Maintenance of intraoral pressure during speech after maxillary resection.

Although structural defects such as cleft palate and severe anterior open bite alter vocal tract resistance, compensatory responses usually result in maintaining consonant pressures at an adequate level. The purpose of the present study was to determine if individuals with an acquired palatal defect spontaneously develop similar compensatory behaviors. The pressure-flow technique was used to measure aerodynamic variables associated with consonant production after surgery and obturation. Although intraoral pressures decreased considerably immediately after surgery, pressures were maintained at a mean level of 3.5-cm H2O. Respiratory volumes increased as much as fourfold without obturation and were normal with obturation. Voice-voiceless differences in air volumes among consonants were maintained even in the presence of the defect. These findings suggest that compensatory responses are directed toward maintaining an appropriate level of intraoral pressure for consonant production.