“…1,2 An example for a long-term injectable substance is calcium hydroxylapatite (Radiesse: Bioform Medical, Inc., San Mateo, CA). 3 Short-term duration injectable substances include collagen (Cymetra: Life-Cell, Branchburg, NJ), 4 autologous fat, 5 and hyaluronic acid (HA) 6,7 and are mainly used for temporary augmentation as they show an unpredictable effect. 8 The polysaccharide HA is a universal component of the extracellular matrix and part of the lamina propria of vocal folds.…”