Anatomy and physiology of velopharyngeal closure and insufficiency.

The velopharynx is a complex structure that is responsible for separation of the oral and nasal cavities during speech production and swallowing. Incompetence of this mechanism can lead to hypernasality, with nasal air emission and incomprehensible speech, as well as nasopharyngeal regurgitation. There can be a significant social stigma associated with velopharyngeal dysfunction, and surgical treatment can be curative in many cases. Knowledge of the normal anatomy and physiology of the velopharyngeal complex is essential when planning for surgical repair.