Human identification based on cranial computed tomography scan: a case report

A Novel Algorithm for Forensic Identification Using Geometric Cranial Patterns in Digital Lateral Cephalometric Radiographs in Forensic Dentistry

Lateral cephalometric radiographs are crucial in dentistry and orthodontics for diagnosis and treatment planning. However, their use in forensic identification, especially with burned bodies or in mass disasters, is challenging. AM (antemortem) and PM (postmortem) radiographs can be compared for identification. This study introduces and evaluates a novel algorithm for extracting cranial patterns from digital lateral cephalometric radiographs for identification purposes. Due to the unavailability of AM cephalograms from deceased individuals, the algorithm was tested using pre- and post-treatment cephalograms of living individuals from an orthodontic archive, considered as AM and PM data. The proposed algorithm encodes cranial patterns into a database for future identification. It matches PM cephalograms with AM records, accurately identifying individuals by comparing cranial features. The algorithm achieved an accuracy of 97.5%, a sensitivity of 97.7%, and a specificity of 95.2%, correctly identifying 350 out of 358 cases. The mean similarity score improved from 91.02% to 98.10% after applying the Automatic Error Reduction (AER) function. Intra-observer error analysis showed an average Euclidean distance of 3.07 pixels (SD = 0.73) for repeated landmark selections. The proposed algorithm shows promise for identity recognition based on cranial patterns and could be enhanced with artificial intelligence (AI) algorithms in future studies.

Quantifying the potential of morphological parameters for human dental identification: part 1-proof of concept

In forensic identification, lack of eccentric characteristics of intact dentitions hinders correct ante-mortem/post-mortem (AM/PM) matching. It remains unclear which morphological dental parameters hold strong potential as identifiers. This study aimed to establish a method to quantify and rank the identifying potential of one (or a combination of) continuous morphological parameter(s), and to provide a proof of concept. First, a statistic was defined that quantifies the identifying potential: the mean potential set (MPS). The MPS is derived from inter-observer agreement data and it indicates the percentage of subjects in the AM reference dataset who at least need to be considered to detect the correct PM subject. This was calculated in a univariate and a multivariate setting. Second, the method was validated on maxillary first molar crowns of 82 3D-digitally scanned cast models. Standardized measurements were registered using 3D modeling software (3-Matic Medical 12.0, Materialise N.V., Leuven, Belgium): tooth depth, angles between cusps, distances between cusps, distances between the cusps, and the mesial pit. A random sample of 40 first molars was measured by a second examiner. Quantifying and ranking the parameters allowed selecting those with the strongest identifying potential. This was found for the tooth depth (1 measurement, MPS = 17.1%, ICC = 0.879) in the univariate setting, and the angles between cusps (4 measurements, MPS = 3.9%) in the multivariate setting. As expected, the multivariate approach held significantly stronger identifying potential, but more measurements were needed (i.e., more time-consuming). Our method allows quantifying and ranking the potential of dental morphological parameters as identifiers using a clear-cut statistic.

Radiographic presentation of artifactual dyed hair on lateral cephalograms, chemical processing, and forensic application: Novel case report

Forensic assessment employs an array of methods to identify human remains. Radiologic examinations with panoramic radiographs, computed tomography scans, Waters view, and nuclear magnetic resonance imaging may offer evidentiary clues in challenging cases, such as mass disasters. In these cases, alternative forensic tools are used to narrow lists of target victims using their biological features. This study aims to I) report on the unusual radiographic aspect of chemicals used for hair dyeing, and II) discuss the potential forensic application of this finding for human identification. The case depicts an asymptomatic 14-years-old female who presented for orthodontic therapy. During radiographic examination on a lateral cephalogram, numerous thin radiopaque streaks were visible, extending to the posterior neck between the occipital region of the skull base and vertebra C6. Clinical investigations revealed that these were artifactual hair images (possibly documented for the first time in the scientific literature). Inductively coupled plasma mass spectrometry (ICP-MS) analysis of the patient's scalp hair was performed for 10 heavy metals, including zinc, copper, iron, chromium, nickel, cadmium, tin, lead, antimony, and bismuth. Eight of these metals were detected at normal levels, ranging from 160 parts per million (ppm) for zinc to less than 1 ppm for nickel, cadmium, tin, lead, and antimony. Conversely, slightly elevated levels of chromium at 0.41 ppm and bismuth at 0.025 ppm were found in the hair sample. The distinctive radiographic presentation of artifactual hair images combined with the chemical properties of hair exposed to dye products may provide useful traces for human identification, especially in mass disasters.

