Facial growth parameters in Down syndrome: Review of the literature and forensic application for missing persons age progression.

PURPOSE: Individuals with Down syndrome (DS) show growth trajectories which deviate from standard ones due to variations in the growth of facial structures. Studying the effect of aging on the faces of DS individuals is necessary to obtain an accurate result through age progression, a technique based on the study of physiognomic features and used in cases of missing persons. Here we present scientific publications that delve into the rhythms of aging and morphological characteristics of facial features in DS individuals to enable appropriate age progression in cases of missing DS individuals. RESULTS: The scientific literature considered in this review studies the growth of soft tissue and bone substrate by comparing standard growth values with those measured through anthropometric measurements of individuals with DS. Growth trajectories are described by considering morphological trends both by comparing standard values with those found in individuals with DS and by observing individual physiognomic traits. CONCLUSIONS: When a young individual with DS goes missing, the realization of an age progression requires knowledge of the aging dynamics peculiar to the DS face. Therefore, physical, cognitive, and clinical factors must be considered. Delayed physical development and early aging, such as the onset of puberty and weight gain, have an important impact on the realization of age progression. In fact, depending on the life period to be considered, the effects of aging must be calibrated based on the knowledge gathered from scientific research.

Evaluating the accuracy of population-specific versus generic stature estimation regression equations in a South African sample.

Accurate estimates of stature play an important role in the personal identification of unknown decedents, however a drawback in the application of many stature estimation equations is the need for known sex and population, the assignment of which can be challenging. Researchers have formulated equations for stature estimation that are neither population- nor sex-specific and thereof the aim of this study was to assess the applicability of these stature estimation equations proposed by Albanese et al.. (2016) (Albanese J, Tuck A, Gomes J, Cardoso HFV (2016) An alternative approach for estimating stature for long bones that is not population- or group-specific. Forensic Sci Int 259:59-68). The physiological length of the femur, condylar malleolar length of the tibia and a combination of these measurements, collected from Magnetic Resonance Imaging Scanograms of adult (20-60 years) White South African males (n = 30) and females (n = 44) were used to assess the accuracy of the Albanese et al. (Albanese J, Tuck A, Gomes J, Cardoso HFV (2016) An alternative approach for estimating stature for long bones that is not population- or group-specific. Forensic Sci Int 259:59-68). sex-specific and generic stature estimation equations. The stature estimates were compared with measured living stature (LSM), using paired t-tests. Results indicated that the Albanese et al. (Albanese J, Tuck A, Gomes J, Cardoso HFV (2016) An alternative approach for estimating stature for long bones that is not population- or group-specific. Forensic Sci Int 259:59-68). equations underestimated living stature by between 1.1 and 5.0 cm. These underestimations were significantly different between the LSM and the sex-specific estimates for females and the LSM and the generic estimates for males and the tibia for sex-specific equation. All stature estimates however fell in between two standard error of estimates for the sex-specific equations for males and the generic equations for the females. Although, the equations by Albanese et al. (Albanese J, Tuck A, Gomes J, Cardoso HFV (2016) An alternative approach for estimating stature for long bones that is not population- or group-specific. Forensic Sci Int 259:59-68). can be used to estimate stature in White South Africans in certain cases, the use of sex/population-specific equations remains the method of choice.

Piece by piece-a computer-aided method for virtual re-association of commingled fragmented remains.

