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.

3D segmentation of dental crown for volumetric age estimation with CBCT imaging.

In adult dental age estimation, segmentation of dental volumetric information from different tooth parts using cone-beam computed tomography (CBCT) has proven beneficial in improving the regression model reliability. This segmentation method can be expanded in the crown part since the volumetric information in the crown is affected by attrition in the enamel and secondary dentine in the dentine and pulp chamber. CBCT scans from 99 patients aged between 20 and 60 were collected retrospectively. A total of 80 eligible teeth for each tooth type were used in this study. The enamel to dentine volume ratio (EDVR), pulp to dentine volume ratio (PDVR) and sex were used as independent variables to predict chronological age (CA). The EDVR was not affected by PDVR. The highest R2 was calculated from the maxillary canine (R2 = 0.6). The current approach in crown segmentation has proven to improve model performance in anterior maxillary teeth.

Exploring the degrees of distortion in simulated human bite marks.

The properties of the skin and the posture of the body during photographic recording are factors that cause distortion in the bite mark injury. This study aimed to explore the degree of distortion between a 'touch mark' (method 1) and a 'bite mark' (method 2) on the left upper arm at three different positions (arm relaxed; arm flexed in two different positions). A pair of dental casts with biting edges coated in ink was used to create a mark in 30 subjects (6 ♂, 24 ♀) aged 20-50 years old. Photographs were taken using a Nikon DX digital camera (D5000). The mesiodistal widths and angle of rotations of both upper right central incisor and lower right central incisor and the inter-canine distances were analysed and compared with the true measurements using Adobe Photoshop CC 2017. Statistical analysis was carried out using SPSS Statistics 22 applying a 2 (mark type) × 3 (position) repeated measures ANOVA. For all measures studied, there was a statistically significant difference between mark types and positions. In the case of bite marks, a great degree of distortion was detected, and this increased further when changing the position of the arm. The findings demonstrated that skin properties and posture influence distortion. This could lead to inaccurate measurements and misleading pattern interpretation of bite mark injuries.

Testing the London atlas for age estimation in Thai population.

Objectives: To test the London atlas for dental age (ADA) estimation in Thai population.Materials and methods: The London atlas for age estimation was tested in 111 digital panoramic radiographs of children (57 ♂ and 54 ♀) aged between 4.00 and 15.99 years. The difference between chronological age (CA) and ADA was investigated using a paired subjects t-test. The significance of the difference between CA and ADA was tested using the F-tests of the one-way ANOVA. The analysis of variance considered the effects of sex, age group and the interaction between sex and age group. Other analyses included the difference of ADA by age group and the comparison between CA and ADA by sex. SPSS Statistics 24 was used for all analyses (SPSS Inc., Chicago, IL).Results: ADA correlated to CA with a discrepancy of 1.3 years maximum. There was no significant effect of sex (F (1, 87)=0.278, p = .600), age group (F (11, 87)=1.032, p = .426) and sex and age group (F (11, 87)=1.238, p = .275) between CA and ADA.Conclusions: The estimates of dental ages correlate and reasonably reflect the CAs of Thai children and adolescents for both males and females from age 4.00 to age 15.99.

Age estimation using canine pulp volumes in adults: a CBCT image analysis.

Secondary dentine deposition is responsible for the decrease in the volume of the pulp cavity with age. Therefore, the volume of the pulp cavity can be considered as a predictor for estimating age. The aims of this study were to investigate the relationship strength between canine pulp volumes and chronological age from homogenous (approximately equal numbers of individuals in each age range) age distribution and to assess the effect of sex as predictor in age estimation. This study was performed on 719 subjects of Pakistani origin. Cone beam computed tomography images of 521 left maxillary and 681 left mandibular canines were collected from 368 females and 349 males aged from 15 to 65 years. Planmeca Romexis® software was used to trace the outline of the pulp cavity and to calculate pulp volumes. Regression analysis was performed to assess the correlation between pulp volumes considering with and without sex as a predictor with chronological age. The obtained results showed that mandibular canine pulp volume and sex have the highest predictive power (R2 = 0.33). The relationship between mandibular canine pulp volume and sex with chronological age demonstrates an odd S-shaped non-linear relationship. A statistically significant difference in volumes of pulp was found (p = 0.000) between males and females. The conclusion was that predictions using the pulp volume of the mandibular canine and sex produced the best estimates of chronological age.

