Correlation between olfactory function, trigeminal sensitivity, and nasal anatomy in healthy subjects.
PURPOSE
Few studies have investigated the correlation between chemosensory function (trigeminal and olfactory) and nasal volume in humans, even though nasal anatomy is crucial for the sense of smell. Aim of this study was to evaluate these correlations in normosmic subjects.


METHODS
Two hundred and fifty-six healthy volunteers (age range 19-69 years) participated. Olfactory function was investigated for (the rose-like) phenylethyl alcohol odor threshold and odor identification (OI) using the Sniffin' Sticks test, while nasal structure was evaluated by acoustic rhinometry (AR); trigeminal sensitivity was assessed in terms of detection "thresholds" for the odorless carbon dioxide (CO2).


RESULTS
There were negative correlations between olfactory sensitivity at threshold level and minimum cross-sectional area (MCSA) in both nostrils. No significant correlations were found between OI and nasal anatomy. Similar to olfactory sensitivity, with regard to the trigeminal stimulus CO2 for the right nostril subjects were the more sensitive the smaller the MCSA.


CONCLUSIONS
The current results emphasize the significance of nasal anatomy for trigeminal/olfactory threshold perception. Interestingly, correlations were not found between suprathreshold odor identification and nasal anatomy. Other than odor identification, odor thresholds appear to depend on subtle differences in nasal anatomy.
['Masala|Carla|C|http://orcid.org/0000-0001-5272-8421', 'Käehling|C|C|', 'Fall|F|F|', 'Hummel|T|T|']
D000328:Adult D000368:Aged D005260:Female D064368:Healthy Volunteers D006801:Humans D008297:Male D008875:Middle Aged D009666:Nose D055696:Olfactory Perception D012016:Reference Values D023842:Rhinometry, Acoustic D012684:Sensory Thresholds D012903:Smell D014276:Trigeminal Nerve
Olfactory function Nasal anatomy Acoustic rhinometry Chemosensory system Sniffin’ Sticks