Postmortem Dental Radiographs Research Articles

Dental radiographic superimposition: An exciting addition to the forensic odontology armamentarium

• Forensic odontology plays an important role in the identification of severely decomposed or carbonised corpses. • Forensic odontologists were consulted for the identification of a severely carbonised corpse with extensive dental restorative work. • Superimposition of ante- and post-mortem dental radiographs were utilised in the positive identification process. Forensic odontology plays an important role in the identification of severely decomposed or carbonised corpses, particularly when conventional identification methods fail. This case report highlights the use of dental radiographic superimposition of extensive dental restorative work in the identification of a severely carbonised corpse. Ante- and post-mortem radiographs were analysed via superimposition using the Adobe Photoshop® 2021 image manipulation software. Multiple concordant features, as well as near-perfect radiographic superimposition, enabled a positive identification of the carbonised corpse. This emphasises the need for consultation of forensic odontologists in cases where dental restorative work is noted during post-mortem examination.

Dental Post-mortem Computed Tomography for Disaster Victim Identification: A literature review

Abstract Over the last decade, post-mortem computed tomography (PMCT) has been increasingly adopted within the forensic setting. The three-dimensional (3D) capability and non-destructive approach of PMCT allows it to have several advantages over conventional x-rays, and as such it may be of potential use within forensic odontology for disaster victim identification (DVI). However, the implementation of dental PMCT can only have a real forensic benefit if its accuracy is comparable to that of conventional post-mortem (PM) dental radiographs; which is currently standard practice. Therefore, the purpose of this review was to evaluate if dental PMCT is as accurate as PM dental radiographs. A review of the current literature has shown the accuracy of dental PMCT to be comparable or similar to that of PM dental radiographs. As a result, there is a potential for dental PMCT to replace conventional PM dental radiographs in the DVI process of Mass Fatality Incidents (MFIs). However, further research is required to establish an international standard protocol for dental PMCT before it can be recognised as a new standard practice within the forensic setting.

Comparison of Missing tooth and Dental work detection using Dental radiographs in Human Identification

Victim identification plays a vital role for identifying a person in major disasters at the time of critical situation when all the other biometric information was lost. At that time there is a less chance for identifying a person. The major issues of dental radiographs are dental work and missing or broken tooth was addressed in this paper. This algorithm can be established by comparing both ante mortem (AM) and post-mortem (PM) dental images. This research work is mainly focuses on the detection of dental work and broken tooth or missing tooth, then comparison of active contour model with mathematical model-based shape extraction for dental radiographic images are proposed. In this work, a new mathematical tooth approximation is presented and it is compared with online region-based active contour model (ORACM) is used for shape extraction. Similarity and distance-based technique gives better matching about both the AM and PM dental radiographs. Exact prediction of each method has been calculated and it is validated with suitable performance measures. The accuracy achieved for contour method is 94%, graph partition method is 96% and finally the hit rate of this method is plotted with cumulative matching characteristic (CMC) curve.

Dental identification by comparison of antemortem and postmortem dental radiographs: Influence of operator qualifications and cognitive bias

Dental forensic identifications based on comparison of antemortem and postmortem radiographs provide effective and reliable evidence. There are no standardized procedures for assessing similarities between different types of dental radiographs (e.g. orthopantomograms, bitewings, and periapical radiographs), and the operator's subjective judgment can considerably affect identification. The purpose of this study is to evaluate the potential influence of experts’ qualifications, training, and cognitive bias on the accuracy of identification. Seventy-eight differently qualified and experienced experts underwent an identification test. The expert sample was composed of 10 specialists in emergency care (ER), 10 specialists in legal medicine (ML), 20 pregraduate dental students (STU), 12 dentists (DENT), 20 dentists educated in forensic odontology (DENT-TRA), and 6 experienced forensic odontologists (FOR). The simulated cases required participants to assess the possible matching of 42 postmortem intraoral radiographs with 16 antemortem panoramic radiographs. Accuracy and specificity for the different operator groups were as follows: ER, 0.76–0.70; ML, 0.76–0.88; STU, 0.89–0.82; DENT, 0.87–0.97; DENT-TRA, 0.88–0.92; and FOR, 0.97–1. As evidenced by high rates of accuracy and repeatability, the most experienced forensic odontologist consistently outperformed operators less or differently educated and trained, especially for difficult cases. In our sample, the dentists who received additional education in forensic odontology did not necessarily perform better than dentists who had not received this additional education. Some cognitive bias, mainly the so-called observer effect, emerged as a possible source of outcome variability among the operator groups.

