Ear identification: A multi-ethnic study sample.

The external human ear is considered to be highly variable among individuals. Hence, forensic applications could be explored for human identification. This research compares the usefulness of Cameriere's ear identification method, in samples originating from six different countries (Brazil, India, Japan, Russia, South Africa and Turkey) in order to examine possible differences in their accuracy values. A sample of 2,225 photographs of the external human ear (1,134 left and 1,091 right ears) from 1,411 individuals (633 females and 778 males) was collected. The samples included healthy subjects with no systemic disorders and without any craniofacial trauma, maxillofacial abnormalities, auricular anomalies, ear diseases or previous auricular surgery. Cameriere's ear identification method was applied and measurements were performed on the images of each ear, considering four anatomic regions: helix, antihelix, concha, and lobe. The quantified measurement values were converted into a proposed coded number system. A search for identical codes was accomplished to find out the distinctiveness of the morphology of the human ear. The combined codes of left and right ears of each of the 814 subjects were not repeated in this multi-ethnic study sample. Dirichlet's distribution and the inherent study equation showed that the probability of two different individuals having the same code (false-positive identification) was found to be <0.0007. Because of the distinctive metrics of the ratios of external human ears, studies with Cameriere's ear identification method may be valuable for human identification. Studying the differences between the left and right ears of the same individual and across different ethnic groups could contribute to the development of supplementary tools for human identification.

Use of non-clinical smile images for human identification: a systematic review.

Human identification using Forensic Dentistry occurs through comparative analysis of ante-mortem (AM) and post-mortem (PM) data. With the constant improvement of technology, photographs became a common source of AM data. When clinical dental records are not available, images showing the smile can be useful in human identification. The aim of this study was to investigate human identification techniques through the analysis of smile images in the available literature. Studies on human identification through the analysis of smile images were searched in the scientific literature. The search resulted in 4,043 studies. After screening, 14 studies were considered eligible. Eleven were case reports, two were pilot studies and one a technical note. From the eligible studies, in addition to the methodological data, information about the sample, used techniques and results regarding human identification were extracted. Three techniques were detected: direct comparison of morphological characteristics, AM/PM image overlap, and the analysis of smile lines. One or more associated techniques were used for human identification. Authors highlighted as a common limitation of the techniques the quality of the available images, the difficulty in reproducing PM the same images AM, and the eventual image modifications performed by the victim before posting in social media. Advantages included the low-cost aspect of the technique, as well as a potential fast and accurate procedure (depending on the quantity and quality of evidence). In general, studies considered the technique useful and adjuvant for human identification.

Radiographic changes in endodontically treated teeth submitted to drowning and burial simulations: is it a useful tool in forensic investigation?

Dental radiographs, endodontic treatment and materials are a source of useful forensic data. The response of dental materials to death-related events are widely studied and provide forensic evidence for experts. This study aimed to analyze the radiographic images of endodontically treated teeth submitted to burial and drowning simulation, verifying its forensic feasibility, applicability and usefulness. MATERIAL AND METHOD: n=20 bovine incisor teeth were endodontically treated then divided into two groups: burial and drowning scenarios. Teeth were radiographed two times (before and after scenario) with an aluminium stepwedge, and optical density (OD) was assessed in each root third, in both radiographs, and then compared (ANOVA and Tukey test) for each scenario. RESULTS: Burial scenario did not significantly alter radiopacity. As for the drowning scenario, there was no difference in radiopacity between the root thirds before the test. After drowning, the apical third demonstrated lower OD (p<.05) than the other two thirds. Comparing the OD before and after drowning, medium third presented lower and cervical third demonstrated higher means (p<.05) after drowning. CONCLUSION: We concluded that drowning conditions could alter the radiopacity of endodontically treated teeth, more specifically in the medium and cervical thirds. There is no evidence that this also occurs in burial situations. This has the potential to be useful in forensic casework as an initial sign of the type of ambient in which the body was supposedly exposed or set.

Sex estimation by maxillary sinus using computed tomography: a systematic review.

Sex estimation is an important part of forensic human identification, and when primary methods cannot be applied, forensic anthropology becomes an important auxiliary method of identification. The maxillary sinus may remain intact even if the skull is severely damaged and could thus be used in forensic investigations. The objective of this study was to verify the effectiveness of the evaluation of the maxillary sinus as a technique for sex estimation. Articles published in the past 10 years were searched using PubMed, Web of Science, Scopus, and Cochrane databases, including those that used computed tomography to perform maxillary sinus measurements with the purpose of sex estimation. Studies that used radiographs to perform the measurements were excluded because they do not allow for a three-dimensional analysis. Studies that did not provide information regarding the origin of the analyzed population were also excluded. The selected articles were evaluated for methodological quality according to the indication of the objective, studied population, inclusion and exclusion criteria, parameters for obtaining the computed tomography image, measurements evaluated, bias discussion, and ethical authorization. From the 52 articles found, 18 were included. The populations studied included Indians, Iraqis, Iranians, Egyptians, Brazilians, French, Dutch, and Turkish. Height, width, length, and volume of the maxillary sinus were measured. The maxillary sinus can act as an auxiliary tool for sex estimation in forensic investigations.

Applicability of forensic facial approximation in the recognition process of unclaimed victims.

