Tongue to palate contact during speech in subjects with and without a tongue thrust.

The aims of this study were to determine the location and movements of the tongue on the palate during pronunciation of Persian consonants and selected words in subjects with and without a tongue thrust (TT). Ten patients with a TT and 10 control subjects, 9-13 years of age, matched for age, gender, ethnicity, type and severity of malocclusion, with no history of orthodontic treatment, surgery, or systemic disease were selected. Maxillary alginate impressions were taken to construct upper removable appliances with 12 electrodes. Fine wires connected the electrodes to a specially designed electropalatovision (EPU) device. The removable appliance was inserted in the upper arch and then the Persian consonants and some selected words were pronounced by both groups. An electromechanical marker was included on each electrode which showed the tongue movements on the palate. Tongue movements, the quantity of the tongue contacts, and the location of the tongue were compared using t- and Chi-square tests. In the TT group, the tongue had more contact with the palate on six electrodes (P < 0.001). When pronouncing the consonants, the tongue made contact anteriorly on the palate in the TT group. The quantity of tongue contacts with the palate was similar in both groups. During pronunciation of selected words, the contact points of the tongue to the palate were similar in both groups.