An Evaluation of the Caudal End Deviation of the Nasal Septum Using the Quantitative Analysis of Computed Tomography

Abstract

Objectives: This study was designed to determine objective surgical indications of correcting caudal end deviation of the nasal septum. Methods: We employed quantitative computed tomographic (CT) analysis and assessed the validity by comparing this with anterior rhinoscopic findings (AR findings). The study population consisted of 300 patients. The archived CT data were transferred to a workstation, and 3D CT volume-rendered images were generated using computer graphics tools. In the plane of the nostril entrance, we calculated ratios of the cross-sectional area of the convex side (narrower side) and the concave side (wider side), which is abbreviated as the N/W ratio. We also examined the presence of laterality between the right and the left cross-sectional area of the nasal valve based on the AR findings. Surgical procedures for whether to expose the caudal end were planned based on the AR findings and the N/W ratio. Results: A significant correlation was found between the AR findings and the N/W ratio. After surgery, the average N/W ratio improved from 0.53 ± 0.15 to 0.81 ± 0.15, and the average values of VAS scaling for nasal obstruction improved from 8.1 ± 0.2 to 1.0 ± 0.1. Conclusions: The quantitative CT analysis proposed in the study is a useful modality to objectively determine the surgical indications of managing the caudal end of the nasal septum.