[Influence of experimental palatal plate on mandibular position during continuous [n] phonation in complete denture wearers].

OBJECTIVE: To clarify the influence of an experimental palatal plate on the mandibular position during continuous [n] phonation and at the physiological rest position in complete denture wearers. METHODS: Ten complete denture wears volunteers were investigated. Two kinds of experimental palatal plate with a thickness of 3 mm and 5 mm (from the denture basal surface to denture polished surface) were fabricated and used for each subject. The mandibular position was recorded by a K7 mandibular kinesiograph during continuous [n] phonation and at the physiological rest position under three conditions: wearing a palatal plate with different thickness of 3 mm, 5 mm and without a plate(control). The interocclusal distance both in vertical and anteroposterior direction during continuous phonation and physiological rest position under all three conditions were measured and compared. RESULTS: Under the control condition without wearing of a plate, the mean values of interocclusal distance (IOD) during continuous [n] phonation were (1.69±1.26) mm vertically and (1.74±1.18) mm anteroposteriorly. After insertion of the experimental plates, there was an increase in the IOD during continuous [n] phonation, but this difference from the normal condition was not statistically significant. The mean IOD at the physiological rest position in these 2 directions were (2.91±2.28) mm and (2.56±1.88) mm, respectively. After insertion of the experimental plates, there was a decrease in the IOD, with the 3 mm plate, (2.52±1.88) mm vertically and (2.46±1.64) mm anteroposteriorly; with 5 mm plate, (2.45±1.70) mm vertically and (2.22±1.31) mm anteroposteriorly. No significant differences were found between the control and 2 experimental conditions. CONCLUSION: The mandibular position during continuous [n] phonation was not influenced by the experimental palatal plates and physiological rest position was also not affected by experimental palatal plates.