Searching for alternative high DNA-yielding bone types for DNA analysis of aged skeletal remains.

The petrous bone contains significantly higher amounts of DNA than any other human bone. Because of highly destructive sampling and because it is not always part of the recovered remains, the need for alternative sources of DNA is important. To identify additional optimal bone types, petrous bones were compared to femurs, tali, and calcanei sampled from 66 adult skeletons from two distinct modern-era Christian cemeteries. An extraction method employing full demineralization was used to obtain DNA, real-time PCR quantification to ascertain DNA quantity and degradation, and a commercial forensic short tandem repeats (STR) PCR amplification kit to determine genetic profiles. Statistical analysis was performed to explore the differences in DNA yield, DNA degradation, and success of STR amplification. A systematic studies exploring intra-skeletal variability in DNA preservation including various excavation sites differing by time period and geographical position are rare, and the second part of the investigation was based on a comparison of both archaeological sites, which allowed us to compare the effect of different post-mortem intervals and environmental conditions on DNA preservation. The older burial site in Crnomelj was active between the 13th and 18th century, whereas the more recent Polje burial was in use from the 16th to 19th century, creating different temporal and geographical environments. Results for the Crnomelj burial site revealed that the petrous bone outperformed all other bone types studied, except the calcaneus. At the Polje archeological site calcanei, tali, and femurs yielded the same STR typing success as petrous bones. The results obtained highlight the importance of careful bone sample selection for DNA analysis of aged skeletal remains. In addition to petrous bones, calcanei were found to be an alternative source of DNA when older burial sites are investigated. When more recent burial sites are processed, calcanei, tali, and femurs should be sampled besides petrous bones, not only because they exhibited good performance, but also because of easier sampling and easier grinding in the case of trabecular bones. This study contributes valuable insights into the potential use of various skeletal types as a source of DNA for investigation of aged skeletal remains, and it offers practical implications for forensic and archaeological investigations.

[Forensic age diagnosis by assessment of sternum ossification processes]. / Sudebno-meditsinskaya diagnostika vozrasta posredstvom otsenki protsessov ossifikatsii grudiny.

OBJECTIVE: To study the sternum ossification processes that take place over time as well as the possibilities of sternum X-rays application to evaluate the age on the modern Russian population in forensic terms. MATERIAL AND METHODS: Sternum X-rays with fragments of ribs' chondral parts were obtained from 369 male and female corpses aged 12-96 years without pathological and traumatic changes. The X-rays were done in frontal projection. The set of examined parameters included: complete and partial synostosis of manubrium and body, induration along the synostosis (or on the articulated edges of manubrium and body), complete and partial synostosis of body segments, traces of body segments union, complete and partial synostosis of body and xiphoid process, induration along the synostosis (or on the articulated edges of manubrium and body), form of costal notches, induration of articular edges of body, presence of calcification foci in sternal edge of II-VII ribs' cartilages, depth of sternum notches, overgrowths on articular edges of body, presence of union between body's costal notches and calcification centers of ribs' cartilages. Mean values, standard deviation and correlation coefficient were determined. RESULTS: The maximal correlation with age was found in such parameters such: overgrowths on articular edges of body (r=0.6), presence of calcification foci in sternal edge of II-VII ribs (r=0.6), induration of body's articular edges (r=0.5), presence of union between costal notches and calcification centers of ribs cartilages (r=0.5), synostosis of body and xiphoid process (r=0.4). CONCLUSION: A subsequent construction of linear model for age diagnosis has its details when comparing the predicted age with the real.

Bibliometric Analysis of Forensic Human Remains Identification Literature from 1991 to 2022.

OBJECTIVES: To describe the current state of research and future research hotspots through a metrological analysis of the literature in the field of forensic anthropological remains identification research. METHODS: The data retrieved and extracted from the Web of Science Core Collection (WoSCC), the core database of the Web of Science information service platform (hereinafter referred to as "WoS"), was used to analyze the trends and topic changes in research on forensic identification of human remains from 1991 to 2022. Network visualisation of publication trends, countries (regions), institutions, authors and topics related to the identification of remains in forensic anthropology was analysed using python 3.9.2 and Gephi 0.10. RESULTS: A total of 873 papers written in English in the field of forensic anthropological remains identification research were obtained. The journal with the largest number of publications was Forensic Science International (164 articles). The country (region) with the largest number of published papers was China (90 articles). Katholieke Univ Leuven (Netherlands, 21 articles) was the institution with the largest number of publications. Topic analysis revealed that the focus of forensic anthropological remains identification research was sex estimation and age estimation, and the most commonly studied remains were teeth. CONCLUSIONS: The volume of publications in the field of forensic anthropological remains identification research has a distinct phasing. However, the scope of both international and domestic collaborations remains limited. Traditionally, human remains identification has primarily relied on key areas such as the pelvis, skull, and teeth. Looking ahead, future research will likely focus on the more accurate and efficient identification of multiple skeletal remains through the use of machine learning and deep learning techniques.

