Forensic Dentistry: Helpful Solution - Essay Example

Running Head: Forensic Dentistry Forensic Dentistry: Helpful Solution of the of the What do youdo when a forensic case comes up to you and you have absolutely no where to begin with Do you hand it over to some one who can identify it Or you just try to guess around with the possibilities. If you're a dentist then have no fear, the teeth are here. Or at least what's left of them. Teeth are no doubt the most stubborn remnants of the human body, and have been extremely helpful in identifying the deceased individuals that you may come across with. It is now an established fact that no two mouths are alike, and therefore leave a personal imprint in the bite. Usually the mandible delivers more force than the maxilla, and therefore the stronger impression is of the lower teeth on the skin. The timing in recording these evidences is small, as bite marks alter with time on the skin depending upon the individual. It is in addressing this problem that the ABFO recommends frequent photographs of the bites at periodic intervals. (Forensic Odontology, 2006) The identification of individuals was seriously appreciated when the results of a study conducted on five identical twins took place in 1982. The study demonstrated that even identical twins have difference in their dental morphologies. (Bowers, 2000) It is in the same context that we have come to identify the individuality of the dental bite marks. It is a general consensus that bite marks are quite individual for every human, and chances of same bite marks be found from another human are rare. (Bowers, 2000) Pretty and Sweet (2001) very sweetly describe forensic dentistry as "the overlap between the dental and the legal profession." A complete statement in itself. Forensic dentistry has proved itself as an integral part of the forensic health studies, where it has been accurate in identifying different cases where other evidences were scarce. (Pretty & Sweet, 2001) Another name that has been given to it is "bite mark evidence expertise". The process is simple. It involves "identifying the assailant by comparing a record of their dentition (set of teeth) with a record of a bite mark left on a victim."(Forensic Odontology, 2006) Most of the dental identification procedures follow the guidelines set by the American Board of Forensic Odontology, 1984. It has in detail explained the various procedures to be carried out under different cases and circumstances. These guidelines have been extremely helpful in providing oriented framework for postmortem dental procedures. (ABFO Guidelines, 1984) So what do we do and how do we help the law Simple. Forensic dentistry works by identifying the individual and assessment of the dental bites. It becomes a very helpful tool in situations where the victim died due to a natural calamity, or when the victim's body was too damaged to provide a single shred of identity. One of the most important events where dental records and forensic dentistry played its part was in the identification of victims of the 09/11 attack. If the role of forensic dentistry was to be outlined it would be as follows. (What is Forensic Dentistry) "Forensic dentistry helps in the identification of living and dead individuals. It helps in the bite mark analysis, identification and comparison Lip print and rugae print analysis, identification and comparison Patterned injury identification, analysis and comparison Identifying dental specimens at the crime scene or elsewhere Evaluation of orofacial trauma Malpractice and negligence claims"(Forensic Dentistry) Many procedures are undertaken to identify the body. The most common approach is the comparative identification approach. This approach relies on comparing the postmortem records with antemortem records of the individual. These records can be various office notes,study casts or radiographs, or photographs of the individual. Naturally, the complication arises when the individual did not have any significant dental treatment done. In other words, if the body's dental status is not significant, the search for identity can be very tiresome. (Pretty & Sweet, 2001) So what does the "forensic dentist" do when he comes face to face with the body He is to give the body full "oral examination" and is to note down the features and the structures of the oral and the perioral areas. This charting not only includes the dental tissues but the stomatognathic soft tissues as well. The dentist will take various photographs and radiographs of the individual, and if antemortem records have been located, he or she will replicate the photos and the radiographs on the same angulations as the antemortem records. This will allow the dentist to easily compare and evaluate the dental structures. (Pretty & Sweet, 2001) The dental records consist of the universal numbering system method, and include the charting of filling/s, extraction/s, surface structure/s, root configuration, adjacent teeth and twisted/tilted teeth. (Forensic Odontology, 2006) Other aids to identification include teeth whether natural, synthetic, and removable or fixed the type of bone, presence of foreign bodies, configuration of the sinuses, the sutures of the skull, the soft tissue features, comparisons through photography, and DNA analysis. (Forensic Dentistry) This comparison is an exhaustive procedure, where each and every tooth is examined in the finest of details. Discrepancies in such cases must be taken into account which may be due to time lapse between the antemortem and postmortem records. These discrepancies can be explainable or unexplainable and if unexplainable, the exclusion criteria must be followed. (Pretty & Sweet, 2001) When identifying the individual with the help of radiographs, two approaches are taken, feature extraction and feature matching. Feature extraction records the individual details of the patient's dental morphology for example the contours of the teeth etc. the analysis is carried out via the radiograph segmentation technique. (Jain & Chen, 2003) In this technique the dental radiographs are segmented into blocks so that each segment contains a tooth and then is analysed individually. This is carried out by first separating the upper and lower teeth segments followed by individual tooth analysis. Within this segmentation the dentist looks for gap valleys, isolated teeth, contours extraction and root contour extractions, and shape matching. (Jain & Chen, 2003) The identification of bite marks becomes most important cases of "homicide, sexual assault and child abuse" (Pretty & Sweet, 2000) Biting in the case of the victim is a way to defend one self, where as in the case of the assaulter is "an expression of dominance, rage and animalistic behavior." (Pretty & Sweet, 2000) Bite marks are evaluated by physical examination, and by evaluation of photographs on skin or other substances. Since this analysis is the example of comparative analysis, emphasis is placed on correct magnifications and resolutions to most accurately draw conclusions. Use of the incremental lines of scales helps in correctly reproducing the resolutions. The process has become more sensitive thank to digital imaging systems. (Bowers, 2001) The "Dorian method" involves microscopic examination of the bite mark. (Forensic Odontology, 2006) Bite marks if observed intently can be very often discovered during routine dental office visits. These bites can be found in children, spouses or elders, and correct identification and notification to appropriate authorities can help in preventing further incidences. (Tsang & Sweet, 1999) Bite marks can give significant amount of information about the assault and the identification of the assaulter. The "impression" that a bite mark leaves on the victim is defined as "clearly defined, obviously defined, quite noticeable or lacerated". (Forensic Odontology, 2006) In the same way, the type of injury that these bite marks can cause are divided in to seven categories. These are "hemorrhage, abrasion, contusion, laceration, incision, avulsion and artifact."(Forensic Odontology, 2006) The location of the bite mark varies with the kind of assault. Bites on breasts and legs are mostly seen in women in sexual assaults where as in males the bite marks are seen on the shoulders and arms. Other areas commonly bitten are the hands. (Bite Marks, 2001) The appearance of the bite mark is usually circular or elliptical, doughnut like, or U-shaped. The central area between the marks of teeth is usually bruised and extravascular bleeding is noted. (Bite Marks, 2001) Salivary swabs are also taken in bite cases. But it is not always possible to identify the assaulter with bite mark alone as some times the "bite marks do not have the level of forensic value." (Bower's 2000) They can easily be overlooked in some cases as simple bruising and only the deep bites are usually recognized as such. For such cases the introduction of the "tool mark" technology has been immensely helpful in the identification process. The technology works by identifying the distinguishing features of the bite mark or pattern, not only the class characteristics but also the individual dental characteristics. The association between the bite and the assaulter is made by examining the missing teeth, pattern of rotation, angulations or position of the tooth" found in the bite.(Bowers, 2000) Usually the bite marks on any food stuff is more accurate, as it provides a three dimensional impression compared to the two dimensional impression on the skin. (Forensic Fact Files, 2001) So at the end of the day after all your exhaustive efforts to identify the guy or girl at your examination table, you still don't pinpoint the identity. Now what to do Well you can always look up to dental profiling. With the help of this method the dentist is able to produce the general features of the individual. Dental profiling is carried out in the cases where the dentist has failed to locate any dental records and has been unable to identify the individual through the routine procedures. In such cases the dentist limits the search of records to population areas where the victim may belong to. The practice increases the chances of locating the antemortem records of the victim and thereby identifying