Root Morphology and Anatomical Patterns in Forensic Dental Identification: A Comparison of Computer‐Aided Identification with Traditional Forensic Dental Identification*

Abstract: An online forensic dental identification exercise was conducted involving 24 antemortem–postmortem (AM–PM) dental radiograph pairs from actual forensic identification cases. Images had been digitally cropped to remove coronal tooth structure and dental restorations. Volunteer forensic odontologists were passively recruited to compare the AM–PM dental radiographs online and conclude identification status using the guidelines for identification from the American Board of Forensic Odontology. The mean accuracy rate for identification was 86.0% (standard deviation 9.2%). The same radiograph pairs were compared using a digital imaging software algorithm, which generated a normalized coefficient of similarity for each pair. Twenty of the radiograph pairs generated a mean accuracy of 85.0%. Four of the pairs could not be used to generate a coefficient of similarity. Receiver operator curve and area under the curve statistical analysis confirmed good discrimination abilities of both methods (online exercise = 0.978; UT‐ID index = 0.923) and Spearman’s rank correlation coefficient analysis (0.683) indicated good correlation between the results of both methods. Computer‐aided dental identification allows for an objective comparison of AM–PM radiographs and can be a useful tool to support a forensic dental identification conclusion.     

Distinguishing Atherosclerotic Calcifications in Dry Bone: Implications for Forensic Identification

Atherosclerotic calcifications, as calcified atheromatous elements, are markers of cardiovascular disease. However, the literature gives little information regarding their morphological aspect, making their identification very rare in skeletonized cases. In this paper, we document the morphological, histological, and SEM aspects of atherosclerotic plaques collected from unclaimed cemeterial skeletal remains from an identified osteological collection and extracted from well‐preserved cadavers autopsied at the medico‐legal institute of Milan. Each of the three analyses provided similar results: atherosclerotic calcifications are convex‐concave plaques with a stratified structure, a pale‐yellow coloration in autopsy cases and yellow to brown when recovered in dry bone. Histologically, undecalcified and decalcified sections showed a stratified aspect formed by superimposed layers. Lastly, the SEM analysis showed a precise view of the stratified structure of the plaques in transverse section. As markers of disease, atherosclerotic calcifications can provide important antemortem information on the deceased that may be compared to antemortem data.     

Identification of a Carbonized Body Using Implanted Surgical Plates: The Importance of Computed Tomography

In addition to clinical examination, forensic odontologists can use diagnostic imaging as an auxiliary method for identification. This paper reports a case where forensic odontologists from the Afrânio Peixoto Legal Medicine Institute in Rio de Janeiro (Brazil) positively identified a carbonized and partially calcined body using oral and maxillofacial imaging. The cadaver showed several metallic plates fixed with metallic screws on bones of the neurocranium and viscerocranium. Family members provided spiral computed tomography scans of the skull and a panoramic radiograph that were acquired after an accident that required surgical procedures. Comparative analysis between the clinical exam and the maxillofacial images demonstrated complete coincidence, confirming the victim's identity. Dactyloscopy, which is the most commonly used method of identification, was not possible because of the body carbonization. Thus, diagnostic imaging, especially computed tomography, was essential for elucidation of this case.     

Antemortem and Postmortem Nonapposite Data—A Multidisciplinary Identification Strategy

Identification of human remains is often achieved by comparing documented reference data with the same type of evidence obtained from the remains. We present a case of a decomposed unidentified body, whose identity was presumed but because of the low validity range of the available data, the identification process could not be completed. Antemortem radiographs of the teeth found in the house of the reputed victim could not be compared to the edentulous cadaver and the kinship between the victim and the only living relative that could provide DNA for comparison was too tenuous. Isolated teeth found at the scene, were neither a source of DNA reference information nor questioned data to be compared to the antemortem radiographs. The strategy implemented by the investigators to reallocate the status of the isolated teeth from the questioned source to the reference source of DNA to be compared with the cadaver is presented.     

Computer‐aided Dental Identification: An Objective Method for Assessment of Radiographic Image Similarity*

Abstract: A pilot study evaluated a computer‐based method for comparing digital dental images, utilizing a registration algorithm to correct for variations in projection geometry between images prior to a subtraction analysis. A numerical assessment of similarity was generated for pairs of images. Using well‐controlled laboratory settings, the method was evaluated as to its ability to identify the correct specimen with positive results. A subsequent clinical study examined longitudinal radiographic examinations of selected anatomical areas on 47 patients, analyzing the computer‐based method in making the correct identification based upon a threshold level of similarity. The results showed that at a threshold of 0.855, there were two false negative and two false positive identifications out of 957 analyses. Based on these initial findings, 25 dental records having two sets of full mouth series of radiographs were selected. The radiographs were digitized and grouped into six anatomical regions. The more recent set of films served as postmortem images. Each postmortem image was analyzed against all other images within the region. Images were registered to correct for differences in projection geometry prior to analysis. An area of interest was selected to assess image similarity. Analysis of variance was used to determine that there was a significant difference between images from the same individual and those from different individuals. Results showed that the threshold level of concordance will vary with the anatomical region of the mouth examined. This method may provide the most objective and reliable method for postmortem dental identification using intra‐oral images.     