A preliminary study to quantify the efficacy of 3D data acquisition for human bone replication

BACKGROUND

Three-dimensional imaging is a rapidly growing technology that has revealed exciting insights in disparate fields of research, especially in medicine, forensics, and archaeology. Recent advancements in this technology have also made a remarkable impact in the field of anthropology and odontology. A major benefit of this technology is that they offer effective methods of creating digital records that can aid in physical documentation and can be digitally stored for later assessment and research.

AIM

The aim of the current study is to evaluate the metric accuracy of 3D models generated using three different 3D acquisition techniques for performing metric analytical procedures.

MATERIALS AND METHOD

Twenty standard craniometric linear measurements (using both sliding and spreading callipers) were taken on two craniums and eight standard measurements were taken on 2 mandibles (using sliding callipers and a mandibulometer); these measurements were then replicated on 3D digital models.

RESULTS

Statistical analysis of these dataset using Analysis of Variance (ANOVA) and post hoc Bonferroni test suggested that the physical and virtual measurements were accurate, comparable, and concordant (p > 0.05).

CONCLUSION

These findings open up numerous avenues for future study, especially in the fields of forensics and clinical studies. However, in order to overcome the limitations faced in using the digital method certain standardised protocols and guidelines must be established to record these data.

Role of post-mortem multi-slice computed tomography in the evaluation of single gunshot injuries

Post-mortem multi-slice computed tomography (MSCT) is a new approach in forensic pathology for gunshot injuries. This study determines the role of MSCT in the characterisation of single gunshot injuries. We report three cases. In the first case, an 80-year-old man was found dead in his bedroom with a gun. External examination showed devastating head injuries. In the second case, an 81-year-old man was found dead in his apartment, without a gun. External examination showed gunshot injuries. In the third case, a 56-year-old man was found dead on a road. MSCT and autopsy were performed in all these cases. MSCT not only allowed the determination of entrance and exit wounds but also showed some artefacts. In conclusion, radiology is fundamental for the reconstruction of gunshot injuries, and the manner of death can only be ascertained by autopsy.

Morphometric study of the facial skeleton in Jordanians: A computed tomography scan-based study

Several studies have shown variability in osteometric measurements of the skull between populations. Therefore, each population should have specific standards to optimize the accuracy of identification. The aim of this study was to evaluate the sexual dimorphism in metric relations between anatomical points of the skull using CT scans in a Jordanian population by means of discriminant function analysis, to determine which continuous variables discriminate between sexes, and to examine the craniofacial changes according to age. 500 CT scans (240 males and 260 females) were used and a total of 11 craniofacial parameters were studied. The data were analyzed using distriminant function analysis. Sexual dimorphism was found mainly in the young adult group. Significant age related changes were noticed in minimum frontal breadth, orbital height and orbital index. In all subjects, the analysis of multivariate (dimorphic variables) and stepwise functions gave an accuracy of 58.8% and 57.0% respectively. Using stepwise analysis, the most dimorphic variables to estimate sex were maximum frontal breadth, bimaxillary breadth and orbital index. The multivariate analysis of all variables gave an accuracy of 58.8%. The percentages of correct sexing in Jordanian population were high using the single variable analysis in females only. In females, classification accuracies of 70.4% using bimaxillary breadth, 70.0% using the orbital index, and 68.1% using maximum frontal breadth were obtained. Additionally, discriminant analysis was conducted separately for each age group. Higher percentages of correct sexing were obtained only in young adults. The results of the discriminant function analysis did not appear to be significant. The results of discriminant function were insignificant in middle aged and elderly groups. Being female and young increases the percentages of correct sexing. Generally, low levels of accuracy of sexual dimorphism were obtained in our study, suggesting that population estimates of dimorphism are highly variable and the equations derived from the discriminant function analysis are not reliable in sex estimation in Jordanians.

