Smile photograph analysis and its connection with focal length as one of identification methods in forensic anthropology and odontology.

To positively identify a highly decomposed body forensic experts often use information obtained from the dentition. In this study authors try to employ a method of comparing incisal borders of the anterior teeth from antemortem (AM) and postmortem (PM) photographs within an experimental scenario with living individuals. The second purpose was to determine how focal length of the lens affects compared smile lines. The research was divided into two stages. In procedure 1, the participants (28 individuals) were asked to provide a photo (for the purpose of the research considered as "antemortem") in which the anterior teeth were visible. A series of experimental photographs (considered as "postmortem") were then taken trying to reproduce the position of the person's head in relation to "AM" picture as faithfully as possible. The procedure 2 (10 individuals) consisted of taking "AM" photos under controlled conditions using an accidental focal length, then taking "PM" photos using a priori established focal lengths: 18 mm, 55 mm and 80 mm. In both procedures, the final stage involved marking and comparing the incisal borders from "AM" and "PM" photographs. Procedure 1 showed that in 82% of cases the compared smile lines are fully compatible. 11% was marked as "tolerable", and only 2% as "insufficient". Procedure 2 proved that the choice of focal length when taking a PM photograph is significant and that the medium focal lengths (range of 55-85 mm) are suggested in case of unknown focal length in AM photo. The results indicate that this method can be reliably applied in forensic cases when AM photographs of deceased are available.

Applicability of a pre-established set of facial proportions from frontal photographs in forensic age estimation of a Brazilian population.

Child pornography on the internet is one of the crimes with highest increasing incidence worldwide. In this specific type of crime, the victim's age has important legal implications. To overcome the lack of scientifically established protocols, European researchers explored and proposed a set of facial proportions obtained from images to estimate age. Within a validation scope, the present study aimed to test the applicability of morphological proportions from frontal photographs of the face to estimate age in a Brazilian population. Standardized frontal view photographs from 800 Brazilians (400 females and 400 males) homogeneously distributed in 4 age groups (6, 10, 14 and 18 years ± 30 days) were randomly selected from a Civilian Database of the Brazilian Federal Police. The selected images were analyzed with the aid of cephalometric landmarks. After landmarking the photographs, eighteen metric relations pre-established by Cattaneo et al. (C. Cattaneo, Z. Obertová, M. Ratnayake, L. Marasciuolo, J. Tutkuviene, P. Poppa, D. Gibelli, P. Gabriel, S. Ritz-Timme, Can facial proportions taken from images be of use for ageing in cases of suspected child pornography? A pilot study, Int. J. Leg. Med. 126 2012 139-144) were assessed and analyzed through parametric statistical tests and discriminant analysis. Two indexes had a moderate correlation with age, while ten had a weak correlation and six were not correlated with age. Eleven indexes were statistically different between sexes (p < 0.05). The discriminant analysis showed that 49.6% of the pooled sample was correctly classified into the respective age group. This percentage increased when each sex was analyzed separately: 50.2% for females and 53.5% for males. The set of facial proportions from frontal images proposed by Cattaneo et al. (2012) is related to facial development. As expected, the discriminant power of this approach did not reach optimal effectiveness in the Brazilian sample. In practice, this age estimation method must be adapted for more reliable application in Brazilians.

Validation methods of Fazekas and Kósa and Molleson and Cox for age estimation of the ilium in Western Mediterranean non-adult population: proposal of new regression formulas.

The purpose of this study is to test the applicability of the age estimation methods of Fazekas and Kósa [1] and Molleson and Cox [2] in Western Mediterranean non-adults and to develop accurate and rapidly applied formulas for their age estimation, using a sample of 149 non-adults of known sex and age from the cemetery of San José in Granada (Spain). Measurements have been taken of the maximum length and width of each ilium for application of the formulas of Fazekas and Kósa [1] and Molleson and Cox [2]. There has been no significant intra- or inter-examiner variation in measurements. The documented age of the individuals has been underestimated with the Fazekas and Kósa method and overestimated with Molleson and Cox. Based on these findings, new formulas are proposed for the age estimation of non-adults in Western Mediterranean populations.

Image analysis of pubic bone for age estimation in a computed tomography sample.

Radiology has demonstrated great utility for age estimation, but most of the studies are based on metrical and morphological methods in order to perform an identification profile. A simple image analysis-based method is presented, aimed to correlate the bony tissue ultrastructure with several variables obtained from the grey-level histogram (GLH) of computed tomography (CT) sagittal sections of the pubic symphysis surface and the pubic body, and relating them with age. The CT sample consisted of 169 hospital Digital Imaging and Communications in Medicine (DICOM) archives of known sex and age. The calculated multiple regression models showed a maximum R (2) of 0.533 for females and 0.726 for males, with a high intra- and inter-observer agreement. The method suggested is considered not only useful for performing an identification profile during virtopsy, but also for application in further studies in order to attach a quantitative correlation for tissue ultrastructure characteristics, without complex and expensive methods beyond image analysis.