Forensic Odontology

An Essential Guide

Catherine Adams, Romina Carabott, Sam Evans

• Publisher: Wiley
• Year: 2013
• ISBN:
  9781118526132
• Edition: 1
• Topic: Medicina
• Subtopic: Medicina forense

An accessible, essential introduction to forensic odontology. Written by a team of well-established, active practitioners in the field, Forensic Odontology is invaluable for those needing an introduction to the subject for the general dental practitioner who has an interest in forensic dentistry and is contemplating practicing in the field. It will also be useful as a reference during practice.

After a brief introduction the book covers dental anatomy and development, expert witness skills, mortuary practice, dental human identification, disaster victim identification, dental age assessment, bite marks, forensic photography and the role of the forensic odontologist in protection of the vulnerable person. Chapters outline accepted and recommended practices and refer to particular methodologies, presenting different schools of thought objectively.

Chapter 1

Brief introduction to forensic odontology

Romina Carabott

expertFORENSICS Ltd, Cardiff, UK

1.1 Introduction

According to Keiser Neilsen (1970; cited in Cameron and Sims, 1974), forensic odontology is:

that branch of dentistry which—in the interests of justice—deals with the proper handling and examination of dental evidence and with the proper evaluation and presentation of dental findings.

Forensic odontology, or dentistry, has been around for a long time: the identification of Lollia Paulina from her ‘distinctive’ teeth being as early as AD49, and the first use of bite mark evidence in court in a case of grave robbing in 1814.

The recent attention of the media on forensic ‘specialities’ featured in various fictional television series has seen an increased interest in this already fascinating subject. This heightened interest, however, has not always been for the right reasons. The use of dental identification in mass fatalities as the more efficient means of identification of severely decomposed bodies has attracted particular attention in natural disasters such as the Boxing Day tsunami in Thailand (2004), the Black Saturday bushfires in Australia (2009) and the Christchurch earthquake in New Zealand (2011). On the other hand, The Innocence Project (see references) has highlighted the ‘abuse’ and ‘misuse’ of bite mark analysis as reliable evidence in court; see also Bowers (2006), Pretty and Sweet (2010), Bush (2011) and Metcalfe et al. (2011).

To those involved in bite mark analysis research, this ‘attack’ on the validity of this identification science may not have come as a complete surprise (Clement and Blackwell, 2010; Pretty and Sweet, 2010). Bite mark evidence may be perceived by some in the investigative arena, who are not familiar with this area of forensic odontology, as a science akin to fingerprint analysis or DNA analysis. This is not the case, as was clearly highlighted in the report of the National Academy of Sciences (NAS) entitled Strengthening Forensic Science in the United States: A Path Forward (2009):

there also are important variations among the disciplines relying on expert interpretation. For example, there are more established protocols and available research for fingerprint analysis than for the analysis of bite marks. (p. 87)

Much forensic evidence—including, for example, bitemarks and forearm and tool mark identifications—is introduced in criminal trials without any meaningful scientific validation, determination of error rates, or reliability testing to explain the limits of the discipline. (p. 107)

The potential for bite mark evidence to be as useful as other forensic science disciplines may exist, but to date the very nature of the evidence renders sound and rigorous scientific research extremely difficult. Numerous publications have highlighted the lack of sound empirical evidence backing the two basic postulates of bite mark evidence and the paucity of rigorous research surrounding this discipline (Bowers, 2006; Pretty and Sweet, 2010; Bush, 2011). This is not to say that sound research has not been conducted over the years, but merely that more of such high-level research needs to come through. Until such a time when ‘the barriers to such encompassing and rigorous research to support bite mark evidence’ (Pretty, 2006) can be overcome, bite mark analysis needs to be applied to forensic case work with extreme caution.

