Nasal airway in breathing and speech.

Clefts of the lip and palate frequently produce nasal deformities that tend to reduce the size of the nasal airway. Approximately 70% of the cleft population have nasal airway impairment and about 80% "mouth-breathe" to some extent. Surgical correction of nasal, palatal, and pharyngeal structures may further compromise breathing. Type of cleft appears to affect airway size, with unilateral clefts demonstrating the smallest airway. Although a pharyngeal flap may further decrease airway size, some individuals do not notice a postoperative change because of airway compromise prior to flap placement. Speech is a modified breathing behavior that uses the respiratory system to provide an energy source and involves structures within the respiratory tract to modulate this energy into meaningful sounds. The oral, nasal, and pharyngeal structures that are affected by cleft lip and palate during breathing are often compromised for speech as well. The nasal airway plays an important role in controlling speech pressures when velopharyngeal function is impaired. A "good" nose for breathing is often a "bad" nose for speech under such circumstances.