Resumen de Foramen Venosum in macerated skulls from the North-East of Brazil: morphometric study

José Jailson Costa do Nascimento, Eulâmpio José da Silva Neto, Elayne Cristina de Oliveira Ribeiro, Maurus Marques de Almeida Holanda, Marcelo Morais Valença, Louisie Dayane Oliveira Gomes, Nilton Alves

• The foramen venosum (FV) is a small, inconstant orifice in the middle cranial fossa, located anterior and medial to the foramen ovale (FO). The object of the present study was to analyse the frequency of the FV, its side of appearance, diameter and distance from the FO, in macerated skulls of adult Brazilians from the north-eastern region of Brazil. 194 macerated skulls were analysed. The diameter of the FV and its distance from the FO (FV-FO) were measured with a digital calliper. The FV was present in 18.5% of the skulls. Unilateral presence (12.4%) was more frequent than bilateral (6.1%). When unilateral, the FV was more frequent on the left side (9.3%) than the right (3.1%). We observed asymmetry in the size of the FV, which was larger on the left side (p=0.043). No statistically significant difference was observed between sides for FV-FO, however this distance was significantly greater in women than in men (p=0.006). The FV is an important anatomical variation, and may occur bilaterally or unilaterally. It is asymmetrical, with larger diameter found on the left side. The findings of this study provide important information for surgeons and morphologists on the anatomy of the middle cranial fossa.