Application in Forensic Odontology - Essay Example

Forensic Odontology Abstract Forensic Odontology is widely used in criminal investigation particularly in identification of remains of unknown or deceased individuals as well as identifying assailants of victims of crimes through bite mark analysis. Several procedures must be accomplished by a forensic odontologist to carry out a dental examination of the remains of an unknown person during post mortem examination. Results will be compared to the ante mortem dental data of the individual under investigation. Photography, radiography, jaw resection and dental impressions are necessary procedures that must be undertaken by a forensic odontologist to accurately present an objective dental post mortem examination report to investigators. Photography, for example, has evolved in forensic odontology. Digital photography has been commonly used in recent times over traditional film photography. Such shift in photographic preference delves on the issue of accuracy, cost efficiency and portability. Forensic Odontology Introduction Forensic odontology forms part of the branches of forensic medicine which is being used to assist in the provision of justice in criminal investigation. It specifically appropriately examines, handle and present dental evidence in court of justice. A forensic odontologist is the appropriate person that carries out the role of forensic odontology in criminal investigation. Table 1 shows the specific roles of a forensic odontologist in crime investigation as outlined by the British Association of Forensic Odontology (Pretty, n.d.) which is carried out usually in close coordination with forensic pathologist and forensic anthropologist. Table 1 Role of Forensic Odontologist in Crime Investigation 1. Identify unidentified remains of human through the use of dental records. 2. Assist situations of mass disaster such as terrorist attack, fire, etc. 3. Analyse bite marks on victims of attack. 4. Identify bite marks found in other materials such as wood, leather and food that will be useful in crime investigation. 5. Analyse marks of weapons using the guidelines of analysing bite marks. 6. Present evidences of bite and weapon marks in court. 7. Establish an image of way of life and dietary habits in a site for archaeology. The above information showed the importance of the role of forensic odontologists to the establishment of justice in criminal cases by creating a picture of the persons involved in criminal situation thereby identifying either the victim or the attacker. Either way of identification will greatly shed light on who are involved in criminal acts helping criminal investigators establish the commission of a crime and who are involved in it. Consequently, the court of law will be able to analyse criminal cases and arrive at an objective decision using the evidence established by forensic odontologists. Identification of unidentified remains and analysis of bite marks are the crucial roles of forensic odontology in criminal investigation. It sums up the various roles of forensic odontology outlined in Table 1. The discussion of this essay will focus on these two crucial roles of forensic odontology in criminal investigation. However, there is a need to discuss first why odontology is significant in forensic medicine or in the provision of justice in the court of law to give a logical background on why the roles of forensic odontology in identifying unidentified remains and analysing bite marks is significant in criminal investigation. Significance of Odontology in Criminal Investigation Odontology is the science that studies the composition of teeth. It is currently used intensively in both civil and criminal investigation particularly in identifying victims and committer of crimes. The ability of the teeth to survive even in disastrous circumstances (Bowers, 2004, p.1) makes forensic odontology an important branch in forensic medicine and criminal investigation. There are characteristics present in the shape of teeth, its appearances, its fragments, its restorations, the skull and the jawbone that is unique only to one person (p.1); hence making it an important tool for identification of missing person and unidentified remains. Even twins have different dental structures as found out during identification of victims of Indian Ocean Tsunami in December 26, 2004 (Rai & Anand, 2007). Deoxyribo Nucleic Acid or DNA present in the interior of teeth and saliva is an important contribution of forensic odontology to identification of missing or unknown persons (p.1). Dental records are particularly significant in cases where fingerprints are not available such as cases where decayed or human skeleton (p.2) is the only evidence that investigators have. It is further significant if such situation lacks other direct identification such as identification cards, residential address or registration of vehicle. Availability of dental information before and after the death of a person is crucial in identification (p.3). In the absence of dental records, a DNA testing of the dentition of a decayed remains or dead person can help identify such person. Teeth or bite marks are manifested in “food, soft objects, and on human skin” (p.3) which can either be left on a crime scene or on bodies of victims of assault. Forensic odontologists compare such bite marks