Operator Exposure to Scatter Radiation from a Portable Hand-held Dental Radiation Emitting Device (Aribex™ NOMAD™) While Making 915 Intraoral Dental Radiographs*

Abstract: Operator exposure to backscatter radiation while using an Aribex™ NOMAD™ radiation emitting device (a portable, self-contained, cordless, hand-held dental X-ray unit) was determined while the operator employed various typical and atypical use scenarios during the exposure of 715 digital and/or film-based dental radiographs and 200 study control exposures. Study data was compared to the radiation safety occupational exposure annual Maximum Permissive Dose (MPD) of 50 mSv (5000 mrem) to determine the possible exposure risk to an unprotected operator using this device. The results showed the reproductive organs received the highest dose and the thyroid the least. The average operator whole body dose for the study was determined to be 0.047 mSv (4.47 mrem) or 0.09% of the annual MPD. Extrapolating the data as an expression of averaged annual operator exposure resulted in a whole body dose of 0.4536 mSv (45.36 mrem) or 0.9% of the annual MPD, These results are well below established occupation exposure limits and are compatible with those published by the manufacturer.     

Minor corrections, clarifying changes, and a minor policy change--NRC. Final rule

The Nuclear Regulatory Commission is amending its regulations to make minor corrections and clarifying changes to the NRC's 10 CFR Part 20, "Standards for Protection Against Radiation." The final rule is also intended to conform other regulations with the Commission's 1991 revised radiation protection requirements. In addition, the final rule includes a minor policy change that raises the monitoring criteria for minors from 0.05 rem (0.5 mSv) to 0.1 rem (1 mSv) in a year and for declared pregnant women from 0.05 rem (0.5 mSv) to 0.1 rem (1 mSv) during their pregnancies. The 0.1 rem (1 mSv) in a year deep dose equivalent monitoring criterion is consistent with the public dose limit and represents a quantity more consistent with the measurement sensitivity of individual personnel dosimetry. Licensees are still required to ensure that the occupational dose limit of 0.5 rem (5 mSv) in a year is not exceeded for minors, that the dose limit of 0.5 rem (5 mSv) to an embryo/fetus due to occupational exposure of a declared pregnant woman is not exceeded during the course of the pregnancy, and that sufficient effort is made to ensure that substantial variations above a uniform monthly exposure rate for a declared pregnant woman are avoided. These changes to the threshold for monitoring exposures to radiation and radioactive material to demonstrate compliance with the limits do not change the occupational dose limits for minors or declared pregnant workers.     

The Analysis of a World War I U.S. Service Member's Dental Remains Recovered in France

In October 2009, the grave of an unknown World War I (WWI) U.S. service member was exhumed in Rembercourt‐Sur‐Mad Village, in the Lorraine Region of France. The skeletal remains and material evidence were accessioned into the Joint POW/MIA Accounting Command's (JPAC) Central Identification Laboratory (CIL). The personnel records for the associated casualty were requested, received, and reviewed. A dental profile was present among the service member's personal information. There were multiple points of concordance between the dental records of the associated casualty, and the recovered dental remains to include eight restored teeth, 15 unrestored teeth, and three antemortem missing teeth. Distinctive restorations which compared favorably included a porcelain crown and multiple gold foil fillings. All lines of evidence (historical, material evidence/personal effects, anthropological, and dental) and the circumstances of loss compared positively with the associated casualty. On April 1, 2010, the previously unaccounted‐for U.S. service member was positively identified and on June 23, 2010, was buried with full military honors at Arlington National Cemetery.     

