Assessment of septal deviation with computed tomography (CT). The presence of septal deviation was evaluated using coronal CT scans. The superior insertion of the nasal septum at the crista galli (C), its inferior insertion at the level of the anterior nasal spine (S), and the apex of the nasal septal deviation (A) were all marked on the CT scan. The septal deviation angle was defined as the angle between the midline (C–S line) and the line from the crista gali to most markedly deviated point (C–A line). CT = computed tomography.