What is Velopharyngeal Dysfunction?
Normal Velopharyngeal Function
To understand velopharyngeal dysfunction, you need to first understand normal velopharyngeal function for speech.
Figure 1. Anatomy of the oral cavity
Figure 2. Velum during nasal breathing
Figure 3. Velum during speech
Figure 4. Velopharyngeal insufficiency (the velum is too short for closure)
Figure 5. Adenoids in the pharynx (throat)
Figure 6. Velopharyngeal incompetence (the velum doesn’t move well enough for closure)
Kummer AW. (2014). Cleft Palate and Craniofacial Anomalies: Effects on Speech and Resonance, 3rd Edition. Clifton Park, NY: Delmar Cengage.
Figure 1 shows the structures of the roof of the mouth. These are the hard palate and the soft palate (also called the velum).
The velopharyngeal valve is very important for normal speech production. This valve is made up of the following structures:
- Velum (also called soft palate)
- Lateral pharyngeal walls – the side walls of the throat
- Posterior pharyngeal wall – the back wall of the throat
Figure 2 shows the velum resting against the back of the tongue for nasal breathing. This allows the air that is inhaled through the nose to go through the throat (pharynx) to the lungs and back up again.
Figure 3 shows how the velum closes against the back wall of the throat during speech. The side walls close against the velum so that all of these structures come together as a valve. When the velopharyngeal valve closes, the air and sound are sent into the mouth for speech.
Types of Velopharyngeal Dysfunction
Velopharyngeal dysfunction (VPD) is a general term. It is used to describe different disorders of the velopharyngeal valve. These include:
- Velopharyngeal insufficiency, which is due to abnormal structure
- Velopharyngeal incompetence, which is due to abnormal movement
- Velopharyngeal mislearning, which is due to abnormal speech sound production
Figure 4 shows velopharyngeal insufficiency, which is usually caused by an abnormality of soft palate. Velopharyngeal insufficiency is common in children with cleft palate or a submucous (under the skin) cleft. Signs of a submucous cleft are often hard to see when looking in the mouth. Sometimes a submucous cleft can only be seen by putting a scope in the nose to see the top of the soft palate.
Velopharyngeal insufficiency can also occur after adenoidectomy. This is because the adenoids are in the area where the velopharyngeal valve closes. For some children, adenoids help the valve close.
Figure 5 shows the position of the adenoid pad in the throat.
Figure 6 shows velopharyngeal incompetence, which is caused by poor movement of the velopharyngeal structures. This is due to a disorder or injury of the brain or cranial nerves. Cerebral palsy and traumatic brain injury are examples of disorders that cause velopharyngeal incompetence.
Velopharyngeal mislearning is when the child makes sounds in the pharynx, rather than in the mouth. Because of this placement, the velopharyngeal valve is open and the air and sound go through the nose, just like when there is velopharyngeal insufficiency.
Velopharyngeal Dysfunction and Speech
Velopharyngeal dysfunction causes a leak of sound and / or air into the nose during speech. It can cause several speech problems, including:
- Hypernasality, where there is too much sound in the nose during speech
- Nasal emission of air when making certain speech sounds
- Weak consonants because of the leak of air through the nose
- Making speech sounds in the throat due to the lack of air in the mouth
Treatment of Velopharyngeal Dysfunction
The treatment of a velopharyngeal dysfunction depends on the type and cause of the problem. The treatment of velopharyngeal insufficiency or velopharyngeal incompetence usually requires surgery. When surgery is needed, it does not change the way the child has already learned to talk.
Speech therapy is usually needed after the operation to help the child learn how to make sounds correctly. If the problem is due to velopharyngeal mislearning, speech therapy alone will correct abnormal speech. If therapy is needed, the speech-language pathologist on our team will talk with the child’s current speech-language pathologist about effective methods of treatment.
Note: Blowing, sucking and oral-motor exercises are not effective in improving velopharyngeal closure or abnormal resonance.
Velopharyngeal Dysfunction Resources
Helping Your Child
Parents should be active members of their child’s treatment team. They can help in the following ways:
- Parents should follow-up on the advice from the surgeon and speech-language pathologist.
- When the child is getting speech therapy, it is important that the parents work with the child in between therapy sessions. Several short practice sessions each day are the best way to help the child at home.