Morphometric and morphological assessment of the piriform aperture in dry crania: anatomical observations and...

The piriform aperture (PA) is a critical anatomical structure that forms the bony framework of the nasal inlet and influences nasal airway patency and support of the nasal base. This study aimed to present detailed morphometric and morphological data on the PA to contribute to the surgical anatomy of PA enlargement.

Seventy adult crania (female, n = 34; male, n = 36) were included. Using standardized digital images, PA length, PA width, related craniometric distances, and planimetric area were measured with ImageJ software. PA morphology was classified into six types.

PA length was 4.71 ± 0.67 cm in females and 5.54 ± 0.50 cm in males; PA width was 3.52 ± 0.39 cm in females and 3.80 ± 0.35 cm in males. PA area was 12.61 ± 2.77 cm² in females and 15.99 ± 2.82 cm² in males. PA length, width, width at the level of the infraorbital foramen, the nasion-anterior nasal spine distance, inter-infraorbital distance, rhinion-right/left infraorbital foramen distances, and PA area were significantly higher in males. Regarding morphological type distribution, the pear type was most frequent (42.86%), followed by inverted heart (21.43%), round (12.86%), teardrop (10%), and oval (8.6%). PA length in the round type was lower than in the pear/oval/teardrop types, whereas PA area in the oval type was higher than in the round type.

PA morphometry demonstrates marked sexual dimorphism. In males, PA length was approximately 18% greater and PA area approximately 27% greater, reflecting the combined effect of increased length and width.