Hypernasality occurs when the soft palate and posterior pharyngeal wall, or throat wall, fail to achieve a complete seal between the nose and the mouth during speech sounds. As a result air will escape through the nose during speech. Occasionally one might see liquids regurgitate through the nose as well. This is called velopharyngeal insufficiency, or VPI.
WHAT CAUSES HYPERNASALITY?
Velopharyngeal insufficiency is most commonly the result of anatomical abnormalities of the soft and/or hard palate such as a cleft palate. However, it can also occur with normal appearing palate anatomy that has poor function, which is usually a result of neurologic issues like cerebral palsy or musculoskeletal disorders. Rarely it occurs after an adenoidectomy. The incidence of this rare surgical complication is between 1:20,000 and 1:40,000 cases.
HOW DO YOU WORK UP HYPERNASALITY?
Patients should undergo a multidisciplinary approach involving an otolaryngologist (ear, nose and throat doctor) and a speech therapist. A complete VPI workup is done in conjunction with a speech therapist, which often involves speech endoscopy, cineflourography, pressure flow techniques, and nasometers to meausure nasal emissions, as well as other objective tests to evaluate for abnormally increased nasal airflow. These tests evaluate for nasal airflow by both directly visualizing the closure pattern of the soft palate and the throat wall and by measuring the airflow through the nose.
HOW DO YOU TREAT HYPERNASALITY?
Children should be enrolled in speech therapy and undergo therapy focused on hypernasality. If there is a failure to improve over a period of time, consideration is given to surgical options. There are different surgical approaches to improve hypernasality. The two speech surgical procedures include the pharyngeal flap and the sphincter pharyngoplasty. The most common surgery utilized is the pharyngeal flap, where a segment of the posterior pharyngeal musculature (or back of the throat wall) is rotated and inset into the back part of the soft palate. This helps to physically plug the gap and decrease the nasal emissions. This surgical procedure requires a general anesthetic, takes about an hour, and is done through the mouth. It typically requires a 1 or 2 day hospitalization for pain control and hydration.
COMPLICATIONS OF SPEECH SURGERY
The goal of speech surgery is to walk a fine line between providing adequate closure between the nose and the mouth without causing too much nasal obstruction. If too large a pharyngeal flap is inset, or the sphincter is sewn too tight, it can result in nasal obstruction and obstructive sleep apnea. The inability to achieve complete closure is also possible, and continued nasal emissions can occur after surgery. Occasionally, the surgical area will need to undergo a revision.