Air crashes or explosions with numerous victims may result in thousands of fragmented human remains that present a massive challenge for disaster victim identification teams. Genetic identification may present important financial and technical limits, and the physical re-association of fractured bones by forensic anthropologists may require a time-consuming phase of cleaning and drying. A virtual re-association (VRA) of fragmented human remains using postmortem computed tomography (CT)-scan images could enhance the identification process and reduce the number of genetic analyses required. Therefore, this study investigated the advantages and limitations of a VRA protocol in comparison with physical re-association (PRA) in a laboratory setting and in a real case scenario. As a first step, six porcine femurs were scanned by multi-detector CT before and after physical fragmentation. PRA of the dry bones and VRA of the 3D models of the fragments were then performed. The physically reconstructed dry bones were then once more scanned with CT. The mean distance between intact and reconstructed models, the number of re-associated fragments, and the time needed for the reconstruction were evaluated. In a second step, 87 fragmented remains resulting from a controlled pig bombing were collected, scanned, and virtually re-associated to test the feasibility of the protocol in a real context. The reconstruction of the femurs showed no difference in accuracy between PRA and VRA. Although the VRA was faster than PRA, the preparation of the material still needs to be taken into consideration. The VRA after the controlled pig bombing was limited to 8% of the total fragments. Differences in alveolar and cortical osseous structure and the presence of cartilage resulted in segmentation approximations and difficulties in the re-association itself. The explosion produced an important loss of intermediate bone elements. The VRA method still needs further evaluations with a larger sample size and different fragmentation mechanisms. However, the presented research shows promising results towards enhancing the efficiency of identifying individuals after a mass disaster. Key points: Mass disasters with highly fragmented bodies represent a major challenge for the disaster victim identification (DVI) teams.Using CT-scans of the fragments, a virtual re-association method could enhance the DVI process and reduce the number of genetic analysis required.A laboratory setting using porcine femurs shown that the VRA process could start earlier and was faster than the physical re-association.Although methodological limits were highlighted, and the efficiency of the method has to be re-evaluated, the controlled bombing showed that the VRA could be applied in a real case scenario.

Correlation of spheno-occipital synchondrosis and mandibular condylar cortication with chronological age using computed tomography in Indian population- A cross-sectional study.

BACKGROUND: Forensic age estimation is a procedure which utilises many methods to estimate the age of both living and deceased individuals, including those who have died in natural disasters or man-made catastrophes. The pattern and closure of spheno-occipital synchondrosis (SOS) fusion, along with subchondral ossification of the mandibular condyle, can be used to estimate age. AIM AND OBJECTIVES: This study aims to estimate age using computed tomographic (CT) images of spheno-occipital synchondrosis fusion (SOS) and mandibular condylar cortication (MCC), and to correlate these findings with chronological age. MATERIALS AND METHODS: The present study included 435 CT images of individuals aged 10-25 years. SOS fusion was assessed using a four-stage system, and MCC was assessed bilaterally using a three-stage system on the sagittal plane. Data on fusion stages and cortication types were entered along with chronological age, and then statistically analysed. RESULTS: SOS fusion stage 2 occurred at similar age in males (19.82 ± 2.67 years) and females (19.23 ± 2.93 years). Earlier fusion of other stages was observed in females by a mean age of 2 years. MCC was completed 1 year earlier in females, with statistically significant differences (p ≤ 0.001). When comparing cortication types and different fusion stages, only type II cortication showed statistically significant differences compared to different fusion stages (p ≤ 0.001). CONCLUSION: Mandibular condylar cortication (MCC) and spheno-occipital synchondrosis (SOS) fusion were positively correlated with chronological age, suggesting that these parameters can be used as an adjunct method for age estimation.

A statistical evaluation of the sexual dimorphism of the acetabulum in an Iberian population.

Sex estimation is essential for human identification within bioarchaeological and medico-legal contexts. Amongst the sexually dimorphic skeletal elements commonly utilised for this purpose, the pelvis is usually preferred because of its direct relationship with reproduction. Furthermore, the posterior part of the innominate bone has proven to have better preservation within degraded contexts. With the aim of investigating the potential of the vertical acetabular diameter as a sex marker, 668 documented individuals from three different Iberian skeletal collections were randomly divided into training and test samples and eventually analysed using different statistical approaches. Two traditional (Discriminant Function Analysis and Logistic Regression Analysis) and four Machine learning methodologies (Support Vector Classification, Decision Tree Classification, k Nearest Neighbour Classification, and Neural Networks) were performed and compared. Amongst these statistical modalities, Machine Learning methodologies yielded better accuracy outcomes, with DTC garnering highest accuracy percentages of 83.59% and 89.85% with the sex-pooled and female samples, respectively. With males, ANN yielded highest accuracy percentage of 87.70%, when compared to other statistical approaches. Higher accuracy obtained with ML, along with its minimal statistical assumptions, warrant these approaches to be increasingly utilised for further investigations involving sex estimation and human identification. In this line, the creation of a statistical platform with easier user interface can render such robust statistical modalities accessible to researchers and practitioners, effectively maximising its practical use. Future investigations should attempt to achieve this goal, alongside examining the influence of factors such as age, on the obtained accuracy outcomes.

