Test-retest reliability and normative data for “Seven-iTT”, a test for the assessment of taste and oral trigeminal function

Assessment of taste and somatosensory perception in clinical practice lacks fast tests that are validated and reliable. Recently, a 12-item identification test for taste and oral trigeminal perception, and its shorter version, the Seven-iTT, was developed. The objectives of this study were to evaluate its test-retest reliability and establish normative data. Two-hundred participants (120 women, 80 men) with a good sense of taste performed a whole-mouth identification test using 12 filter-paper strips impregnated with low and high concentrations of sweet, sour, salty, bitter, astringency, and spiciness. Fifty of them repeated the task, with a median interval of 122 days from the first visit. Test-retest reliability was determined using Spearman correlation and the Bland–Altman plot method. There was a significant correlation in identification score between the first and the second session for both versions of the test (r ≥ 0.28; p ≤ 0.048). The Bland–Altman plot reflected a good congruence between the results of the two sessions. Additionally, frequencies of correct identification were consistent between sessions, with women outperforming men (p = 0.005). Hypogeusia was established at Seven-iTT score of 3 of less. The identification test combines taste and somatosensory perception, thus creating a more detailed diagnosis tool. Scores were correlated with self-rated taste perception. The present results confirmed the applicability of Seven-iTT for a reliable, fast evaluation of taste and somatosensory perception in the general population, that can be extended to clinical practice.