GrinLine Identification Using Digital Imaging and Adobe Photoshop*

Abstract: The purpose of this study was to outline a method by which an antemortem photograph of a victim can be critically compared with a postmortem photograph in an effort to facilitate the identification process. Ten subjects, between 27 and 55 years old provided historical pictures of themselves exhibiting a broad smile showing anterior teeth to some extent (a grin). These photos were termed “antemortem” for the purpose of the study. A digital camera was used to take a current photo of each subject’s grin. These photos represented the “postmortem” images. A single subject’s “postmortem” photo set was randomly selected to be the “unknown victim.” These combined data of the unknown and the 10 antemortem subjects were digitally stored and, using Adobe Photoshop software, the images were sized and oriented for comparative analysis. The goal was to devise a technique that could facilitate the accurate determination of which “antemortem” subject was the “unknown.” The generation of antemortem digital overlays of the teeth visible in a grin and the comparison of those overlays to the images of the postmortem dentition is the foundation of the technique. The comparisons made using the GrinLine Identification Technique may assist medical examiners and coroners in making identifications or exclusions.     

Radiographic Recognition of Dental Implants as an Aid to Identifying the Deceased

Abstract:  This study was undertaken to determine if dental implants can be radiographically differentiated by company type to aid forensic identification of the deceased. Recognition of dental implants on intraoral radiographic images was assessed in a blind study using a radiographic examination guide to highlight differences between dental implants. Inter- and intra-examiner comparisons were conducted and a computer program (Implant Recognition System^®) was evaluated to see whether it improved the accuracy of implant recognition. The study found that dental implants could be radiographically differentiated by company type. The Implant Recognition System^® in its current form was of little benefit for radiographic assessment of dental implants for forensic odontologists. Prior knowledge of implant types, with a McNemar's statistical value of 92.9, proved to be most significant in identification.     

Antemortem dental records: attitudes and practices of forensic dentists

This study was designed to provide insight concerning the attitudes and practices of forensic dentists regarding antemortem dental records reviewed for purposes of dental identification. Forensic dentists were invited to participate in a 10 item survey. The majority of the respondents reported a considerable amount of experience in dental identifications of the deceased. Sixty-six percent reported having suspected dental negligence or fraud in their antemortem record reviews. Only 17% believe that a forensic dentist should report suspected dental negligence, while 31% agree that dental fraud should be reported. Their response to additional issues addressed in the study suggests diversity in the practices and attitudes of forensic dentists in the use of antemortem dental records. In conclusion, opening a dialogue among practicing forensic dentists may lead to a standardized set of recommendations by the appropriate societies in the forensic dental community.     

Testing a Novel 3D Printed Radiographic Imaging Device for Use in Forensic Odontology

There are specific challenges related to forensic dental radiology and difficulties in aligning X‐ray equipment to teeth of interest. Researchers used 3D printing to create a new device, the combined holding and aiming device (CHAD), to address the positioning limitations of current dental X‐ray devices. Participants (N = 24) used the CHAD, soft dental wax, and a modified external aiming device (MEAD) to determine device preference, radiographer's efficiency, and technique errors. Each participant exposed six X‐rays per device for a total of 432 X‐rays scored. A significant difference was found at the 0.05 level between the three devices (p = 0.0015), with the MEAD having the least amount of total errors and soft dental wax taking the least amount of time. Total errors were highest when participants used soft dental wax—both the MEAD and the CHAD performed best overall. Further research in forensic dental radiology and use of holding devices is needed.     

Usefulness of Forensic Dental Symbols© and Dental Encoder© database in forensic odontology

Abstract: A new universal graphic dental system, Forensic Dental Symbols^©, has been created to provide precision in the construction of dental records, improve standardization, and increase efficiency in dental identification procedures. Two hundred and thirty‐four different graphic symbols representing the most frequent clinical status for each tooth were designed. Symbols can be then converted to a typographic font and then are ready to use in any computer. For the appropriate use, manipulation, and storage of dental information generated by the Forensic Dental Symbols^©, Dental Encoder^© database has been created. The database contains all the information required by INTERPOL Disaster Victim Identification (DVI)‐dental‐forms. To explore the possibilities that Dental Encoder^© offers, an antemortem dental database from a Spanish population of 3920 military personnel had been constructed. Data generated by Dental Encoder^© were classified into sex and age groups. The program can perform an automatic search of the database for cases that match a selected clinical status presented in a single tooth or a combination of situations for several teeth. Moreover, Dental Encoder^© allows information to be printed on INTERPOL DVI‐dental‐forms, or the inclusion of any completed form into any document, technical report, or identification of dental report.     

