Many children speak with a nasal tone. You may have also come across children who either can't speak clearly or speak in a way that's hard to understand. If your child has similar problems, it could be a sign of velopharyngeal dysfunction (VPD) — a condition in which parts of the mouth and throat don't work properly during speech.
The good news is that VPD can be treated with methods like surgery and speech therapy. These procedures have high success rates, making them the best way to bring your child's speech pattern back to normal.
What Happens During Normal Velopharyngeal Function?
The term velopharyngeal can be broken down into these two words:
- Velo: This refers to the velum or the soft palate (the soft tissue that makes up the back of the roof of your mouth).
- Pharyngeal: This means the pharynx, commonly called the throat.
When you speak or breathe through your nose, these velopharyngeal structures shift their position so that the air can move in the right direction. For example, during nasal breathing, the soft palate rests against the back of your tongue to block the passage to your mouth. So, when you breathe through your nose, the air moves freely through your throat, goes into your lungs, and comes back up again.
But when you're speaking, the velum rises to connect with the back of your throat. At the same time, the side walls of your throat close in around the velum. These structures together form the velopharyngeal valve. During normal speech, this valve closes, which blocks the passage to the nasal tract. This forces all the air to move through your mouth, which creates sounds you hear as speech.
What Happens in Case of Velopharyngeal Dysfunction (VPD)?
Velopharyngeal dysfunction (VPD) usually occurs due to problems in the structure and/or function of the velopharyngeal valve. In most cases of VPD, the soft palate fails to touch the back of the throat while speaking or swallowing. This creates an opening between the oral and nasal cavities. As a result, when kids with VPD try to speak or swallow, the air and sound escape through their noses, rather than going out through their mouths.
This adds a nasal tone to their speech and even makes it hard to understand their words in severe cases.
What are the Different Types of Velopharyngeal Dysfunction?
Velopharyngeal dysfunction is a general name used to describe different kinds of problems that occur with the velopharyngeal valve. People can have one or more than one kind of VPD. So, when someone goes for VPD treatment, the doctor first tries to determine which type(s) of VPD they have. This helps them find the best course of treatment for such patients.
There are three types of velopharyngeal dysfunctions that your child can have. Those include:
Velopharyngeal insufficiency (VPI). VPI occurs when there's less or "insufficient" tissue in the soft palate. As a result, the velum is unable to touch the back of the throat when your child tries to speak or swallow. VPI usually occurs in children whose soft palates have an abnormal structure due to the presence of a cleft or split in them.
The chance of having velopharyngeal insufficiency is high in children whose adenoids have been removed. Adenoids are masses of lymphatic tissue that sit high up in the throat, at the back of the nose. This position also puts them close to the velopharyngeal valve. As a result, when adenoids are removed, it often ends up damaging the structure of the valve. This prevents the velopharyngeal valve from closing properly, which leads to VPI.
Velopharyngeal incompetence (VP incompetence). It occurs due to the abnormal movement of the velopharyngeal structures. In this condition, the velum and the walls of the throat fail to form a proper barrier between the oral and nasal cavities. As a result, air leaks out through the nose while speaking and swallowing.
Velopharyngeal incompetence is usually caused by traumatic brain injury or a medical condition like cerebral palsy that affects the brain or the cranial nerves.
Velopharyngeal mislearning (VPM). In this condition, your child may learn to make sounds the wrong way. VPM usually happens when:
- Despite having a fully functioning palate, the child doesn't use it while making sounds, which results in unusual speech patterns.
- The child learns to make sounds without using their soft palate to make up for the problems with their velopharyngeal structures.
- Instead of their mouth, the child makes sounds in their throat.
Who Is at Greater Risk of Having Velopharyngeal Dysfunction?
While velopharyngeal dysfunction does occur in some adults, it's mostly seen in children. VPD can occur by itself or along with other genetic or medical disorders.
People with these conditions have the highest risk of having VPD:
What Are the Symptoms of Velopharyngeal Dysfunction?
In people with VPD, the velopharyngeal valve doesn't close properly. This causes air to leak through the nose and results in speech disorders like:
- Hypernasality: If, while saying letters like l, r, w, and y, your child's voice gets a nasal tone, it could be a sign of hypernasality.
- Nasal air emission: In this condition, air escapes through a child's nose, producing sounds like squeaks and puffs when they say letters like d, g, p, b, and z.
