[Spiral computed tomographic analysis of frontal recess regions]

The purpose of the study was to determine the prevalence of frontal recess cells in Chinese patients who did not have frontal sinus disease related symptoms.

Forty-nine Chinese patients without frontal sinus disease symptoms were undergone spiral computed tomography (CT). Then multiplanar reconstruction images were evaluated using a standard triplanar reconstruction protocol on a computer workstation.

The prevalence of agge rnasi cell was 94% (92/98). Sixty-four uncinate processes (65%, 64/98) had one superior attachment for each uncinate process, the other thirty-four uncinate processes (35%, 34/98) had two superior attachments for each uncinate process. The uncinate process' single superior attachment into the surrounding structures was identified to have the following distribution: 53% (52/98) to the lamina papyracea, 9% (9/98) to the middle turbinate, 3% (3/98) to the skull base. Most of the uncinate process' two superior attachments were either into the lamina papyracea and the skull base (24%, 23/98) or into the lamina papyracea and the middle turbinate (10%, 10/98). Only one uncinate process (1%) superiorly attached to the skull base and the middle turbinate. The prevalence of recessus terminalis was 87% (85/98). Of all the frontal cells identified in 32 sides (33%) of frontal recesses, the prevalence of type I, type II, type II and type IV cells were 23% (23 sides), 2% (2 sides), 7% (7 sides) and 0% (0 side) respectively. Supra bullar cell, frontal bullar cell and interfrontal septal cell were identified in 30 sides (31%), 7 sides (7%) and 7 patients (14%) respectively.

The result characterized normal frontal recess pneumatization in Chinese. That, together with the variations of the uncinate process' superior attachment emphasized the roles of agger nasi cell and the uncinate process in endoscopic frontal sinus surgery.