2005 Volume 9 Issue 2 Pages 127-138
【Objectives】The purpose of this study was to develop an objective and general standard for evaluating tongue motor function by measuring maximum tongue pressure，duration of tongue contact，pressure integral，time taken to reach maximum pressure，etc．in bolus formation and transfer during swallowing．
【Subjects and Methods】The subjects were 14 healthy volunteers （8 men and 6 women， mean age 29.1）， who individually had normal occlusion．Two palatal plates were produced for each person；one plate was used every day before measuring，and the other plate used for measuring contained a pressure sensor at three points： the mid-point between the left and right mesial sides of the first molar， the palatal side of the mesial side of the left first molar，and the point equidistant between the first two points．The pressure when the tongue was pressed with maximum pressure against the palate (isometric pressure) was measured．Next，saliva，food A (5 cc of water)， food B (2.5 g of food to which was added 2 g of thickening agent in 100 cc of water)，and food C (2.5 g of food to which was added 3 g of thickening agent in 100 cc of water) were swallowed and the tongue pressure was measured． The maximum tongue pressure，duration of tongue contact，pressure integral，and time taken to reach maximum pressure were analyzed．
【Result】A difference was found between men and women in tongue pressure formation．The isometric tongue pressure was formed better，compared to the maximum tongue pressure．Regarding the maximum tongtie pressure，the difference among parts was not remarkable，and even when the food viscosity increased，no tendency toward increase in pressure was found．The duration of tongue contact on the side edge of the tongue was significantly longer than that of the central part of the tongue．As the food viscosity increased，the pressure integral for males was significantly larger，and the duration of tongue contact and the time taken to reach maximum pressure were significantly increased for both males and females．Regarding the time taken to reach maximum pressure，a significant difference was found for all parts．
【Conclusion】For bolus formation and transfer，it is necessary to force the side edge of the tongue against the palate．Tongue motor function assessment in bolus formation and transfer is not based only on the maximum tongue pressure；rather，the duration of tongue contact，pressure integral，and time taken to reach maximum pressure must also be evaluated．The time taken to reach maximum pressure is an important parameter which refiects food viscosity．
