The development of endoscopy of the palatopharyngeal isthmus.
D002648:Child; D004724:Endoscopy / Q000379:methods*; D006801:Humans; D010159:Palate / Q000002:abnormalities / Q000033:anatomy & histology; D010614:Pharynx / Q000002:abnormalities / Q000033:anatomy & histology; D013060:Speech / Q000502:physiology; D013064:Speech Disorders / Q000175:diagnosis*