Forensic Anthropology in the identification of human remains found at sea: History of two judicial cases connected by the same marine context of discovery.

Background: Calculating the immersion time at sea of human skeletal remains is a challenge for forensic investigations and the answer to this question would solve many court cases in the shortest possible time. Remains in water create profound structural changes due to countless variables that lead to difficulties in interpretation during investigations. Case report: In this paper, two forensic cases found at sea were analysed, Case A, an extensively skeletonised corpse, and Case B, an isolated, intact foot with soft tissue, both found only 9 km away from the shores of the Tyrrhenian Sea (Southern Italy). A preliminary radiodiagnostic examination was performed for both cases. Subsequently, macroscopic observation of two tattoos found on case A was carried out. Autopsy examination was then carried out with subsequent anthropometric analysis to reconstruct the biological profile of both subjects, (case A) and (case B). Finally, histological and genetic analyses were performed. Conclusions: The examinations carried out made it possible to determine two compatible biological profiles, despite the taphonomic difference, and these examinations were corroborated by the anthropometric and genetic correlation, which led to the solution of a single judicial case. In conclusion, all the investigations carried out made it possible to state that the skeletonised corpse (Case A) and the isolated foot (Case B) belonged to the same individual in life. This result made it possible to identify the victim, thus establishing the profile of an individual who had disappeared in the previous two months due to a shipwreck.

A global survey of the attitudes and perspectives of cognitive bias in forensic anthropology.

It is now well established that decision making can be susceptible to cognitive bias in a broad range of fields, with forensic science being no exception. Previously published research has revealed a bias blind spot in forensic science where examiners do not recognise bias within their own domain. A survey of 101 forensic anthropology practitioners (n = 52) and students (n = 38) was undertaken to assess their level of awareness of cognitive bias and investigate their attitudes towards cognitive bias within forensic anthropology. The results revealed that the forensic anthropology community (∼90%) had a high level of awareness of cognitive bias. Overall ∼89% expressed concerns about cognitive bias in the broad discipline of forensic science, their own domain of forensic anthropology, and in the evaluative judgments they made in reconstruction activities, identifying a significant reduction in the bias blind spot. However, more than half of the participants believed that bias can be reduced by sheer force of will, and there was a lack of consensus about implementing blinding procedures or context management. These findings highlight the need to investigate empirically the feasibility of proposed mitigating strategies within the workflow of forensic anthropologists and their capabilities for increasing the transparency in decision making.

Human gender estimation from CT images of skull using deep feature selection and feature fusion.

This research endeavors to prognosticate gender by harnessing the potential of skull computed tomography (CT) images, given the seminal role of gender identification in the realm of identification. The study encompasses a corpus of CT images of cranial structures derived from 218 male and 203 female subjects, constituting a total cohort of 421 individuals within the age bracket of 25 to 65 years. Employing deep learning, a prominent subset of machine learning algorithms, the study deploys convolutional neural network (CNN) models to excavate profound attributes inherent in the skull CT images. In pursuit of the research objective, the focal methodology involves the exclusive application of deep learning algorithms to image datasets, culminating in an accuracy rate of 96.4%. The gender estimation process exhibits a precision of 96.1% for male individuals and 96.8% for female individuals. The precision performance varies across different selections of feature numbers, namely 100, 300, and 500, alongside 1000 features without feature selection. The respective precision rates for these selections are recorded as 95.0%, 95.5%, 96.2%, and 96.4%. It is notable that gender estimation via visual radiography mitigates the discrepancy in measurements between experts, concurrently yielding an expedited estimation rate. Predicated on the empirical findings of this investigation, it is inferred that the efficacy of the CNN model, the configurational intricacies of the classifier, and the judicious selection of features collectively constitute pivotal determinants in shaping the performance attributes of the proposed methodology.

How reliable is stature estimation by dental means? Systematic review and meta-analysis.

