Clinical Implications of Septal Deviation in Lateralized Olfaction

Area of Science:

• Otolaryngology
• Neuroscience
• Olfactory Research

Background:

• Birhinal olfaction typically aligns with dominant nostril function.
• However, birhinal olfaction can be impaired compared to monorhinal olfaction.
• Deviated nasal septum's impact on this phenomenon requires investigation.

Purpose of the Study:

• To investigate the effect of deviated nasal septum on birhinal olfaction in patients with lateralized olfaction.
• To examine the efficacy of septoplasty in improving olfaction in these patients.

Main Methods:

• Retrospective study of 518 patients undergoing butanol threshold tests (BTTs).
• Lateralized olfaction defined by BTT score difference >2 between nostrils.
• Underestimated birhinal olfaction defined by birhinal BTT score >2 lower than dominant nostril.

Main Results:

• 112 patients had lateralized olfaction; 20.5% showed underestimated birhinal olfaction.
• Septal deviation towards the dominant nostril was more frequent in the underestimated group (73.9% vs. 37.6%).
• Five patients with septal deviation to the dominant nostril underwent septoplasty, all showing improved lateralized olfaction post-surgery.

Conclusions:

• Septal deviation towards the dominant nostril is linked to underestimated birhinal olfaction.
• Septoplasty may enhance olfaction by improving airflow to the dominant olfactory side.