A probability model for estimating age in young individuals relative to key legal thresholds: 15, 18 or 21-year.

Age estimations are relevant for pre-trial detention, sentencing in criminal cases and as part of the evaluation in asylum processes to protect the rights and privileges of minors. No current method can determine an exact chronological age due to individual variations in biological development. This study seeks to develop a validated statistical model for estimating an age relative to key legal thresholds (15, 18, and 21 years) based on a skeletal (CT-clavicle, radiography-hand/wrist or MR-knee) and tooth (radiography-third molar) developmental stages. The whole model is based on 34 scientific studies, divided into examinations of the hand/wrist (15 studies), clavicle (5 studies), distal femur (4 studies), and third molars (10 studies). In total, data from approximately 27,000 individuals have been incorporated and the model has subsequently been validated with data from 5,000 individuals. The core framework of the model is built upon transition analysis and is further developed by a combination of a type of parametric bootstrapping and Bayesian theory. Validation of the model includes testing the models on independent datasets of individuals with known ages and shows a high precision with separate populations aligning closely with the model's predictions. The practical use of the complex statistical model requires a user-friendly tool to provide probabilities together with the margin of error. The assessment based on the model forms the medical component for the overall evaluation of an individual's age.

Cephalometric Analysis of Maxillary Sinus for Gender Determination Using Lateral Cephalogram: A Novel Retrospective Study in the North Indian Population.

BACKGROUND: Underlying disorders of the maxillary sinus (MS), including a history of sinus surgeries, chronic sinusitis, or congenital anomalies can potentially impact sinus function and structure, necessitating careful evaluation and management. Moreover, intact sinuses are crucial in gender determination in forensic anthropology. The present study was undertaken to check the accuracy and reliability of MS in gender determination using morphometric parameters. MATERIALS AND METHODS: This retrospective study was carried out on 74 lateral cephalograms (37 males and 37 females) aged between 18 to 50 years from the North Indian population. The MS area was measured using a NewTom CBCT machine (NewTom, Imola, Italy) with slicer software. The anatomical landmarks for the sinus were identified, and the area was calculated in square millimeters (mm2). RESULTS: In terms of surface area, females had a mean of 13,210.40 mm2 with a standard error of 713.46. Males, however, exhibited a higher mean surface area of 18,713.82 mm2, but with a significantly larger standard error of 3,371.70. The difference in MS area between males and females was statistically significant (p<0.01). In the receiver operating characteristic (ROC) curve, the area under the curve (AUC) was 0.77, suggesting good discriminative ability. CONCLUSION: The MS area on lateral cephalograms shows significant sexual dimorphism. Overall, the findings suggest that the MS surface area can be a useful anatomical feature for distinguishing between male and female North Indian subjects, given the statistically significant difference and the good discriminative performance indicated by the ROC curve analysis.

Age estimation from median palatine suture using computed tomography reconstructed 3D images: a comparison of Northern and Southwestern Chinese populations.