Dental measurements have been proposed as parameters for stature estimation for at least 85 years. The scientific literature on the topic, however, is controversial regarding the performance of the method. This systematic literature review of observational cross-sectional studies aimed to compile evidence to support decisions in the forensic practice regarding the use of dental measurements for stature estimation. Embase, LILACS, MedLine (via PubMed), SciELO, Scopus, Web of Science, DansEasy and Open Access Thesis and Dissertations (OATD) were searched. Data regarding the rate of correct stature classifications were extracted. A meta-analysis with a Random Intercept Logistic Regression model and a Logit Transformation was conducted. The search led to 10.803 entries, out of which 15 were considered eligible (n = 1486 individuals). The studies were published between 1990 and 2020 and were authored by South American (n = 7) and Asian (n = 8) research teams. Dental measurements were predominantly (93.34 %) performed on dental casts or via intraoral inspection. The overall rate of correct classifications based on stature was 68 %. Excluding outliers, the overall accuracy of the method decreased to 64 % (95 %CI: 54-73 %). Significant heterogeneity was detected (I² = 72.4 %, τ2 = 0.24, H = 1.91, p < 0.001). Egger's test (p = 0.94) and the funnel plot did not reveal publication bias. Dental measurements are not reliable for stature estimation in the forensic field.

Stature estimation equations for modern American Indians in the American Southwest.

Stature estimation is a core component to the biological profile in forensic anthropology casework. Here we provide mathematical equations for estimating stature for contemporary American Indians (AI), which currently are lacking in forensic anthropology. Drawing on postmortem computed tomography data from the New Mexico Decedent Image Database we regressed cadaveric length on four long bone length measures of the tibia, femur, and humerus to produce 11 combinations of models. Separate regression models were calculated for the entire pooled sample, by sex, broad AI language groups, and age + sex subsamples and compared. Sex-specific models were statistically better than general models, which were more accurate than language group and age + sex models. Equations were created for general and sex-specific models. Application to an independent test sample demonstrates the equations are accurate for stature estimation with overestimates of less than 1 cm. The equations provide similar levels of precision to stature estimation programs like the FORDISC 3.0 module and other stature equations in the literature. We provide recommendations for equation use in casework based on our results. These equations are the first for estimating stature in contemporary AI. This paper demonstrates the appropriateness of these newly created stature equations for use in New Mexico and the surrounding region.

Deep learning in sex estimation from photographed human mandible using the Human Osteological Research Collection.

Sex estimation is a necessary part of forensic and osteological analyses of skeletal human remains in the construction of a biological profile. Several skeletal traits are sexually dimorphic and used for skeletal sex estimation. The human mandible and morphological traits therein have been long used for sex estimation, but the validity of using the mandible in this purpose has become a concern. In this study, we examined the potential of artificial intelligence (AI) and especially deep learning (DL) to provide accurate sex estimations from the mandible. We used 193 modern South African mandibles from the Human Osteological Research Collection (HORC) in the Sefako Makgatho Health Sciences university with known sex to conduct our study. All mandibles were photographed from the same angle and the photographs were analyzed with an open-source DL software. The best-performing DL algorithm estimated the sex of males with 100% accuracy and females with 76.9% accuracy. However, further studies with a higher number of specimens could provide more reliable validity for using AI when building the biological profile from skeletal remains.

Can human sex be estimated based on the dimensions of the maxillary sinuses? A systematic review of the literature on cone-beam and multi-slice computed tomography.

PURPOSE: To critically appraise and summarize the potential of linear and/or volumetric dimensions of the maxillary sinuses obtained with cone-beam and multi-slice computed tomography. METHODS: A bibliographic search was conducted in seven databases in August 2023. Cross-sectional retrospective studies using linear and volumetric measurements of the maxillary sinuses obtained with cone-beam and multi-slice computed tomography for sex estimation and presenting numerical estimation data were included. Narrative or systematic reviews, letters to the editor, case reports, laboratory studies in animals, and experimental studies were excluded. The critical appraisal and certainty of evidence were assessed using the guidelines described by Fowkes and Fulton and GRADE, respectively. RESULTS: A total of 656 studies were found, 32 of which were included. A total of 3631 individuals were analyzed and the overall sex estimation rate ranged from 54.9 % to 95 %. When compared with isolated measurements, combined linear measurements of the right and left maxillary sinuses, such as width, length, and height, provided a higher rate of sex estimation (54.9-95 %). In most of the studies (62.5 %), all measurements were higher in men than in women. Multiple methodological problems were found in the studies, especially distorting influences in 84.4 % of the answers. The certainty of evidence varied from very low to low. CONCLUSIONS: The combination of height, width, and length measurements of the right and left maxillary sinuses from cone-beam and multi-slice computed tomography can be useful in the estimation of sex of humans. Further primary studies are needed to increase the certainty of evidence. PROSPERO REGISTER: CRD42020161922.

