Validation of the auricular surface method for sex estimation in non-adult human remains

Abstract

Sex of non-adult individuals is usually not estimated in bioarchaeological and forensic studies because it is argued that skeletal sexual dimorphism is minimal before puberty. However, several methods have been developed to address this issue. In 2017, a new approach based on the shape of the auricular surface of the ilium was proposed by Luna and co-authors after the analysis of the Coimbra skeletal Collection. The present study aims to test if the sexual dimorphic variables obtained in that research are equally accurate in another sample that includes younger ages. Sixty-one individuals (30 males, 31 females) from the Lisbon Collection, aged between 1 day and 18 years-old, were analyzed by two observers without previous knowledge of the sex of the individuals. Data shows a low interobserver error (ICC>0.92; K>0.74). The discriminant function classified correctly 86.7% of the males and 71% of the females, and the logistic regression, 80.0% and 74 .2%. The percentage of accuracy of both the overall and apex morphology was found to be 76.7% for males and 80.6% for females, and the morphometric ratios provide correct results in at least 76.7% of males. The method was equally reliable in younger (0-12y.o.) and older (13-18y.o.) individuals and slightly more accurate in males. The percentages of correct estimations are not influenced by the cause of death (e.g. infectious, heart problems) of the individuals. This study confirms the usefulness of auricular surface shape for sexual estimation of non-adults individuals. Additional validation tests in documented individuals from other geographic regions are suggested.