Olfactory Cleft Width and Volume: Possible Risk Factors for Postinfectious Olfactory Dysfunction.

Objectives/hypothesis: Upper respiratory tract infections are a common cause of temporary and permanent olfactory dysfunction in the general population. Postviral or postinfectious olfactory loss (PIOL) develops only in rare cases. The aim of this study was to investigate the anatomical features of olfactory cleft (OC) in patients with PIOL to shed light on possible predisposing factors for PIOL.

Study Design: Retrospective study.

Methods: We retrospectively evaluated paranasal sinus computed tomography (CT) scan results of patients diagnosed with PIOL. A control group consisted of normosmic individuals who underwent paranasal sinus CT scans before septoplasty surgery. We compared the olfactory fossa depth, OC width, and volume on the CT scans of the PIOL and control groups.

Results: In total, 71 individuals fulfilled the study criteria (PIOL group, n = 32; control group, n = 39). There was no statistically significant difference in the olfactory fossa depth in the two groups. The OC width and volume in the PIOL group was found to be significantly increased than that in the control group (P < .001 for both).

Conclusions: Patients with PIOL had increased OC width and volume than the healthy controls. An extra-wide olfactory cleft may be a predisposing factor in the pathogenesis of PIOL.

Level Of Evidence: 4 Laryngoscope, 131:5-9, 2021.