Abstract
Purpose: The purpose of this study was to compare contact patterns of tongue-to-palate and alveolar or maxillary dentures in edentulous patients with and without their dentures, during the production of [sa] and [∫i] sounds.
Methods: The subjects were 10 edentulous adults (3 men and 7 women). Artificial palates, made of black vinyl covering the palate and alveolar ridge of the maxilla, were coated with white alginate powder, and were then inserted into the mouths of the subjects. After pronunciation of the test sounds, the tongue contact areas on the artificial palates were demonstrated by wetting of the powder and assesing the change in color from white to black. An image processor system was employed for averaging five samples of the same sound for each subject. The averaged pattern of each subject's palatograms was then converted to the standardized dental arch form, added, and stored. Seventy percent of each subject's common parts were extracted from the combined palatograms of the same sound.
Results and Conclusions: On comparing the contact patterns of the edentulous stage (E) with the contact patterns of the denture-wearing stage (D), in both [s] and [c] sounds, the contact area of E was found to be wider than that of D, and also the distance between the right and left contact region of E was shorter than that of D.
