Relation Between Speech Production and Oro-facial Structures in Individuals with Isolated Clefts of the Palate

Abstract

Most investigators agree that some relation exists between the adequacy of speech articulation and variations in the dentition. The acceptance of such a relation does not necessarily imply cause and effect since many individuals with severe malocclusions can have adequate speech articulation while others with good occlusion have less than adequate speech articulation skills. The presence of an oral cleft and its subsequent management adds a series of variables which renders the relationship between articulation and the orofacial structures much more difficult to study. Thus, the purpose of this investigation was to compare orofacial structures and speech phonemes in subjects with isolated clefts of the palate who exhibited various degrees of velopharyngeal competency and articulatory proficiency; and to correlate the various orofacial measurements with sound production. Literature review McDermott (3) examined 54 individuals with repaired palatal clefts in order to explore the factors which effect /s/ sound production. Judgments were made of the presence and degree of deviation in the anterio-posterior relationships of the dental arches, the continuity of the cutting edge of the anterior teeth, the general configuration of the hard palate and the mobility of the tongue. He found significant differences in articulation adequacy of the /s/ sound between subjects with severe deviations and subjects with the slight and moderate deviations. McDermott's results suggest that the combination of deviations of various aspects of dental structures mitigate against correct /s/ sound production. Subtelny and Subtelny (6) examined 27 adult cleft palate individuals. They obtained cephalometric laminagraphs and tape recordings of a nonsense-syllable articulation test. The laminagraphs were traced and analyzed to quantitate velopharyngeal and dental relationships. Tape recordings were played back to a panel of listeners for phonetic transcriptions. Their findings indicate that the total