Methods: Four individuals with complete denture wearers (2 male and 2 female, age: 76-85, average age: 79.5) were included in the present study. Three dentures (normal, 5mm increase, and 3mm decrease) were inserted and measured brain function before and after gum chewing. Changes in brain function activity were estimated by recording electroencephalogram (EEG). EEG (2-40Hz) was taken for 3 minutes by 21-channel on the skin of the head. EEG measurement was performed in the semi-anechoic room. EEGs were taken using ESA-pro (Brain Function Laboratory, Inc., Kanagawa, JAPAN). The data obtained were transferred to the brain wave analysis center at Brain Functions Laboratory Inc., and calculated Da using the Diagnosis Method of Neuronal Dysfunction (DIMENSION) analysis. The ANOVA and Bonferroni (a = 0.05) was used to compare brain function activity (Da).
Results: Mean brain function (Da) of all dentures were increased after gum chewing. The mean value of Da was the order of normal (0.0071), 5mm increase (0.0055), and 3mm decrease (0.0037). Although brain function after gum chewing using normal denture was most activated, there was no statistically significant difference (p > 0.05).
Conclusions: This study indicated that use of denture with reduced vertical dimension was hindered activation of brain function, in addition possibility of brain function can be improved through the use of correct denture was suggested.