A practical test for retronasal odor identification based on aromatized tablets

Olfactory perceptions elicited by odors originating from within the body (retronasal olfaction) play a crucial role in well-being and are often disrupted in various medical conditions. However, the assessment of retronasal olfaction in research and the clinical practice is impeded by the lack of commercially available tests and limited standardization of existing testing materials. The novel ThreeT retronasal odor identification test employs 20 flavored tablets that deliver a standardized amount of odorous stimuli. The items represent common food- and non-food-related odors. The ThreeT test effectively distinguishes patients with olfactory dysfunction from healthy controls, achieving a specificity of 86% and sensitivity of 73%. Its scores remain stable for up to 3 months (r=.79). ThreeT test exhibits a strong correlation with “Tasteless powders” measure of retronasal olfaction (r=.78) and classifies people into healthy and patient groups with similar accuracy. Test-retest stability of ThreeT is slightly higher than the stability of “Tasteless powders” (r=.79 vs r=.74). ThreeT is suitable for integration into scientific research and clinical practice to monitor retronasal odor identification abilities. •The olfactory system consists of orthonasal and retronasal routes.•Retronasal olfaction assessment methods are limited.•ThreeT test assesses retronasal odor identification with aromatized tablets.•ThreeT effectively distinguish people with smell dysfunction from healthy controls.•ThreeT is validated for use in scientific research and in the clinical practice.