Tomographic morphometry of the foramen magnum and its relation to sex and Mapuche ethnicity.

INTRODUCTION: The foramen magnum is an important surgical anatomical structure in the compression syndromes of the central nervous system, which are compromised neuronal function and circulation. OBJECTIVE: To determine the morphometric values of the foramen magnum on CT and its relation to sex and Mapuche ethnicity. MATERIAL AND METHOD: Descriptive cross-sectional type made by non-probabilistic convenience sampling of 100 brain CT scans (CT) performed at the Hospital Hernán Henríquez Aravena in 2010 reported as "normal" for radiologists. Were selected 50 men and 50 women, integrating within each group 25 TC of subjects with surnames belonging to the Mapuche ethnicity. We measured the transverse diameter, anteroposterior diameter and area, in addition to determining the shape. The data was analyzed using Stata 10.1, comparing different variables with t-test, considering statistically significant a p value < 0.05. All subjects remained under anonymity in the built databases. RESULTS: We found statistically significant differences in all measurements between menand women, being higher in males. There are also significant differences in the measurement of the area between Mapuche and non Mapuche patients, being lower in the first ones. The oval shape was predominant. DISCUSSION: The different measurements between sexes are consistent with the literature. There are differences in measures of foramen magnum of Mapuche and non Mapuche patients and can serve as data for further studies in the area.