Anatomic variations of the bone in sinonasal CT.

Coronal plane computed tomographic (CT) scanning is important as a preoperative test for functional endoscopic sinus surgery. Coronal CT reveals details of mucosal abnormalities and anatomic variations of the bone. In 75 patients, mucosal abnormalities in each paranasal sinus were investigated on CT. The incidence of anatomic variations of the bone such as agger nasi cells, Haller's cells, middle turbinate, pneumatization, paradoxically curved middle turbinate, and uncinate pneumatization were also reported. The incidence of each finding was compared in patients with (chronic sinus group) and without (non-sinus group) symptoms of chronic sinusitis. The incidence of mucosal abnormalities in the anterior ethmoidal sinus was the highest (86.0%) in the chronic sinus group. Although there was no significant difference in the incidence of anatomic variations of the bone between the two groups, some variations were considered pathogenic for chronic sinusitis and recurrence of sinusitis in the chronic sinus group.