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ePaper created 2015-02-10, 15:02:41 | version 1.33.01
Dr Richard Bassed Australia Nowadays, most people will associate forensic dentistry pri- marily with identification and bite markanalysis. These areas do indeed form the majority of an odontologist’s workload. There are, however, other as- pects of the discipline that are just as important but perhaps less well known. These include cranio-facial trauma analysis, age estimation for both living and deceased individuals, den- tal manifestations of child abuse, dental malpractice in- vestigations, as well as dental insurance fraud. Forensic odontology is an integral part of the medico-legal process. With this comes a re- sponsibility borne by forensic odontology practitioners for the requisite education, qualifica- tions and ongoing training. Courts and legal institutions now require that we have evidence- based research upon which we can rest our findings and conclu- sions.Inadditiontoknowledgeof the law, we have to have knowl- edge of human anatomy and its relationship to injury patterns andinterpretation.Knowledgeof bitemarkpatternsduetoassault, trauma and sexual abuse, as well as child abuse injury manifes- tations, is also required, as is knowledge of assessment tech- niques used when the age of an individual is unknown. Finally, there is a need to have knowl- edge of human identification methods, principles and prac- tices, as well as mass disaster identification procedures and protocols, and the ethical issues involved in the examination and management of dead bodies, and to have an understanding of human rights issues involved in war crimes investigations. All of these require thorough knowledge of cranio-facial ana - tomy, dental anatomy, dental and skeletal development, injury interpretation and medico-legal report writing. It is also impor- tant to have a good understand- ing of the law relating to the practice of dentistry, the coronial system, and the criminal justice system. As the majority of the forensic odontology caseload concerns the identification of unknown deceased individuals, most discussion in this article will concentrate on this. Honouring the dead is a fun- damental precept in all societies. The extent of this communal attention to the deceased varies across the world, but in essence every person hopes that his or her remains will be treated with respect after death. This respect for the dead includes, for many societies, robust identification of the deceased so that relatives and friends are able to treat the remains with appropriate cere- mony and are able to visit the resting place of the deceased whenever they wish. So impor- tant is the perception of personal identification in almost all so- cieties that authorities will go to extraordinary lengths to ensure that deceased individuals are notinterredinunmarkedgraves, or cremated without a name. To be buried anonymously goes against all of our religious, cultural and ethical belief sys- tems, and implies that a life unremembered and unmourned was really a life without con - sequence. William Gladstone, Prime Minister of Britain in the mid-1800s, encapsulated this sentimentbetterthanmostwhen he said, “Show me the manner in which a nation cares for its dead and I will measure with mathe- matical exactness the tender merciesofitspeople,theirloyalty to high ideals, and their regard for the laws of the land.” Hal Hallenstein, the Victorian State Coroner from 1986 to 1994, also had firm views concerning the importance of human identi- fication,articulatedinthefollow- ing quotation: “It is a hallmark of our civilisation that we regard it as an affront, an indignity, an abrogation of our responsibili- ties, that a person could live amongst us, die and be buried without a name.” In fact, the importance of identification of the deceased is enshrined in the Victorian Coroners Act 2008 (Sec- tion 67), which states “A coroner investigating a death must find, if possible, the identity of the deceased,thecauseofdeath,and the circumstances in which the death occurred.” Positive identification of the deceased not only satisfies a commitment to probity, but also resolves many legal issues sur- rounding an individual’s death, such as inheritance and life in- surance. If a deceased person remains unidentified, then tech- nically he or she will not be de- clared dead for a number of years, thus creating further dis- tress to families who not only are unable to put their lost loved one to rest, but may suffer financially as well. Personal identification of the deceased, and occasionally the living, is achieved through a va- riety of scientific and sometimes unscientific methods. Practition- ers from forensic science, foren- sic medicine, law enforcement and coroners’ offices apply their own particular set of skills to an identification problem in order to arrive at an answer. The most common method used to identify the deceased in all jurisdictions is undoubtedly visual recogni- tion by a relative or close friend. There is continual debate con- cerning the veracity of this method, given the propensity for error, which has been well doc- umented, especially in mass ca- sualty events and in situations in which the deceased has suffered trauma to the face. From the forensic medical/scientific per- spective, visual recognition is not proof of identity, but is only presumptive. Theory of human identification Methods used to achieve pos- itive human identification can be separated into two broad cate- gories. The first consists of those methods that are presumptive for identification, such as cir- cumstantial evidence, property associated with the body, and vi- sual recognition. These methods involve a high degree of subjec- tivity and rely on identifiers that arenotintrinsicto thebodyitself, are dependent on lay interpre- tation, and therefore can be fal- sified or mistaken (commonly known as secondary identifiers). The second category relies on scientific analysis of identifiers that are intrinsic to the body, such as dental restorations, fin- gerprints, DNA, and verifiable medical records (primary identi- fiers). These involve character- istics that can be objectively appraised and compared to ante- mortem exemplars in both a quantitative and a qualitative way and that are difficult or impossible to falsify. Of all the scientific methods, molecular biology is the only method that can mathematically quantify the degree of certainty for a particular match, with the other methods (including odon- tology) being somewhat depend- ent on more subjective method- ology and expert opinion. This reliance on even a small level of subjectivity can raise issues in courts when lay people do not haveadeepunderstandingofthe methods employed in an expert’s conclusion. Confusion can arise from the fact that there is often no unanimousindicationregarding which and how many character- istics are necessary in order to achieve a positive identification. The recurrence of discordant features excludes identity; the occurrence of several concor- dant features commonly ob- served within the population does not allow a final judgment on identification, whereas even a few features rarely observed can lead to a positive match. An example of this is a case in which the written dental chart describes amalgam restorations in each first molar. If the same is found in the de- ceased, is this sufficient evidence to confirm identity? Definitely not, as many people share this restoration pattern. If, however, we also have ante-mortem ra- diographs of those restorations displaying the exact shape, size and location within each tooth, and these compare favourably with the post-mortem radio- graphs, then few would argue that a positive match cannot be confirmed. There is, however, still no way to quantify this match, to put a probability ratio or a percentage certainty to it. It may be necessary in some cases to compare all of the teeth in a mouth in order to arrive at a match. In other cases, a single tooth with an unusual or com- plex restoration may be suffi- cient. It has long been the wish of identification experts to be able to quantify such matches, but no reliable method has yet Figs. 1: Comparison of ante-mortem (AM) and post-mortem (PM) radiographs, leading to a positive identification. Forensic odontology— Broader than just identification ‡ page 22DT Figs. 2a–c: A more difficult case highlighting that sometimes a degree of interpretation is required. DENTALTRIBUNE Asia Pacific Edition No. 1+2/2015 Trends & Applications 21 Fig. 1 Fig. 2a Fig. 2b Fig. 2c DTAP0115_21-23_Bassed 09.02.15 11:01 Seite 1 DTAP0115_21-23_Bassed 09.02.1511:01 Seite 1