Abstract

Introduction: The foramen magnum (FM) is an anatomical structure located in the posterior fossa of the skull. This foramen becomes relevant in compressive syndromes of the central nervous system, which compromised the neuronal function and circulatory failure. The purpose of this study is to determine the morphometric values of the foramen magnum in studies by image and its relationship with the sex, ethnicity and pre- and post-natal history, being the first of its kind in our region.

Material and Method: This are an observational, cross-sectional and retrospective study. We analyzed 152 images of computed tomography of individuals (0 - 4 years old) of both sexes that did not present pathologies that affect the morphology of the skull. We analyzed the CT obtained from the year 2013 onwards. These images are part of the files of the Service of Neuroimaging Studies of the Pediatric Hospital S.A.M.I.C.; “Prof. Dr. Juan P. Garrahan", City of Buenos Aires. Methods were used based on morphometry of the linear measurements, angles and distances, obtaining a total of four measures. An AGFA software was used for image processing, getting the length of the foramen magnum, the transverse diameter, its area and shape. 

Results: 82 of the subjects were boys and 70 girls. The mean length of the FM increases gradually, being 28,43 mm at birth and 33,95 at age 4, in the same way, the mean transverse diameter increases from 21,06 mm at birth to 28,83 mm at age 4. The FM area grows from 453,63 mm² at birth to 718,28 mm² at age 4. The predominant shape of the foramen magnum in both sexes was pentagonal.

Conclusion: There are significant differences in longitude and area of the FM between men and women, being higher in males. It was also observed an increase in the results concomitant with age. 

Keywords: Skull; Foramen Magnum; Children; Anthropometry; Variations

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