RESUMEN
Aim: This study evaluated radiographic variations and measured dimensions of the non-pathologic frontal sinuses. Study Design: Retrospective. Place and Duration of Study: Orthodontics Department, Dental School, Shahid Beheshti University of Medical Sciences, 2003 to 2012. Methodology: Subjects older than 12 years with no sinus pathology were included. Borders of the frontal sinus were traced. Line drawings were scanned, and sinus dimensions were calculated by computer software by two examiners. In addition, asymmetry and shape of superior margin of sinus were evaluated. Gender differences were analyzed by independent sample t-test and chi square with a 0.05 level of significance. Results: A total of 66 subjects were included (40 female and 26 male). Height, width and area of the frontal sinus in the sagittal plane were 2.26 cm, 1.13 cm and 1.37 cm2, respectively. The corresponding numbers in the frontal plane were 2.79 cm, 5.00 cm and 7.04 cm2, respectively. Although all dimensions were larger in men than in women, it was not significant (P>0.05). Most of the cases had relatively symmetric frontal sinus. Conclusion: Size and shape of the frontal sinus varies among individuals. Frontal sinus is relatively larger in men than women.