Issues Involved in the Evaluation of Velopharyngeal Closure

Abstract

The development and use of frontal and base-view fluorography have increased the value of cinefluorogra-phy in the evaluation of velopharyngeal closure. This paper discusses problems in the fluorographic examination of the closure mechanism, the need for other measures of velopharyngeal closure, and the validation of closure measures. Reliability data are needed for measurements made from frontal and base-view films and tapes. Measures in addition to those of a fluorographic nature are needed for the identification of persons with questionable velopharyngeal closure and for use in the evaluation of training procedures that may contribute to improved use of the velopharyngeal closure mechanism. A pattern of relationships among fluorographic and nonfluorograph measures of velopharyngeal closure can be studied in the validation of both classes of measures. A preoccupation with certain issues is reflected in the annual scientific meeting and publication programs of the American Cleft Palate Association. Repeated discussion of a given issue sometimes generates complaints. However, the continuing search for better solutions to abiding problems is more to be commended than criticized if it is well performed. One abiding issue concerns methods for evaluating velopharyngeal closure—both the closure that is performed by an individual at a given time and his potential to improve incompetent velopharyngeal performance without surgery or prosthesis. A viewpoint is developed in this paper that evaluation of velopharyngeal closure for speech requires consideration of patterns among a number of variables. For some years, velopharyngeal Closure has been assessed directly by sagittal fluorography and indirectly by measurement of variables that are influenced by velopharyngeal closure. Indirect phenomena studied include articulation, air pressure and flow, and oral and nasal sound pressure level. Attempts have been made to correlate fluorographic measures with indirect closure measures in order to decrease need for x-ray observation. Improvements in radiation pulsing and image intensification and also availability of videofluorographic recording