The distribution of skull shapes reveals significant variation between genders. The most prevalent PA shape among males is "triangular to oval," accounting for 79.2%, while females predominantly exhibit a "triangular" shape at 56.3%. Notably, the "long & narrow" and "tending to roundness" shapes are the least common in both genders, indicating a lower frequency of these PA configurations in the studied population. Similar findings were reported by Asgar et al ⁸ who found triangular to oval in 83.5% of skulls followed by tending to roundness in 15% of skulls.The most common type of piriform aperture in males and females was triangular to oval (III) in 79.2% and triangular(II) in 56.3% respectively matching with Ofodile et al ⁹ study, who found oval (equivalent to types III and IV) in Ashanti, triangular (type II) in Austrians and American Indians, and varied from oval to triangular in black Americans (type III).

The PAI provides further insight into the structural dimensions of the PA. The "long & narrow" shape has the lowest mean PAI (64.0 ± 4.2), highlighting a narrower aperture relative to other shapes. In contrast, the "tending to roundness" shape exhibits the highest mean PAI (89.3 ± 9.3), indicating a broader aperture. The "triangular" and "triangular to oval" shapes display intermediate PAIs, with means of 77.2 ± 5.7 and 85.0 ± 6.1, respectively. These findings underscore the significant variability in PA dimensions across different shapes, potentially influencing nasal airflow and respiratory functions.

Males exhibit significantly longer nasal bone lengths (15.4 ± 2.9 mm) compared to females (11.8 ± 2.8 mm), with a highly significant p-value (<0.001). This difference may be attributed to sexual dimorphism in craniofacial growth patterns. Similarly, males have wider nasal bones (8.3 ± 2.3 mm) than females (6.9 ± 1.0 mm), with a p-value of 0.026, further supporting the presence of gender-specific morphological traits. In study by Durga Devi G et al ¹⁰ length and width of nasal bone was 16.3± 1.9 and 11.3 ±1.6 mm in male and 17.4± 2.3 and 12.05 ± 1.7 mm in female which was comparable to ours in males only. Hwang ¹¹ found length and width of nasal bone in Korean origin 25.9±3.8mm & 9.2±2.4mm in male and 24.5±3.7mm &8.8±2.6mm in female. Lang ¹² worked on German origin and found mean nasal length and width 24.9±3.2 & 13±2.4 respectively. Karadag et al ¹³ studied 80 Anatolian patients and reported the mean nasal bone length of 30.6 mm in males and 29.01mm in females. None of studies showed significant sexual differences in contrast to ours which may be due to regional variations.

The PA dimensions also vary significantly between genders. While PA length does not differ markedly between males (31.9 ± 2.2 mm) and females (31.4 ± 3.7 mm) with P value of<0.610, PA width is significantly greater in males (27.5 ± 2.1 mm) compared to females (24.3 ± 1.6 mm) with a p-value of <0. 001.This is like studies done by Adil Asghar et al ⁸ who found mean nasal bone breadth of 24.9±1.59mm & 22.77±1.57mm in males and females with p value of<0.0105 and Moreddu et al ¹⁴ who reported mean PA width as 24.00 mm (±1.77) in females and 25.32 mm (±1.86) in males with p value <0.001. Yuzbasioglu et al ¹⁵ found greater mean width of 24.6mm in males than 23.3mm in females although of lesser statistical significance. Consequently, the PAI is higher in males (85.3 ± 7.4) than in females (77.4 ± 7.2), with a p-value of 0.002, indicating broader PA’s in males similar to Adil Asghar et al 8 (mean PAI of 79.91±11.55 and 77±9.64 in males and females with p value of <0.041).De Araujo et al ⁷ also found higher length and breadth in Brazilian males than female although of lesser statistical significance(length of 31.4±3.3 in males vs 29.4±3.9 in females and breadth of 25.7±1.9 in males vs 25.7±2.5 in females).

All acknowledgement to department of anatomy for providing skulls and necessary instrument for this study.

The knowledge of the morphometric measurements is of relevance for performing surgical procedures such as rhinoplasty, osteotomies and plastic reconstructions besides being useful in sex, race ethnic determination.