Forensic dental training in the dental school curriculum

This article reviews the literature regarding forensic education in the dental school curriculum and describes an exercise in forensic identification of victims of a mass casualty. Radiographs were made of dentate human cadavers in the gross anatomy laboratory at the Southern Illinois School of Dental Medicine. The jaws were then removed to provide "wet specimens" for the exercise. Several restorations were performed on the cadaver teeth, after which radiographs of the dissected jaws were made. One author wrote up mock dental records for each of the victims. These records included the first set or "premortem" radiographs. Students participating in the exercise were provided with a plane crash scenario, the dental records of the passengers on the manifest, the dissected jaws, and the second set or "postmortem" radiographs. Students were expected to form three teams. The first two teams evaluated the ante-mortem and postmortem dental records. The third team compared the ante-mortem and postmortem records to arrive at identification. The purpose of the exercise was twofold. It introduced dental students to forensic dentistry and emphasized the need for complete and accurate record keeping in the dental office. Several factors lessened the realism of the exercise and made it difficult to reproduce in the future. These included the uniformity of the dental records and the destruction of cadaver material following the exercise.     

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.     

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.     

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.     

The design and assessment of mock mass disasters for dental personnel

Mass disasters represent a significant challenge for dental personnel who are frequently called upon to provide identifications. Recently-published materials have highlighted the need to prepare such groups for the disaster challenge and to report inadequacies in existing preparation methods with an emphasis on team integration, organization, and the psychological and emotional effects of such work. Many studies have retrospectively reported errors that have been made in disaster situations, but few have addressed the issues proactively. In an effort to provide a prepared team of dental members, a mock disaster exercise (Operation: DENT-ID) is conducted annually in Vancouver, Canada. The present study analyzes the effectiveness of this exercise in relation to team organization, assessment of preparedness, and the emotional and psychological issues. An index of preparedness is developed and described. This index, in the form of a questionnaire, can be given to participants in mock disasters to assess the effectiveness of such exercises. While the focus of this paper is on the assessment of dental personnel, the indices and methods used can be applied to any group working within the disaster team. Results indicate that the increase in preparedness as a result of the exercise was highly significant.     

The mental health and substance misuse needs of male ex-armed forces personnel in prison

Ex-armed forces personnel constitute the largest known occupational group in prison but there is little evidence regarding their mental health, or substance misuse, needs. A total of 105 participants were interviewed and measures assessing symptoms of common mental health (CMH) problems and substance misuse were completed along with a review of their health care records. Forty (38%) participants screened for current CMH problems (CCMH) and high levels of dual symptomology and alcohol misuse were assessed. Thirty-nine (37%) had a mental health diagnosis recorded, most commonly for post-traumatic stress disorder (PTSD), depression and personality disorder. Those who screened for a CCMH problem were more likely to have pre-service vulnerability to negative health outcomes and those with dual symptomology were more likely to have experienced deployment during their service. Findings suggest the mental health needs of this group are similar to the general prison population. Potentially higher prevalences of PTSD and alcohol misuse may direct service provision.     

Forensic dental training in Australia

To facilitate in the identification of victims of a major disaster a trained dental manpower reserve is required. In the state of New South Wales, Australia, an annual three-day training course has been designed to familiarize dentists from both the public and private sectors with identification techniques. The course is aimed to preserve the flexibility of personnel so that they can be utilized in a variety of roles rather than rigidly structuring the make up of a team. It is envisaged though, that in a mass disaster situation teams would be specialized into dental autopsy, antemortem or comparison roles.     

Searching for Kin Amidst Tragedy—Disaster Victim Identification Operations for US Bangla Flight 211

The nature of air disasters includes factors that exacerbate challenges in the identification process. Of the 49 deceased in the US Bangla air crash in Kathmandu, Nepal, four were intact, 11 presented with burn injuries, another 11 presented with partial charring, and 23 were completely charred. Personal belongings were useful in the identification phases for all types of victims. Fingerprints were obtainable and useful in intact victims and victims with less severe burn injuries; medical and surgical information was useful in bodies with burn injuries; finally, dental findings were useful in cases of extensive charring. Other useful methods in the process included marks of identification, physical features, and exclusion. In certain resource‐limited settings, especially in closed population disasters, where scientific identification (DNA, dental records, etc.) is not currently available, personal belongings, clothing, and physical findings analyzed by an identification team using a structured organization may be cautiously used as the primary means of identification.     

