Morphometric Characterization of Frontal Sinus and Outflow Tract Anatomy: Implications for Surgical Planning

Introduction The frontal sinus and its outflow tract are integral to sinonasal physiology and play a key role in the development of chronic rhinosinusitis. Their complex anatomy often poses challenges in endoscopic sinus surgery. This study aimed to provide a morphometric characterization of the frontal sinus and its drainage patterns to support safer and more effective surgical planning. Methodology A descriptive cross-sectional cadaveric study was conducted on 30 hemisections derived from 15 formalin-fixed cadaveric head and neck specimens at the All India Institute of Medical Sciences (AIIMS) Bibinagar. Frontal sinus height and depth were measured using digital vernier calipers. Drainage routes were traced with a probe in relation to the uncinate process, and anatomical variations were recorded. Data were analyzed using descriptive statistics in Jamovi. Results The frontal sinus demonstrated a mean height of 21.3±5.9 mm and a mean depth of 14.9±4.0 mm. Drainage was predominantly anteromedial in 17 specimens (58.6%), followed by anterolateral in eight specimens (27.6%) and posterolateral in four specimens (13.8%). Frontal sinus aplasia was observed in one specimen (3.3%), hypoplasia in two specimens (6.7%), and septation in two specimens (6.7%). One aplastic frontal sinus was excluded from morphometric measurements. Conclusion This study shows significant variations in the dimensions and drainage pathways of the frontal sinus. An understanding of frontal sinus anatomy enhances surgical safety and reduces complications.