Comparison of Cottle-Area-2 and Cottle-Area-3 in Computed Tomography Scans of Patients with Nasal Obstruction and Controls

<b>Background/Objectives</b>: Data that compare nasal Cottle-area-2 (i.e., nasal valve) and Cottle-area-3 are sparce. We intended to compare these areas in subjects with and without nasal obstruction. <b>Methods</b>: We compared cross-sectional areas, derived by computed tomography, of Cottle-area-2 (CT-CSA_COT-2) and Cottle-area-3 (CT-CSA_COT-3), in cases planned for surgery due to chronic nasal obstruction and controls with trauma not involving the head. In these cases, we investigated the correlation of the size of narrow and wide sides with active anterior rhinomanometry (AAR). <b>Results</b>: In 56 cases, CT-CSA_COT-2 were 15% smaller than CT-CSA_COT-3 (all <i>p</i> < 0.007). However, both were similarly large in 56 controls (all <i>p</i> > 0.2). Both narrow sides of the CT-CSA_COT-2 and CT-CSA_COT-3 were significantly smaller in cases (69 ± 23 mm² and 79 ± 28 mm², respectively) than in controls (91 ± 21 mm²; <i>p</i> < 0.001 and 93 ± 21 mm²; <i>p</i> = 0.004, respectively). However, only the size of the total nasal airway of CT-CSA_COT-2 was significantly smaller in cases (<i>p</i> < 0.001), not that of CT-CSA_COT-3 (<i>p</i> > 0.2). Correlations of AAR with CT were significant only on the narrow sides (all <i>p</i> < 0.037), but not on the wide sides (all <i>p</i> > 0.2). <b>Conclusions</b>: In contrast to Cottle-area-3, the total nasal airway of Cottle-area-2, i.e., nasal valve, was smaller in patients with nasal obstruction, the latter of which may not be easily identified before nasal surgical procedures.