Palatopharyngeal activity in cleft palate subjects.
A literature review of the nature of the musculature of the cleft palate and the pharynx is provided and a rationale presented for determining the anatomic level at which muscle activity occurs. Nasal endoscopy with a rigid telescope and the placement of miniaturized pressure transducers against the pharyngeal walls were the techniques used to investigate palatopharyngeal defects in cleft palate subjects. Ten basic patterns of palatopharyngeal movement are described and the likely interplay of the various muscles in producing these complex movements is discussed. Closure patterns of the palatopharyngeal isthmus varied according to whether the subjects were speaking, sucking, or swallowing. It was concluded that the presence of an obturator in the pharynx affects the pattern of activity and that the obturator should be developed to speech function rather than to swallowing.