The influence of intraoral cooling on taste and smell perception.

Background: Cryotherapy using ice chips has been successfully used to prevent chemotherapy-induced oral mucositis. Although effective, concerns have been raised that the low temperatures that are obtained in the oral mucosa during cooling may be potentially harmful to taste and smell perception. Thus, this study aimed to investigate whether intraoral cooling permanently affects taste and smell perception.

Subjects and methods: Twenty subjects inserted an ounce of ice chips and moved the ice around in the mouth to cool as large a part of the oral mucosa as possible. Cooling continued for 60 min. At baseline (T0 - minutes), and following 15, 30, 45, and 60 min of cooling, taste and smell perception were registered, using the Numeric Rating Scale. The same procedures were repeated 15 min (T75 - minutes) after completion of cooling. Taste and smell were evaluated using four different solutions and a fragrance, respectively.

Results: A statistically significant difference was seen for taste perception with Sodium chloride, Sucrose, and Quinine at all the follow-up time points tested as compared to baseline (p < .05). Citric acid and smell perception proved to be significantly different from baseline following 30 min of cooling. When the same assessments were carried out 15 min following completion of cooling, i.e. T75, all taste and smell perceptions had recovered to some extent. For taste perception, however, a statistically significant difference was still seen for all solutions tested as compared to baseline (p < .01).

Conclusion: In healthy individuals, intraoral cooling with IC leads to a temporary reduction in taste and smell perception, with a tendency to return to baseline values.