The effect of pharyngeal flap surgery on the movements of the lateral pharyngeal walls.

Observations of prepharyngeal and postpharyngeal flap degrees of lateral pharyngeal wall movement seem to indicate that some individuals have the ability to alter patterns of lateral pharyngeal wall motion. However, most of the subjects did not show changes in lateral pharyngeal wall motion, and in those who did show changes, the effects of speech therapy could not be excluded. Therefore, the suggestion that pharyngeal flaps should be "tailored" to the size of the gap in the velopharyngeal sphincter seems valid. Or, to put it differently, it seems likely that in many individuals, if the pharyngeal flap constructed is not as broad as the velopharyngeal gap, velopharyngeal insufficiency and hypernasality are likely to persist because most often the lateral pharyngeal wall movement will not adapt to the presence of a new structure in the pharynx.