Discussing a Forensic Dental Examination of 1861--A Scientific and Historic Overview.

This work is a discussion on a report of dental examination and exclusion made by a British dentist Francis Robertus Lloyd on 30th April 1861. The report entitled: 'Dentistry as a means of Identification' was published in the 'British Journal of Dental Science' under the section 'Miscellanea' in 1861; Mr. Lloyd was contacted by the Indian authorities in order to identify a skull. He may well be the first British dentist to officially report a dental examination in an academic journal. The aims of this discussion are to briefly analyze the difficulties of access to scientific techniques in that century and to provide Mr. Lloyd recognition of his report in the history of Forensic Dentistry.

Biological profiling using the human mandible.

BACKGROUND: In the absence of soft tissue, skeletal remains are analyzed to identify the deceased. This assessment involves establishing the biological profile that aids medicolegal investigations and fulfils the right of the dead to be identified. Since the mandible is the strongest bone in the skull and easily identifiable, even when fragmented, this study aimed to systematically review its value in constructing the biological profile in the published literature. We searched PubMed, ScienceDirect, Scopus, and Latin American and Caribbean Health Sciences Literature and collected cross-sectional studies published in English before 2021. A risk of bias assessment was completed based on Joanna Briggs Institute's critical appraisal tools. The data are presented descriptively and were analyzed using Microsoft Office Excel 365. HIGHLIGHT: Of the 104 eligible articles, 94 examined the sexual dimorphism of the mandible, while 25 attempted to estimate age. Ancestry and stature were the least explored biological characteristics (five and one articles, respectively). A metric analysis was the most common approach (n = 80), followed by morphological analysis and combined morphologic and metric techniques (n = 18 and n = 6, respectively). The results showed no statistically significant correlation between an individual's mandible and stature. Orthopantomogram radiography continues to be the most common radiographic technique for assessing the mandible. CONCLUSION: The mandible is reliable when used for sex estimation; however, caution should be exercised in relying solely on it for morphological assessments. This review provides guidance on estimating age, sex, and ancestry directly from mandibular specimens or radiographs.

A scoping review of websites for forensic odontology training programs.

BACKGROUND: Forensic Odontology developed as a discipline in 1898 with the publication of its first textbook; however, 126 years later, a standardised core curriculum for formal training in Forensic Odontology has yet to be decided. This website scoping review aims to provide information on three main distinct categories (and 17 subcategories): Availability, Content, and Quality of Forensic Odontology education globally. The information on formal education programmes was gathered by conducting a web search using 'Google Search' in English, Arabic, Spanish, and French languages between June and July 2022. HIGHLIGHTS: Fifty-six programmes from 18 countries met the inclusion criteria. Of the 14 master's and 42 diploma programmes, only 7.14% provided information on their websites from all the subcategories investigated. The highest numbers of master's and postgraduate diploma programmes were identified in Europe (18 programmes), South America (15), North America (11) and Asia (7). A practical aspect was included by 10 master's and 12 diploma programmes' websites. Research integration in various forms was included by 11 master's and seven diploma programmes. CONCLUSION: Programme providers and applicants must critically consider the quality of the programme being designed or applied to as there are currently no international training standards in Forensic Odontology. This study has developed an 'International Database of Forensic Odontology Programmes' (IDFOP).

Binary decisions of artificial intelligence to classify third molar development around the legal age thresholds of 14, 16 and 18 years.

Third molar development is used for dental age estimation when all the other teeth are fully mature. In most medicolegal facilities, dental age estimation is an operator-dependent procedure. During the examination of unaccompanied and undocumented minors, this procedure may lead to binary decisions around age thresholds of legal interest, namely the ages of 14, 16 and 18 years. This study aimed to test the performance of artificial intelligence to classify individuals below and above the legal age thresholds of 14, 16 and 18 years using third molar development. The sample consisted of 11,640 panoramic radiographs (9680 used for training and 1960 used for validation) of males (n = 5400) and females (n = 6240) between 6 and 22.9 years. Computer-based image annotation was performed with V7 software (V7labs, London, UK). The region of interest was the mandibular left third molar (T38) outlined with a semi-automated contour. DenseNet121 was the Convolutional Neural Network (CNN) of choice and was used with Transfer Learning. After Receiver-operating characteristic curves, the area under the curve (AUC) was 0.87 and 0.86 to classify males and females below and above the age of 14, respectively. For the age threshold of 16, the AUC values were 0.88 (males) and 0.83 (females), while for the age of 18, AUC were 0.94 (males) and 0.83 (females). Specificity rates were always between 0.80 and 0.92. Artificial intelligence was able to classify male and females below and above the legal age thresholds of 14, 16 and 18 years with high accuracy.

The radiographic diversity of dental patterns for human identification - Systematic review and meta-analysis.

This study aimed to revisit the scientific literature related to the diversity of dental patterns observed in radiographs. The rationale was to find evidence to support dental human identifications. A systematic review was performed following the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P). Strategic search was accomplished in five electronic data sources (SciELO, Medline/Pubmed, Scopus, Open Grey and OATD) were searched. The study model of choice was observational analytical cross-sectional. The search resulted 4.337 entries. The sequential screening based on title, abstract and full-text reading led to 9 eligible studies (n = 5.700 panoramic radiographs) published between 2004 and 2021. Studies from Asian countries were predominant (e.g., South Korea, China, and India). All the studies showed low risk of bias (measured according to the Johanna Briggs Institute's critical appraisal tool for observational cross-sectional studies). Morphological, therapeutic, and pathological identifiers were charted from radiographs to create dental patterns across studies. Six studies (n = 2.553 individuals) had similar methodology and outcome metrics and were included in the quantitative analysis. A meta-analysis was performed and revealed a pooled diversity of the human dental pattern of 0.979 combining maxillary and mandibular teeth. The additional subgroup analysis with maxillary and mandibular teeth have a diversity rate of 0.897 and 0.924, respectively. The existing literature shows that human dental patterns are highly distinctive, especially if morphological, therapeutic and pathological dental features are combined. The diversity of dental identifiers found in the maxillary, mandibular and combined arches is hereby corroborated by this meta-analyzed systematic review. These outcomes support applications for evidence-based human identification.

Volumetric assessment of canines using post-mortem computed tomography (PMCT) for sexual dimorphism in a Malaysian population.

Background: Recent research has explored volumetric assessment in three-dimensional (3D) imaging procedures for sexual dimorphism. The 3D techniques have enabled a more realistic, accurate, and non-invasive visualization of sex-related anatomical parameters, such as the size and shape of human teeth. Aim: To perform sexual dimorphism based on dental tissue volumes of permanent left maxillary and mandibular canines in a Malaysian population. Methods: A cross-sectional study was carried out on 220 post-mortem computed tomography (PMCT) scans of Malaysian subjects (114 males and 106 females) aged between 18 and 40 years old. The permanent left maxillary and mandibular canines were analysed based on the volume of their (I) enamel cap, (II) coronal dentine, and (III) root, as well as the combination between the three dental tissue volumes (DTV). 3D Slicer version 4.10.2 computer software was used to perform a semi-automated segmentation of the anatomic regions of interest of each tooth. Results: The DTV of the permanent left maxillary and mandibular canines showed sexual dimorphism as the males presented larger DTV than females (p < 0.05). After binary logistic regression, the DTV revealed an overall sex classification rate of 60 to 74.1%. The DTV of the permanent left mandibular canine had more discriminant power to correctly classify males and females compared to the left maxillary canine. Conclusions: The volumetric assessment of the dental tissues of the permanent left maxillary and mandibular canines could discriminate sex in the Malaysian population. Given the limited classification rate, this approach could act solely as a supplementary tool to existing sex estimation methods.

CBCT in dental age estimation: A systematic review and meta analysis.

OBJECTIVES: This study aimed to investigate the reproducibility of dental age estimation methods in cone beam computed tomography (CBCT) and the correlation between dental (DA) and chronological (CA) ages. METHODS: The scientific literature was searched in six databases (PubMed, Scopus, LILACS, Web of Science, SciELO, and OATD). Only observational studies were selected. Within each study, the outcomes of interest were (I) the quantified reproducibility of the method (κ statistics and Intraclass correlation coefficient); and (II) the correlation (r) between the dental and chronological ages. A random-effect three-level meta-analysis was conducted alongside moderator analysis based on methods, arch (maxillary/mandibular), population, and number of roots. RESULTS: From 671 studies, 39 fulfilled the inclusion criteria, with one study reporting two different methods. The methods used in the studies were divided into metric (n = 17), volumetric (n = 20), staging (n = 2), and atlas (n = 1). All studies reported high examiner reproducibility. Group 1 (metric and volumetric) provided a high inverse weighted r ([Formula: see text] = -0.71, CI [-0.79,-0.61]), and Group 2 (staging) provided a medium-weighted r ([Formula: see text] = 0.49, CI [0.44, 0.53]). Moderator analysis on Group one did not show statistically significant differences between methods, tooth position, arch, and number of roots. An exception was detected in the analysis based on population (Southeast Asia, [Formula: see text] = -0.89, CI [-0.94,-0.81]). CONCLUSION: There is high evidence that CBCT methods are reproducible and reliable in dental age estimation. Quantitative metric and volumetric analysis demonstrated better performance in predicting chronological age than staging. Future studies exploring population-specific variability for age estimation with metric and volumetric CBCT analysis may prove beneficial.

Exploring the use of selfies in human identification.

BACKGROUND AND AIMS: The comparison of post-mortem evidence to ante-mortem data is the usual approach Forensic Odontologists take in managing human identification cases. Although dental charts and radiographs are widely used as ante-mortem dental evidence, photographs, including non-clinical ones such as selfies are not regarded as such. Therefore, photographs are not regularly assessed in identifying the deceased. This cross-sectional study was aimed to investigate the possible contributions of selfies in human identification and to suggest a structured methodology to assess selfie images with the data collected. MATERIAL AND METHODS: An e-survey composed of five open and seven close-ended questions was designed using JISC Online Surveys program (2020) to explore the opinions of practising Forensic Odontologists and related professionals on the use of photographs and selfies in human identification. Responses to the survey were collected and analysed into descriptive charts and statistics. RESULTS: Eighty-two out of 200 professionals completed their responses (40.8% response rate). 73.2% of them acknowledged that selfies could be used as a main or adjunct evidence in dental identification. Experienced participants in selfies assessed dental anatomy (n = 6), dental restorations (n = 6), craniofacial landmarks (n = 5), oral soft tissues (n = 3), and implement the use of photo-editing software (n = 3) when provided with photographs to analyze using the direct comparison technique. CONCLUSION: It may be concluded that selfies could be supplementary dental ante-mortem evidence. The designing of a step-by-step visual analysis of dental characteristics on a selfie photograph could subsequently be incorporated into official Forensic Odontology association guidelines worldwide. Further research in this area should be carried out along with the advancements in technology.

Regressive changes of crown-root morphology and their volumetric segmentation for adult dental age estimation.

Cone-beam computed tomography (CBCT) enables the assessment of regressive morphological changes in teeth, which can be used to predict chronological age (CA) in adults. As each tooth region is known to have different correlations with CA, this study aimed to segment and quantify the sectional volumes of the tooth crown and root from CBCT scans to test their correlations with the chronological age (CA). Seventy-five CBCT scans from individuals with age between 20 and 60 years were collected retrospectively from an existing database. A total of 192 intact maxillary anterior teeth fulfilled the eligibility criteria. The upper tooth volume ratio (UTVR), lower tooth volume ratio (LTVR), and sex were used as predictor variables. The UTVR and LTVR parameters were both found to be differently correlated to CA and independent from each other. Regression models were derived from each tooth, with the highest R2 being the maxillary lateral incisor (R2  = 0.67). Additional single predictor models using each ratio were capable of reliably predicting the CA. The segmentation approach in volumetric adult dental age estimation proved to be beneficial in enhancing the reliability of the regression model.

