The Relationship Between the Width of the Frontal Recess and the Frontal Recess Cells in Japanese Patients

Objective: The agger nasi cell (ANC) is an easily identifiable landmark when approaching the frontal sinus. The success of endoscopic frontal sinus surgery may be influenced by the width of the frontal recess (FR). The aim of this study is to examine the relationship between the FR width and the ANC size in Japanese patients. In addition, the effect of various frontal recess cells (FRCs) on the development of frontal sinusitis has been examined. Materials and methods: Multiplanar computed tomography (CT) scans of the nasal cavities and paranasal sinuses in 95 patients (190 sides) before endoscopic sinus surgery were reviewed. The presence of FRCs, the thickness of the frontal beak (FB), the ANC size, and the anterior-to-posterior (A-P) length of the frontal isthmus (FI) and FR were evaluated in patients with and without frontal sinusitis. Results: The prevalence of the ANC, frontal cell types 1, 2, 3, and 4, frontal bullar cell (FBC), suprabullar cell, supraorbital ethmoid cell, and interfrontal sinus septal cell was 85.3%, 11.6%, 0%, 7.9%, 0%, 25.3%, 45.8%, 16.8%, and 15.3%, respectively. The ANC volume showed a significant positive correlation with the A-P length of the FI and FR. The incidence of frontal sinusitis in the patients with FBCs was significantly higher than that without FBCs. Conclusion: A large ANC offers a greater potential to facilitating the approach to the frontal sinus because of the extensiveness of the FR in Japanese patients. The presence of FBCs may be related to a higher incidence of frontal sinusitis.