A Range of Postmortem Assault Experiments Conducted on a Variety of Denture Labels Used for the Purpose of Identification of Edentulous Individuals

Abstract:  Forensic organizations worldwide have recommended that dental prostheses should be labeled with at least the patient's name and preferably with further unique identifiers such as social security number, etc. The practice of denture marking has been conducted over many years and several denture marking systems have been reported in the dental literature. However, very little is known about the resilience of such systems to conditions experienced in the majority of post- and perimortem assaults. The purpose of this investigation therefore, was to expose a selection of 10 denture labels to a series of hostile environments. Results of the study indicate that the majority of the denture labeling systems appear capable of withstanding a range of common, and not so common postmortem assaults. With regard to thermal insult, however, most performed badly with the exception of a label constructed from stainless steel orthodontic band. However, another label in the form of an electronic RFID-tag performed above expectations in the majority of experiments. Furthermore, its cosmetic appearance has proven most popular with many patients.     

Denture marking--patient preference of various methods

Dental forensic organizations world wide have recommended that dental prostheses should be labeled with at least the patient's (wearer's) name and preferably with further unique identifiers such as social security number. A range of methods are available and the purpose of this study was to determine, via the means of a visual questionnaire, which are the most preferable to those patients who wear complete dentures. One hundred edentulous patients attending the Manchester Dental Hospital were shown a range of denture labeling methods and asked to rank these according to their preference. The most preferred method was that of an embedded radio frequency identification microchip (38% rated this as first) and the second was an inclusion technique using onion paper (24% rated this as first). The least preferred method was the use of a groove cut into the denture flange with 71% of patients rating this as the poorest in terms of esthetics. The study demonstrates that the method of denture labeling is important to patients and to ensure that denture labeling is performed routinely esthetic preferences must be considered.     

Contemporary methods of labeling dental prostheses--a review of the literature

Forensic identification (ID) based on an assessment of the dentition is commonplace. However, despite an increase in the oral health of Western populations, there are still many millions of individuals who are edentulous and whom have been treated with completed dentures. In the United Kingdom alone over 300,000 patients are rendered edentulous each year. In order to facilitate the ID of such individuals a number of forensic and governmental organizations have recommended that dentures be labeled. A number of labeling systems exist which can be broadly separated into inclusion systems, marking systems, and novel methods. Each of the commonly described systems are demonstrated with an assessment of their strengths and weaknesses. It is recommended that an inclusion denture marker, preferably metallic, should be used in order to withstand the most common postmortem assaults.     

2D Barcodes: A Novel and Simple Method for Denture Identification

Several methods of denture marking have been described in the literature. However, most of them are expensive, time‐consuming, and do not permit the incorporation of large amounts of information. We propose a novel and simple method incorporating 2D codes which has several advantages over the existing methods. A 2D code was generated in the dental office and inserted into a maxillary denture. The code was then read using software downloaded into a mobile phone giving access to the website containing details about the patient. The denture was also subjected to durability tests, which did not hamper the efficacy of the 2D code. 2D coding for dentures is a simple, less expensive method with the potential of storing a large amount of information that can be accessed on‐site by the forensic investigator, thus allowing quick identification of the denture wearer.     

Antemortem records of forensic significance among edentulous individuals

The identification of edentulous individuals is problematic due to poor provision of labelled dental prostheses. Dental records may still provide useful information for odontologists in the comparative identification process. The purpose of this study was to determine the level of forensically significant information contained within the dental records of a population of denture wearers attending the University of Manchester School of Dentistry. Two hundred and two dental records were examined and a proforma completed. The mean age of the patients was 72 years. Medical history were absent in 4% of all records and only 67.8% of the written records were rated as good. Thirty-two percent of the records contained one or more panoramic radiographs but 30% of these were over 3 years old rendering their usefulness in identification procedures questionable. In total only 18% of the examined records contained antemortem information that would enable identification. These data suggest that the process of denture marking is an essential in order to ensure that the identification of this population can be undertaken expediently by dental means.     

