SUMMARY:The aim of the study was to establish morphometrically the infraorbital foramen (IOF) location in the sagittal and transversal plan of the skull and to analyze the variations, as well as verifying the symmetry with the contralateral IOF. 210 skulls were analyzed and as exclusion criterion, were not analyzed skulls of children. Digital paquimeter was used and had been carried through two bilateral measures: a)sagittal measure; from infraorbital margin until the superior margin of the IOF; b) transversal measure, of the lateral margin of piriformis opening until the medial margin of the IOF, using the transversal plan. These measures had formed an angle of 90º between itself. The data were analyzed by the Kolmogorov-Smirnov to verify the Gaussian distribution and and Person's test to evaluate the correlation, considering significantly the differences that had presented a p≤ 0,05. The mean±SD in the sagital measures were respectively; right side 6,71±1.70 mm and 6,83±1.83 mm for left side (p≤0.0001). Transversal measures were: right side 13,28±2.17mm and 13,31±2.19 mm for left side (p≤0.0001). Were observed supranumerary foramens of the IOF, with presence of the double IOF in 50 cases, being bilateral in 08 specimens, left and right side 21 specimens for each side.The IOF are not absolutely symmetrical and may present pair bilateral and or unilateral opening. The presence of the supranumerary foraminas, as well as, the morphometrics measures in this study may intervene with the anesthesia, thus, suggest that they must be considered in the anaesthesical evaluation and be remembered during the procedures used for the localization of the forame. (Chonghuo, 1993;Chen, 1997;Esper et al. 1997Esper et al. ,1998, require more precise understanding of the surrounding anatomy (Bolini & Del Sol; Karakas et al.). Data on morphometric measurements regarding reference points should reduce risks during procedures, surgical operations and anesthesia (Zide & Swift; Karakas et al.; Du Tolt & Nortje). Therefore, the purpose of this study was to conduct morphometric measurements of the IOF location by using the sagittal and transversal plan of the Brazilian skull as reference, as well as verifying the symmetry with the contralateral IOF.Exclusion criterion of the sample: It was adopted like exclusion criterion all the child skulls and the skulls which the piriformis opening was damaged, unilaterally or bilaterally.In all the samples the presence of right maxilar joined to the left maxilar was considered indispensable to have the absolutely certainty that the studied foramens belonged to the same original skull and the statistic could express reliable results. The variables age, sex and race were not considered. Statistical analysis:The softwareGraph Prism was used in the statistical evaluation of measurement results. From these measurements means and standard deviations (mean±SD) were calculated. The data were analyzed by the KolmogorovSmirnov to verify the Gaussian distribution and and Person's test to evaluate the correlati...