Dentistry

Abstract

Thermal Stimulations Change Perception and Taste Thresholds

Katsuya Kanno*,Hamada Tomohiro,Kawahara Ichiro,Kon Hideki,Satoshi Takada,Takashi Ohno

Purpose: This study aimed to inbestigate perception thresholds and gustatory thresholds for the four basics tastes (sweet, salty, sour and bitter) in the dorsum of the tongue in conjunction with thermal stimulations.

Methods: 10 healthy volunteer subjects were examined. The perception threshold test were used the Semmes-Weinstein Test (SW-test) using Semmes-Weinstein Aesthesiometer (North Coast Medical, Inc., Gilroy CA, USA). The gustatory threshold were used the Taste Disk Gustatory threshold. Thermal stimulations were applied to the tongues before the tests. For the cool stimulation tests, subjects were given ice water that was swished around the mouth in order to keep the temperature at approximately 10-13°C. Similarly, heat stimulation was achieved by giving the subjects water heated to 45°C and having them swish the water around their mouth in order to keep the temperature at approximately 37-39°C.

Results: During the cooling stimulations, significant increases of the cognizable forces were observed at the apex of the tongue. During the heat stimulation, significant increases were observed for the cognizable forces in all of the areas monitored. For the taste sensations, cool stimulation caused a significant increase in the taste thresholds for all four tastes, while heat stimulation also caused changes in the thresholds for the four taste sensations.

Conclusions: Heat stimulations influenced the perception thresholds to a greater degree than that observed for the cool stimulations. However, thermal stimulations had a much stronger influence on taste compared to perception. Salty tastes were more strongly influenced by cool stimulations; sour tastes were more strongly influenced by heat stimulations.