The best way to diagnose laryngomalacia is:

Laryngomalaeia is a congenital disorder characterised by flaccidity of supraglottic larynx which gets sucked in during inspiration producing stridor. Flexible fibreoptic laryngoscopy is the best way to study the dynamics of supraglottis in an awake patient. Direct laryngoscopy may miss the diagnosis as supraglottis is put on stretch by the laryngoscope unless its tip is placed only in the vallecula. Other synchronous congenital lesions of larynx, e.g. glottic cysts, laryngeal paralysis or laryngeal web may also be diagnosed.