Quantifying the ice test in halitosis patients

Objectives: Odor is in the oral air when halitosis occurs orally. Because oral gases shrink when cooled, oral halitosis disappears when a piece of ice is placed in the patient's mouth. This physical phenomenon provides a basis for distinguishing oral from non-oral halitosis but has yet to be quantified. Material and methods: The records of 29 halitosis patients were retrospectively analyzed. Gas concentrations were measured with a portable gas detector (IBRID-MX6) before and after cooling the mouth with 1 × 1 × 2 cm ice for 30 s. Patients were asked to rate their halitosis. Tongue temperature and oral gas concentrations were compared with paired t-tests and one-way ANOVA. Results: The tongue cooled by an average of 13.09°C with ice (from 36.0 to 22.4°C). The mean values of the concentrations of VOC, NH3, H2S, and H2 decreased proportionally with cooling: 74.10%, 77.51%, 81.26%, and 96.12%, respectively. The self-reported halitosis score decreased from 4 to 0 (n = 29, p < 0001). Conclusions: It can be concluded that the ice test suppresses oral gases in sufficient quantity to detect oral halitosis.