MRI Analyses of the Velopharyngeal Mechanism among Different Adult Populations

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DESCRIPTION (provided by applicant): It is likely that there are specific dimensions for the musculature of the velopharynx that are required in order for a child to develop normal sounding speech. If a child has a primary repair of the levator muscle that does not conform to that of normal anatomy, it is likely that they will develop hypernasal speech and would require secondary palate surgery. Data has not demonstrated what constitutes "normal" levator muscle anatomy or how race and sex impact those normative measures. We will elucidate what constitutes normative muscle dimension range based on sex, race, craniometric dimensions, and/or velopharyngeal closure patterns. These results can be directly utilized to guide primary surgery. Such patient specific surgical planning will decrease the incidence of hypernasality during speech development and thus reduce the need for secondary surgical management later in life. The aims of this R03 proposal are to address unresolved issues concerning the interaction of race and sex on the structure and function of the velopharynx. The study will also assess the interaction of craniometric measurements and velopharyngeal closure patterns as it relates to levator dimensions found in different racial/ethnic groups and/or gender groups. Analyses of the relationship of these variables will enable us to identify whether racial differences in oral clefts are a result of morphological differences at the skeleto- muscular level. More applicably, data obtained here will have a direct impact on surgical practices in the treatment of children born with cleft palate. Thus, the long term goal of this study is to improve the diagnostic and surgical planning care for children born with cleft palate. The information gathered from these investigations will lead to improved speech outcome measures as well as a reduced need for subsequent secondary palatal surgeries. The following specific aims are proposed: (a) to identify morphologic differences in the levator muscle at rest and during speech production as a function of race (b) to determine whether sex differences exist in the morphology of the levator muscle at rest or during speech production. A total of 84 subjects will be recruited for participation in the study. Magnetic resonance images will be obtained while the velum is at rest (non-speech) and during speech. MR images will be used to measure craniometric measures and levator muscle morphology. Nasoendoscoy will be performed to determine velopharyngeal closure patterns. The data will be imported into a 3D software system to create a computer model in three dimensions of space for improved measurements and visualization of the internal craniofacial and velopharyngeal structures. PUBLIC HEALTH RELEVANCE: Hardin-Jones and Jones (2005) found 68% of preschoolers with repaired cleft palate were enrolled in speech therapy. More interestingly, 37% had moderate to severe hypernasality or had received secondary surgical management due to an incompetent velopharyngeal mechanism. Primary surgical repair (initial surgery) that is patient specific (based on race, sex, and levator muscle dimensions) would reduce the incidence of aberrant speech found among many children with cleft palate and reduce the need for subsequent surgeries (secondary surgical management).