Dimensional accuracy of structured light scans and 3D prints of various human skeletal elements.

Three-dimensional (3D) structured light scanning is a beneficial documentation technique in forensic anthropology because such models facilitate continued analysis and data sharing; they can also be 3D printed for demonstrative purposes in legal proceedings and training, without risk of damage to the original skeletal material. As its application in forensic anthropology is relatively novel, the aim of the present study is to statistically evaluate the dimensional accuracy of 3D structured light scans and 3D prints for ten bone types, including the cranium, mandible, 2nd cervical vertebra (C2), clavicle, scapula, capitate, 2nd metacarpal, os coxae, femoral head, and patella. Standard linear measurements are acquired in each physical bone, 3D virtual model, and 3D print of the same bone specimen. Variances between measurements of physical, virtual, and printed bones are quantified using the technical error of measurement (TEM), relative TEM (rTEM), and coefficient of reliability (R). Measurements acquired in the virtual models and prints were found to be within ±2 mm average of the same measurements in the physical bones, with a tendency to underestimate true value. rTEM and R values for the virtual clavicle, capitate, scapula and C2, and rTEM for the printed clavicle and capitate, were comparatively less reliable than for other bone types; although all bones were reproduced to within acceptable anthropological error standards (rTEM≤5 %; R≥0.95). This study reaffirms the use of 3D structured light scanning and 3D printing to complement traditional skeletal documentation in forensic anthropology.

[Morphology of sternum for formation of the biological profile of unidentified individual]. / Morfologiya grudiny dlya formirovaniya biologicheskogo profilya neopoznannogo individa.

Identification of a person by general group characteristics does not lose its relevance over a long period. An analysis of publications (2000-2023) devoted to the possibilities of using the sternum to determine gender and age showed a fairly large amount of work on this topic, with very promising results. The trend in the development of this area is the use of modern methods of medical imaging. This becomes the starting point for conducting such studies on the territory of the Russian Federation and developing a methodology that includes the Russian population, taking into account their population characteristics.

Biometrics of the Hand's Middle Finger to Determine Stature in Chilean University Students / Biometría del Dedo Medio de la Mano para Determinar Estatura en Estudiantes Universitarios Chilenos

SUMMARY: Biometrics and forensic osteology play a significant role in human identification, as the morphological uniqueness of every individual enables the differentiation and recognition of skeletal remains. Through meticulous analysis of human remains, it is possible to determine key demographic attributes such as stature, a significant parameter in the forensic identification process. This information is of practical relevance for the identification of individuals in contexts such as disasters, vehicular accidents, terrorist attacks, armed conflicts, and forensic investigations. The objective of this study was to determine the correlation between the hand's middle finger length and stature in a group of Chilean students. A total of 211 students of both sexes from La Araucanía region, Chile, participated in the study. After obtaining informed consent to participate voluntarily in the study, each individual underwent a general anthropometric examination, followed by a specific assessment of the length of the middle finger (MFL) of both hands. The results of the multiple linear regression analysis indicated a significant prediction of stature using the length of the right (R-MFL) and left (L-MFL) middle fingers, F (2, 207) = 79.80, p < 0.001. The equations for estimating stature based on the length of the middle fingers are as follows: for R-MFL, Stature = 91.265 + (8.092 x R-MFL), and for L-MFL, Stature = 83.967 + (8.889 x L-MF). Based on these results, it was found that the length of the middle finger of both hands is predictive of stature.

