What is velopharyngeal dysfunction (VPD)?
A person’s speaking voice takes on a nasal tone when too much air flows through the nose. This happens when the moving tissue at the back of the roof of the mouth, called the soft palate or the velum, fails to close an opening called the velophayngeal port. The result is called velopharyngeal dysfunction (VPD).
VPD is most common in children as it is often associated with other birth/genetic conditions or surgical procedures, such as the removal of tonsils or adenoids. It can be caused by things that happen in adulthood such as surgeries for oral cancer or due to neurologic conditions.
Similar terms are sometimes used to describe different types of velopharyngeal dysfunction (VPD). These include:
- Velopharyngeal Insufficiency (VPI): Structural defects resulting in insufficient tissue to accomplish closure
- Velopharyngeal incompetence: The soft palate lets air into the nose because of a muscular or nerve problem, rather than because of the structure of the back of the mouth.
- Velopharyngeal mislearning: The palate is functioning properly, but a child has learned an unusual speech pattern that doesn’t use it properly.
Sometimes more than one of these types of VPD is present.
Who is at risk of developing velopharyngeal insufficiency (VPI)?
Besides cleft palate, velopharyngeal insufficiency is also common in children with other genetic conditions including:
- Down syndrome
- Velocardiofacial/Digeorge/22Q Deletion Syndrome, which sometimes includes a cleft palate
- Kabuki syndrome, which affects multiple parts of the body
- Neurofibromatosis, which causes tumors to grow in the nervous system
In adults, brain injuries and neurological conditions that weaken muscles are linked to the development of VPI.
What are the symptoms of velopharyngeal insufficiency (VPI)?
A person with VPI might have hypernasal speech, which means there is too much air resonating in the nose and it sounds as if they are speaking through the nose. What they say might be harder to understand, and they might have difficulty making certain sounds because there isn’t enough air pressure in their mouth. The air escaping through the nose might make a sound, such as a snort or a squeak. This is sometimes called “nasal turbulence.” In severe cases, food or liquid might escape through the nose while the person is eating.
There are also things people with VPI do, consciously or subconsciously, to compensate for the problem. They include:
- Nasal grimace, which is an attempt to tighten the facial muscles that makes talking look like hard work
- Talking more loudly or less loudly
- Substituting sounds that are easier to make for the correct sound
What causes velopharyngeal insufficiency (VPI)?
The most common cause of VPI is a cleft palate, a birth defect in which there is an opening in the roof of the mouth because the palate didn’t form properly. Repair of the cleft palate may or may not also eliminate the VPI problem.
Other causes include:
- Other present-at-birth conditions affecting the structure of the mouth or head
- Large tonsils that interfere with the closing of the velopharyngeal port
- VPI can develop after surgery to remove the adenoids, glands in the roof of the mouth that sometimes have to be removed if they grow too large. When this happens the VPI usually goes away after a few weeks, if note ENT follow up is needed.
- A brain injury, or neurological problems caused by a stroke or a disease