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Decision trees provide an alternative to multivariate discriminant analysis, which is still the most commonly used in anthropometric studies. Our study analyzed the metric characterization of a recent virtual sample of 113 coxal bones using decision trees for sex determination. From 17 osteometric type I landmarks, a dataset was built with five classic distances traditionally reported in the literature and six new distances selected using the two-step ratio method. A ten-fold cross-validation was performed, and a decision tree was established on two subsamples (training and test sets). The decision tree established on the training set included three nodes and its application to the test set correctly classified 92% of individuals. This percentage was similar to the data of the literature. The usefulness of decision trees has been demonstrated in numerous fields. They have been already used in sex determination, body mass prediction, and ancestry estimation. This study shows another use of decision trees enabling simple and accurate sex determination., (© 2015 American Academy of Forensic Sciences.)

Few studies have been conducted to determine sex differences in the immature coxal bone and the results were often contradictory. The authors studied sexual dimorphic differences of the pubis using geometric morphometric analysis of five osteometric landmarks recorded by multislice computed tomography (MSCT), based on three-dimensional reconstructions of 188 children (95 boys, 93 girls) living in the region of Toulouse, southwestern France, ranging in age from 1 to 18 years old. They used geometric morphometric methodology first to test sexual dimorphism in size (centroid size) and shape (Procrustes residuals) and second to examine patterns of shape change with age (development) and size change with age (growth). Based on statistical significance test results, the pubic shape became sexually dimorphic at 13 years old, although visible shape differences were observed as early as 9 years old. This work showed that the trajectories of pubis shape (development) and size (growth) differed throughout ontogeny and between sexes., (© 2015 American Academy of Forensic Sciences.)

Adult sexual dimorphism is well established. However, data regarding fetuses are sparse with contradictory results. Our study aimed to look for fetal sexual dimorphism. Multislice computed tomography (MSCT) examinations and three-dimensional (3D) reconstructions were recorded on 93 fetal iliac bones aged between 21 and 40 weeks of amenorrhea (WA). The collection was divided into two age groups, with a cutoff at 30 WA. The 3D geometric morphometric analysis was based on outline analysis. We used elliptic Fourier analysis (EFA) because of the difficulty of landmark positioning. Step-by-step reconstructions allowed a better comprehension of the fine shape details. Principal component analysis (PCA) and linear discriminant analysis (LDA) were performed on the two age groups. Results did not show any difference between male and female shapes, in both age groups. We demonstrate the feasibility of outline analysis for immature shapes, but sexual dimorphism has not been established in our collection., (© 2013 American Academy of Forensic Sciences.)

We studied sexually dimorphic differences in the ilium using geometric morphometric analysis of 10 osteometric landmarks recorded by multislice computed tomography, based on three-dimensional reconstructions of 188 children (95 boys, 93 girls) of mixed origins living in the area of Toulouse, southern France, and ranging in age from 1 to 18 years. We used geometric morphometrics methodology first to test sexual dimorphism in size (centroid size) and shape (Procrustes residuals) and second to examine patterns of shape change with age (development) and size change with age (growth). On the basis of statistical significance testing, the ilium shape became sexually dimorphic at 11 years of age, although visible shape differences were observed as early as 1 year of age. There was no statistically significant difference in size between sexes. Trajectories of shape (development) and size (growth) differed throughout ontogeny and between sexes., (© 2012 American Academy of Forensic Sciences.)

The authors studied sexually dimorphic differences in coxal shape using geometric morphometric analysis of 15 osteometric landmarks recorded by multislice computed tomography (MSCT), based on three-dimensional reconstructions of 65 Caucasian adults. Geometric morphometric analysis, principal component analysis, canonical variates analysis, and other discriminant analysis (Goodall's F-test and Mahalanobis distance) were performed for the three separate bones of the left innominate (pubis, ilium, and ischium), the modified pubis (pubis and ischiopubic ramus), the modified ilium (ilium and ischial spine), three bone complexes (ischiopubic, iliopubic, and ilio-ischial), and the complete innominate. A cross-validation test was also performed. All areas studied were dimorphic, but results for sexual dimorphism in decreasing order were as follows: the modified pubis, followed by the ischiopubic complex, the iliopubic complex and the complete innominate, the pubis, the modified ilium, the ilio-ischial complex, the ilium, and finally the ischium. These results show the potential of this approach for future anthropological research., (© 2011 American Academy of Forensic Sciences.)

