover, particularly increased true vocal fold mass and stiffness.