Velopharyngeal Insufficiency

A competent velopharyngeal mechanism is required for normal speech. The velopharyngeal sphincter functions in concert with the mouth and larynx for speech production. The palate separates the nasal cavity from the vocal tract and forms a part of the velopharyngeal sphincter. Closure of the sphincter is accomplished by the movement of the soft palate (tension and elevation) as well as lateral and posterior movement of the posterior pharyngeal wall.

Velopharyngeal insufficiency (VPI) results from an inability to completely close the velopharyngeal sphincter. Velopharyngeal insufficiency is characterized by hypernasality; nasal emission; and adaptive changes in articulations, such as pharyngeal fricatives, sound substitution, and glottal stops.

The goal of palatal repair is to restore accurate phonation and functional anatomy. Most techniques of palatal repair result in a 20-30% incidence of velopharyngeal insufficiency.

Diagnosis

If a child is found to have velopharyngeal insufficiency based on speech derangement, additional quantitative and dynamic measurements are required. Pressure and airflow measurements, both oral and nasal, are generally used only as screening tools, because they provide no details about sphincter function.

In order to compare nasendoscopy (NE) with multiview fluoroscopy (MVF) in the assessment of velopharyngeal gap size and to determine the relationship between these assessments and velopharyngeal insufficiency severity, Lam et al demonstrated that NE and MVF assessments provide complementary information and are correlated.[9] Both are associated with velopharyngeal insufficiency severity. However, the bird's-eye view provided by NE has a stronger correlation with velopharyngeal insufficiency severity than MVF.

Radiologic methods of assessment include soft-tissue radiography and videofluoroscopy. Radiography provides a 2-dimensional (2-D) image of the relationship between the soft palate and the posterior pharyngeal wall, but it is not a dynamic technique. Conversely, videofluoroscopy provides dynamic information regarding the sphincter mechanism. Flexible and rigid endoscopy can also be used to assess velopharyngeal insufficiency. The advantage of endoscopy is that it allows direct observation of sphincter function.

Velopharyngeal insufficiency can be surgically corrected with the use of pharyngeal flaps, pharyngeal sphincter reconstruction (pharyngoplasty), or pharyngeal wall implants.

Advertisement
Copyright © 2014 Healing Smile Foundation, All Rights Reserved.