Validation of a physical anthropology methodology using mandibles for gender estimation in a Brazilian population.

UNLABELLED: Validation studies of physical anthropology methods in the different population groups are extremely important, especially in cases in which the population variations may cause problems in the identification of a native individual by the application of norms developed for different communities. OBJECTIVE: This study aimed to estimate the gender of skeletons by application of the method of Oliveira, et al. (1995), previously used in a population sample from Northeast Brazil. MATERIAL AND METHODS: The accuracy of this method was assessed for a population from Southeast Brazil and validated by statistical tests. The method used two mandibular measurements, namely the bigonial distance and the mandibular ramus height. The sample was composed of 66 skulls and the method was applied by two examiners. The results were statistically analyzed by the paired t test, logistic discriminant analysis and logistic regression. RESULTS: The results demonstrated that the application of the method of Oliveira, et al. (1995) in this population achieved very different outcomes between genders, with 100% for females and only 11% for males, which may be explained by ethnic differences. However, statistical adjustment of measurement data for the population analyzed allowed accuracy of 76.47% for males and 78.13% for females, with the creation of a new discriminant formula. CONCLUSION: It was concluded that methods involving physical anthropology present high rate of accuracy for human identification, easy application, low cost and simplicity; however, the methodologies must be validated for the different populations due to differences in ethnic patterns, which are directly related to the phenotypic aspects. In this specific case, the method of Oliveira, et al. (1995) presented good accuracy and may be used for gender estimation in Brazil in two geographic regions, namely Northeast and Southeast; however, for other regions of the country (North, Central West and South), previous methodological adjustment is recommended as demonstrated in this study.

Validation of a physical anthropology methodology using mandibles for gender estimation in a Brazilian population

Validation studies of physical anthropology methods in the different population groups are extremely important, especially in cases in which the population variations may cause problems in the identification of a native individual by the application of norms developed for different communities. OBJECTIVE: This study aimed to estimate the gender of skeletons by application of the method of Oliveira, et al. (1995), previously used in a population sample from Northeast Brazil. MATERIAL AND METHODS: The accuracy of this method was assessed for a population from Southeast Brazil and validated by statistical tests. The method used two mandibular measurements, namely the bigonial distance and the mandibular ramus height. The sample was composed of 66 skulls and the method was applied by two examiners. The results were statistically analyzed by the paired t test, logistic discriminant analysis and logistic regression. RESULTS: The results demonstrated that the application of the method of Oliveira, et al. (1995) in this population achieved very different outcomes between genders, with 100% for females and only 11% for males, which may be explained by ethnic differences. However, statistical adjustment of measurement data for the population analyzed allowed accuracy of 76.47% for males and 78.13% for females, with the creation of a new discriminant formula. CONCLUSION: It was concluded that methods involving physical anthropology present high rate of accuracy for human identification, easy application, low cost and simplicity; however, the methodologies must be validated for the different populations due to differences in ethnic patterns, which are directly related to the phenotypic aspects. In this specific case, the method of Oliveira, et al. (1995) presented good accuracy and may be used for gender estimation in Brazil in two geographic regions, namely ...

Proporções áureas em crânios humanos esqueletizados / Golden proportion in human skulls skeletonized

As proporções na face e no corpo humano são analisadas desde a antiguidade, a exemplo do Homem Vitruviano de Leonardo da Vince. A existência das proporções Divinas ou proporções áureas em crânios esqueletizados é um campo de estudo que apresenta um potencial colaborador para as áreas de sobreposição de imagens, reconstrução facial e identificação forense. O objetivo deste trabalho é estabelecer parâmetros antropométricos regionais baseados nas proporções áureas, instituindo coeficientes e índices faciais específicos para a amostra composta por sessenta crânios esqueletizados (n=60), oriundos do Instituto Médico Legal da Bahia. As mensurações foram realizadas diretamente sobre o crânio utilizando paquímetros digitais. Foram selecionadas 14 medidas craniométricas diferentes e a partir delas foram calculados 06 relações horizontais, 04 verticais e 06 índices faciais. Os dados foram tabulados e descritos por valores de média e desvio padrão, utilizou-se o intervalo de confiança da média (p<0,05). A proporção áurea (1,618) não foi encontrada na população examinada, entretanto foi possível estabelecer índices faciais e coeficientes próprios para as medidas, construindo parâmetros antropométricos regionais baseados nas proporções estudadas. A proporção altura da cabeça em relação a altura da face (V-GN/N-GN) igual a 1,69 foi a variável que mais se aproximou do número de ouro e a relação entre a altura nasal ser igual a metade da altura da face (N-SN=N-GN/2) como valor de 0,92 foi a variável que mais se aproximou entre as igualdades. Admiti-se que a partir de uma medida é possível alcançar a outra utilizando os índices faciais e as retas de regressão calculadas. Este estudo fornece indicadores úteis, pois busca estabelecer proporções nos crânios que são reproduzíveis na face, contribuindo para o aperfeiçoamento das técnicas auxiliares de Reconstrução Facial e Sobreposição de Imagens em estudos futuros.

The proportions of the human face and body have been studied since, at least, Leonardo da Vinci and his Vitruvian Man. The existence of divine or Golden Ratios in human skulls may collaborate with Image Superposition, Facial Reconstruction and Forensics Identification. The goal of this study is establishing regional anthropometrics parameters based on golden ratios, using specifics facial coefficients and indexes for sixty skulls (n=60), obtained from Institute of Legal Medicine of Bahia, BRA. The measurements were done directly over the skull using a digital pachymeter. Fourteen different measurements were selected and, from them, 06 horizontals and 04 verticals relations and 06 facial indexes were calculated. The data was charted and described by average and standard deviation. An average confidence interval was used (p<0,05).The golden ratio (1,618) has not been found among the population analyzed, however was possible establishing facial indexes and coefficients for the measurements, building regional anthropometric parameters based on the studied proportions. The proportion height of the head related to the height of the face (V-GN/N-GN) equal to 1,69 was the closest variable to the golden number and the relation between nasal height being equal to half a height of the face (N-SN=N-GN/2) as 0,92 was the closest variable between equalities. Admitting that from one measurement to another can be achieved using the facial indexes facial and linear regression calculated. This study provides useful indicators since tries to establish proportions on the skull that can be reproducible on the face, contributing for the improvement of auxiliary techniques of Facial Reconstruction and Images Superposition in future studies.