Types and causes of velopharyngeal dysfunction.

The velopharyngeal valve is responsible for production of oral speech sounds. There are three components to normal velopharyngeal function: anatomy, physiology, and learning. velopharyngeal dysfunction (VPD) is a condition where the velopharyngeal valve does not close consistently and completely during the production of oral sounds. Velopharyngeal dysfunction can be caused by abnormal anatomy (velopharyngeal insufficiency), abnormal neurophysiology (velopharyngeal incompetence), or particular articulation errors (velopharyngeal mislearning). The purpose of this article is to acquaint the reader with what is required for normal velopharyngeal function. In addition, there will be a discussion of the types of velopharyngeal dysfunction and various causes of each. Implications for treatment and prognosis will be discussed. © Thieme Medical Publishers.