A forensic odontologist's expertise in bite mark analysis lies in his/her ability to recognise the limitations of bite mark analysis for each individual case (Pretty, 2006). If such caution is applied, the credibility of bite mark analysis will not be irrevocable damage in the long term despite the wrongful convictions documented to date. With the progress of technology in leaps and bounds and ‘the willingness to utilise’ (Clement and Blackwell, 2010) such technology and science, there will still be a place for bite mark analysis in the investigators' arsenal.

Dental identification has attracted less media attention than bite mark analysis: the methodology is well understood and accepted, and its efficiency, cost-effectiveness and success have been witnessed on numerous occasions (Schuller-Götzburg and Suchanek, 2007; Bush and Miller, 2011; Hinchcliffe, 2011; Tengrove 2011); but that does not mean that it doesn't have challenges to contend with. Improvements in oral care—with an associated reduction of restorations available for comparison—highlight the importance of dental radiography which allows unique anatomical features to assist in establishing a dental identification. Chemical, biological, radiological and nuclear (CBRN) threats call for safe means of collecting dental evidence at the scene, such as cone-beam CT technology. Educating the members of the dental team in the advantages of dental identifications, ideally as early as undergraduate level, is required so as to continue to address the age-old problem of poor ante-mortem dental records which has always hindered the dental identification process. The advent of dental record keeping software addresses part of the problem but has been known to create other minor issues that must be kept in mind.

Mobilisation of individuals from areas of conflict into Europe has increased the requirement for a means to reliably assess the age of a living individual. Discussions are on-going, particularly in the UK, as to the reliability of dental age estimation of young adults and the ethical implications associated with exposing an individual to radiation for these purposes. In the author's view, the expertise of a forensic odontologist is not reflected in how well he/she mastered the age estimation techniques, but in his/her awareness of the limitations of these methods. Arguably, more important is the skill of explaining clearly to a judge and jury those same limitations and how they may apply to the particular case at hand. Interpreting the results and the statistical background of the methodology used in a way that is clear to the uninitiated is probably the main challenge; more so when various statistical approaches have been applied and then superseded over the years.

1.2 Forensic odontology in the 21st century

Forensic odontology has seen very few major developments over the last 20 years. Changes were mainly related to the assimilation of IT developments into this area of expertise. A very clear example is the improvement in bite mark analysis, previously relying on manual overlay production, while today it is often done with the aid of software such as Adobe Photoshop®.

Research and development in forensic odontology is hampered by two main problems:

1. Ethical issues make adequate research in bite mark analysis, child protection cases and age assessment difficult to conduct.

2. Securing funding for such research and development is notoriously difficult as most funding tends to be directed towards traditional medical and dental specialities (Pretty, 2006).

Despite these difficulties over the last few years, through the dedication of those interested in this area and postgraduate student research, the application of forensic odontology is slowly acquiring a more robust backing from rigorous scientific research (Sheets et al., 2012, 2013; Bush et al., 2011). The application of medical devices, software and improved technology to address difficulties in forensic dentistry is seen as a move in the right direction.

The following are some examples of recent and current research:

• Portable X-ray units, developed largely with the veterinary services in mind, were brought to the attention of the international forensic dental community by the New Zealand DVI (Disaster Victim Identification) team during identification of the victims of the Boxing Day tsunami in Thailand. One of these units is now on the essential equipment list of the UK DVI team and, coupled with digital x-ray software, it eliminates the need for removing jaws for radiographic examination (both in isolated identifications as well as in mass fatality scenarios), when the only purpose for such removal of jaws is radiographic examination with traditional dental radiographic equipment.
• Mobile multi-slice computed tomography (MSCT) has been part of various research programmes into the application of virtual autopsies in multiple fatality scenarios where CBRN contamination is known or suspected. Concomitant current studies are also assessing whether a similar principle could be applied to dental identification in such scenarios. Cone-beam CT (CBCT) technology provides superior quality dental detail to MSCT and, if applicable, may have the potential to provide post-mortem dental information without the need for direct examination of contaminated bodies.
• Three-dimensional imaging for patterned injuries (bite m...