Frontal recess anatomy and frontal sinusitis association from the perspectives of different classification systems

Objective: As the management of frontal sinusitis (FS) is challenging, a clear understanding of the frontal recess (FR) area is crucial. The purpose of this study was to compare the radiologic prevalence of frontal cells (FCs) according to the 2 widely used classification systems in patients with and without FS. Methods: Computed tomography (CT) scans of paranasal sinuses of normal individuals (control group) and patients with isolated FS (FS group) were reviewed to identify the mucosal disease and variations of FR cells according to 3 classification systems (IFAC, European Position, and Lee) as follows: agger nasi cells (ANCs), suprabullar cells (SBCs), supraorbital ethmoid cells (SOECs), frontal bullar cells (FBCs), interfrontal sinus septal cells (IFSSCs) frontal cells type 1 to 4 (FCs), and anterior/posterior/medial frontethmoid cells. Data were collected on the right and left sides, and 56 sides were evaluated. Logistic regression analysis was used to compare the distribution of FR cells in the FS and control groups. The AP diameters of the FR, frontal beak, and frontal isthmus, as well as the mediolateral diameter of the FR and the distance between the two frontal recesses, were measured. Results: There was no significant association between FS and the presence of FCs according to the included classifications. The prevalence of FS in our study did not show a statistically significant difference for most measurements. Conclusion: The findings of this study provide evidence that mucosal disease is an unneglecfactor leading to FS. However, in addition to anatomical blockage, there are other underlying factors that lead to refractory FS.