Lessons learned from large-scale comparative dental analysis following the South Asian tsunami of 2004

The aim of this study was to examine the quality of the ante-(AM) and postmortem (PM) dental data that were submitted for entry into the PLASS data system in Phuket, Thailand, following the Boxing Day (December 26) Tsunami, 2004. The investigators were two forensic odontologists who were part of the New Zealand Disaster Victim Identification team that worked at Wat Yang Yao morgue and at the Information Management Center in Phuket. Our findings underline the usefulness of dental data in human identification, but point to a number of significant sources of error. Of the 78 PM records received, only 68% of radiographs and 49% of photos confirmed the accompanying dental charting. This underlines the value, particularly of photographs of the dental arches, in quality control. It also points to a large error component, which may have been due to inexperience of the operators, fatigue, poor conditions in the temporary morgue, or the problem of tooth-colored fillings. Of the 106 AM records received, 62% were of unacceptable quality and 64% were either not accompanied by radiographs or had poor quality radiographs. These results indicate that AM data collection ideally needs to be collated and checked by a forensically trained dentist(s) in the country of origin.     

Positive Dental Identification Using Tooth Anatomy and Digital Superimposition

Dental identification of unknown human remains continues to be a relevant and reliable adjunct to forensic investigations. The advent of genomic and mitochondrial DNA procedures has not displaced the practical use of dental and related osseous structures remaining after destructive incidents that can render human remains unrecognizable, severely burned, and fragmented. The ability to conclusively identify victims of accident and homicide is based on the availability of antemortem records containing substantial and unambiguous proof of dental and related osseous characteristics. This case report documents the use of digital comparative analysis of antemortem dental models and postmortem dentition, to determine a dental identification. Images of dental models were digitally analyzed using Adobe Photoshop^TM software. Individual tooth anatomy was compared between the antemortem and postmortem images. Digital superimposition techniques were also used for the comparison. With the absence of antemortem radiographs, this method proved useful to reach a positive identification in this case.     

Effect of Heat on the Fluorescence Properties of Tooth‐Colored Restorative Materials and Their Forensic Implications

During antemortem and postmortem comparison of dental records of carbonized victims, restorations may be part of such records. The objective of this study was to evaluate the effect of heat on the fluorescence behavior of contemporary tooth‐colored restorative materials and natural tooth structure when subjected to range of temperatures, using illumination with 405 nm wavelength light. A total of 132 human extracted teeth restored with tooth‐colored restorative materials were exposed to heat (200, 500, 900, 1200°C) in an oven for 30 min. Samples were imaged before and after heat treatment. All tooth‐colored restorative materials underwent changes in color and in fluorescence properties, at each of the temperatures used. Resin‐based restorative materials still fluoresced at 200°C, and at 500°C underwent major color changes due to volatilization of resin. Materials containing inorganic fluorophores still fluoresced at 900°C, while at 1200°C, none of the materials tested in this study showed any fluorescence.     

Anthropological and Radiographic Comparison of Antemortem Surgical Records for Identification of Skeletal Remains*

Abstract: This case review illustrates the important contributions of forensic archeological methods and forensic anthropological analysis to the identification of found skeletal remains. After reassociation of skeletal remains found in two locations, anthropological analysis provided the basis for a presumptive identification and a request for antemortem medical records. Partial DNA profiles were supportive but not conclusive and antemortem dental records were not available. Comparison of antemortem traumas, skeletal morphology, and surgical artifacts with antemortem radiographs and surgical records led to positive identification of an individual missing for almost a decade.     

Use of diagonal teeth measurements in predicting gender in a Turkish population

Mesiodistal and buccolingual measurements, commonly used as a means of sex determination from teeth, can sometimes cause difficulties. The aim of this study is to test whether diagonal measurements can make it possible to take more accurate measurements. The results of diagonal measurements of dental casts taken from 30 males and 30 females have been evaluated by discriminant function statistics. Intra- and interobserver error tests did not indicate any statistically significant differences between the findings of two observers. Seven of the 14 measurements on the maxilla and 10 of the 14 measurements on the mandible have been found to be significantly greater in males. According to the results of the stepwise discriminant function statistics, the most contributory measurements to the function were upper first incisor mesiobuccal-distolingual (MBDL) and distobuccal-mesiolingual, lower second incisor MBDL, and lower canine MBDL. The highest reliability was obtained in MBDL measurements. It was realized that diagonal measurements of teeth, especially of canines, revealed clear dimorphic differences. Classification accuracy was found to be 83.3% for total sample, 78.3 for upper jaw, and 85.0% for the lower jaw. Accuracy rate was higher in the lower teeth. Commonly seen orthodontic anomalies, such as tooth rotations, crowding, attritions, deep dentin-enamel junction defects, and certain types of fillings, could make it difficult to correctly take width measurements or could cause other mistakes to occur. This explains the reason why this research has been considered to be of some use in diagonal measurements, which is an accurate method, particularly when employed for the front teeth.     