The Teaching of Denture Marking Methods in Dental Schools in the United Kingdom and the United States*,†

Abstract: Forensic organizations worldwide have recommended that dental prostheses should be marked with, at a minimum, the patient’s name and preferably with further unique identifiers such as a social security number. The current study aimed to assess the denture marking practice of dental schools within the United States and the United Kingdom. A questionnaire‐based survey was employed to gain both quantitative and qualitative data on the methods, practices, and ethos behind denture marking in 14 U.K. and 32 U.S. dental schools. One hundred percent of U.K. and 87.5% of U.S. schools returned surveys and the results suggest that, for dental schools where there is no legal or legislative need for denture marking, the practice is inconsistently taught and appears to be reliant on internal forces within the school to increase awareness. Among those schools practicing marking, only 18% employ a technique likely to withstand common postmortem assaults; this is a concern.     

Quick Response Code In Acrylic Denture: Will it Respond When Needed?

Use of acids and other caustic substances in destroying the human body to avoid personal identification is drawing great deal of attention in recent times. With rapid industrial growth, incidence of industrial disasters has increased. In an event of chemical industry disaster, human identification can become a challenge. Embedding bar codes and other electronic means for identification in denture have proved to be a novel innovation in identification of edentulous patients. However, the validity of this method in events of chemical extremes has not been assessed. Hence, the study was undertaken to know the effect of different acids on dentures embedded with quick response codes. Results of this study indicate that simple bar code can be readable up to 33 h after acid treatment. With minimal armamentarium, bar code can be generated incorporating large data into it, providing it to be a cheap and reliable means of denture identification.     

Attitudes,Perceptions, and Preferences of Individuals from Temuco (Chile) About Denture Marking

Denture marking (DM) helps identify edentulous people with different methods. Analyzing perceptions and attitudes of denture wearers would enable understanding of the practical aspects, an analysis still absent in South America. Fifty‐three individual candidates for removable dentures were instructed on disaster victim identification (DVI) and the usefulness of DM for this purpose. They were physically shown eight DM systems and a questionnaire to which they responded by highlighting preferences in those systems. Although 98.11% did not know that dentures could be marked, only 9.43% denied interest in some type of DM. The 90.57% would mark their dentures with some system, preferring the inclusion of QR codes or a micro SIM card. The proven weaknesses of DVI and propensity for disaster mean this community in Chile is an opportunity to implement DM systems. Obstacles may come not from patients but from their dentists, educational institutions, or a lack of public policies.     

侦查机关内设鉴定机构的负面影响与消解

侦查活动的特殊性使其染指于司法鉴定,侦查机关基于侦查工作之必要内设鉴定机构。侦查机关内设的鉴定机构又因侦查的追诉性质在鉴定活动中难以保持中立性,致使侦查机关的鉴定机构的性质与法律的中立性要求出现一些紧张关系,在诉讼中造成了一些负面影响。司法鉴定制度的改革旨在借助司法行政部门对司法鉴定的统一管理来催生侦查机关的鉴定机构和侦查活动相分离,从而保持侦查机关的鉴定机构具有相对的独立性,并通过制度调整后的外在监督力量与程序的制约机制来缓解这一紧张关系,以促进侦查机关的鉴定机构在诉讼中真正发挥发现事实真相的作用。     

Roadmap to solving security and privacy concerns in RFID systems

This paper focuses on privacy and security concerns in Radio Frequency IDentification (RFID) systems and paves the way towards a roadmap for solving security and privacy concerns in RFID systems. RFID systems have captured much interest around the World. The technology has many advantages and applications in a real world situation. Examples of such scenarios will be discussed in this paper.This paper reviews privacy and security concerns within the context of the advantages the technology offers and reviews solutions to overcome the privacy and security challenges. However, this research found that many proposed technological solutions are not “bullet proof” and policy regulations have to be employed as well. Few such RFID policies have been proposed. However, this paper argues that users/consumers of RFID systems should be given the mandate to have control over their products and systems and in order to fully address solution to the security concerns.     

Implantation of an RFID-tag into human molars to reduce hard forensic identification labor. Part 2: physical properties

Modifying and implanting existing RFID-tags into extracted human molars was described previously [P. Thevissen, G. Poelman, B. Puers, M. De Cooman, G. Willems, Implantation of RFID-tag into human molars to reduce hard forensic identification labor. Part 1. Working principle, Forensic Sci. Int. 156 (2006)]. Maximal vertical occlusal load during which the implanted RFID-tags remain active was evaluated in vitro. The temperature dependency of the implanted RFID-tags was studied on the extracted teeth to find out the maximal obtainable temperature before failure and a test with embedded thermistors to verify temperature distributions. The maximal working temperature of the implanted RFID-tags was revealed and gave indications for the set-up of measuring intra oral and intra tooth temperature during the cremation of a human body. Fatigue was induced on the implanted teeth by thermocycling. The results of this investigation showed the need of putting an extra insulating layer around the modified tags before implantation. The different in vitro tests indicated that the implanted RFID-tags can support certain oral and forensic circumstances.     

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.     

The Reliability of Facial Recognition of Deceased Persons on Photographs

In humanitarian emergencies, such as the current deceased migrants in the Mediterranean, antemortem documentation needed for identification may be limited. The use of visual identification has been previously reported in cases of mass disasters such as Thai tsunami. This pilot study explores the ability of observers to match unfamiliar faces of living and dead persons and whether facial morphology can be used for identification. A questionnaire was given to 41 students and five professionals in the field of forensic identification with the task to choose whether a facial photograph corresponds to one of the five photographs in a lineup and to identify the most useful features used for recognition. Although the overall recognition score did not significantly differ between professionals and students, the median scores of 78.1% and 80.0%, respectively, were too low to consider this method as a reliable identification method and thus needs to be supported by other means.     

Frequencies of morphological characteristics in two contemporary forensic collections: implications for identification

Positive identification relies on comparison of antemortem and postmortem data. Some identifications are based on morphological features such as fracture, pathological condition, and surgical hardware, despite little literature indicating the frequencies of such traits. This study examines whether such features are sufficiently rare as to be deemed individualizing. Data were collected on two modern North American skeletal collections (N=482 individuals). Presence/absence of features was scored by skeletal element and side. Results indicate that frequencies vary by geographic region (higher frequency of fractures and pathological conditions in New Mexico while individuals in Tennessee were more likely to have surgical interventions), many features such as fractures are remarkably common and that even suites of traits may not be individualizing. Caution is warranted when using written data rather than radiographic comparisons as the primary source of identification. The implications of these findings to missing person databases are also discussed.     

The Odontology Victim Identification Skill Assessment System*,†

Abstract: Mass fatality identification efforts involving forensic odontology can involve hundreds of dental volunteers. A literature review was conducted and forensic odontologists and dental educators consulted to identify lessons learned from past mass fatality identification efforts. As a result, the authors propose a skill assessment system, the Odontology Victim Identification Skill Assessment System (OVID‐SAS), which details qualifications required to participate on the Antemortem, Postmortem, Ante/Postmortem Comparison, Field, and Shift Leader/Initial Response Teams. For each qualification, specific skills have been identified along with suggested educational pedagogy and skill assessment methods. Courses and assessments can be developed by dental schools, professional associations, or forensic organizations to teach and test for the skills required for dental volunteers to participate on each team. By implementing a system, such as OVID‐SAS, forensic odontologists responsible for organizing and managing a forensic odontology mass fatality identification effort will be able to optimally utilize individuals presenting with proven skills.     

Analytical survey of restorative resins by SEM/EDS and XRF: databases for forensic purposes

Frequently in forensic cases, unknown substances must be identified. Automated databases can ease the burden of comparison as materials may be compared against many known standards in a relatively short period of time. It has been shown that dental resins can be named according to brand or brand group even in conditions as harsh as cremation. Databases are already in use for many materials, but no such database exists for dental resins. Thus, two databases were generated. One utilized a laboratory-based method, scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDS), in conjunction with the Spectral Library Identification and Classification Explorer (SLICE) software. The other was based on portable X-ray fluorescence (XRF). The ability to perform database comparison with portable instrumentation can thus be brought directly to the field. Both the SLICE and XRF databases were evaluated by testing unknown resins. EDS is a well-established technique and the SLICE program was demonstrated to be a good tool for unknown resin identification. Portable XRF is a relatively new instrument in this regard and its databases have been constructed mostly for metal alloy comparison and environmental soil testing. However, by creation of a custom spectral library, it was possible to distinguish resin brand and bone and tooth from other substances.     

