A comparative reliability analysis of computer-generated bitemark overlays

This study compared the reliability of two methods used to produce computer-generated bitemark overlays with Adobe Photoshop (Adobe Systems Inc., San Jose, CA). Scanned images of twelve dental casts were sent to 30 examiners with different experience levels. Examiners were instructed to produce an overlay for each cast image based on the instructions provided for the two techniques. Measurements of the area and the x-y coordinate position of the biting edges of the anterior teeth were obtained using Scion Image software program (Scion Corporation, Frederick, MD) for each overlay. The inter- and intra-reliability assessment of the measurements was performed using an analysis of variance and calculation of reliability coefficients. The assessment of the area measurements showed significant variances seen in the examiner variable for both techniques resulting in low reliability coefficients. Conversely, the results for the positional measurements showed no significant differences in the variances between examiners with exceptionally high reliability coefficients. It was concluded that both techniques were reliable methods to produce bitemark overlays in assessing tooth position.     

Adherence of forensic odontologists to the ABFO guidelines for victim evidence collection

Certifying boards for different professions have the duty to help establish standards and guidelines for methodologies routinely performed within the discipline. For forensic dentists, this responsibility is placed upon the American Board of Forensic Odontology (ABFO). The purpose of this study was to examine whether board certified and noncertified forensic odontologists adhere to the ABFO Guidelines outlined in the collection of victim bitemark evidence. A questionnaire was developed to assess the compliance and attitudes towards the typical evidence collected, the photographic documentation, and the handling of the bite site injury. The results indicate the majority of the respondents in both representative groups routinely follow the guidelines set forth by the ABFO. The lack of personally photographing the bite injury on a consistent basis is an area of concern for all examiners. The photographic evidence is an instrumental part of the investigation and often cannot be utilized due to improper procedures being followed. The film type utilized, bite site impression techniques, and excision of any tissue samples remain an individual choice and vary significantly among each forensic odontologist.     

Digital bite mark overlays--an analysis of effectiveness.

U.S. courts have stated that witnesses must be able to identify published works that define operational parameters of any tests or procedures that form the basis of scientific conclusions. Such works do not exist within the field of bite mark analysis. As the most commonly employed analytical technique in bite injury assessment. this study defines quantifiable variables for transparent digital overlays. A series of ten simulated, postmortem bites were created on pigskin and, with accompanying overlays, assembled into cases. Using two separate studies with four examiner groups, the study defined values of intra- and inter-examiner reliability, accuracy. sensitivity, specificity, and error rates for transparent overlays. Methods and statistical treatments from medical decision-making and diagnostic test evaluation were employed. Forced decision models and receiver operating characteristic analyses were utilized. Sensitivity and specificity values are described. and the results are consistent with other dental diagnostic systems. It was concluded that the weak inter-examiner reliability values explain the divergence of odontologists' opinions regarding bite mark identifications often stated in court. The effect of training and experience of the examiners was found to have little effect on the effective use of overlays within this study. The authors conclude that further research is required so that the results of the current study can be placed into context, but this represents a significant first step in establishing the scientific basis for this aspect of forensic dentistry.     

Digital dental radiographic identification in the pediatric, mixed and permanent dentitions.

The purpose of this paper is to investigate the utility of digital dental radiographic superimposition in the various stages of development of the human dentition. Digital, computer assisted dental identification is a means of identification which allows the spatial relationships of the root and support structures of the teeth to be compared one to the other. The technique has not been tested in patients with developing dentitions. Dental radiographs from patients in the pediatric, mixed and permanent dentition stages of development, simulating "antemortem" and "postmortem" radiographs, were digitized using a flat field radiograph scanner. Anatomic features were used as points of comparison utilizing image editing software whereby anatomic sections were digitally cut from the antemortem image and compared to the same anatomic locations on the postmortem image to assess for points of concordance. The technique was applied to 25 cases within the primary dentition, 25 cases within the mixed dentition and 25 cases within the permanent dentition. Results showed that this was a viable technique within both the pediatric and permanent dentition although it was of little value within the mixed dentition.     

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.     

Dental participants in mass disasters--a retrospective study with future implications

Mass casualty incidents continue to require the services of forensic dentists to determine the identity of victims. Across North America and Europe. teams of forensic dentists train, using mock disaster exercises, to prepare for such duties. It is vital that these mock exercises simulate the features of real disaster situations as far as possible. In order to inform those responsible for the design and implementation of mock exercises, a study was undertaken to determine the features of actual disasters that dental personnel had attended. Using a questionnaire, data were solicited from 38 odontologists. The average number of disasters attended by the respondents was eight, with an average casualty number of 94. Aircraft crashes were the most frequent cause of disasters that were attended by the odontologists. The authors conclude that future mock disaster exercises should replicate features of aircraft crashes as closely as possible by using commingled, fragmented, and burned remains. In addition, mock disasters should require the identification of a realistic number of individuals to ensure authenticity and the maximum logistical preparedness of participants.     

Reversing delegation? Politicization,de-delegation,and non-majoritarian institutions

Elected governments and states have delegated extensive powers to non-majoritarian institutions (NMIs) such as independent central banks and regulatory agencies, courts, and international trade and investment organizations, which have become central actors in governance. But, far from having resolved the balance between political control and governing competence or removed certain issues from political debate, NMIs have faced challenges to their legitimacy by elected officials and sometimes attempts to reverse delegation through “de-delegation”. Our special issue studies the politicization of NMIs, and then whether, why and how it leads to de-delegation through reducing the formal powers of NMIs or increasing controls over them. In this article, we examine how to analyze de-delegation, how politicization of NMIs has developed, and how it has affected de-delegation. We underline not only institutional rules that constrain elected officials but also the actions of NMIs themselves and their relationships with other NMIs as part of multi-level governance systems. We find that politicization has varied, but even when strong, elected officials have not introduced widespread and long-lasting de-delegation; on the contrary, they have frequently widened the powers of NMIs. Insofar as elected politicians have sought to curb NMIs, they have often preferred to use existing controls and non-compliance. Finally, we consider the wider implications of the combination of politicization and lack of de-delegation for broader issues of governance such as the division of powers between the elected and unelected and democratic accountability.