Craniometric study of the Orbital Index in brazilian skulls

Abstract

ABSTRACT Objetive To determine the percentage of correctness of the Orbital Index (OI) for estimation of sex, ancestry and age in Brazilian skulls. Methods Cross-sectional study of 183 human dry skulls from the southeastern Brazil. A total of 100 skeletons were males and 83 females; of which 36 were aged up to 39 years, 60 aged between 40 and 59 years, and 87 aged 60 years or older. As for ancestry, 103 were from white, 51 mixed race, and 29 black individuals. The OI was calculate by the formula = height/width x 100. The data were submitted to Student’s t test, F (ANOVA), Tukey and Kruskal Wallis tests as well as to discriminant analysis, with a 5% significance level. Results The sample was characterized as mesoseme, with a mean age of 56.62 (±19.97) years. No significant difference was observed (p=0.511) between the OI in females (right: 86.43 ± 6.58 and left: 86.70 ± 5.93) and males (right: 85.78 ± 6.69 and left: 86.37 ± 6.20). There were no significant differences between age, ancestry and the variables analyzed (p>0.05). The right and left orbital widths were significantly dimorphic between sexes (p<0.001). The percentage of correctness of the method for estimation of sex, age and ancestry was found to be 65.6%, 43.7%, and 43.6%, respectively. Conclusions The OI is not an appropriate method for estimation of sex, ancestry and estimation of age in this Brazilian sample. The methodology should be expanded to other population groups so that it can be improved.

Keywords

• Age groups
• Ethnic groups
• Forensic anthropology
• Orbit
• Sexual dimorphism
• Skull