Identification through X-ray fluorescence analysis of dental restorative resin materials: a comprehensive study of noncremated, cremated, and processed-cremated individuals

Tooth-colored restorative materials are increasingly being placed in the practice of modern dentistry, replacing traditional materials such as amalgam. Many restorative resins have distinct elemental compositions that allow identification of brand. Not only are resins classifiable by elemental content, but they also survive extreme conditions such as cremation. This is of significance to the forensic odontologist because resin uniqueness adds another level of certainty in victim identification, especially when traditional means are exhausted. In this three-part study, unique combinations of resins were placed in six human cadavers (total 70 restorations). Simulated ante-mortem dental records were created. In a blind experiment, a portable X-ray fluorescence (XRF) unit was used to locate and identify the resin brands placed in the dentition. The technique was successful in location and brand identification of 53 of the restorations, which was sufficient to enable positive victim identification among the study group. This part of the experiment demonstrated the utility of portable XRF in detection and analysis of restorative materials for victim identification in field or morgue settings. Identification of individuals after cremation is a more difficult task, as the dentition is altered by shrinkage and fragmentation, and may not be comparable with a dental chart. Identification of processed cremains is a much greater challenge, as comminution obliterates all structural relationships. Under both circumstances, it is the nonbiological artifacts that aid in identification. Restorative resin fillings can survive these conditions, and can still be named by brand utilizing elemental analysis. In a continuation of the study, the cadavers were cremated in a cremation retort under standard mortuary conditions. XRF was again used to analyze retrieved resins and to identify the individuals based on restorative materials known to exist from dental records. The cremains were then processed and the analysis was repeated to determine whether restorative resins could be found under this extreme condition. Under both circumstances, sufficient surviving resin material was found to distinguish positively each individual in the study group. This study showed the utility of XRF as an analytical tool for forensic odontology and also the significance of the role of restorative resins in victim identification, even after cremation.     

Identification of the Edentulous Individual: An Investigation into the Accuracy of Radiographic Identifications*

Abstract: The dental identification of edentulous individuals can be challenging based on the lack of antemortem materials and unique features visible on radiographs. The constant resorption of the alveolar ridges further complicates the process. The purpose of this study was to quantify the error rate and reliability of dental identifications based on a comparison of synthesized antemortem and postmortem radiographs of edentulous individuals. Ten observers examined ten cases on two occasions and reported dichotomous and conclusion level decisions. These were analyzed using Kappa and Receiver Operator Characteristics. The mean area under the curve was 0.75 and the mean sensitivity was 0.57 and specificity was 0.83. These results suggest that dental identifications of edentulous individuals using radiographs alone have a high error rate and should be dual reported. These data add further weight to the argument that all dental prostheses should be labeled.     

MSCT及图像后处理在鼻骨骨折法医鉴定中的应用

目的探讨多层螺旋CT(MSCT)及图像后处理在鼻骨骨折法医学鉴定中的应用价值。方法采用MSCT对134例被鉴定人进行薄层扫描并行多平面重建(MPR)和表面遮盖成像(SSD)。比较MSCT与常规X线诊断结果。结果线型骨折55(41.04%)例,粉碎型骨折46例(34.33%),凹陷型骨折27例(20.15%),未见骨折6例(4.48%)。X线平片及CR片漏、误诊48例(35.82%)。MSCT正确诊断133例(99.25%)。两者诊断结果存在显著差异(χ2=45.0816,P<0.001)。结论MSCT及后处理图像应作为鼻骨骨折法医鉴定的主要依据。