Physio-Acoustic Considerations in the Radiographic Study of Speech

Abstract

Definitive discussion of roentgenography applied to the study of palatopharyngeal function should be prefaced by a statement of the purposeof that study and the parameters selected for investigation. If the parameters selected require a specification of the size and shape of the pharynx and a} specification of oral and pharyngeal soft tissues, including lymphatic tissue, then cephalometric roentgenography is recommended. C'ephalometric Roentgenography In clinical practice, a primary objective is to quantify the degree of palatopharyngeal opening, the degree or level of velar elevation, and they'vertical dimension over which palatopharyngeal contact is estab— lished. For these needs, cephalometric roentgenography (still films) is the procedure of choice. Subtle differences in velopharyngeal relationships or physiologic details of small magnitude are revealed best by the cephalometric headplate. V ' Some features of cephalometric roentgenography which recommend its use for the physiologic parameters designated here will be enu— merated. Cephalometric roentgenography provides a rigorous standardization of technique, making it possible to control magnification and dis— tortion, both of which are inevitable in radiographic films. There is no appreciable movement occurring during exposure. As a result, soft tissue relationships are delineated clearly. These features make quantitative measurements in the palatopharyngeal region possible and applicable to a well-defined skeletal reference. In summary, cephalometric roent-genOgraphy is a reliable, valid, relatively accessible, and economical technique. Its use, in conjunction with other diagnostic procedures, is highly recommended for assessment of palatopharyngeal competence. Although the research value of cephalometric films possibly has been exploited in study of palatopharyngeal function, the technique may be utilized to study other areas of interest to speech physiologists. Sound '