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.     

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.     

Validation of X-ray fluorescence spectrometry for determining osseous or dental origin of unknown material

Forensic anthropological examinations typically involve the analysis of human skeletal remains, but in cases where samples are very small and/or physically compromised, it may first be necessary to determine whether the material is even osseous or dental in origin. X-ray fluorescence spectrometry (XRF) is a technique that reveals the elemental composition of materials and is hypothesized to have utility in such cases. XRF analysis was conducted on a variety of tissues and materials in unaltered and altered (damaged) states. With few exceptions, osseous and dental tissues in unaltered and altered conditions contained characteristic levels of calcium and phosphorus, while other materials did not. Materials could be accurately identified as osseous or dental in origin based on the calcium and phosphorus levels identified by XRF, and we therefore conclude that XRF analysis is a valid and effective means of determining osseous or dental origin of unknown material.     

Estimating age in Maori, Pacific Island, and European children from New Zealand

The islands of New Zealand are populated by persons of European, Maori, and Pacific Island extraction. The purpose of this research is to quantify the levels of dental maturation of each of these three populations, in order to obtain data that will be useful in forensic identification and age estimation. The sample consisted of 1383 orthopantomographs (660 males, 723 females) of 477 Maori, 762 European, and 144 Pacific Island children between the ages of 3 and 14 years. Each radiograph was digitized and the stages of mineralization of the seven left mandibular permanent teeth were assessed using the eight stages described by Demirjian. Values for 1, 3, 5, 50, 95, 97, and 99% confidence intervals are listed for each maturity score. Intra-observer reliability was evaluated using Bland-Altman's method on data from re-scoring one out of every 20 radiographs and standard dental maturation curves were constructed for the three populations by means of a quantile regression method. Despite the fact that quantile regression analysis showed that across the age group investigated there were differences between boys and girls, knowledge of the sex does not increase the accuracy of the age estimate, simply because the magnitude of the error of age estimation is greater than the difference between the sexes. Our analysis also shows that population divergence is most marked after the age of 9 years, with a peak difference seen at age 10.     

数字全口牙位曲面体层片的法医学同一认定指标

目的采用颌面全口牙位曲面体层片,针对牙齿无病变者筛选简洁实用的法医学同一认定识别指标并进行编码、统计分析及评估。方法随机选取170例牙齿无病变者的颌面数字全口牙位曲面体层片进行观测．根据牙齿的生理变异特征和牙齿的排列特征分别筛选全口牙型和牙列型识别指标。按设计的编码标准对全口牙型、牙列型逐一编码,统计分析编码的多样性,以评估两类识别指标的应用价值。结果170例中共有74种全口牙型编码,多样性为43．53％：170例中共有129种牙列型编码,多样性为75．88％;170例同时进行全口牙型和牙列型编码．则共有150种全口牙型／牙列型编码,多样性为88．24％。结论全口牙型编码多样性较低,单独使用尚不能满足法医学同一认定的要求。牙列型编码的多样性比较高,具有一定的法医学同一认定价值。如果同时进行全口牙型和牙列型编码,多样性明显提高,有较高的法医学同一认定价值。     

Study of Chilean Children’s Dental Maturation*

Abstract: In forensic science, determining a person’s chronological age has become a challenge for researchers. Determining age using dental calcification is becoming increasingly important. The objective of this study is to estimate the dental age of the children’s population in Region VIII, Chile. The sample was randomly taken from children under the care of the Faculty of Dentistry at the Universidad de Concepción in Chile. The study encompasses 159 children between 3 and 14 years of age. The dental age was determined following the Demirjian method. The Bland–Altman method was applied to establish the correlation. It was determined that the range between chronological and dental age is similar, and the degree of correlation between both ages is nearly perfect. In conclusion, the degree of correlation between the chronological and dental ages for each gender is also very good although it is slightly higher for females.     

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.