Comparing dental identifier charting in cone beam computed tomography scans and panoramic radiographs using INTERPOL coding for human identification

According to INTERPOL, the comparison of antemortem and postmortem dental identifiers is a scientifically reliable approach for human identification. This study aimed to quantify the prevalence of corresponding INTERPOL coded dental identifiers in cone beam computed tomography (CBCT) scans and panoramic radiographs (PR). The sample consisted of 100 CBCT scans and 100 PR taken the same day from the same patients (35 males and 65 females). Randomly and independently, forty-one INTERPOL coded dental identifiers were searched in each image. Wilcoxon test compared the prevalence of codes in CBCT scans and PR, Chi-square tested the dependence between codes and teeth; and multiple correspondence analyses (MCA) explored the association between codes and teeth in color maps for CBCT scans and PR. No statistically significant differences between the prevalence of identifiers in CBCT scans and PR were detected (p=0.693). In CBCT scans and PR, dependence between teeth and codes was detected (p<0.05). In the study sample, the strongest associations were found between the codes unerupted (UNE), partially erupted (ERU) and impacted (IMV) and third molars, both in CBCT scans and PR. INTERPOL coded dental identifiers registered on CBCT scans and PR can be exchanged during human identification.

Post-mortem computed tomography (PMCT) radiological findings and assessment in advanced decomposed bodies

PURPOSE

The aim of the study is to report radiological findings and features in advanced decomposed bodies obtained by post-mortem computed tomography (PMCT) with autopsy correlation.

MATERIALS AND METHODS

This retrospective descriptive multicentric study included 41 forensic cases examined between May 2013 and November 2016. All the bodies were PMCT-scanned prior to autopsy, and internal putrefactive state was determined using the radiological alteration index (RAI) by a radiologist with expertise in forensic radiology and a forensic pathologist trained in forensic imaging. After PMCT scans, grade of external putrefaction (GEP) was assigned during the external examination and the complete autopsy was performed by forensic pathologists.

RESULTS

The PMCT images evaluation revealed that the RAI index was > 61 in all bodies, corresponding to a moderate-massive presence of putrefactive gas. The gas grade was > II in correspondence of the major vessels, heart cavities, liver parenchyma, vertebra L3 and subcutaneous pectoral tissues, and varied from I to III in correspondence of the kidney. Cadaveric external examination revealed the presence of advanced transformative phenomena, with a GEP3 and GEP4 in most of the cases, with body swelling, eyes and tongue protrusion, body fluids expulsion and fat liquefaction.

CONCLUSION

Radiological imaging by PMCT as an adjunct to autopsy in advanced decomposed bodies represents a useful tool in detecting post-mortem gas, even in very small amounts. A correct interpretation process of the PMCT data is essential to avoid images pitfalls, due to natural decomposition that can be mistaken for pathologic processes.

Forensic Identification of Decomposed Human Body through Comparison between Ante-Mortem and Post-Mortem CT Images of Frontal Sinuses: Case Report

Objective

The aim of this paper is to report on a case of positive human identification of a decomposed body after the comparison of ante-mortem (AM) and port-mortem (PM) computed tomography images of frontal sinus.

