The Relationship Between the Frontal Anterior Buttress and the Frontoethmoidal Angle in 2-Dimensional Assessment and Its Impact on Endoscopic Frontal Sinus Surgery Outcomes

Objective This study aims to investigate the two-dimensional relationship between the anterior frontal buttress (AFB) and the frontoethmoidal angle (FEA), and its impact on surgical difficulty and complications in endoscopic frontal sinus surgery (EFSS). Methods A retrospective analysis was conducted on 35 adult patients who underwent EFSS between 2021 and 2024. Preoperative high-resolution sagittal computed tomography (CT) scans were used to measure angles between the frontal apex and superior (BS/FA), inferior (BI/FA) frontal buttress, and the nasal spine (NS/FA), as well as the frontal recess diameter (FRD). Patient demographics, SNOT-22 and Lund-Mackay scores, surgical duration, complications, and revision history were recorded. Statistical correlations between anatomical measurements and surgical outcomes were analyzed. Results Thirty-five patients were analyzed; the complication rate was 22.9% (n=8). Frontal apex–related angles did not differ by sex (all p>0.05). Patients with complications had significantly larger bilateral frontal apex–related angles and narrower bilateral frontal recess diameters (all p<0.05), and they also showed longer operative times and higher VAS difficulty (p<0.05). Anatomical angles/FRD were not associated with revision status (p>0.05); however, revision cases had higher preoperative SNOT-22, higher pre- and postoperative LMS, and longer operative time (all p<0.05). Frontal apex–related angles correlated moderately with operative duration and VAS difficulty (r=0.383–0.590; p<0.05). Measurement reliability was excellent (inter-observer ICC=0.92; intra-observer ICC=0.93; both p<0.001). Conclusion Preoperative sagittal CT assessment of the AFB–FEA relationship suggests that more unfavorable frontal outflow anatomy is associated with greater EFSS complexity and complication risk.