845 Int. J. Morphol., 26(4):845-848, 2008. Blind Test of Mandibular Morphology with Sex Indicator in Subadult Mandibles Test Ciego de la Morfología Mandibular como Indicador de Sexo en Mandíbulas de Subadultos *,* Iván Claudio Suazo Galdames; *,* Daniela Alejandra Zavando Matamala & ** Ricardo Luiz Smith SUAZO, G. I. C.; ZAVANDO, M. D. A. & SMITH, R. L. Blind test of mandibular morphology with sex indicator in subadult mandibles. Int. J. Morphol., 26(4):845-848, 2008. SUMMARY: Loth & Henneberg (2001) indicated that it was possible determine the sex with a high degree of accuracy (81%) in mandibles of children by observing the shape of the mandibular body. The purpose of this study was to evaluate in mandibles of Brazilians subadults the proposed method consistency; were used mandibles of 33 Brazilian children between 0 and 1 year of age, known sex, belonging to the collection of skulls of the Federal University Sao Paulo (UNIFESP). We performed a blind test in two sessions by one observer based on the parameters described by Loth & Henneberg. The results show between 57.5 and 60.5% of accuracy, being the most sensitive test for determining male (70%) than for females (38-46%). The results presented are lower than those reported by Loth & Henneberg and justify the need to assess the diagnostic methods of sex in subadults in specific populations. KEYWORD: Sexual dimorphism; Determination of sex; Subadults; Mandible. INTRODUCTION In humans, most of the morphological differences that allow us to classify subjects within a given sex is not seen until puberty, at this time, by action of sex hormones appear characteristics of male and female. The qualitative or quantitative analysis, based on morphological indicators of sexual dimorphism, are therefore less reliable in children, which represents a challenge to identify skeletons with anthropological or forensic purposes, which is why it is more frequent examinations that are required molecular biology for the diagnosis of sex in children. Have been analysed various skeletal segments to identify those that indicate a greater degree of dimorphism, in this regard Reynolds (1945, 1947) noted significant differences in the pelvis of individuals subadults, first in ages ranging from 0 to 1 year, expanding his remarks later to 9 years. He was also described sexual dimorphism in the coxal articular surface of the acroiliac joint in subadults, the authors of the method reported correctly classified 74.1% of individuals analyzed (Mittler & Sheridan, 1992). Moreover, a study in 1034 newborns, which analyzed 34 somatic traits, circumference and width of the head, and the face diameter presented a low dimorphism (Antoszewska & Wolanski, 1992). Rösing (1983) notes that of all the morphological structures and regions of the skeleton there is only one that does not change size or shape after the teeth being initially developed, for this reason, one of the best indicators available for the diagnosis of sex in children is the size of tooth crowns, because the tooth size is determined by genetics. These dimensions can be analyzed through direct intraosseous dissection of the central incisor or the first molar germs, or by X-rays analyzing, requiring both the population-specific dimensions corrections of these (Alt et al., 1998). Loth & Henneberg (2001) indicated that it was possible to determine the sex with a high degree of accuracy (81%) in mandibles of children by mean observing the shape of the mandi- bular body. Its findings were discussed by Coqueugniot et al. (2002), who performed below those reported by Loth & Henneberg. Considering the need to find reliable methods for subadults of sex differences diagnosis in population-specific, the purpose of this study was to evaluate the consistencyof the method proposed by Loth & Henneberg in a Brazilian children mandible sample in the first year of life. * Departamento de Anatomía Normal, Universidad de Talca, Chile. ** Departamento de Morfología y Genética. Universidad Federal de São Paulo, Brasil.