Velopharyngeal inadequacy

Overview
Velopharyngeal inadequacy (VPI) is a malfunction of a velopharyngeal mechanism.

The velopharyngeal mechanism is responsible for directing the transmission of sound energy and air pressure in both the oral cavity and the nasal cavity. When this mechanism is impaired in some way, the valve does not fully close, and a condition known as 'velopharyngeal inadequacy' can develop. VPI can either be congenital or acquired later in life.

Terminology
Different terms can be used to describe this phenomenon in addition to “velopharyngeal inadequacy.” These terms and definitions are as follows:


 * Velopharyngeal insufficiency: The mobility of the velopharyngeal sphincter to sufficiently separate the nasal cavity from the oral cavity during speech.


 * Velopharyngeal incompetency: When the velum and the lateral/posterior pharyngeal walls fail to separate the oral cavity from the nasal cavity during speech.

Although the definitions are similar, the etiologies correlated with each term differ slightly; however, in the field of medical professionals these terms are typically used interchangeably. Velopharyngeal inadequacy is the generic term most often used to describe the functionality of the velopharyngeal valve.

Relationship to cleft palate
A cleft palate is one of the most common causes of VPI. Cleft palate is an anatomical abnormality that occurs in utero and is present at birth. This malformation can affect the lip, the lip and palate, or the palate only. A cleft palate can affect the mobility of the velopharyngeal valve, thereby resulting in VPI.

Classification
The most frequent types of cleft palates are overt, submucous, and occult submucous.

Causes
While cleft is the most common cause of VPI, other significant etiologies exist. These other causes are outlined in the chart below: