Forensic odontology in DVI: current practice and recent advances

Advances in postmortem fingerprinting: Applications in disaster victim identification

Postmortem fingerprinting is the fastest and most reliable way to scientifically identify unknown decedents from mass fatality incidents. In disaster victim identification (DVI), fingerprints, DNA, and dental examinations are the three primary methods of identification. Additional secondary identifiers such as comparative medical radiography, scars, marks, and tattoos can also be used if viable antemortem information can be located. As DNA technology continues to evolve, RAPID DNA may now identify a profile within 90 min if the remains are not degraded or comingled. When there are true unknowns, however, there is usually no DNA, dental, or medical records to retrieve for a comparison without a tentative identity. It is imperative to understand how to properly collect postmortem prints following various postmortem changes, which databases are available to search against, and what additional resources are available prior to any such event occurring. With advances in technology, automated fingerprint searching is faster than ever before. Mobile devices can now search all the major databases within a matter of minutes from a cell phone or tablet utilizing a peripheral fingerprint scanner. Preliminary research into the application of WD-40® when utilizing optical-capacitive scanners has shown to greatly increase the efficacy of capturing usable fingerprints. This additional step allows for the digital capture of fingerprints in even complicated settings, both in daily cases and DVI incidents. This article outlines all the available ways to obtain postmortem fingerprints in complex cases, and how they can be applied to efficiently and effectively used in the DVI process.

Forensic odontology in disaster victim identification

This paper reviews MFI's from a historical perspective commencing with DVI in the late 20th century. For this paper, this era, 1970-90s is designated as the early modern period. As DVI by DNA analysis is introduced into the process, in the beginning of the mid-1990s, or late modern period, a shift in ID modality usage is noted. A statistical analysis of the primary identification (ID) methods established that dental identification was the majority identifier, or gold standard, in the early modern era. Although primarily viewed from a United States (US) perspective, referenced international incidents parallel the incidents investigated by US authorities. The introduction of DNA demarcated the early from the late modern era. Through research, development, and application this highly discriminating ID method would effectively, surpass dental ID as the gold standard into the late modern era. DNA ID would eventually overcome early criticism regarding cost and time consumption. In the MFI's discussed, the discriminating accuracy of DNA, when referenced against the dental identifications, validated the reliability of dental ID. Errors will be significantly minimized through confirmatory reconciliation by more than one ID method. In conclusion despite increased usage of DNA, dental ID has not been eliminated and remains a major contributor to DVI. Dental ID continues to develop through increased application of advanced imaging technology. Despite DNA's rapid advancement and application to DVI, the multidisciplinary approach to scientific identification should remain in the near future. Therefore, comparative dental ID will remain an important and reliable contributor to DVI.

Forensic odontology in DVI-A path forward

Dental identification is a pillar of disaster victim identification (DVI). Dental identification is accurate, efficient, inexpensive, and accepted in courts of law. The (known) antemortem (AM) dental charts and radiographic images acquired from the dentist of the missing person are evaluated, processed, and compared to post mortem (PM) findings present in the dentition or fragments of the dentition of the deceased individual. These comparisons evaluate and assess individuating restorative dental work, dental anatomical areas of concordance, spatial relationships of teeth one to another, and occasionally calculate the degree of "uniqueness" of either or both of the AM and PM dentition compared to known population databases. In a multiple fatality incident, odontologists may utilize age stratification to assist other means of identification. Computer comparison algorithms using recorded data can indicate possible matches between AM and PM data sets. Following clinical assessment, collection of post mortem tooth specimens for DNA profiling generation may be undertaken. This paper will highlight modern and efficient use of these tools. The framework for how dental identification in these incidents is currently managed is presented. The authors propose a change to this approach that moves away from interpretive subjective assessment toward comparisons based largely on objective data. The aim of this paper is to highlight the benefits of minimizing subjective decisions and maximizing objective data in the dental DVI process while simultaneously reducing risk to clinical personnel and minimizing costs by reducing the number of clinicians required onsite.

Positive identification through comparative dental analysis in mass disaster: a systematic review and meta-analysis

PURPOSE

The study aimed to assess the probability of achieving positive identification through comparative dental analysis (CDA) and to determine the factors that influence its success rate in mass disaster scenarios.

METHODS

An electronic literature search was conducted across six databases for observational studies that reported both the total number of mass disaster victims and the count of victims identified through CDA alone. A random-effect meta-analysis, using the proportion of victims identified with CDA as the effect size, was conducted alongside subgroup analyses based on the type of disaster (natural or non-natural), the disaster classification (open or closed), and the geographical region (i.e., Europe, Asia).

RESULTS

The search yielded 3133 entries, out of which 32 studies were deemed eligible. Most of the studies (96.8%) presented a low risk of bias. The meta-analysis revealed a mean weighted-proportion probability of 0.32, indicating that forensic odontology could identify about one-third of the victims in a mass disaster. The probability of comparative dental identification was three times higher in closed mass disasters compared to open disasters (p < 0.05) and was higher in mass disasters occurring in North America and Europe compared to other regions (p < 0.05).

CONCLUSION

The current result suggested that CDA can identify approximately 32% of a victim in a hypothetical scenario, emphasizing the integral role of teeth and forensic odontology in victim identification framework.

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.

Gonial Angle in Forensic Anthropology to Determine Age and Gender: A Population-Specific Analysis

Background The study highlights the gonial angle as a key craniofacial landmark for age and gender determination in forensic cases. It emphasizes population-specific analysis, enhancing precision by recognizing variations between populations. By clarifying the gonial angle's forensic use, the study offers clear guidelines, improving forensic practices. Moreover, the gonial angle and age and gender correlations are thoroughly examined, offering important information on their forensic relevance. The results highlight how crucial population-specific research is to improving the precision and dependability of forensic age and gender estimation techniques, which advances forensic anthropology and supports forensic investigations around the globe. Aim and objective The purpose of this study is to assess the accuracy of age and gender estimates using gonial angles. The objectives of this research are to evaluate the precision of age and gender estimates utilizing the gonial angle. Materials and methods This present study comprises two groups based on age groups: Group I belongs to 51 to 60 years of age, and Group II belongs to 61 to 70 years of age. Making use of G-Power software (version 3.1.9.4, Düsseldorf, Germany), the sample size was determined. The calculation ensured 95% statistical power at a significance level (alpha error probability) of 0.05. To achieve sufficient statistical power, a total of 1000 samples were included, with a projected required sample size of 92. A total of 1000 samples, consisting of 500 male and 500 female panoramic radiographs, were meticulously selected for the study. The samples picked were within the age range of 51 to 70 years. Orthopantomograms were determined using Planmeca software (Planmeca Romexis®, Version 6.0, USA Inc.). Descriptive statistics, including prediction classification analysis of age and gender, were conducted using SPSS Statistics version 16.0 (SPSS Inc., Released 2007, SPSS for Windows, Version 16.0, Chicago, SPSS Inc.). Results According to this study, the mean gonial angle of males aged 51 to 60 years is larger (124.7370 degrees) than that of females (119.6371 degrees). The female group's mean estimates are more accurate, as seen by the smaller standard error (0.20844) compared to the male group's (0.60998). A statistically significant difference in mean gonial angles between the genders is evident, with males having a larger gonial angle (p-value <0.001). In the age range of 61 to 70 years, the mean gonial angle of females is higher (128.4322 degrees) than that of males (124.0529 degrees). In this instance, the male group's standard error is smaller (0.14968) than the female group's (0.30028), indicating more accurate mean estimates. Once more, a statistically significant difference is indicated by a p-value of less than 0.001, with females having a larger gonial angle than males. Conclusion Our study revealed that the gonial angle of the mandible can be considered a reliable parameter for gender identification. The study's limitation is its inability to reliably identify gender in the subadult population and in cases of edentulousness. An orthopantomogram is a trustworthy and accurate method for taking the different measurements needed to identify the gender of a particular mandible.

Accuracy of the third molar maturity index (I3M) for diagnosing the legal majority of young southern Brazilians

Background

The numerous techniques for identifying adulthood require research testing the accuracy of each method in different populations. This study verified the accuracy of the third molar maturity index (I3M) proposed by Cameriere et al. (2008) for diagnosing the age of majority in a southern Brazilian population sample.

Material and Methods

Panoramic radiographs of patients with dental element 38 treated at the School of Dentistry of the University of Passo Fundo (UPF), RS, Brazil, were analyzed. The patients were separated into age groups between 15.00 and 22.99 years. The Cameriere (2008) method was applied to each radiograph. The study sample comprised 671 individuals, with 385 women (mean age 19.67 ± 2.05) and 286 men (mean age 19.5 ± 2.11).

Results

The original cut-off value of I3M≤0.08 classified individuals younger and older than 18 years. ROC curve plotting resulted in an overall accuracy of 0.69 and 0.84 for women and men, respectively. The most favorable cut-off value for southern Brazilian men was 0.06, and women showed better results with an I3M adjusted to 0.13. The new cut-off values produced an accuracy of 0.78 for women and 0.84 for men. The original cut-off point to the I3M (0.08) was not the most appropriate for the studied sample.

Conclusions

Thus, index adjustments to 0.13 for women and 0.06 for men may improve method performance among southern Brazilian individuals. Key words:Molar, third, radiography, panoramic, forensic dentistry, age groups, imputability.

Optimization of forensic identification through 3-dimensional imaging analysis of labial tooth surface using open-source software

Purpose

The objective of this study was to determine the minimum number of teeth in the anterior dental arch that would yield accurate results for individual identification in forensic contexts.

Materials and Methods

The study involved the analysis of 28 sets of 3-dimensional (3D) point cloud data, focused on the labial surface of the anterior teeth. These datasets were superimposed within each group in both genuine and imposter pairs. Group A incorporated data from the right to the left central incisor, group B from the right to the left lateral incisor, and group C from the right to the left canine. A comprehensive analysis was conducted, including the evaluation of root mean square error (RMSE) values and the distances resulting from the superimposition of dental arch segments. All analyses were conducted using CloudCompare version 2.12.4 (Telecom ParisTech and R&D, Kyiv, Ukraine).

Results

The distances between genuine pairs in groups A, B, and C displayed an average range of 0.153 to 0.184 mm. In contrast, distances for imposter pairs ranged from 0.338 to 0.522 mm. RMSE values for genuine pairs showed an average range of 0.166 to 0.177, whereas those for imposter pairs ranged from 0.424 to 0.638. A statistically significant difference was observed between the distances of genuine and imposter pairs (P<0.05).

Conclusion

The exceptional performance observed for the labial surfaces of anterior teeth underscores their potential as a dependable criterion for accurate 3D dental identification. This was achieved by assessing a minimum of 4 teeth.

Forensic exploration of endodontic cements: Unveiling macroscopic and radiographic changes under high temperatures

OBJECTIVE

To evaluate macroscopically and radiographically the behavior of four endodontic sealers submitted to high temperatures, with forensic purposes.

METHODS

Sixty-four lower anterior teeth were included. All teeth were endodontically treated, and simulation of external cervical resorption (ECR) was performed. Half of the sample was filled with AH-Plus™ cement and had ECR sealed with Bio-C-Repair™. The other 32 teeth were filled with Bio-C-Sealer™ cement and had their respective ECR sealed with MTA-Repair™. Then, all teeth were introduced into a bovine bone block to simulate the alveolar bone. The teeth were submitted to incineration at temperatures of 600, 800, 1000, and 1140 °C. All teeth were radiographed before and after incineration. The pre-and post-incineration radiopacity of cements and dentin were evaluated using the ImageJ™ software and compared using a t-test for paired samples.

RESULTS

It was possible to confirm color change and appearance of cracks in the tissues and dental materials tested, varying according to the temperature. Radiographically, it was observed that the dental crowns completely detached at 1000 ° and 1140 °C, and, only at 1140 °C, the roots showed cracks. Regarding the radiopacity, there was a significant difference in the shades of gray in AH-Plus™ when subjected to 1000 ° and 1140 °C, and at 600 ° and 1000 °C in Bio-C-Sealer™. In Bio-C-Repair™ and MTA-Repair™, a difference was observed at 600 ° and 1140 °C.

CONCLUSIONS

There were macroscopic and radiographic alterations of the materials. This data is important in Forensic Dentistry and may contribute to identifying carbonized victims.

Accuracy of Age Estimation Using Three Dental Age Estimation Methods in a Young, Large, and Multiethnic Patient Sample

European countries have become host countries for migrants and unaccompanied minors. However, many migrants arrive without identity documents. Many methods exist to estimate age; among them, several methods using dental age have been proposed. Our objective was to evaluate the accuracy of biological age determination in a multiethnic sample using dental age estimated using three methods: Nolla, Demirjian, and the London Atlas. Orthopantomograms collected for 324 patients of various ethnicities aged from 4 to 20 years old were included. Then, for each orthopantomogram, a blind trained examiner used the three methods of age estimation. For each method, the estimated mean age was greater than the real mean age (p < 0.0001). The accuracy after 18 years old with a 1-year margin was under 50%. Demirjian's method gave a less accurate estimated age than Nolla's method (p < 0.0001) or the London Atlas (p < 0.001). The most accurate methods were those of Nolla and the London Atlas, with average absolute deviations of 1.3 and 1.2 years, respectively. Demirjian's method was much less accurate, with a deviation of around 2 years. The evaluated methods are unable to provide reliable information to determine if an individual is a minor.

Convolutional neural networks for automated tooth numbering on panoramic radiographs: A scoping review

Purpose

The objective of this scoping review was to investigate the applicability and performance of various convolutional neural network (CNN) models in tooth numbering on panoramic radiographs, achieved through classification, detection, and segmentation tasks.

Material and Methods

An online search was performed of the PubMed, Science Direct, and Scopus databases. Based on the selection process, 12 studies were included in this review.

Results

Eleven studies utilized a CNN model for detection tasks, 5 for classification tasks, and 3 for segmentation tasks in the context of tooth numbering on panoramic radiographs. Most of these studies revealed high performance of various CNN models in automating tooth numbering. However, several studies also highlighted limitations of CNNs, such as the presence of false positives and false negatives in identifying decayed teeth, teeth with crown prosthetics, teeth adjacent to edentulous areas, dental implants, root remnants, wisdom teeth, and root canal-treated teeth. These limitations can be overcome by ensuring both the quality and quantity of datasets, as well as optimizing the CNN architecture.

Conclusion

CNNs have demonstrated high performance in automated tooth numbering on panoramic radiographs. Future development of CNN-based models for this purpose should also consider different stages of dentition, such as the primary and mixed dentition stages, as well as the presence of various tooth conditions. Ultimately, an optimized CNN architecture can serve as the foundation for an automated tooth numbering system and for further artificial intelligence research on panoramic radiographs for a variety of purposes.

Influence of the amount of saliva deposition and time elapsed after deposition on bite mark analysis

Bite mark analysis is among the most interesting research fields in forensic odontology; however, it is limited by its dependence on the employed method as well as assessor subjectivity, particularly when using morphological analysis or DNA profiling. These limitations are due to differences in DNA collected from saliva adhering to a living or inanimate body, as well as differences in exocrine fluid secretion and deposition amount among individuals. This study aimed to analyze the effectiveness of DNA profiling when there are differences in the amount of saliva adhering to a living body and when time has elapsed since deposition. Most allele peaks could be identified in 1 µl of saliva, even 9 h after saliva deposition and examination. Consistent results were obtained following saliva deposition in an individual who had engaged in up to 9 h of free activity. The results of this study demonstrate the validity and reliability of DNA profiling for bite mark analysis and are extremely important as they can demonstrate the usefulness of the little information left by a suspect on a victim's body.

[Forensic dentistry for identity verification. A survey at the state police level]

BACKGROUND

In Germany, the identification of unknown dead persons is the responsibility of the police. According to INTERPOL standards, primary (e.g., DNA, fingerprints, and teeth) and secondary (e.g., tattoos) characteristics are examined. Forensic dentistry is already used internationally as an efficient method. In this study, the approach of state police in Germany was analyzed. The methods used for identification, the role of forensic dentistry, the cooperation with dentists, and possible optimization approaches are investigated.

METHODS

By means of a digital questionnaire, police officers competent in all federal states for the discovery of unknown dead bodies were asked about identification methods and specifically about the use of forensic dentistry.

RESULTS

Eighty-five officers from at least 11 federal states participated in the survey. The procedure turned out to be department specific. In 72.6% of the cases, different characteristics are combined in the identification process, most frequently DNA with dental status (37.1%). DNA analysis is used most frequently. Of the respondents, 62.9% agreed that dental identification is used "often." The percentage of identifications using dental status is estimated to be 1.6-8.1%. For forensic dentistry, 19.4% have a fixed point of contact. A digital platform to contact dentists was estimated to be helpful by 56.5%.

DISCUSSION

Forensic dentistry is currently still lagging behind DNA analysis, which could change through increasing digitalization if, for example, ante-mortem data are more reliably available and platforms for interdisciplinary exchange are created.

Maintenance of dental records and awareness of forensic odontology among pakistani dentists: a mixed-method study with implications for dental data repository

OBJECTIVE

Dental records and forensic odontology play an important role in both healthcare and the legal system, aiding in personalized patient care, human identification, and legal proceedings. This study aims to investigate dental record-keeping practices and assess the awareness of forensic odontology among Pakistani dentists over 12 months. This study aims to collect data from 500 dentists, identify areas for enhancement, and develop a strategic action plan to improve record-keeping quality and forensic odontology application, culminating in a comprehensive dental data repository to support legal and criminal investigations in Pakistan.

METHODOLOGY

This study employed a mixed-method approach conducted at Hamdard Dental College from January to March 2023. The quantitative phase involved distributing questionnaires to 463 dentists, chosen through stratified random sampling. Out of these, 413 responded, yielding an 86% response rate. These questionnaires focused on dental record-keeping practices and dentists' awareness of forensic odontology. Subsequently, based on the questionnaire results, face-to-face interviews were conducted with 20 purposively selected dentists to gain deeper insight into the challenges and potential solutions. Data from both phases were integrated and analyzed accordingly.

RESULTS

The study included 413 participants, mainly females (79%), with ages ranging from 27 to 65 years and an average age of 46.4 years. Most dentists had 5-20 years of work experience (53%), and most (87.4%) were practicing in private clinical settings. All the dentists generated medical and dental records, but the duration of their record-keeping varied, with some maintaining them for up to a year and others for two years or longer. Five themes were generated from the qualitative content analysis. These themes were dentists' perceptions, barriers and challenges, knowledge and awareness, and improvement strategies.

CONCLUSION

Our study revealed that local practitioners in Pakistan exhibit subpar practices in dental record-keeping and maintenance of patient history, irrespective of whether they use a digital or traditional file-based system. Even though dentists are cognizant of the importance of record-keeping, they do not actively maintain comprehensive records. This suggests the need for improved training and system improvements to address the gaps in record-keeping practices.

3D-3D dentition superimposition for individual identification: A study of an Eastern Chinese population

Recently, 3D dental intraoral scanning technology has been developed rapidly and applied widely in everyday dental practice. Since 3D dental scanning could provide valuable personal information, it enabled researchers to develop novel procedures for individual identification through 3D-3D dentition superimposition. This study aimed to test the applicability of this method in an Eastern Chinese population and propose a threshold for personal identification. For this purpose, 40 volunteers were recruited, and the initial 80 (upper and lower) 3D intraoral scans (IOS) were collected. After one year, 80 IOS of these volunteers were repeatedly collected. In addition, the other 120 IOS of 60 patients were extracted from the database. The 3D models were trimmed, aligned, and superimposed via Geomagic Control X software, and then the root mean square (RMS) value of point-to-point distance between the two models was calculated. The superimposition of two IOS belonging to the same individual was considered as a match, and superimposition of two IOS belonging to different individuals was considered as a mismatch. Totally, superimpositions of 80 matches and 3120 mismatches were obtained. Intra- and inter-observer errors were assessed through the calculation of relative technical error of measurement (rTEM). Mann-Whitney U test verified possible statistically significant differences between matches and mismatches (P < 0.05). The rTEM of intra- and inter-observer repeatability analyses was lower than 4.7 %. The range of RMS value was 0.05-0.18 mm in matches and 0.72-2.28 mm in mismatches without overlapping. The percentage of accurate identification reached 100 % in blind test through an arbitrary RMS threshold of 0.45 mm. The results indicated that individual identification through the 3D-3D dentition superimposition was effective in Eastern Chinese population. Successful identification could be achieved with high probability when the RMS value of the point-to-point distance of two dentitions is <0.45 mm.

Preparedness toward participation in disaster management: An online survey among dental practitioners in a disaster-prone region of Eastern India

BACKGROUND

Dentists are often overlooked resources in the workforce for disaster management (DM). To determine the knowledge, attitudes, willingness, and self-perceived effectiveness to participate in DM among general dental practitioners (GDPs) of Eastern India.

MATERIALS AND METHODS

A web-based online survey was conducted among 256 Dental Council of India registered GDPs of Cuttack district, Odisha. The 45-item survey comprised closed-ended questions on the demographic data of the participants, years of practice, previous experience in DM, and willingness to participate. Other domains assessed were the participants' objective knowledge of DM, attitude, and self-perceived effectiveness toward participation during disasters. Data were analyzed descriptively, and the Chi-square and Mann-Whitney U tests were used for statistical analysis, with a significance threshold of P < 0.05.

RESULT

A total of 154 responses were analyzed, giving a response rate of 60.16%. The average age was ≤35 years, 59.1% were BDS dentists and 78.6% had less than 10 years of practice. Only 18% of them had previous experience with DM, and merely 3.2% were formerly trained; however, 95.5% of the dentists were willing to participate in DM. The mean DM knowledge and attitude scores were 16.12 (CI = 15.4-16.8) and 5.79 (5.45-6.13), respectively. Knowledge and attitude showed a significant correlation. About 56% indicated that they would be able to respond effectively to a disastrous event. Significant associations were observed between age group (P = 0.008), years of clinical practice (P = 0.001), qualification (P = 0.012), previous participation (P = 0.029), and self-perceived effectiveness.

CONCLUSION

The knowledge regarding DM among respondents was at an average level. However, the majority of them were found to have a positive attitude toward participation in DM. Thus, including DM in dental curricula and drills for dental professionals might prove beneficial as almost all GDPs were showing greater self-perceived effectiveness and willingness to participate in disasters.

Identification of victims of the collapse of a mine tailing dam in Brumadinho

The collapse of the B1 Dam of VALE SA mining company in Brumadinho, Minas Gerais, Brazil was the largest humanitarian disaster and occupational accident in the country's history, and it posed challenges regarding the management and identification of multiple victims. We evaluated the impact of the iron ore tailings on the victims' bodies. We examined the scientific identification of the victims and the dynamics of the disaster over the 1st year after it occurred. We also determined the socio-demographic profiles of the victims. In this retrospective, cross-sectional study, we investigated the expert reports of the victims' biological remains from 25 January 2019 to 25 January 2020. We analysed the socio-demographic data, identification methods, identification status, identification time, and necroscopic information. During the study period, 259 of 270 victims were identified, and 603 biological materials were analysed; among them, 86.2% were body parts and 13.8% were whole bodies. Of the total cases registered that year, 476 (78.9%) were submitted during the first 10 weeks after the disaster. Friction ridge analysis accounted for 67.9% of primary identifications and DNA analysis did so for 91.6% of re-identification cases. Body dismemberment was 3.4 times greater among mine workers than among community victims. Adult males accounted for the greatest number of victims (P < 0.001). Polytraumatic injury was the prevalent single cause of death. Necropsy examination revealed the occurrence of asphyxia in 7% of cases. The higher number of fatalities and greater dismemberment among employees than with community residents underlines the occupational dangers in the mining industry and clarifies the dynamics of the disaster. In the initial weeks after the dam collapsed, friction ridge analysis was the most appropriate method for identification. Subsequently, DNA analysis became the most-used technique for identification and re-identification owing to the great volume of body parts and decomposed biological tissue. Autopsy allowed diagnosis of the causes of death to be clarified according to the Brazilian criminal legal system.

Dental pattern diversity in a military population and its usefulness for assessing the degree of certainty in dental identification

In forensic dentistry, the analysis of dental diversity forms the basis of probability calculations in dental identification. The present study aimed to contribute to the knowledge of dental diversity in a Spanish military population (considering isolated teeth, sets of different numbers of teeth, and combinations of teeth of forensic interest) and its implications for dental identification. A further aim was to compare the performance of three coding systems (detailed, generic, and binary) to assess dental pattern diversity. Dental diversity of a representative sample of the Spanish military population (3920 individuals aged between 18 and 55 years) was calculated according to a genetic (mitochondrial DNA) model in which diversity was defined as the likelihood that two randomly selected individuals in a sample would exhibit different patterns. By performing all pairwise comparisons of dental patterns in the dataset, the total number of matches was generated, and the diversity of dental patterns was then derived. First and third molars were the teeth that showed the highest levels of diversity, and a high diversity value (>0.99) was obtained with only 5 teeth (16, 36, 38, 46, and 48) when detailed coding was used. In addition, dental diversity in the full dentition and posterior teeth exceeded the threshold of 0.99 in all three coding systems. Although a very high diversity value (≥0.999) was only achieved with detailed coding, it should be noted that the generic coding system requires less time and skill to use, and can also provide high diversity values. Our findings show that further efforts should be made to establish large, periodically updated dental datasets of different populations in order to assess dental pattern diversity (without excluding third molars) based on empirical comparison, and to substantiate the certainty of dental identification.

Cadaveric Identification through Macroscopic Analysis of Dental Implants Subjected to High Temperatures-An Experimental Model

The aim of this study was to determine the possibility of identifying a dental implant through the measurement of the apical width and the interspiral distance in a periapical radiograph after being subjected to high temperatures for certain lengths of time. In total, 11 fresh human anatomical models were selected, in which 137 implants were placed. Previous periapical radiographs were performed using parallelizers in each implant. Subsequently, the anatomical models were introduced into a crematory oven at different temperatures and for various durations: 500 °C/15 min, 500 °C/30 min, 700 °C/15 min, 800 °C/15 min, 800 °C/45 min, 500 °C/15 min, 700 °C/15 min, and finally, 1000 °C/120 min. After this, X-rays were taken via a parallel technique, and the apical width and interspiral distance were measured. The implants were disinserted, and the coronal width was used to calculate magnification or possible distortion. All data were analyzed by the Mann-Whitney U test. There were no statistically significant differences for the apical width parameter, except when the temperature was raised to 700 °C/15 min and to 800 °C/45 min. For the interspiral distance parameter, there were no statistically significant differences, except when the implants were subjected to 800 °C/15 min and 1000 °C/120 min. It was determined that there were changes in some groups based on the increase in temperature and exposure time. Neither of the two parameters were completely useful for the identification because some of the groups studied in both variables presented differences, which makes them difficult to identify correctly.

Implementation of a personal identification system using alveolar bone images

OBJECTIVE

In recent years, personal identification has been performed using antemortem panoramic X-ray images and postmortem-CT images. Using these, we have developed a personal identification method that focuses on the alveolar bone. This study examined the effectiveness of this method and aimed to implement a reproducible system.

MATERIALS AND METHODS

For personal identification, a total of 633 CT images and panoramic X-ray images belonging to three groups with different conditions were used.　These images were 160 sets in the same person group and 96,820 in the other groups. The similarity of alveolar bone images was calculated using the landmark method of Procrustes analysis. The processes were system implemented and the methodology was validated.

RESULTS

The ability to identify between the same person group and other person groups showed 0.9769 as the area under the curve (AUC: ROC curve). At the cutoff value of 4.978, there was no false rejection rate, but false acceptance rate was slightly higher.

CONCLUSION

This method was useful as a screening method for personal identification. In addition, system implementation was efficient and reduced human error. In the future, we aim to realize a more efficient personal identification method using distortion-corrected images and including auto-detective landmarks using deep learning.

Palatal Rugae Patterns in Fars, Turkmen, and Sistani Ethnicities in the Eastern Part of the Caspian Littoral of Iran

In forensic medicine, it is important to identify whole or fragmented bodies. This aim can be particularly challenging in mass disasters. Palatal rugae patterns can be used as a surrogate parameter in forensic medicine. This stems from the difficulty in falsifying these patterns, their resistance to trauma, to decomposition for several days postmortem, and to combustion under high-temperatures, as well as being distinguishable among different races. The present study aimed to analyze the differences in the palatal rugae patterns among three Iranian ethnicities (Fars, Turkmen, and Sistani). This retrospective study involved the use of archived materials. The study casts were selected from the database of patients who visited a private orthodontics clinic. A total of 309 dental casts (103 Fars, 103 Turkmen, and 103 Sistani) were assessed, which belonged to 181 females and 128 males aged between 12 and 30 years (mean: 16.86 ± 3.18 years). The difference in the mean number of palatal rugae in women between the three ethnicities was statistically significant. Also, the differences in the total number of straight rugae were significant between the three ethnic groups. The most common rugae shapes in the three ethnic groups were the straight and wavy shapes. The length of the palatal rugae in the primary and secondary rugae among the study subjects younger than 18-years-old was significantly different between the three ethnic groups. Thus, the present research highlighted the differences in palatal rugae patterns among three Iranian ethnicities. Therefore, palatal rugae can be used in forensic medicine as a complementary approach to human identification.

Dental hygiene students' matching accuracy when comparing antemortem dental radiographs and oral photographs to simulated postmortem WinID3® odontograms

Matching dental antemortem (AM) and postmortem (PM) data for human identification is especially challenging when the workforce is limited. Dental hygienists have served mass fatality incidents (MFIs) due to dental-related expertise. However, forensics within dental hygiene education and research on transferable skills is limited. This qualitative balance design study assessed senior dental hygiene students' match accuracy of simulated cases varying in dental identifiers based on AM full mouth series (FMS) radiographs and oral photographs to PM WinID3^® odontograms to demonstrate possible disaster victim identification (DVI) transferable skills gained during formal education. A convenience sample of senior dental hygiene students (n = 31) was presented information on WinID3^® interpretation, then presented with 5 mismatched cases and asked to visually interpret each to make 10 total matches; five based on AM FMS with simulated PM WinID3^® odontograms and five based on AM photographs with PM WinID3^® odontograms. Match accuracy scores ranged from 41.9% to 58.1% for cases with 1-10 identifiers, and 77.4% to 93.5% for cases with 11-40 identifiers. Accuracy when matching AM radiographs to PM odontograms versus AM photographs to PM odontograms was compared and revealed no statistical differences in match accuracy depending on image type (p = 0.388 to 1.000). Results of this pilot study suggests transferable match accuracy skills resulted from the participants' dental hygiene formal education. These baseline skills with additional specialized training support the rationale for dental hygienists serving on DVI teams. More research is needed in education and practice when preparing dental hygienists for forensic-based service.

Dental age estimation by cementum incremental lines counting: A systematic review and meta-analysis

The estimation of dental age by cementum incremental lines (CIL) is a widely investigated method; however, its reliability remains uncertain. The aim of this article was to assess whether CIL are a reliable biological indicator for estimating dental age. A search was performed in Embase, LILACS, PubMed/MEDLINE, SciELO, Scopus and Web of Science databases using a combination of terms related to the topic. Two independent reviewers used inclusion and exclusion criteria so that relevant articles were selected and evaluated. For the risk of bias analysis, a checklist from The Joanna Briggs Institute was applied. For the meta-analysis, Pearson's Correlation Coefficient between chronological age and estimated age was considered as an effect measure. The heterogeneity of studies was assessed using the Cochran's Q statistical test (p < 0.05), and the publication bias using the asymmetry of the Funnel plot and Egger's linear regression test (p < 0.05). Most selected articles had low risk of bias. Although not all studies were included in the meta-analysis, it demonstrated the presence of high heterogeneity among them. Despite this, the synthesized result indicated that the age estimated by CIL count has a high correlation with chronological age. Furthermore, the graphical analysis suggested the absence of publication bias, which was confirmed by the Egger's linear regression test. Therefore, there is scientific evidence that CIL are reliable in estimating dental age, but the method requires a standardized protocol to be followed, as well as the rigorous choice of the root area to be analyzed.

A guide to classify tattoo motives in Mexico as a tool to identify unknown bodies

Justification

In Mexico, the number of unidentified bodies has been steadily rising for years. By now, more than 50,000 bodies are considered unidentified. Forensic laboratories that could perform comparative molecular genetic investigation are often overburdened and examinations can take months. Therefore, pragmatic approaches that can help to identify more unknown bodies must be sought. The increased use of distinctive physical features might be one, and the high rate of tattooed people in Mexico points towards a great potential of tattoos as a tool for identification. The prerequisite for a comparison of antemortem (missing persons) and postmortem (unknown bodies) data is an objective description of the particularities, e.g., of the tattoos. The aim of this study was to establish an objective classification for tattoo motives, taking into consideration local preferences.

Methods

In the database of the medicolegal services of the Instituto Jaliscience de Ciencias Forenses (IJCF) in Guadalajara, postmortem data of 1000 tattooed bodies from 2019 were evaluated. According to sex and age, the tattooed body localization and the tattoo motives were categorized.

Results

The 1000 tattooed deceased showed tattoos on 2342 body localizations. The motives were grouped and linked to the following 11 keywords (with decreasing frequency): letters/numbers, human, symbol (other), plant, symbol (religious), animal, object, fantasy/demon/comic, tribal/ornament/geometry, other, unrecognizable.

Conclusion

Using the proposed classification, tattoo motives can be described objectively and classified in a practical way. If used for antemortem (missing persons) and postmortem (unknown bodies) documentation, motives can be searched and compared efficiently—helping to identify unknown bodies.

Automatic detection of teeth and dental treatment patterns on dental panoramic radiographs using deep neural networks

Disaster victim identification issues are especially critical and urgent after a large-scale disaster. The aim of this study was to suggest an automatic detection of natural teeth and dental treatment patterns based on dental panoramic radiographs (DPRs) using deep learning to promote its applicability as human identifiers. A total of 1 638 DPRs, of which the chronological age ranged from 20 to 49 years old, were collected from January 2000 to November 2020. This dataset consisted of natural teeth, prostheses, teeth with root canal treatment, and implants. The detection of natural teeth and dental treatment patterns including the identification of teeth number was done with a pre-trained object detection network which was a convolutional neural network modified by EfficientDet-D3. The objective metrics for the average precision were 99.1% for natural teeth, 80.6% for prostheses, 81.2% for treated root canals, and 96.8% for implants, respectively. The values for the average recall were 99.6%, 84.3%, 89.2%, and 98.1%, in the same order, respectively. This study showed outstanding performance of convolutional neural network using dental panoramic radiographs in automatically identifying teeth number and detecting natural teeth, prostheses, treated root canals, and implants.

It is useful to use dental panoramic radiographs to perform the disaster victim identification (DVI).

Dental Radiographic/Digital Radiography Technology along with Biological Agents in Human Identification

The heavy casualties associated with mass disasters necessitate substantial resources to be managed. The unexpectedly violent nature of such occurrences usually remains a problematic amount of victims that urgently require to be identified by a reliable and economical method. Conventional identification methods are inefficient in many cases such as plane crashes and fire accidents that have damaged the macrobiometric features such as fingerprints or faces. An appropriate recognition method for such cases should use features more resistant to destruction. Forensic dentistry provides the most appropriate available method for the successful identification of victims using careful techniques and precise data interpretation. Since bones and teeth are the most persistent parts of the demolished bodies in sudden mass disasters, scanning and radiographs are unrepeatable parts of forensic dentistry. Forensic dentistry as a scientific method of human remain identification has been considerably referred to be efficient in disasters. Forensic dentistry can be used for either "sex and age estimation," "Medical biotechnology techniques," or "identification with dental records," etc. The present review is aimed at discussing the development and implementation of forensic dentistry methods for human identification. For this object, the literature from the last decade has been searched for the innovations in forensic dentistry for human identification based on the PubMed database.

Effect of cranium structure on dose distribution during intraoral radiography

OBJECTIVES

This study aimed to evaluate, the effect of the cranium structure on dose distribution by measuring the dose using the RANDO phantom for safe use of an X-ray unit during personal identification work at a large-scale disaster site.

METHODS

As the subject, the head and neck of the RANDO Phantom (Alderson) containing a dry skull composed of a tissue-equivalent substance and having a shape similar to that of a living body were studied. With the body in the supine position, the air doses per second of irradiation time were measured for a total of six sections of the anterior, premolar, and molar teeth (molar on the left side) at a tube voltage of 60 kV and tube current of 10 mA during maxilla and mandible intraoral radiography.

RESULTS

The region having the highest exposure dose was the main X-ray direction in both the mandible and maxilla. Conversely, the dose tended to be low in the range from the temporal region to the occipital region on both sides of the horizontal plane, from the frontal region to the occipital region of the sagittal plane, and in the parietal region of the frontal plane.

CONCLUSIONS

It would be preferable to examine from the top of the body where the dose tends to decrease for all imaging sites.

Not so simple: Understanding the complexities of establishing identity for cases of unidentified human remains in an Australian medico-legal system

Discussions regarding the importance and complexities associated with the identification of deceased persons have typically focused on disaster or humanitarian contexts where there has been large scale loss of life. In contrast, identification efforts for unidentified human remains (UHR) cases in routine domestic casework contexts have received relatively little attention. The aim of this paper was to present the situation regarding the count of UHR cases in the state of Victoria, Australia, dating between 1960 and 2020, and to provide a constructively critical appraisal of the factors that have, and continue to, hinder their identification. Over the six decades a total of 132 coronial cases remained unidentified; an average of 2-3 cases per annum. For each case, the preservation of the remains, geographical location of where they were recovered from, primary (fingerprints, dental, DNA) and secondary identification methods that had been employed, potential for additional identification testing and current curation of the remains, were recorded. The difficulty with providing a "total count" of UHR cases is discussed, as well as the ways in which preservation, availability of identification methods, changes in policies and procedures, record management, changes in practice and advancements in technology, have impacted the identification process. This paper demonstrates the complexity of the investigation of UHR cases, and why individuals continue to remain unidentified in 2021.

Explosion-related deaths: An overview on forensic evaluation and implications

Purpose

Explosion-related deaths are uncommon events which require expertise and confidence so that an appropriate death investigation can be performed. The present study aims to provide a detailed forensic analysis of the issues and implications arising in the event of an explosion.

Methods

A retrospective review of casualty data was conducted on electronic literature databases. Cases concerning deadly explosions registered at the Milan Institute of Legal Medicine were examined and analyzed altogether.

Results

Explosions may involve closed or open systems. A security assessment of the site is always necessary. Alterations of the site due to rescue procedures can occur; thus, on-site forensic investigation should be adapted to the environment. Then, a study protocol based on autopsy procedures is presented. Application of the postmortem radiology enforces forensic procedures both for the analysis of blast injuries and skeleton fractures, and for identification purposes. Blast injuries typically cause lacerations of the lungs, intestine and major vessels; moreover, hyoid fractures can be documented. Histopathology may help to define blast injuries effectively. Forensic chemistry, toxicology and ballistics provide useful investigative evidence as well as anthropology and genetics. Different forensic topics regarding explosions are discussed through five possible scenarios that forensic pathologists may come across. Scenarios include self-inflicted explosion deaths, domestic explosions, work-related explosions, terrorist events, and explosions caused by accidents involving heavy vehicles.

Conclusion

The scenarios presented offer a useful instrument to avoid misinterpretations and evaluation errors. Procedural notes and technical aspects are provided to the readers, with an insight on collaboration with other forensic experts.

When DNA profiling is not enough? A case of same-sex siblings identification by odontological assessment after gas explosion-related building collapse

We aimed to show the usefulness of odontological assessment in forensic investigation. Charred remains of two female siblings were found in a collapsed building after a gas explosion. Due to thermal damage of the bodies, the facial characteristics, fingerprints, height and weight could not be used to distinguish between siblings. Since the victims, 4 and 10-year-old, died simultaneously and all personal belongings were lost, DNA profiling performed with their parents only confirmed the relationship. As dental charts of siblings were not found, we could not easily discriminate which remains would be of the elder and which of the younger sister. The odontological examination enabled us to discriminate between the siblings based on differences in deciduous and permanent dentition. We conclude that although DNA profiling is becoming a standard method of personal identification in some cases it should be supported by additional methods to deliver comprehensive forensic reports.

[Skull-facial anthropometric traits of forensic odontological interest for estimating sex, race and age. Review of the literature]

One of the main functions of anthropologists and forensic dentists is to identify subjects according to physical characteristics of the features presented using non-routine methods. These characteristics, especially bone, allow professional to determine the sex, age and racial origin of the remains or skeleton found. Dentist focus on features belonging to the stomatognathic system, while anthropologists study the bones that make up the human body. In this study, we describe the investigations of cranio-facial anthropometric features of dental interest carried out by anthropologists to identify the sex, race and age of skeletal remains or skeletons. in addition, we describe the so-called dental anthropology that studies the elements of the stomatognathic system from an anthropological point of view. Electronic literature was reviewed through search engines such as PUBMED, Google Academic and SciELO with the search terms "Forensic Dentistry, Forensic Anthropology, Sex Determination, Ancestry Determination and Age Determination". Knowledge of the craniofacial anthropological features from the forensic point of view is of great importance in individualized and multidisciplinary studies by forensic dentists and anthropologists in the identification of skeletal remains.

