Cleft palate is the most frequently occurring facial birth defect in the United States. Although infants typically undergo surgery to repair the palate by 10 months of age, most will exhibit delayed production of stop consonants well into the second year of life. The reasons for such delays are not entirely known. It is known, however, that even after the emergence of stop consonants, approximately 20% to 30% of infants with repaired cleft palate will eventually require secondary palatal surgery to achieve adequate velopharyngeal function for normal speech production. Typically, objective assessment of velopharyngeal function is not possible until children are 3 to 4 years of age and cooperative for clinical and instrumental techniques.
The specific aims of the proposed project are to determine 1) the time course and factors - middle ear status, symbolic language, cleft type, and sex - that account for the emergence of stop consonants in children with cleft palate following surgical repair, 2) the time course and factors that account for consistent velopharyngeal closure for stop consonants in children with and without repaired cleft palate, and 3) if a novel aerodynamic measure of velopharyngeal closure for stop consonants at 24 months of age predicts velopharyngeal function at 36 and 48 months of age. Thirty-six infants with repaired cleft palate, 18 typically-developing infants without cleft palate, and 18 infants without cleft palate but with middle ear disease will be followed at two-month intervals from approximately 10 to 24 months of age. Symbolic language ability will be assessed through unstructured and structured play. Middle ear function will be assessed by tympanometry. Nasal ram pressure will be obtained as an indicator of velopharyngeal closure for stop consonants elicited during play. At 36 and 48 months, additional measures of velopharyngeal function will be obtained via nasal airflow and direct magnitude estimation of perceived hypernasality. Developmental trajectories of children relative to stop emergence and velopharyngeal closure for stops will be described using discrete-time survival and binomial logistic regression analyses. Covariates will be included in the models to determine the relative effects of middle ear status, language ability, cleft type, an sex. It is anticipated that the results will a) identify the cause(s) of delayed emergence of stops in children with repaired cleft palate, b) provide developmental data to optimize the timing of either behavioral and/or secondary surgical interventions, and c) further validate a novel and relatively simple assessment procedure to determine velopharyngeal closure of stop consonants in young children.
This research aims to describe the time course and factors that determine the emergence of stop consonants in children with cleft palate following surgical repair. A novel and relatively non- invasive aerodynamic technique will be used to determine velopharyngeal closure of stop consonants over time. The study will provide developmental data that may help to optimize the timing of either behavioral and/or secondary surgical management in young children with cleft palate.
|Zajac, David J (2015) The Nature of Nasal Fricatives: Articulatory-Perceptual Characteristics and Etiologic Considerations. Perspect Speech Sci Orofac Disord 25:17-28|