Application of the London Atlas Software App 2nd edition for the radiographic assessment of dental development.

Background: Assessing the dental development of children and adolescents is an important part of treatment planning. The radiographic visualization of dental developmental stages prior to age estimation is currently feasible by means of digital software apps. Testing the existing software tools is necessary to safeguard application in practice. This study applied the London Atlas Software App 2nd edition™ for dental age estimation in Brazilian children. Material and Methods: The software was applied to 1.104 digital panoramic radiographs of females (n = 509) and males (n = 595) with ages between 6 and 15.99 years (mean = 10.88 ± 2.84 years). The sample included at least 100 individuals similarly distributed based on sex within 10 age categories of one year each (6├ 15.99) years. Metrics of errors were quantified between the estimated (EA) and chronological (CA) ages. Results: The mean absolute errors among females and males were 0.56 and 0.60 years, respectively (overall = 0.58 years for the combined sample). The lower error values were observed in the age interval of 6 ├ 9.99 years. Error values above one year were detected in older age intervals (10 ├ 15.99 years). Statistically significant differences in dental development were not observed between females and males (p> 0.05). Conclusions: The London Atlas Software App 2nd edition led to specific error rates that can be acceptable for case-specific clinical applications. In the forensic field, caution is advised if the application is planned in the transition between late childhood and early adolescence - when third molars play a major role among the scarce developing teeth. Key words:Brazil, children, dental age estimation, forensic dentistry, radiology.

Diagnostic performance of convolutional neural networks for dental sexual dimorphism.

Convolutional neural networks (CNN) led to important solutions in the field of Computer Vision. More recently, forensic sciences benefited from the resources of artificial intelligence, especially in procedures that normally require operator-dependent steps. Forensic tools for sexual dimorphism based on morphological dental traits are available but have limited performance. This study aimed to test the application of a machine learning setup to distinguish females and males using dentomaxillofacial features from a radiographic dataset. The sample consisted of panoramic radiographs (n = 4003) of individuals in the age interval of 6 and 22.9 years. Image annotation was performed with V7 software (V7labs, London, UK). From Scratch (FS) and Transfer Learning (TL) CNN architectures were compared, and diagnostic accuracy tests were used. TL (82%) performed better than FS (71%). The correct classifications of females and males aged ≥ 15 years were 87% and 84%, respectively. For females and males < 15 years, the correct classifications were 80% and 83%, respectively. The Area Under the Curve (AUC) from Receiver-operating Characteristic (ROC) curves showed high classification accuracy between 0.87 and 0.91. The radio-diagnostic use of CNN for sexual dimorphism showed positive outcomes and promising forensic applications to the field of dental human identification.

Age Estimation Using Monoradicular Teeth by comparing Pulp/Tooth Area Ratios between Bucco-lingual and Mesio-distal Periapical Radiographs.

BACKGROUND: Age estimation is an integral tool in identification of the victims when visual identification is not possible. Secondary dentin deposition is a regular ageing process and can be utilized in dental age estimation when development and eruption parameters cannot be utilized. METHODS: In total, 38 monoradicular teeth of Nepalese subjects were assessed for tooth pulp ratio. Intraoral periapical radiographs of these teeth were taken, and pulp tooth ratio was calculated and dental age was estimated. RESULTS: The mean chronological age was 46.79 years and the mean estimated age was 44.32 years. The pulp/tooth area ratios calculated were in the range of 0.012 to 0.195, and 0.052 to 0.256 for mesio-distal and bucco-lingual planes respectively. CONCLUSIONS: Pulp tooth ratio of maxillary lateral incisors and mandibular lateral incisors showed the highest correlation with values of 90% and 76% respectively. Mesio-distal assessment was more accurate in dental age estimation than bucco-lingual view.

