The effect of cleft palate speech aid prostheses on the nasopharyngeal airway and breathing.

This study determined the effect of a speech aid prosthesis on resting breathing. Nasal cross-sectional area was measured during inspiration and expiration in eight cleft palate patients. The measurements were made for the unobturated defect during both phases of respiration and then repeated while the defect was obturated by a speech aid prosthesis. The results of the study revealed that the presence of a speech aid prosthesis significantly decreased the cross-sectional region of the nasal airway. In 50% of the subjects, the cross-sectional region was less than 0.40 cm2 with concomitant impairment in nasal respiration when the speech aid prosthesis was present in the oral cavity. The data suggest that the design of these prostheses should account for breathing requirements as well as for speech.