Case report

An unknown, highly decomposed human body, aged between 30 and 40 years, was found in a forest region in Brazil. The dental autopsy revealed several teeth missing AM and the presence of removable partial prostheses. The search for AM data resulted in a sequence of 20 axial images of the paranasal sinuses obtained by Multislice Computed Tomography (MSCT). PM reproduction of the MSCT images was performed in order to enable a comparative identification. After a direct confrontation between AM/PM MSCT, the data were collected for morphological findings, specifically for the lateral expansion of the left lobe, the anteroposterior dimension, and the position of median and accessory septa of the sinuses.

Conclusion

The importance of storing and interpreting radiographic medical data properly is highlighted in this text, thus pointing out the importance of application of forensic radiology in the field of law.

Antemortem identification by fusion of MR and CT of the paranasal sinuses

Radiologic forensic identification is usually performed by comparing antemortem and postmortem radiographs. While computed tomography (CT) has become a valuable addition to radiologic identification, magnetic resonance (MR) imaging has only rarely been used for this purpose. In our case, identification was accomplished using fused MR- and CT images in a survivor of a gunshot injury to the head. This case supports and highlights the possibility to perform intermodality radiologic identification comparing preexisting MR imaging to subsequently aquired CT data in living (or deceased) humans as long as manual modifications of windowing, color and contrast enable differentiation of the two modalities in the fused image.

Dental Identification Through Endodontic Radiographic Records: a Case Report

OBJECTIVE OF WORK

The present study aims to report a case of successful human identification based on the comparison of ante-mortem and post-mortem records of endodontic treatment. Based on these, the legal value of storing and updating clinical records is highlighted throughout the text.

CASE REPORT

An unknown body was recovered from a traffic accident site. Forensic examination was conducted in order to establish the identity of the victim. Based on the absence of ante-mortem fingerprint registration in the national database, the search for AM data was performed using periapical radiographic records from private dental clinics. A positive dental identification was achieved analyzing evidence of endodontic treatment.

CONCLUSION

Dental radiographs play a valuable role as legal tools supporting the criminal demands on the daily forensic practice. Specifically in endodontics, periapical radiographs are essential for a proper treatment. In forensics, these radiographs represent a solid source of ante-mortem data for human identifications.

Improving traditional dental autopsies in postmortem examinations of intraoral gunshot wounds

Despite the recent advances in the post-mortem forensic examinations, some medico-legal institutes are limited in accessing improved technological facilities, hampering an optimal autopsy. Specifically in developing countries, high-cost imaging devices are not afforded, making necessary the development of alternative autopsy techniques. In parallel, in dental autopsies muscle stiffness is often observed lacking mouth opening. This situation is specifically worse in cases of intraoral firearm injuries, in which detailed description of the detected wounds must be reported post-mortem. Based on this context, the present study aims to illustrate two cases of intraoral firearm injuries, in which the dental autopsies were performed considering a conservative and alternative technique for the improvement of mouth opening. Both cases provided optimal results, indicating the new approach as a valuable tool for dental autopsies.

The conclusive role of postmortem computed tomography (CT) of the skull and computer-assisted superimposition in identification of an unknown body

Computed tomography is commonly used in modern medicine, and thus, it is often helpful for medicolegal purposes, especially as part of the antemortem record. The application of postmortem computed tomography and 3D reconstruction of the skull in challenging cases is reported, and its valuable contribution to positive identification is discussed. This paper presents a case in which the body of an unknown individual is identified. Positive identification had not been possible despite a multidisciplinary examination. The postmortem use of computerized tomography and 3D reconstruction of the skull followed by the comparison of individual morphological characteristics of the viscerocranium showed the concordant points between the deceased and a missing person. Finally, superimposition using a 3D-reconstructed skull instead of the skeletonized skull demonstrated an adequate degree of morphological consistency in the facial images of the analyzed individuals that lead to positive identification. It was concluded that where other methods of personal identification had failed, the use of postmortem computed tomography had proved to be instrumental in the positive identification of the deceased.