Macromorphoscopic evaluation of the mastoid process for sex estimation in contemporary Brazilian skulls: an accuracy study

This study aimed to analyze the accuracy of the macromorphoscopic evaluation of the mastoid process of the temporal bone in identified human skeletons for estimating sex. A total of 832 mastoid processes from individuals of both sexes, aged at least 20 years, were examined. All the mastoid processes were analyzed concerning their anatomical characteristics and classified according to the types established by Buikstra and Ubelaker (1994), assigning scores in which the lowest values (1 and 2) correspond to females, higher values (4 and 5) to males and value 3 represents a zone of indeterminate sex. For the total sample, score 3 was predominant, while score 1 was less frequent for both mastoid processes. In addition, men showed more occurrences of score 4, while women showed more classifications in score 2, both on the right and left, with a statistically significant relationship between sex and mastoid process. Overall accuracy was 76%, with males showing a higher percentage of correct observations than females (89.7% and 61.1%, respectively). The right mastoid process showed greater accuracy in predicting sex (p<0.001). Despite the greater number of studies on metric methods in the literature, morphoscopic methods are important in forensic anthropology, especially for sexual diagnosis, given their easy applicability and potential for good results.