Multidisciplinary forensic, anthropological, and radiological studies of bone fragments encased in a concrete block were carried out to determine whether or not the bones were human. Multislice computed tomography (MSCT) investigation was performed before the bones were removed from the concrete. MSCT study pinpointed the location of the bone fragments within the concrete block, which was helpful for their extraction and recovery, and identified most of their types and nature. Osteological study on dry bones provided more accurate identification of the bones and of their side. According to both methods, the human skeletal remains were compatible with those of a child, aged 8-13 years old, with a minimum height of 128 cm. Neither investigation identified sex or racial phenotype. Both studies identified the skeletal remains as consisting of two animal and five human bones. Furthermore, both methods revealed that the concrete completely encased bones, suggesting a secondary burial., (© 2011 American Academy of Forensic Sciences.)

Macroscopic study of the first rib has been described by Kunos et al. as an efficient method of age estimation. We retrospectively reviewed a test sample of 160 first right ribs obtained from multislice computed tomography (MSCT) clinical investigations of living individuals aged 15-30 years old. Based on the descriptions of Kunos et al., we analyzed the morphological appearance of the sternal end of the first rib on two- and three-dimensional MSCT reconstructions and defined changes in appearance in stages (from 2 to 5). We also studied the calcification and ossification of the costal cartilage as an independent feature. By statistical analysis (ANOVA), we determined for each gender the correlation between the estimated stage of the costal face, the appearance of the costal cartilage, and the documented age of the subjects. We demonstrated that MSCT of the first rib appears to be an efficient noninvasive modality for bone age estimation.

Many authors have studied the thyroid cartilage ossification process using radiographic features for age estimation of individuals. Their results were various: Sugiyama reported excellent correlation coefficients between ossification rates and civil age, unlike most other authors. We hypothesized that recent advances in imaging techniques would enable more precise evaluation of the ossification of the thyroid cartilage. We retrospectively analyzed the CT scans of 312 French patients using postprocessing software to examine the pattern of thyroid cartilage ossification, calculating the ossified volume of the cartilage on 3D reconstructions. Pearson's correlation coefficients for volume were 0.73 for men and 0.75 for women (standard error 18.02 and 17.06), indicating considerable inter-individual variability. Although a correlation between civil age and morphological changes was found, these methods based on thyroid cartilage ossification were not accurate enough for the assessment of individual age.

Thanks to recent advances, computed tomography is now seen as a tool of great value in the field of physical anthropology. In this study, we focused on the posterior pelvis and the auricular surface and evaluated the accuracy of 3D reconstructions of the auricular surface, using a methodology derived from a previous study by Lovejoy et al. We also looked for trabecular bone criteria expressing age-related changes. Forty-six coxal bones were scanned, and scoring of macroscopic criteria showed a good agreement between 3D reconstructions and photographs, especially for transverse organization (k = 0.90). The changes occurring in the posterior part of the sacropubic trabecular bundle were evaluated on CT reconstructions via three new criteria, which exhibited a good intra- and inter-observer agreement (k = 0.77-0.89), and were particularly useful in identifying older subjects. We concluded that these CT-evaluated trabecular bone criteria are promising and yield useful information about age at death.

A 17-month-old male infant died at home. The infant's right arm was immobilized because of a humeral fracture 1 month earlier. The circumstances of death appeared unclear to the police investigators and a medicolegal autopsy was carried out. External examination revealed diffuse ecchymoses of varying color. Postmortem imaging was performed prior to autopsy (X-rays, multislice computed tomography [MSCT], and focused brain magnetic resonance imaging [MRI]). These investigations revealed four rib fractures of varying ages, one of which was posterior. Cerebral and pericerebral traumatic lesions were also diagnosed: bilateral subdural hematomas, intraventricular, meningeal, and interpedoncular hemorrhages. In the abdomen, fresh blood was visible within the anterior abdominal wall and the mesenteric root. Autopsy and microscopic study confirmed these lesions. This case report illustrates the valuable assistance rendered by MSCT and MRI to diagnose abuse when a child has died in unclear circumstances.