Abbreviations: N, nasion; RIOF, right infraorbital foramen;LIOF, left infraorbital foramen; DRIOF, distance from the right infraorbital foramen to the nasion; DLIOFN, distance from the left infraorbital foramen to the nasion; DIOF, distance between the infraorbital foramina; PIOFN, perimeter formed by lines between the infraorbital foramina and the nasion; ATIOFN, area of the triangle formed by lines between the infraorbital foramina and the nasion
IntroductionThe human skull is considered to be the second most useful indicator for determining an individual's sex, after the pelvis.1 It is also responsible for furnishing important data for identifying the sex of living individuals and even cadavers.2,3 For forensic experts to perform these tasks, precise methods and techniques are required. 4,5 Male skulls are generally formed by coarser or rougher structures because of the presence of stronger muscle insertions. Moreover, they are also larger than female skulls. 4,5 Two methods are used in the process of determining individuals' sex from parts of the craniofacial skeleton: the qualitative or morphological method and the quantitative or metric method. Most studies have used the morphological method, in which characteristics such as the frontal sinuses, teeth, glabellae, bone thickness, eyebrow ridge thickness and chin shape have been studied. 5 On the other hand, the quantitative method makes use of measurements between preestablished points on the skull. This method, which is considered to possibly be more efficient, has contributed greatly towards determining individuals' sex. 2,6 Most authors in the literature on skull measurements from quantitative or metric variables have used samples from other countries (i.e. not from Brazil).6-8 This places limitations on the applicability of these studies to the Brazilian population, given that without knowledge of the parameters for measurements on Brazilian skulls, researchers are obliged to use international tables. This could lead to uncertainty regarding the results.2 Therefore, the present study had the objective of determining sexual dimorphism in Brazilian skulls from measurement of the area of the triangle formed by lines between the infraorbital foramina (IOFs) and the nasion.
Materials and methodsIn this study, 242 dry human skulls were used: 148 male skulls and 94 female skulls, ranging in age from 18 to 91years. The skulls had been obtained in accordance with law no. 8501 of 1992, which deals with use of unclaimed cadavers for use in studies and research. These skulls belong to the Study and Research Center for Anatomy and Forensic Anthropology (CEPAAF) of Tiradentes University.This was a morphometric study in which the following were measured: distance of the right infraorbital foramen to the nasion (DRIOFN), distance of the left infraorbital foramen to the nasion (DLIOFN), distance between the infraorbital foramina and perimeter and area of the triangle formed bylines between the infraorbital foramina and the nasion (Figure 1). The linear measurements were...