Comparison of data mining algorithms for sex determination based on mastoid process measurements using cone-beam computed tomography

Purpose

The mastoid region is ideal for studying sexual dimorphism due to its anatomical position at the base of the skull. This study aimed to determine sex in the Iranian population based on measurements of the mastoid process using different data mining algorithms.

Materials and Methods

This retrospective study was conducted on 190 3-dimensional cone-beam computed tomographic (CBCT) images of 105 women and 85 men between the ages of 18 and 70 years. On each CBCT scan, the following 9 landmarks were measured: the distance between the porion and the mastoidale; the mastoid length, height, and width; the distance between the mastoidale and the mastoid incision; the intermastoid distance (IMD); the distance between the lowest point of the mastoid triangle and the most prominent convex surface of the mastoid (MF); the distance between the most prominent convex mastoid point (IMSLD); and the intersecting angle drawn from the most prominent right and left mastoid point (MMCA). Several predictive models were constructed and their accuracy was compared using cross-validation.

Results

The results of the t-test revealed a statistically significant difference between the sexes in all variables except MF and MMCA. The random forest model, with an accuracy of 97.0%, had the best performance in predicting sex. The IMSLD and IMD made the largest contributions to predicting sex, while the MMCA variable had the least significant role.

Conclusion

These results show the possibility of developing an accurate tool using data mining algorithms for sex determination in the forensic framework.

Human identification: a review of methods employed within an Australian coronial death investigation system

Whilst many identification methods have been widely described and discussed in the literature, and considered in disaster and humanitarian contexts, there has been limited reporting and evaluation of the identification methods used in domestic medico-legal death investigation contexts. The aim of this study was to evaluate the identification methods utilised at the Victorian Institute of Forensic Medicine (VIFM), which forms part of a coronial medico-legal death investigation system. The method of identification and time taken to complete the identification were reviewed for all cases admitted to the VIFM over a five-year period from 1 July 2015 to 30 June 2020. The majority, 91%, of individuals admitted to the VIFM were visually identified. The remaining 9% of cases required identification by primary methods (i.e. fingerprints, DNA or dental) or, when those methods were not possible, by secondary methods (i.e. circumstantial). Visual identifications were the timeliest, taking an average of 1.5 days, whilst primary identification methods required an average of 5 days to complete. The triaging of identification methods, dependent on the case context, body preservation, availability of ante-mortem data, legal requirements and admissibility of the method, are determined by identification coordinators within the Human Identification Service (HIS) to ensure the most appropriate and timely method is employed. This review of human identification methods provides the foundation for future analyses to compare workflow processes and improve identification methods utilised in domestic medico-legal contexts.

Forensic odontology identification response to terrorist attacks in Paris November 2015

The terrorist attacks of November 2015 led to the immediate death of 129 victims admitted to the Legal and Forensic Medicine Institute of Paris, including 41 unidentified. During the Disaster Victim Identification (DVI) operations, 22 bodies were examined by the postmortem (PM) dental team with the aim of establishing PM odontograms. At the same time, the dental expert in the antemortem (AM) unit collected a large number of dental files, progressively filtered as the list of missing persons became reduced. Feedback from these events has highlighted the difficulties of implementing the DVI chain principles in a legal framework, published the day before the attacks, and also the technical complexity of collecting dental data on a week end of terror. The return on experience after this event has represented a paradigm shift on previous methods of DVI in Paris and even more in France. Indeed, the victim identification procedure was redesigned, integrating new technical means such as a CT scan directly on spot, allowing the extraction of maxillofacial data as soon as possible in order to support the PM dental examination team. Moreover, the National Dental Council proceeded to the overall remodeling of the dental identification unit, which is composed of trained members, from local, regional and national aspects. These forensic experts are dedicated, at the request of the legal authorities, to DVI operations and deployed throughout the country capable of managing AM and PM data. This unit aims also to share experiences and awareness-raising among health professionals and investigators in order to optimize a better submission of AM elements and also to enhance the major interest of odontology as a primary identifier in disaster.

The use of tattoos to identify unknown bodies

The identification of unknown bodies is the fulfilment of a moral obligation towards the deceased, serves to maintain legal security within a society, and gives families the certainty they need to mourn. Taking into account respective local conditions, the aim should always be to achieve a secure and quick identification. To achieve this goal, a functioning cooperation between investigating authorities and forensic sciences is essential.

The main objective of this study was to clarify the potential role of tattoos in the identification process of unknown deceased persons in the state of Jalisco, Mexico. Post-mortem data of 2045 bodies from the Instituto Jaliscience de Ciencias Forenses in Guadalajara were evaluated.

Of the deceased 46% were tattooed (male: 47%, female: 39%), with 29% of all bodies (male: 29%, female: 26%) showing tattoos at body locations usually visible in everyday life (i.e. head and neck, forearms and hands). The male bodies were most frequently tattooed on the shoulders and upper arms, followed by the forearms and hands and the torso. Female bodies mostly showed tattoos on the forearms and hands, followed by the torso and legs.

Taking local tattooing habits into account, the authors developed a classification for tattoo motives. With decreasing frequency, the following keywords could be assigned to the motives: letters and/or numbers, human, symbol (other), plant, symbol (religious), animal, object, tribal/ornament/geometry, fantasy/demon/comic, other.

Results of the study indicate the great importance of tattoos as a possible mean of identification in Jalisco, Mexico – either as a stand-alone identification method, as a complementary tool or for planning and prioritizing subsequent investigations.

Modern advances in disaster victim identification

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