Investigations of a pressure-sensitive theory of marginal velopharyngeal inadequacy

Purpose: This two-part project was designed to test a pressure-sensitive th eory of marginal velopharyngeal inadequacy (MPVI). Specifically are select subgroups of children with MPVI perceived as hypernasal because they fail t o achieve consistent closure during vowels and semivowels while demonstrati ng adequate closure during pressure consonants? Methods: In part one, 36 children with cleft palate and other craniofacial anomalies were examined using a clinical assessment protocol that included nasometry and perceived ratings of hypernasal resonance. Children with nasa lance percentages above threshold during low-pressure (LP) productions and below threshold for high-pressure (HP) productions were placed in one group (group 1), while children with nasalance percentages below threshold for b oth LP and HP sentences were placed in another (group 2). Children in the t wo groups were age- and sex-matched. In part two, endoscopic data were exam ined for 10 additional children who received nasometry, perceived hypernasa l resonance scores, and videoendoscopy on the same day and who received hig her mean nasalance measures during production of LP sentences than during p roduction of HP sentences, Results: The results of part one confirmed that children in group 1 were pe rceived as being significantly more hypernasal than children in group 2 (me an(group 1) = 2.17, mean(group 2) = 1.50; t = 2,75, p = .01). However, resu lts of endoscopic testing failed to demonstrate a consistent observable phy siologic pattern of vetopharyngeal inadequacy that would confirm the theory that some patients with MVPI are perceived as being hypernasal because of difficulty achieving velopharyngeal closure during vowels and semivowels. Conclusions: The findings provide partial support for a pressure-sensitive theory of MVPI and demonstrate the value of using both HP and LP sentences to evaluate patients with MVPI.