To investigate the potential of computed tomography (CT) images of median palatine suture (MP) for adult age estimation in the Northern and Southwestern Chinese populations. A total of 1110 cranial CT scans from individuals aged 10-79 years, including 557 northern Chinese and 553 southwestern Chinese, were collected for analysis. After volume reformation and multiplanar reconstruction, a total of 20 slices of median palatine suture were selected from each individual. The closure of sutures was analyzed into four stages, and the cumulative scores of 20 slices were recorded as the suture closure score (SCS). The correlations between SCS and age were compared among the two Chinese populations residing in diverse geographic regions. Regression models were established for age estimation. The estimation accuracy was evaluated based on the test set. The mean absolute error (MAE) and the correlation between predicted age and chronological age were calculated to evaluate estimation accuracy. The SCS of MP exhibited a significant correlation with age (0.613, northern male; 0.678, southwestern male; 0.730, northern female; 0.704, Southwestern female; 0.662, total). Furthermore, there were statistically significant differences in SCS among different regions and sex groups (p < 0.001). The cubic regression model had the highest R2 value in all subjects, especially among Northern females and Southwestern males, while the power and quadratic regression models showed the highest R2 value in Northern males and Southwestern females, respectively. In the test set, the Northern cohort demonstrated a lower MAE (9.06 ± 7.32 years, males; 9.17 ± 5.28 years, females) compared to the Southwestern cohort (9.19 ± 7.49 years, male; 10.61 ± 6.83 years, female). Additionally, it was observed that males exhibited a lower MAE than females in both regional groups. This study demonstrated the potential utility of CT images of the MP for age estimation in Chinese populations, emphasizing the significance of incorporating regional and sex factors within this context.

Still waters run deep: a unique case of mummification under extreme conditions.

In rural Crete, Greece, a mummified body was discovered inside a screw-top plastic barrel next to a dry riverbed. Local authorities conducted a field investigation along with a forensic pathologist, and the body was transferred inside the barrel to the Forensic Medicine Unit of the University of Crete for further investigation. Forensic examination included radiographs taken using a portable X-ray machine in situ followed by extraction of the remains, a full-body postmortem computed tomography scan, autopsy, DNA extraction, tissue and biofluid sampling, and histological and toxicological analyses. Two butane camping gases were recovered from inside the barrel. The remains were determined to belong to a middle-aged adult male. The postmortem interval was estimated to be over 4 months. DNA comparison revealed that the body belonged to a 58-year-old man who was reported missing 28 months prior to discovery. Examinations showed no evidence of skeletal or other trauma, and death was attributed to asphyxia due to oxygen deprivation. Careful examination of the barrel, which bore several peculiar modifications, in conjunction with contextual information pertaining to the deceased's personal life, led to successful case resolution. Key points: Advanced decomposition and taphonomic alterations present challenges for forensic practitioners.A case of a set of mummified remains discovered inside a plastic screw-top barrel is reported.A multidisciplinary approach, including examination of the barrel and contextual information regarding the deceased, led to case resolution.

Moving from the unknown to the known: a multidisciplinary approach to the identification of skeletal remains from Sandy Point, Australia.

When human remains are inadvertently located, case-related circumstantial information is used to generate an identification hypothesis, and the preservation of the remains typically informs which identification methods may then be used to validate that hypothesis. What happens, however, when there is no contextual information to generate an identification hypothesis? This paper presents the case of a near-complete human skeleton discovered at Sandy Point in Victoria, Australia. The circumstances of the case did not facilitate an identification hypothesis, and with no hypothesis to triage the identification process, all possible identification methods were employed. Preservation of the individual meant neither a visual nor a fingerprint identification was possible, and the lack of an identification hypothesis meant there was no antemortem reference data to compare with the postmortem DNA or dental information. Consequently, in addition to historical research, novel methods, such as radiocarbon dating and genetic intelligence, were utilized to complement information provided by the forensic anthropology and odontology analyses, which ultimately resulted in the identification. This example highlights the complexity of cases of unidentified skeletal remains and emphasizes the fact that identification is a process that necessarily requires a multidisciplinary and collaborative approach. Key points: Human skeletal remains were recovered from Sandy Point, Victoria.The absence of circumstantial information and the poor preservation (i.e. skeletonized) of the remains precluded the formation of an identification hypothesis, rendering the identification process complex.Only through the integration of anthropology, odontology, molecular biology, radiocarbon dating, historical research, and genealogy were the remains able to be identified as Mr. Christopher Luke Moore, who drowned in 1928.Human identification is a process that necessarily requires a multidisciplinary and collaborative approach.