La biometría y la osteología forense desempeñan un papel relevante en la identificación humana, dado que la singularidad morfológica de cada individuo permite la diferenciación y reconocimiento de restos óseos. Mediante el análisis meticuloso de los restos humanos, es posible determinar atributos demográficos clave como la estatura, un parámetro significativo en el proceso de identificación forense. Esta información posee relevancia práctica para la identificación de personas en contextos de desastres, accidentes vehiculares, ataques terroristas, conflictos armados e investigaciones forenses. El objetivo de este estudio fue determinar la correlación entre la longitud del dedo medio de la mano con la estatura, en un grupo de estudiantes chilenos. Se evaluaron 211 estudiantes de ambos sexos de la región de La Araucanía, Chile. Tras obtener el consentimiento informado para participar voluntariamente en el estudio, se sometió a cada individuo a un examen antropométrico general, seguido de una evaluación específica de la longitud del dedo medio (MFL) de ambas manos. Los resultados del análisis de las regresiones lineales múltiples indicaron una significativa predicción de estatura utilizando la longitud de los dedos medios derecho (R-MFL) e izquierdo (L-MFL), F (2, 207) = 79.80, p < 0.001. Las ecuaciones para estimar estatura basados en la longitud de los dedos medios son las siguientes: para R-MFL, Stature = 91.265 + (8.092 x R-MFL) y para L-MFL, Stature = 83.967 + (8.889 x L- MF). A partir de estos resultados, se encontró que la longitud del dedo medio de ambos manos es predictora de estatura.

Study of Lip Conditions Associated with Lip Print Patterns: A New Perspective on Cheiloscopy / Estudio de Afecciones Labiales Asociadas a sus Patrones de Huellas: Una Nueva Perspectiva en Queiloscopía

SUMMARY: Although almost all studies exclude lip conditions because they would affect furrow patterns, some authors maintain that they should be considered temporary or permanent disabilities, all of which require further research in this context.We present a study in which we associate lip conditions with lip print patterns to associate both morphological elements for fieldwork purposes. Fifty-seven women and 48 men aged between 19 and 38 years who resided in Temuco (Chile) were included. The lip conditions and their prints were recorded, and an analysis, comparison, evaluation, and verification protocol (ACE-V) for lip prints was applied. Of the participants, 27.4 % had healthy lips, while 71.7 % had some type of condition. Although patterns related to temporary and permanent lip conditions were recognized in the lip prints in a non-significant way, the diagnosis of "healthy" or "altered" lip status could be made significantly by a calibrated examiner. Although these conditions do not represent identifying variables without empirical studies to validate them, they can affect the quality of the evaluated lip print; therefore, they should be recognized during the analyses considering the prevalence of these conditions.

Aunque casi todos los estudios excluyen las afecciones labiales pues afectarían los patrones de sus surcos y huellas, algunos autores sostienen que deben ser consideradas alteraciones temporales o permanentes, por lo que se requiere mayor investigación en este aspecto. Se presenta un estudio en el que se asocian afecciones labiales con sus patrones de huellas para evaluar conjuntamente ambos elementos morfológicos con fines de trabajo forense de campo. Se incluyeron 57 mujeres y 48 hombres con edades entre 19 y 38 años residentes en Temuco (Chile). Se registraron las afecciones de los labios y sus huellas, y se aplicó un protocolo de análisis, comparación, evaluación y verificación (ACE-V) para las huellas labiales. De los participantes, el 27,4 % tenía labios sanos, mientras que el 71,7 % presentaba algún tipo de afección. Aunque los patrones relacionados con afecciones labiales temporales y permanentes se reconocieron en las huellas labiales de manera no significativa, un examinador calibrado podría realizar significativamente el diagnóstico de estado labial "sano" o "alterado". Si bien estas condiciones no representan variables de identificación sin estudios empíricos que las validen, pueden afectar la calidad de la impresión labial evaluada; por lo tanto, deben ser reconocidos durante los análisis considerando la prevalencia de estas condiciones.

Bone mineral density and geometric morphometrics: Indicators of growth in the immature pars basilaris.

The pars basilaris forms a central component of the immature basicranium and owing to its resilience to post-mortem and taphonomic changes, holds significance across evolutionary, clinical, and forensic contexts. While size and shape parameters of the pars basilaris have been investigated, little is known about the influence of the underlying bone mineral density on the morphometry of this bone during growth. This study aimed to investigate the development and growth of the pars basilaris with specific reference to changes in bone density patterning and development of osteological features, during the prenatal and early postnatal periods of life. A total of 109 pars basilari were sourced from the Johannesburg Forensic Paediatric Collection, University of the Witwatersrand, South Africa. The study sample was subdivided into early prenatal (<30 gestational weeks), prenatal (30-40 gestational weeks) and postnatal (birth to 7.5 months) groups and micro-CT scanned to assess bone mineral density patterns across seven regions of interest. Size and shape changes were analysed using 11 digitized landmarks and geometric morphometrics. When comparing across age groups, the assessed dimensions increased with growth manifesting as a deepening at the anterior border of the foramen magnum, development of the lateral angles and widening of the bone at the lateral projections and spheno-occipital synchondrosis. However, no significant changes in the distribution of bone mineral density were observed. An appreciation of morphological changes and bone quality at specific growth sites in the pars basilaris is essential when analyzing remains of unknown provenance for the purposes of identification in disaster victim settings.