BACKGROUND: Identifying bodies in a state of putrefaction, skeletonization or mutilation is often difficult. In these cases, it is possible to use auxiliary methods such as forensic facial approximation, considering the possibility of recognition by a relative or acquaintance, helping to obtain ante-mortem data for the identification process. The aims of the present study were to evaluate the capacity of recognition of individuals from digital facial approximation and to verify the association between the level of understanding of the issue by evaluators and the recognition success index. METHODS: 16 skulls with previous photographic records were selected and then utilized for three-dimensional approximation using the digital technique, scanned by photogrammetry, and reconstructed by computerized method using open-source software. Twenty evaluators tried to recognize the facial approximation performed from images present in the photospreads. RESULTS: The mean overall score was 23.75%, and it was observed that in only five approximations (31.24%) the option of correct recognition of the victim was the one that obtained the highest number of selections. False positives and negatives corresponded, respectively, to 11.56% and 12.5%. CONCLUSIONS: It can be concluded that the methodology can provide recognition albeit in low numbers, and permitting the acquisition of ante-mortem data for the proper process of human identification through primary methods.

Revisiting autopsies of death by mechanical asphyxia in the search for post-mortem pink teeth.

BACKGROUND: In contemporary forensic practice, Medicine and Dentistry combine forces to improve the search for the cause of death and human identification. The pink tooth phenomenon (PTP) is a cadaveric sign that allegedly manifests more often in victims of asphyxia. However, the scientific literature is scarce and controversial on this aspect. OBJECTIVE: This study aimed at screening victims of mechanical asphyxia in order to search for post-mortem pink teeth. MATERIAL AND METHODS: Retrospectively, autopsy reports from a local medico-legal institute in South Brazil were revisited in the search for victims of death by asphyxia. Autopsy reports of twenty one victims aged between 6 and 67 years (mean age: 40.6 years ±19.20; median: 37 years) were found and analyzed. RESULTS: The different modalities of asphyxia included drowning (n=7; 33.33%), strangulation (n=1; 4.76%) and hanging (n=13; 61.91%). A single case of PTP was detected (4.76%) - a 26-year-old male victim of hanging. CONCLUSION: This study illustrates and highlights the unspecific aspect of the PTP. In practice, forensic experts must avoid interpretations of this phenomenon as conclusive evidence of the cause of death, such as asphyxia by drowning, strangulation or hanging.

Colour stability of dental restorative materials submitted to conditions of burial and drowning, for forensic purposes.

The aim of this study was to evaluate the effect of earth and water on the colour stability of tooth-coloured dental restorative materials: composite resin (CR) and glass ionomer cement (GIC). Aiming to distinguish between one and another tooth-coloured material and to estimate the period in which they could be submitted to the factors earth and water, the proposed method may contribute to the proceedings of human identification of victims of burial and submersion in water. Forty bovine incisors were prepared (6 x 6 x 2mm) and restored with CR FiltekTM Z250 XT (3M ESPETM) and GIC KetacTM Fil Plus (3M ESPETM). After initial colour read-outs (VITATM Easyshade spectrophotometer), the samples were separated into two groups (n=10), according to the conditions to which they were submitted: simulations of burying and submersion in water, for periods of 1, 3, 6 and 12 months, when new read-outs were taken. The values of colour change (ΔE, ΔL*, Δa*, and Δb*) were subjected to 3-way ANOVA statistical analysis, repeated measures, Bonferroni (p<.05), and it was verified that both factors produced colour changes in the restorative materials, which were higher for glass ionomer cement (p<.05) after 12 months of burial, and 6 months of submersion in water. The authors concluded that the analysis of colour change in the material contributed to the forensic odontology casework depending on the time during which the victim was submitted to the condition of burial or submersion in water.

Age estimation by facial analysis based on applications available for smartphones.

BACKGROUND: Forensic Dentistry has an important role in the human identification cases and, among the analyses that can be performed, age estimation has an important value in establishing an anthropological profile. Modern technology invests for new mechanisms of age estimation: software apps, based on special algorithms, because there is not interference based on personal knowledge, cultural and personal experiences for facial recognition. MATERIALS AND METHODS: This research evaluated the use of two different apps: "How Old Do I Look? - Age Camera" and "How Old Am I? - Age Camera, Do You Look Like in Selfie Face Pic?", for age estimation analysis in a sample of 100 people (50 females and 50 males). Univariate and multivariate statistical methods were used to evaluate data. RESULTS: A great reliability was seen when used for the male volunteers. However, for females, no equivalence was found between the real age and the estimated age. CONCLUSION: These applications presented satisfactory results as an auxiliary method, in male images.

Forensic odontology education:from undergraduate to PhD - a Brazilian experience.

BACKGROUND: Forensic Odontology is a topic present in the majority of Dental Schools in Brazil, and due to this reality, some universities develop activities related to undergraduate and graduate students, from the Dentistry course until the Ph.D. degree. AIM: To present the education experience related to Forensic Odontology at School of Dentistry of Ribeirão Preto (USP - University of São Paulo), showing the strategies and activities in the different degrees (Dental course, Forensic Odontology Specialization Program, Specific Professional Training, Master, and Ph.D.). RESULTS: To the undergraduate students, many activities are developed in order to demonstrate all the possibilities that Forensic Dentistry allow, including theoretical and practical activities; in the Forensic Odontology Specialization Program, the dentists are trained to act as Forensic Odontologists in all its amplitude; in the Specific Professional Training, some courses are available, related to specific topics as DVI, Forensic Facial Reconstruction, Auditor in Dental Care Insurance and others; and in the Master and Ph.D. Programs, the professionals receive training in skills like teaching, research, student's guidance and others. CONCLUSION: In Brazil, Forensic Odontology is a well-known field in Dentistry and universities develop an important role in training a qualified workforce.