1. Velopharyngeal dysfunction (VPD) refers to when there is a deficiency in structure or in movement of the soft palate, causing air to leak out of the nose during speech. VPD is resonance disorder although it is commonly mistaken for a voice disorder. The most well known cause of VPD is cleft palate, however, VPD can also occur following neurological damage or after removal of adenoid tissue. Cleft palate can be an isolated anomaly but can also be part of a genetic syndrome. A cleft palate is typically repaired before 1 year of age and approximately 20% of those children will require an additional surgery (called a pharyngoplasty) to manage speech quality. VPD can also be caused by a submucous cleft palate, which is when the skin/mucosa of the soft palate come together but the muscles do not. A submucous cleft is not always identified at birth. An early sign of a submucous cleft may be nasal regurgitation (food or liquids coming out of the nose) but it may not be identified until later through an oral examination. Children with a cleft palate or submucous cleft palate are also subject to frequent ear infections and speech may be impacted by early hearing loss as well.
2. Speech therapy is often warranted before determining the need for a pharyngoplasty. Individuals with VPD typically present with two problems. First, there is the structural deficit of the soft palate being too short or the soft palate exhibits limited or no movement. The individual then exhibits a hypernasal resonance for vowel sounds and nasal air escape or nasal sound substitutions for oral pressure consonants (16 of the 24 consonant sounds in English are oral pressure consonants). For example, if a child were to produce a nasal sound for the oral sound /b/, their production of “bye-bye” would sound like “my-my.” These are considered obligatory errors. These errors may eventually require surgical intervention to be corrected.
The second problem that can occur is the development of maladaptive (compensatory) articulation. An individual with VPD, or a history of VPD, will frequently compensate for air leaking out of nose by developing maladaptive articulation. An example of a maladaptive error would be a glottal stop in which the child learns to generate pressure for a sound at the level of his or her vocal folds since they are unable to generate pressure from the soft palate closing off the back wall of their throat. Early intervention to correct these errors is crucial, as errors can become more difficult to correct as time progresses. It is also essential because maladaptive errors stray from typical, developmental articulation errors (an example of a developmental error would be a child producing “poon” for “spoon”). It is important to note that maladaptive errors are learned behaviors and can thus only be corrected through speech therapy.\
|Pressure consonant sounds||Nasal sounds||Low pressure sounds (similar to vowel sounds)|
|p, b, t, d, k, g, ch, j, s, z, f, v, sh, zh, th||m, n, ng||w, y, l, r, h|
3. Speech therapy for children with cleft palate or VPD typically involves teaching the correct way to say sounds. Especially in the instance where compensatory articulation has developed, speech therapy is beneficial both before and after surgical intervention. Frequently, teaching a child to occlude the nose while producing pressure consonant sounds is the best way to teach correct articulation. Another useful strategy is having the child “whisper” in order to prevent the vocal folds from overcompensating. Since an individual has developed maladaptive speech, he or she benefits from multimodal feedback to achieve success (i.e. visual cues, auditory feedback, tactile cues, etc). Perhaps the most important factor in helping a child achieve progress is parent involvement. A child will make more gains in his or her speech if speech is also being practiced at home.
4. A child with cleft palate or VPD should be followed by a craniofacial team. A craniofacial team is typically compromised of a plastic surgeon, dentist, orthodontist, speech pathologist, a nurse, and a social worker. A speech pathologist on a craniofacial team has the necessary instrumental equipment and expertise for evaluating resonance disorders. It is also important that speech therapy for VPD is provided by a speech therapist with training or experience in treating a resonance disorder.
Written by Marissa Habeshy, M.S., CCC-SLP
Peterson-Falzone, S. J., Hardin-Jones, M. A., & Karnell, M. P. (2001). Cleft palate speech. St. Louis: Mosby.
Golding-Kushner, K. J. (2001). Therapy Techniques for Cleft Palate Speech and Related Disorders. San Diego: Thomas Learning, Inc.