Forensic dental identification using two-dimensional photographs of a smile and three-dimensional dental models: A 2D-3D superimposition method.

Photographs of a person smiling may provide valuable information about their anterior dentition. These images can be an alternative ante-mortem (AM) dental source in cases with no dental records, which gives the forensic odontologist a significant opportunity for comparative dental analysis. There are no reported studies that have investigated the reliability of a superimposition technique using 2D photographs of a smile and 3D dental models in dental identification. The aim of this study was to explore novel odontological methods by combining 2D photographs with 3D dental models, simulating a dental identification scenario. The objective was to increase the accuracy of dental identification using an AM photograph with the aid of 3D imaging as an alternative to post-mortem (PM) photographs. The study comprised of 31 3D dental models (simulating PM information) and 35 digital photographs (simulating AM information). The data was analysed in two phases: Phase I- Visual Comparison of 2D-3D images and Phase II- 2D-3D superimposition after a wash out period. Both methods were analysed by the principal investigator. Further, one-third (ten) of the sample was evaluated by six raters (three experienced forensic odontologists and three forensic odontology MSc. students). The inter-rater agreement was assessed using intra-class correlation (ICC 2, 1, absolute). The results of the study suggest that the inter-rater and intra-rater reliability using 3D superimposition was highest (ICC ≈ 1.0). In summary, there was an increase in match rates and higher certainty among the opinions reached when using the 2D-3D superimposition method. The procedure attempted to reduce the limitations of previously existing 2D methods and is intended to assist forensic experts with an alternative method in dental identification when expressing conclusions on a case using photographs.

Automated Identification from Dental Data (AutoIDD): A new development in digital forensics.

There has been a significant expansion in the use of 3-dimensional (3D) dental images in recent years. In the field of forensic odontology, an automated 3D dental identification system could enhance the identification process. This study presents a novel method for automated human dental identification using 3D digital dental data by utilising a dental identification scenario. The total study sample was divided into two groups: Group A (120 dental models) and Group B (120 Intra-oral scans-IOS). Group A data was composed of 3D scanned dental models of post-orthodontic treated patients (30 maxillary and 30 mandibular). This data was considered as AM digital data. To generate an identical sample, the dental casts (60) of the same patients were retrieved and laser scanned. These models were considered as PM digital data. Group B data (IOS) was obtained from 30 study participants. To reconstruct a dental identification scenario 30 maxillary and 30 mandibular IOS were obtained from 30 participants and were considered as IOS-AM. After one year, another set of IOS (60) were acquired from the same participants and were considered as IOS-PM. The results showed that the AutoIDD (Automated Identification from Dental Data) software was consistent in accuracy; capable of differentiating "correct matches" (high match percentage) from "non-matches" (very low percentage) by 3D image superimposition. The match percentage of the maxillary and mandibular IOS ranged from 64 to 100% and 81-100 %, with a mean distance (mm) of 0.094 and 0.093 respectively. This study demonstrated the feasibility of using 3D scans through a new automated software - AutoIDD in digital forensics to assist the forensic expert in confirming the identity of a deceased individual from the available AM dental records.

Are dental charts (odontograms) obsolete records for comparative dental analysis? / Os odontogramas são registros obsoletos para uma análise dental comparativa?

This communication aims to briefly present the importance of dental charts (odontograms) in the comparative dental analysis for human identification considering the time elapsed between its introduction and the current use in times of rapid technological changes in Dentistry. Future discussions about the rank of importance amongst the different types of dental records are necessary

Esta comunicação tem como objetivo apresentar brevemente a importância dos odontogramas na análise odontológica comparativa para a identificação humana, considerando o tempo decorrido entre sua introdução e o uso atual em tempos de rápidas mudanças tecnológicas na Odontologia. Discussões futuras sobre o grau de importância entre os diferentes tipos de registros odontológicos são necessárias