Most common congenital anomaly of larynx is

Laryngomalacia (congenital laryngeal stridor): It is the most common congenital abnormality of the larynx. It is characterized by laryngeal excessive flaccidity of supraglottic region which is sucked in during inspiration producing stridor and sometimes cyanosis. Stridor is increased on crying but subsides on placing the child in the prone position. The cry is normal. This condition manifests at bih or soon after, and usually disappears by 2 years of age. Direct laryngoscopy shows elongated epiglottis, curled upon itself (omega-shaped O), floppy aryepiglottic folds and prominent arytenoids. A flexible laryngoscope is very useful to make the diagnosis. Laryngomalacia cannot be diagnosed in a paralyzed patient. Mostly, treatment is conservative. Tracheostomy may be required for some cases of severe respiratory obstruction. Supraglottoplasty is required in cases of severe laryngomalacia. Ref: PL Dhingra 7th edition of Ear, Nose and Throat, pg no. 333