to that of a person suspected of committing the crime. Thus, overall, forensic odontology is very significant in criminal investigation particularly in identification. Consequently, a highly qualified forensic odontologist can surely be an asset to a team of crime investigators. Identification of Deceased or Unknown Individuals Forensic odontology was found effective in the identification of the bodies of the victims of the December 26, 2004 Indian Ocean Tsunami since it can identify “decomposed or damaged bodies” (Rai & Anand 2007 par. 14). The British Association of Forensic Odontology or BAFO gave an example on the significant contribution of forensic odontology in the identification of the remains of a deceased or unknown individual. It can help identify the identity of a month’s old mummified remains of a female, for example, “by studying the development of tooth roots” (BAFO Website par. 8) forensic odontology can help established the age of the unidentified remains of individual which can be matched with the dental records of missing persons in recent moths thereby leading to the individual’s identity. Even in the absence of teeth, x-ray results of jaws and skulls that hold the dentition can provide useful information on the identity of unknown remains of an individual. Forensic odontologist should be present already at the early stage of police investigation to aid authorities in maximising time in solving a case of identifying unknown remains of deceased individuals. His dental examination is usually done either in the morgue, funeral home or private facility for consultation under the direction of the coroner or medical examiner (ABFO 2009 p. 166). Post mortem reports of remains of deceased individuals should be immediately be matched with that of the pre-mortem dental records to established matching of identity. “Burnt, decomposed and severely traumatised cases” (ABFO 2009 p.166) are the usual cases that require dental identification. However, ABFO guidelines required that all cases involving death particularly of unidentified person should have a record of dental information as part of the police report; hence the necessity of retaining a forensic odontologist at the start of case investigation. The following materials should be provided by forensic odontologist to assist case investigators: (1) findings, recommendations and conclusion in a forensic odontology report and (2) necessary documents such as charts, photographs, models and radiographs. Post Mortem Dental Identification Procedures Table 2 below shows a total of eight procedures were outlined by ABFO in the dental identification of deceased or unknown remains of an individual during the post mortem process. A brief discussion of each procedures follows. Table 2 8 Dental Identification Procedures in Post Mortem 1. Examination process 5. Dental examination 2. Photography 6. Narrative description and nomenclature 3. Jaw resection 7. Dental impressions 4. Post mortem dental record 8/ Dental radiography Source: ABFO Guidelines accessed from http://www.forensicdentistryonline.org Examination process. The examination process utilise tools depending on the severity of the case of dental identification involved. Table 3 shows the tools used in three different cases of dental identification. Photographs, radiographs, resection and dental charting or examination are the four tools that were commonly used in dental identification of cases where remains are still visually identifiable, decomposed and skeletonised. These will be further discussed in later sections. Table 3 Tools Used in Dental Examination of 3 Different Forensic Odontology Cases of Identifying Remains of an Individual Visually Identifiable Remains Decomposed Remains Skeletonised Remains Photographs Photographs Photographs Radiographs Radiographs Radiographs Dental Charting Dental Charting Dental Charting Dental Impressions Resection and Preservation of Jaw Specimens Preservation of jaw specimen Resection by Infra-mandibular dissection Photography. A photograph of dental evidence is an objective document necessary in a post mortem dental report. ABFO requires the use of a right angle ruler in taking a dental photography during post mortem. Further, it recommends usage of a single lens reflex 35 mm camera with a bellow system or lenses capable of close up photograph. When taking photograph it is recommended take it at a close up angle view of the anterior teeth with lateral views slightly open in position and occlusal views for both upper and lower teeth (ABFO). Jaw resection. Jaw resection or dissection is sometimes necessary in forensic odontology to gain extensive examination of the dental structures of the remains of a deceased or unknown individual. However, it requires the approval of the coroner or medical examiner (AFBO). It can be applied in cases where there is a need to transfer body parts of an unknown or deceased individual to other testing facilities or when a homicide victim is going to be cremated (AFBO). Post mortem dental record. Basic data, general body description, and description of jaw fragments are the information that should be listed in the post mortem dental record. This information should be comprehensive to ensure finding a quick match in ante mortem records. Case number, time, jurisdiction, location and identification are the basic data needed in the post