Advantage is that collagen is natural component of vocal fold. Disadvantage is that resorption does occur. Botulinum toxin - used to treat adductor spasmodic dysphonia. 25-30 U are injected through the cricothyroid membrane angled laterally and superiorly. Confirmation is made by EMG recording in the thyroarytenoid muscle.
Effects can endure for up to four months.
Best in patients with a tremor component to dysphonia. Transcutaneous technique described by Ward offers advantage of using upright position and visualization of the larynx during injection without direct laryngoscopy. B. Laryngeal Framework Surgery 1. Payr used a tilted U shaped incision on the thyroid ala to make a pedicled cartilage flap which was depressed inward displacing the vocal cord medially. Muerman transplanted autogenous costal cartilage between thyroid cartilage and inner perichondrium.