Role of Radiology in Forensic Dentistry

Forensic radiology is a specialized area of medical imaging utilizing radiological techniques to assist physicians and pathologists in matter pertaining to the law. Postmortem dental radiographs are the most consistent part of the antemortem records that can be transmitted during the forensic examination procedures. Pathologists regularly use radiographic images during the course of autopsy to assist them in identification of foreign bodies or determination of death. Forensic radiology can be used in suspicious death or murder, in analysis of adverse medical events, solving legal matters, to detect child abuse, drug trafficking, body identification and disease identification. Using the possibilities of radiology, special characteristics of the internal structures of the dentomaxillofacial region can be revealed. We can also detect endodontic treatments, healing extraction sockets, implants or even tooth colored restoration. Therefore, we can give answers to problems dealing with identification procedures, mass disaster and dental age estimation.

Postmortem Dental Radiography*

Comparison of postmortem and antemortem dental radiographic films or digital images is a common procedure for establishing identity of human remains. This article describes some problems with producing postmortem dental radiographs in a medical examiner setting and gives methods for circumventing these difficulties. Resection of the jaws, when permitted, significantly simplifies the postmortem radiographic technique. When producing an actual postmortem panoramic dental radiograph (orthopantomogram) from a dry skull, stabilization of the specimen for exposure by the moving beam source may be accomplished simply by placing the specimen upside down on an anthropologist's skull ring. Image "burnout" in the anterior segment, which results from absence of the tissues of the neck, may be avoided by appropriate placement of radiodense objects such as "zippered" plastic bags filled with water or other fluid material, freezer gel packs, or a block of self-polymerizing acrylic. These methods may increase future postmortem dental radiography efficiency.

The Reliability of Digitized Radiographs for Dental Identification: A Web-Based Study

In the era of Daubert and other judicial rulings pertaining to the acceptability of forensic evidence, it is increasingly important that experts are able to testify that their methods have been scientifically tested and that error rates and other factors relating to reliability have been published. The purpose of this study was to determine the reliability of digitized radiographic comparisons for the purposes of dental identification. Participants with various forensic backgrounds and experience levels were passively recruited to the website. Ten forensic identification cases composed of antemortem and postmortem dental radiographs were supplied to examiners using a bespoke website. Participants responded to the cases on two occasions after a one-month washout interval using the ABFO conclusion levels for forensic identifications. A total of 115 first attempts and 87 matched second attempts were received. Of the total responses, 72% were dentally trained respondents who had completed at least one forensic identification case; of these, 38% were experienced forensic dentists who had completed more than 25 identifications. Data relating to accuracy, intra- and inter-examiner agreement, and the effect of case difficulty are presented. Mean accuracy was 85.5% for all cases, with the experienced forensic dentists obtaining a 91% success rate. The inter-examiner agreement on the negative identification cases was classified as poor. The data suggest that dental identifications resulting from the comparison of postmortem and antemortem radiographs are valid, accurate, and reliable when undertaken by experienced odontologists.

