What is velopharyngeal insufficiency?
Velopharyngeal insufficiency (VPI) occurs when the back part of the roof of the mouth (soft palate) and the pharynx (throat) don’t work together to make a good seal when your child is talking. This is often caused by a soft palate that is too short or muscles of the palate that do not work well. Air leaks through the nose and gives their speech a nasal quality. It's often hard to understand a child with VPI, and the child must work very hard to speak and be understood.
What causes velopharyngeal insufficiency?
There are several conditions that can cause VPI. The following are some of the conditions that can cause VPI:
The most common cause of VPI is a cleft palate or submucosal cleft palate (cleft covered by the lining or mucous membrane of the roof of the mouth). About10 to 40% of children who have a cleft palate with or without a cleft lip will have persistent VPI after their cleft palate repair. About 25% of children with a submucosal cleft palate will also have VPI.
Velar dysplasia can be a cause of VPI. Velar dysplasia refers to an abnormality in the growth or development of the velum. The velum is the soft flexible area located toward the back of the roof of the mouth. VPI is common in many craniofacial syndromes, particularly in hemifacial microsomia and related conditions. Related conditions include Goldenhar syndrome, oculo-auriculo-vertebral (OAV) spectrum and facio-auriculo-vertebral (FAV) spectrum.
Cervical spine anomalies
Some patients with craniofacial conditions have a cervical spine (neck bones) that curves backward, causing their throat to be abnormally deep. When this occurs, the velum may not be long enough to contact the back wall of the throat during speech production and cause velopharyngeal insufficiency. Some conditions, such as Klippel–Feil syndrome and Down syndrome, are also associated with cervical spine anomalies that can also cause a deep pharynx.
Adenoid and tonsil problems
Sometimes VPI develops after an adenoidectomy. An adenoidectomy is a surgical procedure to remove adenoids or lymphoid tissue in the back of the nose.
A child’s tonsils can become so big that they intrude into the throat. Tonsils are lymphoid tissue that are located on both sides of the back of the throat. They can restrict the movement of the side walls of the throat and prevent the velum from achieving an adequate velopharyngeal seal during speech.
Surgical removal of tumors in the mouth can affect velopharyngeal closure.