Retronasal olfaction is important in flavor detection and enjoyment. The ability to identify specific individual retronasal odors may play a role in the quality of life for patients with CRS.

Researchers conducted this study to identify patterns and improve understanding of retronasal identification of individual odors in CRS patients.

Patients diagnosed with CRS underwent retronasal and orthonasal olfactory testing and taste testing. Retronasal identification was tested with the presentation of flavored powders on the posterior tongue. Retronasal identification for individual odors was compared with results of orthonasal and taste testing.

Seventy participants were evaluated. Retronasal identification correlated with orthonasal identification and discrimination for most individual odors. Among all patients, cinnamon and apple were identified as better retronasal and banana better orthonasal. Anosmics identified retronasal orange, cinnamon, mushroom, coffee, smoked ham, peach, ginger, grape, and cheese more than would be expected by chance for a forced-choice paradigm with three distractor items, and this was independent of objective taste function for most odors.

The study concluded that most odors’ retronasal and orthonasal identification correlate in CRS patients; however, patients with anosmia can still identify certain retronasal scents more often than expected. These odors do not appear to stimulate gustatory pathways and may involve trigeminal stimulation. Understanding preserved retronasal neural stimuli may allow providers to improve eating-related quality of life in these patients.