Digital Imaging Methods as an Aid in Dental Identification of Human Remains

The physical comparison of known (K) and questioned (Q) evidence samples is an accepted tool in numerous forensic identification disciplines (1). A subset of this process is the use of antemortem and postmortem dental radiographs to identify unidentified human remains. This method has been generally accepted for decades (2). The outcome is performed with a considerable degree of accuracy, due in part to a finite pool of possible candidates for identification derived via the NCIC database, passenger lists, and law enforcement Missing Persons reports. This paper describes a dental identification comparison protocol that incorporated digital imaging technology in this process. The computer was used to create digital exemplars of the K and Q evidence that were spatially and quantitatively compared (3). The digital mode allowed direct metric and morphologic comparison through the aid of a digital camera, desktop computer, monitor, and printer. The well-known computer program Adobe Photoshop 5.0 (4) was used to process the digital information in two forensic cases described in this paper. It is a commercially available digital imaging editing program that is operated on laptop and desktop computers possessing sufficient chip speed and RAM (Pentium II or equivalent and at least 76MB RAM) to open the large-size files generated by high-resolution digital capture devices. This program accepts raster-based image formats (e.g. .JPG, .BMP). Photoshop is noted for its diverse imaging functions, which allow the computer monitor to be used as a comparison microscope when Q and K sample images are tiled side-by-side and/or superimposed. Two and three-dimensional Q and K evidence samples can be individually digitized and then independently resized to allow two-dimensional comparison. The investigator also has the ability to create magnified images (200% to 300%) when the original digital image has been captured at near photoquality resolution (300 dpi). The visual comparison of physical features on the computer monitor permits a large field of view and robust digital control over image quality. Photographic measurement and enhancement features of Adobe Photoshop mimics and in some circumstances surpasses the historic use of conventional photographic manipulation in forensic casework. This paper presents two cases processed via routine forensic odontology identification protocols. These protocols had minimal results due to limitations described in the case histories. The additional application of digital methods proved useful in the ultimate identification of these human remains.

Computed Dental Radiography Used to Reproduce Antemortem Film Position

Visual comparison of conventional antemortem and postmortem dental radiographs is often included in forensic identification. Ten forensic cases employing dry mandibular and maxillary bones and a dry study skull were exposed using the CDR digital dental X-ray system developed by Schick Technologies, Inc. Exposures of 0.08s at 10 mA and 70 kVp were taken with an INTREX intraoral dental X-ray unit. Digital radiography has the ability to produce an image instantaneously, allowing an operator to retake an incorrectly aligned radiograph almost immediately. It gives the forensic scientist a simplified method for reproducing antemortem radiographic position more efficiently and often with greater accuracy than conventional radiography.

Digitized Slice Interposition in Forensic Dental Radiographic Identification

Traditional methods of comparison involving the presence of missing teeth, dental restorations, and other pathological features may be difficult due to the reduction in dental restorations in today's population. This study demonstrates an alternative method of identification using digitized images. It utilizes anatomical structures such as dental root morphology and spatial relations of teeth roots and their supporting structures on simulated antemortem and postmortem radiographs as the basis for identification. A total of 39 mandibular specimens were used and two radiographs representing the antemortem and postmortem radiographs of each hemimandible were exposed by two operators using different x-ray generators. The radiographs were scanned and digitized. The identities of the antemortem and postmortem radiographs were kept from the operator. Following this, horizontal sections were digitally cut from the antemortem radiographs through the roots approximately halfway between the neck of the tooth and the root apex. This section was manipulated onto the postmortem radiograph by using a computer graphics program and a quantitative comparison of the alignment of normal dental anatomical landmarks was undertaken. The technique enabled perfect matching of all 39 specimens by antemortem and postmortem dental radiographs. The mean number of identifying points was 17.5 and the mean number of nonmatching points was 0.1. The mean concordance was 99.2% between the antemortem and postmortem radiographs.

Alterations in Human Bones and Teeth as a Result of Restricted Sun Exposure and Contact with Corrosive Agents

Skeletal remains were discovered in an unused cistern near the Omaha, Nebraska airport and were positively identified through comparison of antemortem and postmortem dental radiographs. Although nearly nine years had elapsed between death and discovery, the bones and teeth revealed evidence of the application of a corrosive substance at or about the time of death, as well as an unusual restricted response to sun exposure, that contributed to the prosecution and murder conviction of a member of Hell's Angels in the Omaha area.