- A habit of stopping the air in the throat or the mouth due to using unusual methods while speaking.
- An inability to make correct speech sounds while speaking.
How Is Velopharyngeal Dysfunction Diagnosed?
It usually takes a team to diagnose and treat velopharyngeal dysfunction. This team could include speech therapists, VPD-trained speech-language pathologists (SLPs), surgeons, and other doctors if needed.
During the first visit, an SLP will carry out a thorough clinical examination of your child. This may include examining your child's mouth and checking if they have a problem with articulation (making sounds with the mouth) or speech coordination (using sounds together) or show signs of hypernasality.
In some cases, imaging procedures could be used to check your child's velopharynx while they try to speak. This may give the VPD specialists a clear idea if your child is showing any relevant symptoms. The most common imaging procedures used during this step are:
- Video nasoendoscopy: During this procedure, a small camera is inserted through the child's nasal cavity. This allows the SLPs to check if the velopharyngeal structures work properly as the child speaks.
- Video fluoroscopy: In this procedure, a barium solution is passed through a child's nose. This solution helps outline the structures inside the nose and the pharynx better. A video is taken as the child speaks, which allows the specialists to see the inner workings of the velopharynx.
In a few cases, SLPs suggest other procedures like a sleep study, an MRI scan, and even genetic testing to find the cause of VPD.
How Is Velopharyngeal Dysfunction Treated?
The ways to treat velopharyngeal dysfunction differ, depending on the type and the cause of the problem. A speech-language specialist can recommend one or more of these treatments, based on what your child needs to develop normal speech patterns:
Speech therapy. Speech therapy can help children, even if their VPD is caused by a structural problem for which they require additional treatments like speech appliance or speech surgery.
With proper speech therapy, kids can learn how to direct the air into their mouths and use their jaw, lips, and tongue to create sounds in the right manner. This is why speech therapy is especially useful for children with velopharyngeal mislearning, as it alone can get their speech back to normal.
In the case of velopharyngeal incompetence, speech therapy is given to kids after the surgery so as to help them make correct sounds. VPD specialists modify their speech therapy based on the specific needs of the child after determining which skills and sounds they have problems with.
Speech surgery. If your child has already learned to speak a certain way, speech surgery may not be able to change it. But surgery can help correct the abnormal structure of the soft palate and some parts of the throat, as is most often the case in VPI. Even children with VP incompetence can benefit from this, as the surgeon can operate on their velopharyngeal valve and get it to function properly.
These are the most common speech surgeries that an SLP may recommend if your child has velopharyngeal dysfunction:
- Sphincter pharyngoplasty: During this procedure, the surgeon creates a bumplike structure at the back side of the throat by moving tissues from the side walls of the throat. This allows the velum to physically connect with the throat while speaking and swallowing.
- Furlow palatoplasty. With this procedure, a surgeon aims to improve the position of the muscles of the soft palate so as to increase its length. As it becomes longer, it becomes easier for the velum to touch the back of the throat. This causes the air to pass through the mouth and produce sounds correctly.
Prosthetic devices. In many cases of VPI and VP incompetence, experts suggest using prosthetic devices before or in place of surgery. Also called speech appliances, these devices are highly effective and can be worn for a short time or for life.
The three most common types of speech appliances used by those with VPD are:
- Palatal lift: This is a removable device that helps to lift the soft palate so that it can touch the back side of the throat. As a result, the air moves through the mouth rather than the nose. A palatal lift is most helpful in cases of VP incompetence.
- Palatal obturator: This prosthetic device works by closing any cleft or defect in the hard or soft palate. This way, a palatal obturator forms a barrier between the oral and nasal cavities, which prevents air from escaping through the nose.
- Speech bulb obturator: This is a removable device used for treating velopharyngeal insufficiency. The bulb in this appliance fills the space left between the throat and the short (insufficient) velum. As the gap closes, it blocks the passage to the nasal cavity, which directs the air to move through the mouth.
If you notice strong nasal tones or incorrect speech sounds when your child talks, it could be a symptom of velopharyngeal dysfunction. Since kids don't usually outgrow speech disorders, talk to a VPD specialist as soon as you can so that your child can begin to unlearn the wrong speaking habits. Treatments like speech surgery and speech therapy have high success rates and can help bring your child's speech pattern back to normal.