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Craniofacial reconstruction recreates a facial outlook from the cranium based on the relationship between the face and the skull to assist identification. But craniofacial structures are very complex, and this relationship is not the same in different craniofacial regions. Several regional methods have recently been proposed, these methods segmented the face and skull into regions, and the relationship of each region is then learned independently, after that, facial regions for a given skull are estimated and finally glued together to generate a face. Most of these regional methods use vertex coordinates to represent the regions, and they define a uniform coordinate system for all of the regions. Consequently, the inconsistence in the positions of regions between different individuals is not eliminated before learning the relationships between the face and skull regions, and this reduces the accuracy of the craniofacial reconstruction. In order to solve this problem, an improved regional method is proposed in this paper involving two types of coordinate adjustments. One is the global coordinate adjustment performed on the skulls and faces with the purpose to eliminate the inconsistence of position and pose of the heads; the other is the local coordinate adjustment performed on the skull and face regions with the purpose to eliminate the inconsistence of position of these regions. After these two coordinate adjustments, partial least squares regression (PLSR) is used to estimate the relationship between the face region and the skull region. In order to obtain a more accurate reconstruction, a new fusion strategy is also proposed in the paper to maintain the reconstructed feature regions when gluing the facial regions together. This is based on the observation that the feature regions usually have less reconstruction errors compared to rest of the face. The results demonstrate that the coordinate adjustments and the new fusion strategy can significantly improve the craniofacial reconstructions. [ABSTRACT FROM AUTHOR]

A recent review paper on cranio-facial superimposition (CFS) stated that "there have been specific conceptual variances" from the original methods used in the practice of skull-photo superimposition, leading to poor results as far as accuracy is concerned. It was argued that the deviations in the practice of the technique have resulted in the reduced accuracies (for both failure to include and failure to exclude) that are noted in several recent studies. This paper aims to present the results from recent research to highlight the advancement of skull-photo/cranio-facial superimposition, and to discuss some of the issues raised regarding deviations from original techniques. The evolving methodology of CFS is clarified in context with the advancement of technology, forensic science and specifically within the field of forensic anthropology. Developments in the skull-photo/cranio-facial superimposition techniques have largely focused on testing reliability and accuracy objectively. Techniques now being employed by forensic anthropologists must conform to rigorous scientific testing and methodologies. Skull-photo/cranio-facial superimposition is constantly undergoing accuracy and repeatability testing which is in line with the principles of the scientific method and additionally allows for advancement in the field. Much of the research has indicated that CFS is useful in exclusion which is consistent with the concept of Popperian falsifiability - a hypothesis and experimental design which is falsifiable. As the hypothesis is disproved or falsified, another evolves to replace it and explain the new observations. Current and future studies employing different methods to test the accuracy and reliability of skull-photo/cranio-facial superimposition will enable researchers to establish the contribution the technique can have for identification purposes. [ABSTRACT FROM AUTHOR]

Human skeletal variability is influenced by several factors, including genetics, environment, and socio-cultural background. Forensic methods being traditionally based on targeted reference groups, it is recognized that they are population-specific. Additionally, secular trends highly impact on the skeletal morphology, but the effect of outdated methods on forensic cases is not yet well documented. This paper compares the sexual dimorphism of femoral dimensions in two samples from the Czech population separated by 60 years in time (Pachner and the Prague National Museum Collections). Significant secular trends are present within this short span in both sexes and for most of the seven tested linear variables. The consequence of secular trends on sex determination is tested with logistic regression, and a decrease in reliability is systematically observed when using the older Czech sample on the 20th century sample, whichever the set of variables included. A model based on a recent Croatian sample provides a higher reliability on contemporaneous Czech individuals. These results imply that above population specificity, temporal consistency may be a major criterion to fulfil when applying forensic anthropology identification methods. [ABSTRACT FROM AUTHOR]