Forensic Identification of Bipartite Patella Misdiagnosed as Patella Fracture

Bipartite patella is recognized as a developmental anomaly of ossification. Most of them are asymptomatic and are discovered incidentally. Bipartite patella is sometimes misdiagnosed as a patella fracture, because the x‐ray images of both these conditions may appear very similar. In this case, the patient complained of left knee pain after x‐ray films revealed a fracture‐like line in the left patella. The patient was then diagnosed as having a patella fracture. In China, the injury degree is categorized as serious injury, minor injury, and trivial injury. As the injury degree of patellar fracture is identified as minor injury, the defendant who injured the patient will be sentenced to prison for ≤3 years. However, the defendant objected to this judgment and applied for the second evaluation of injury degree. On the basis of the site of injury, clinical manifestations, and imaging findings, we diagnosed the patient with bipartite patella which belongs to normal anatomic variant. Therefore, the injury degree of the patient was not minor injury.     

The Importance of Blind Forensic Odontology Analyses

Forensic odontology cases examined from 2012 to 2019 at the Defense POW/MIA Accounting Agency (DPAA) laboratory were reviewed. Five cases from World War II and the Korea War were selected. Three of the cases presented involve dental assemblages, which were built by previous analysts. Postmortem radiographic analyses at the DPAA laboratory of these cases were complicated by the use of an older version of a digital x-ray program and the assumption that teeth placed in the parent bone (maxilla and mandible) did not fully articulate due to the presence of debris at their root apices. Conflicting mitochondrial DNA test results for the submitted teeth and previously believed to be parent bone indicated these elements were not from the same individual. The remaining two cases are examples of how knowledge of findings from other disciplines may sway an opinion and could possibly lead to the rendering of erroneous opinions by the forensic odontologist. Having knowledge of previous examinations or results from other scientists, disciplines, and lines of evidence may lead to a bias in findings or opinions. If not careful, even the best-intended scientist may fall victim to a bias in their opinion/analysis. The forensic odontologist should perform all analysis in the blind, not knowing any information which may bias their opinion, and utilize current versions of digital x-ray software available and their tools when performing their examinations.     

Fimag: The United Kingdom Disaster Victim/Forensic Identification Imaging System

Abstract:  Imaging is an integral diagnostic tool in mass fatality investigations undertaken traditionally by plain X-rays, fluoroscopy, and dental radiography. However, little attention has been given to appropriate image reporting, secure data transfer and storage particularly in relation to the need to meet stringent judicial requirements. Notwithstanding these limitations, it is the risk associated with the safe handling and investigation of contaminated fatalities which is providing new challenges for mass fatality radiological imaging. Mobile multi-slice computed tomography is an alternative to these traditional modalities as it provides a greater diagnostic yield and an opportunity to address the requirements of the criminal justice system. We present a new national disaster victim/forensic identification imaging system—Fimag—which is applicable for both contaminated and non-contaminated mass fatality imaging and addresses the issues of judicial reporting. We suggest this system opens a new era in radiological diagnostics for mass fatalities.     

Identification of incinerated root canal filling materials after exposure to high heat incineration

With the increase in global terrorism there is a higher probability of having to identify victims of incineration events secondary to incendiary explosive devices. The victims of incineration events challenge forensic odontologists when coronal restorations are no longer present to compile postmortem data. With 40 million root canals being completed annually in the United States, a very large pool of antemortem data is available to the forensic odontologist to make positive identifications. When complete and thorough dental records exist, individuals that have undergone surgical and nonsurgical root canal therapy may have materials present in the canal that may aid in identification. This study provides elemental fingerprints of root canal obturation materials to be utilized as a forensic identification aid. This study used scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS) to assess the elemental composition of materials before and after high temperature incineration. Sixteen endodontic materials were analyzed pre-incineration and placed in extracted teeth. The filled teeth were subjected to incineration at 900 degrees C for 30 min to simulate incineration events or cremation. Incinerated materials were radiographed and re-analyzed to determine if they retained their original elemental composition. Endodontic sealers, gutta percha, root-end filling materials, silver points, and separated files were distinguishable in the canal and traceable after incineration. The authors present a fingerprint of the endodontic obturation materials that are capable of withstanding high heat incineration to be used as an aid for postmortem identification. This work represents the initial stage of database generation for root canal filling materials for use as an aid in forensic identification.