Identification success rates in the post-Spanish Civil War mass graves located in the cemetery of Paterna, Spain: Meta-research on 15 mass graves with 933 subjects.

Spain suffered a Civil War between 1936 and 1939 that ended with the victory of the National Forces led by General Franco. Once the Spanish Civil War ended, 2238 subjects were executed and buried in several mass graves in the Cemetery of Paterna, one of Spain's largest mass grave sites. Efforts to locate and identify all the victims of the mass graves of the Paterna cemetery are ongoing, but the actual data of the percentage of DNA identifications remains uncertain. Following this, we conducted a meta-research study including 15 mass graves and 933 subjects to determine the DNA identification rates in the mass graves of the Paterna cemetery. We found that the total proportion of identified subjects in the mass graves was 15.9 % (95 % CI: 10.0-22.9). Moreover, we found that the model between the identification success rate (ISR) and the number of relatives that donated DNA (NRTDD) in the mass graves of the cemetery of Paterna was ISR = NRTDD-0.424. Results obtained about the proportion of identified subjects and the model between the ISR and the NRTDD imply the need for a scientific reflection between all the research groups involved in the identification tasks to modify deficiencies and update identification protocols to obtain better future results.

Three-dimensional prediction of the nose for facial reconstruction: A preliminary study on North Indian adults.

Forensic facial reconstruction is the last recourse to establish the identity of an unknown skull. The facial soft-tissue thickness (FSTT) is required to reconstruct various facial features on a skull. Unlike other facial features, the nose is made of cartilaginous tissue except for a small nasal bone. A large cavity (pyriform aperture) exists on the skull in place of the nose, which makes it a challenging job for reconstruction. The nose is a vital feature for the recognition of a face. Any change in the shape or size of the nose can alter the original aesthetic of the face. The present study proposes angles and regression functions on the bony structure to predict the various parts of the soft nose. A sample of computed tomography (CT) images of 100 males and 100 females aged between 18 and 45 years were included in the study. Apart from measuring fourteen linear parameters with three angles, simple linear regression models were derived for five pairs of parameters. Pearson's correlation coefficients for most of the parameters ranging between 0.221 and 0.872 were found to be significant at p ≤ 0.05 level. FSTT at three anatomical landmarks of the nose was also measured. A morphological observation study was undertaken to find the most frequent direction of the bony anterior nasal spine (ans) and its relation with the position of the pronasale (prn) on the soft nose. The devised parameters proposed in the study may also prove useful for reconstructing the nose in other populations.

An exclusionary screening method based on 3D morphometric features to sort commingled atlases and axes.

In forensic commingled contexts, when the disarticulation occurs uniquely at the atlantoaxial joint, the correct match of atlas and axis may lead to the desirable assembly of the entire body. Notwithstanding the importance of this joint in such scenarios, no study has so far explored three-dimensional (3D) methodologies to match these two adjoining bones. In the present study, we investigated the potential of re-associating atlas and axis through 3D-3D superimposition by testing their articular surfaces congruency in terms of point-to-point distance (Root Mean Square, RMS). We analysed vertebrae either from the same individual (match) and from different individuals (mismatch). The RMS distance values were assessed for both groups (matches and mismatches) and a threshold value was determined to discriminate matches with a sensitivity of 100%. The atlas and the corresponding axis from 41 documented skeletons (18 males and 23 females), in addition to unpaired elements (the atlas or the axis) from 5 individuals, were superimposed, resulting in 41 matches and 1851 mismatches (joining and non-joining elements). No sex-related significant differences were found in matches and mismatches (p = 0.270 and p = 0.210, respectively), allowing to pool together the two sexes in each group. RMS values ranged between 0.41 to 0.77 mm for matches and between 0.37 and 2.18 mm for mismatches. Significant differences were found comparing the two groups (p < 0.001) and the highest RMS of matches (0.77 mm) was used as the discriminative value that provided a sensitivity of 100% and a specificity of 41%. In conclusion, the 3D-3D superimposition of the atlanto-axial articular facets cannot be considered as a re-association method per se, but rather as a screening one. However, further research on the validation of the 3D approach and on its application to other joints might provide clues to the complex topic of the reassociation of crucial adjoining bones.