Frontal Bone Morphology in Different Age and Gender Groups Using Computed Tomography.

Background:  The shape of the forehead is primarily determined by the frontal bone, which holds significance for health and aesthetics. This study evaluated the morphology of the frontal bone in different age groups and genders using computed tomography (CT).

Methods:  This cross-sectional study was conducted on CT scan results of 220 patients divided into three age groups: 20-29.27, 29.27-47.54, and 47.54-95 years. The investigation explored the lower and upper angles compared with the Sella-Nasion (SN) line, the maximum frontal projection with Nasion in the SN plan, and the variations in frontal thickness across different angles (15, 30, 45, 60, 75, and 90 degrees) relative to the SN plane. All data were analyzed using R software, considering the significance level  < 0.05.

Results:  Of 220 patients, 119 were men, and the mean age of the participants was 41.09 ± 18.06 years. The average upper frontal slope (UFS) angle was 56.96 ± 8.17 degrees, which was 59.35 ± 7.92 degrees in females and 54.94 ± 7.86 degrees in males. The mean lower frontal slope (LFS) angle was 86.30 ± 7.96 degrees, which was 90.71 ± 6.67 degrees in females and 82.55 ± 7.00 degrees in males. The average contour nasion (C-N) distance was 7.51 ± 3.72 mm. Also, the frontal thickness at an angle of 15 degrees had the highest value of 13.08 ± 2.68 mm and at 30 degrees had the lowest value of 5.81 ± 1.56 mm. A significant difference was observed between the UFS and LFS among males and females ( < 0.001). Across all age groups, men exhibited a steeper angle, indicating a greater posterior inclination than women. Moreover, males with upper ages reported a significant increase in C-N distance and frontal projection ( < 0.05).

Conclusion:  Our findings emphasize the importance of considering gender-specific variations in frontal bone structure when planning cosmetic or reconstructive procedures involving the forehead.