Velopharyngeal insufficiency is the improper closing of the velopharyngeal sphincter (soft palate muscle) during speech characterized by an acute nasal quality of the voice.
At the back of the mouth is a circle of structures that include the tonsils, the tongue, and the palate. During speech, this apparatus must close off the nose for proper articulation of the explosive consonants "p," "b," "g," "t," and "d." If it does not close, there is a snort sound produced through the nose. Improper function of this structure also produces a nasal tone to the voice.
Causes and symptoms
There are three main causes for this defect:
- Cleft palate is a congenital condition, producing a defect in the palate that allows air to escape upward during speech.
- If tonsil and adenoid surgery is done improperly, velopharyngeal insufficiency may result. The occurrence rate is approximately one in every 2,000-3,000 tonsillectomies.
- Nerve or muscle disease may paralyze the muscles that operate the velopharyngeal sphincter.
The primary symptom is the speech impediment. Some people develop a change in their speaking pattern or a series of facial grimaces to try to overcome the difficulty. If the condition is acute, regurgitation through the nose may occur.
Examination of the velopharyngeal sphincter through ultrasound scans, fiber-optic nasopharyngoscopy, and videofluoroscopy will reveal the extent of velopharyngeal insufficiency. Speech and velopharyngeal sphincter movement are compared to make the diagnosis.
Velopharyngeal insufficiency is treated with a combination of surgery and speech therapy. There are several surgical procedures that can be performed to correct the physical malfunction. They include:
- Pharyngeal flap procedure that moves the skin flap from the pharynx to the soft palate.
- Palatal push-back that separates the hard and soft palate in order to lengthen the soft palate.
- Pharyngoplasty that lengthens the soft palate by turning the pharyngeal skin flaps.
- Augmentation pharyngoplasty that inserts an implant into the pharyngeal wall to enlarge it, thus narrowing the velopharyngeal opening.
- Velopharyngeal sphincter reconstruction.
The combination of surgery to correct the insufficiency and speech therapy to retrain the voice successfully alleviate velopharyngeal insufficiency.
Adenoids— Lymph glands just above the tonsils and the palate.
Cleft palate— Congenital defect marked by a split in the roof of the mouth.
Nasopharyngoscopy— A diagnostic procedure that examines the nasal passageways and pharynx with an instrument outfitted with an optical system.
Pharynx— A canal located between the mouth cavity and the esophagus.
Tonsillectomy— Surgical removal of the tonsils.
Tonsils— Lymph glands in the throat, just behind the back teeth.
Huang M. H., S. T. Lee, and K. Rajendran. "Anatomic Basis of Cleft Palate and Velopharyngeal Surgery: Implications from a Fresh Cadaveric Study." Plastic & Reconstructive Surgery 101 (Mar. 1998): 613-627.