Palatopharyngeal anatomy and physiology.

Current literature concludes that the levator veli palatini and the musculus uvulae are the muscles primarily responsible for palatopharyngeal closure during speech in the normal individual. As a compensatory mechanism in approximately one third of patients with palatopharyngeal insufficiency, the superior constrictor muscle may be active in the form of Passavant's ridge. This ridge occurs infrequently in normal speakers. There is some evidence that this conclusion is too simplistic. There may be more individual variation involved than admitted or understood at present.