mortem report. On the other hand, approximation of age, race, gender and physical condition are information for general description of the remains of the unknown individual. (ABFO). Dental examination. ABFO recommends the use of universal tooth numbering system which would show any missing teeth structure or fragments of the jaw. It will be shown in a dental chart that includes configuration of dental structure, materials used in restoration of the teeth, periodontal condition, and occlusal relationship. A photograph of intra oral condition should also be included to present the anatomical illustration of restorations of the teeth, lesions, etc (ABFO). Narrative description and nomenclature. The dental examination chart must be supplemented by a narrative description of the findings of the post mortem emphasizing the unique condition of the denture. Nomenclature must include universal numbering system including the actual name of the tooth, type of dentition and surfaces of teeth, prosthetics and other restorations used. Dental impressions. Dental impressions are necessary for bite mark analysis. The following section on bite mark analysis will discuss this further. Dental radiography. Dental radiography is required for cases where there is an absence of reputed identification, unlocated ante mortem records and the risk of not retaining the jaws of the victim. Radiograph of intra oral, dental fragments, edentulous areas, and extra oral areas (AFBO) are necessary for post mortem dental examination. It is recommended that that a double pack intra oral film will be used for this procedure. Two sets of films will be retained each by the forensic odontologist and by the coroner or medical examiner. Bite Mark Analysis to Identify Assailant of a Victim New York Times reported a case wherein bite mark analysis was used to include and exclude a suspected person in a criminal prosecution for attacking a victim. The bite marks on the victims body was used as an evidence to convict the suspect (Santos 2007 par. 1). However, DNA testing of the saliva left by the person who had bitten the victim proved that the convicted suspect is not the real criminal; hence he was released from prison. Such case clearly showed the role of bite mark analysis in proving either the innocence or liability of a criminal suspect. The “anatomy and physiology of the skin” (Forensic Science Communication 2001 par. 2) where the bite mark is manifested as well as the position of the victim affects the details of the bite mark consequently affecting its analysis. “Measurements, angles, and other features” (par. 4) of the bite marks in the victims body must be established first before comparison is made to the teeth of the suspect. Bite mark matches Michael Bowers’ (2001) forensic odontology report on bite mark analysis of a case involving a suspect accused of causing such bite mark in a victim’s body recommended that the accused is not the one who have caused the bite mark due to the fact that a comparison of the bite mark and that of the suspect’s teeth structure showed a discrepancy. The impressions on these bite marks were based on physical or visual inspection of the bite mark and on the original autopsy photograph. Analyses from these techniques were matched with the suspect’s teeth structure gathered from his dental records. Such bite mark matches resulted to the recommendation that the suspect is not in any way responsible for the bite mark in the victim’s body therefore there is a higher probability that he was not in any way near the victim when he or she died. Getting bite mark impressions can be maximised using the appropriate supplies and equipment. Suitable trays, alginate, and dental stone are the materials needed for carrying out the dental impressions. Maxillary and mandibular impressions (ABFO) are gathered during dental or bite mark analysis. These two sets of impressions are modelled with proper labels. Characteristics of bite marks and suspect’s teeth. Matching of bite marks with the suspect’s teeth is derived based on its following characteristics as illustrated in Table 2. Table 2 8 Characteristics of Bite Marks and Suspect’s Teeth 1. Distance from cusp to cusp of the teeth 2. Shape of mouth curve 3. Proof of tooth that is out of alignment 4. Width, thickness and spacing of teeth 5. Missing teeth 6. Curves of teeth edges for biting 7. Distinctive restorative dentistry 8. Patterns of wear of the teeth , for example, chips and grinding Source: Police South Wales website If the analysis of the odontologists resulted to non-matching of the characteristics between the bite marks found in the skin of the victim and the teeth of the suspect it will result to non-conviction of the latter. However, if the result is positive the latter will have no choice but to plead guilty to the crime. Saliva analysis The absence of a comparison of dental records of the suspect and the bite mark in the victim’s body can be rectified by using the saliva found in the skin where the bite mark is located as a source of information to identify who attacked the victim. As mentioned earlier, the saliva is a good a source of DNA of a person; hence getting a sample of the saliva present in the bite mark would help identify who caused it. In some court cases, a convicted person found guilty of attacking a victim as evidenced from bite marks is retried and found innocent when the evidence presented from the DNA of the saliva found in the bite mark proved that he is not the person who attacked the victim. Digital Photography in Forensic Odontology Digital photography is slowly replacing traditional photography in forensic odontology. It is basically used for identification and bite mark analysis. Bower and Johansen (2001) emphasized that in bite mark analysis the use of linear scale be placed side by side with the bite mark to rectify any inaccuracies in analysis of the comparison of bite marks. The resizing of the photograph must be life size (Forensic Science Communications 2001) to ensure that analysis of “similarities and dissimilarities in shape, size, positioning, etc seen in the bite mark” (par.1) is accurate. Advantages Digital photography, for example, of the bite mark is an important tool in accurately assessing whether it matched the teeth structure of the suspect. Its higher resolution capability allows such accurate matching (Page 2007, Scarborough, 2005). Using specialised films for forensic dental photography is not easily found nowadays and is costly. Also, processing time using films took longer time to finish and is not convenient and not portable for electronic transfer unlike digital photography. One odontologist shared his experience finding for traditional films wherein it has taken him two weeks to obtain black and white infrared images from the laboratory. Such time frame was impractical since bite marks and wounds are already gone or healed by that time; hence bite mark analysis suffers (Page 2006). Further, another important advantage of using digital photography in forensic odontology is the lower cost of using digital photographs compared to traditional black and white photographs. Disadvantages One of the downside of digital photography is its susceptibility for manipulation. Altering it is much easier compared to traditional film (Page 2006) by just using imaging soft wares. Thus, it becomes the basis of challenging its admissibility in court as evidence for forensic investigation. Also, storage of digital images is another downside to digital photography since it will incur higher cost for the criminal investigation agencies. Conclusion Forensic odontology is a necessity in the identification of victims and perpetrators of crimes. Crucial in its implementation is a highly qualified forensic odontologist that can carry out dental examination process as accurately as possible to ensure that effective and efficient identification is done. It is crucial that a forensic odontologist must be involved at the first stage of case investigation to eliminate delay in identification of persons involved in the crime and subsequent crime resolution. Also, it is important that a set of guidelines be established in carrying out the process of identification of crime victims and assailant. Thus, an established organization like the AFBO or BAFO is necessary to ensure that proper forensic dental identification is carried out for unknown remains of deceased individuals. These organizations will help monitor that investigation agencies carry out properly the procedure of identification using dental examination. References American Board of Forensic Odontology. The ABFO Identification Guidelines [Online] Available at http://www.forensicdentistryonline.org/Forensic_pages_1/ident_guidelines.htm [accessed on 23 August 2009) Bowers, M.C.2004. Forensic Dental Evidence: An Investigator’s Handbook. Elsevier Academic Press. Bowers, M.C. 2001. Report: Crime Evidence. [Online] Available at http://forensic.to/webhome/bitemarks2/ [accessed on 10 August 2009] Bowers, M.C. & Johansen, R.J. 2001. Digital Rectification and Resizing Correction of Photographic Bite Mark Evidence. Forensic Science Communications, Vol. 3, No. 3. British Association of Forensic Odontology.2002. Forensic Odontology [Online] Available at http://www.bafo.org.uk/guide.php [accessed on 12 August 2009] Griffith, D. 2004. The Practice of Crime Scene Investigation: Establishing Identity with Odontology. Compiled by Horswell, J. Introduction to the Steps of Bite Mark Analysis. Forensic Science Communications, July 2001, Vol. 3, No.3. Available at http://www.forensic.to/webhome/bitemarks/ [accessed on 10 August 2009) Page, D. 2006. Forensics Focuses on Digital Photography. Forensic Magazine [Online] Available at http://www.forensicmag.com/articles.asp?pid=36 [accessed on 20 August 2009) Pretty, I. n.d. Forensic Odontology. [Online] (Updated 2009) Available at http://www.all-about-forensic-science.com/forensic-odontology.html on 12 August 2009 Rai, B. & Anand, S.C. 2007. Role of Forensic Odontology in Tsunami Disasters. The Internet Journal of Forensic Science. Vol. 2 No. 1 [Online] Available at http://www.ispub.com/journal/the_internet_journal_of_forensic_science/volume_2_number_1_19/article/role_of_forensic_odontology_in_tsunami_disasters.html [Accessed on 20 August 2009) Santos, F.A. 2007. CSI Effect: Evidence from Bite Marks, It Turns Out, Is Not So Elementary. New York Times [Online] (Updated 12 August 2009) Available at http://www.nytimes.com/2007/01/28/weekinreview/28santos.html?_r=1 [accessed on 12 August 2009]. Scarborough, S. 2005. Film to Digital Conversion. Forensic Magazine, April/May [Online] Available at http://www.forensicmag.com/articles.asp?pid=36 [accessed on 20 August 2009] Read More