Accuracy of the London Atlas to estimate the age of legal majority in a sample of the Amazon Regio.

Background: Estimating the age of majority is a challenging task in forensic odontology, especially because the third molars are usually the only developing teeth between the ages of 16 and 21 years. The London Atlas emerged as an alternative to estimate age using dental development, eruption and deciduous root resorption as parameters. The method has performed well in young age categories, while its performance for age estimation via third molars has been disputed. The present study tested the performance of the London Atlas to estimate the age of legal majority in a sample of individuals from the Amazon Region. Material and Methods: The sample consisted of 1.256 panoramic radiographs of women (n = 694) and men (n = 562) between 16 and 22.9 years. The method was applied to the maxillary (#28) and mandibular (#38) left third molars. For comparative purposes, the sample was divided into seven age groups: 16├ 16.99; 17├ 17.99; 18├ 18.99; 19├ 19.99; 20├ 20.99; 21├ 21.99; and 22├ 22.99 years. Chronological and estimated ages were compared descriptively by means of mean absolute errors (MAE) and root mean squared errors (RMSE), as well as through Receiver Operating Characteristic (ROC) curves and their area under the curve (AUC). Results: The MAE of the age estimates using tooth #28 was 1.76 years for females and 1.52 years for males. When the tooth #38 was used, the MAE for the females and males were 1.68 and 1.51 years, respectively. The MAE and RMSE increased in ascending order between age categories. Tooth #28 led to 74% of correct classifications around the age of legal majority, while tooth #38 reached 77%. The area under the curve was 0.75 for tooth #28 and 0.73 for tooth #38. Conclusions: The London Atlas should be used carefully to estimate the age of legal majority and not as a single method when the age threshold is 18 years. Key words:Age determination by teeth, forensic dentistry, forensic science, third molar.

Diagnostic accuracy of the third molar maturity index (I3M) to assess the age of legal majority in Northern Brazil-population-specific cut-off values.

International guidelines for dental age assessment have recommended the use of methods based on available population-specific data. The Third Molar Maturity Index (I3M) was previously validated in several populations worldwide. This was the first study to evaluate the I3M in a northern Brazilian population and to test the diagnostic accuracy of the method to distinguish between minors and adults. The sample consisted of 1.070 panoramic radiographs retrospectively collected from females (n = 595) and males (n = 475) with ages between 16 and 22 years. I3M's original cut-off value of 0.08 was used to classify individuals below and above the age of 18. Receiver operating characteristic (ROC) curves were plotted to assess the accuracy (ACC) of the method. In females and males separately, the overall ACC was 73.1% and 80%, respectively. The overall ACC for the combined sample was 76.1%. For northern Brazilian males, the best cut-off value remained 0.08, while for females, an adjustment to 0.12 showed optimal outcomes. The new cut-off value led to an ACC of 98.5% for females, which reflected an increase of 25.5% compared to the original cut-off value. The original cut-off value proposed by I3M was applicable to the present sample of northern Brazilian individuals. Adjustments to 0.12, however, may be encouraged to enhance the performance of the method among females.

Postmortem cross-sectional slicing of the frontal sinuses and comparison with antemortem anatomical imagens ­ a technical description / Secção transversal postmortem dos seios frontais e comparação com imagens antemortem ­ descrição de técnica

The anatomical features of the frontal sinuses (FS) are known as highly distinctive and potentially useful for human identification. Assessing these structures with advanced postmortem (PM) imaging, however, is not always feasible in medicolegal units worldwide. This study proposes and validates the anatomical assessment of the FS via cross-sectional slicing of the frontal bone to reproduce images comparable to antemortem (AM) axial views. The bodies of two unknown sisters with advanced decay (decomposition stage III.1) were referred for human identification. The AM data provided for comparative analysis consisted of multi-slice computed tomography (CT) and magnetic resonance images of the skull. In the lack of primary alternatives for human identification, PM assessment of the FS was considered. Justified by the mortuary facilities there were not equipped with CT devices, sequential cross-sectional slicing of the frontal bone was performed. With the skulls in supine position, the technique followed Griesinger's anteroposterior plane using an oscillating saw blade at 90°. Multiple slices (n = 20) of the frontal bone were obtained in craniocaudal direction up to the superior limit of the orbits. The outline of the FS, as well the number of lobes and position of the intersinus septum were visible and compatible with the AM data, enabling positive identification. External validation of the proposed technique was accomplished by reproducing it to successfully identify a male victim in a medicolegal institute 2,000 KM far from the original site

As características anatômicas dos seios frontais (FS) são consideradas distintivas e potencialmente uteis para a identificação humana. A análise imaginológica postmortem (PM) destas estruturas, contudo, não sempre é viável. O presente trabalho tem como objetivo a apresentação e validação de uma proposta de análise anatômica dos seios frontais utilizando a secção do osso frontal a fim de se permitir comparações com imagens axiais antemortem (AM). A corpo de um indivíduo do sexo masculino, não identificado, e em avançado estado de decomposição (estágio III.1) foi encaminhado para identificação. Os dados AM providenciados para análise comparativa consistiram em imagens de tomografia computadorizada (CT) multi-slice e ressonância magnética do crânio. Na falta de alternativas primárias para identificação humana, a análise dos seios frontais (SF). Pelo fato de que o instituto médico-legal era desprovido de unidades de Imaginologia avançada, cortes sequenciais do seio frontal foram realizados. Com os crânios em posição supina, a técnica foi conduzida seguindo o plano anteroposterior de Griesinger's com uma serra oscilatória em 90°. Secções múltiplas (n = 20) do osso frontal foram obtidas no sentido craniocaudal até o limite superior das orbitas. A anatomia dos SF, assim como o número de lobos e a posição do septo intersinual eram visíveis e compatíveis com os dados AM, viabilizando a identificação positiva. A validação externa da técnica proposta se deu durante a identificação de uma vítima do sexo masculino periciada em um instituto médico-legal 2.000Km distante do centro originalmente relatado no presente estudo