the body at a lesser time. Dental profiling is able to determine the victim's age, race, sex, family background, and his or her socioeconomic status. (Pretty & Sweet, 2001) Information regarding the victim's profession, dietary and habitual behaviors, and his or her dental and general health condition can also be identified. (Forensic Fact Files, 2001) Dental tissues can help in the determination of the age of the individual as the formation of the teeth and their calcification patterns can be easily studies to reach the conclusion. This method is especially appropriate when examining neonates, fetuses or very small children and the level of accuracy for determining age is within 1 years of age. In young adults the stage of formation of the third molar helps in assessing the victim's age. With the middle age group, the most useful guides are "periodontal status and the disease progression, excessive wear, multiple restorations, extractions, bone pathosis and complex restorative work." (Identification, 2001) Different dental appliances can also be very useful in identifying individuals where other methods do not give results. For example the orthodontic brackets and the dentures of the patient can be valuable tools in the identification of the victims. (Identififcation, 2001) In assessing the sex of the individual, the main diagnosis is reached through the study of the skull. Teeth in this matter do not provide sexual variation characteristics. But through the evaluation of the DNA in the teeth with focus on the presence of Y- Chromosome helps in diagnosis of the sex of the individual. (Identification, 2001) It is an established fact that saliva deposited on the skin during biting and assault is sufficient to help in identification through DNA testing procedures. The recovery of salivary samples has been made more easier with the introduction of laser and alternative light sources by the forensic and law enforcement agencies. The DNA profile is the most accurate method in identifying the assaulter or the killer of the victim. (Bite Marks, 2001) The most recent technique in DNA technology is the PCR technology. PCR or polymerase chain reaction allows amplification of specific segments of DNA and therefore can be very helpful in accurately identifying the individual. This sample of DNA can be very easily attainable in the dental tissues of the victim, where other sources may not be useful. These dental analyses are then kept in the memory data bases and can then be compared to DNA samples from antemortem samples or parental samples. (Identification, 2001) Also helpful is the mitochondrial DNA, which is inherited from the mother, and can be extracted in large amounts from the victim's body. (Identification, 2001) Malaver (2003) in his study on DNA identification sources in dental tissues stated that the dental pulp shows the "strongest amplification signals." (Malaver,2003) Dentin and cementum showed similar signals and these structures helped in the preservation of the DNA structure in the tooth. (Malaver, 2003) To summarize, dental forensics has established itself as one of the most reliable ways to identify human remains. The application of it is in all areas of forensic diagnostics, whether it is assaults on living individuals, or deceased persons, old or new corpses, and even victims of large disasters and natural calamities. With the introduction of newer DNA techniques along with the use of the age old tried conventional methods, forensic dentistry is very accurate in identifying criminals and help in the legal frameworks. References ABFO Guidelines, 1984. Site last accessed on November 20th, 2006. http://www.abfo.org/ID.htm Bite Marks, Online Study Guides, 2001 site last accessed on November 20th 2006 http://www.forensicdentistryonline.org/Forensic_pages_1/bitemarkguide.htm C. Micheal Bowers, 2001.Digital Rectification and Resizing Correction of Photographic Bite Mark Evidence. Forensic Science Communications, 2001, Vol 3, Number 3. Site last accessed on November 20th, 2006. http://www.fbi.gov/hq/lab/fsc/backissu/july2001/bowers.htm C. Micheal Bowers, 2000.Arguments on the Individuality of Human Teeth. Site last accessed on November 20th,2006. http://forensic.to/webhome/bitemarks Forensic Dentistry. Site last accessed on November 17th,2006. http://hometown.aol.com/_ht_a/dorionr/forensic/Forensic.htm Forensic Fact Files, 2001 NIFS. Forensic Odontology, 2006. Site accessed on November 20th, 2006 http://faculty.ncwc.edu/TOConnor/425/425lect16.htm Identification, Online Study Guide, 2001. site last accessed on November 17th 2006 http://www.forensicdentistryonline.org/Forensic_pages_1/identguide.htm Anil K. Jain and Hong Chen, 2003.Matching of Dental X-ray Images for Human Identification. Pattern Recognition Society 37 (2004) 1519-1532. Site last accessed on November 20th, 2006. http://www.csee.wvu.edu/adis/1.pdf Piedad C. Malaver & Juan J. Yunis, 2003. Different Dental Tissues as Source of DNA for Human Identification in Forensic Cases. 2003. Croation Medical Journal. 44(3): 306-309, 2003 Site last accessed on November 20th, 2006 http://www.cmj.hr/2003/44/3/12808723.pdf A.Pretty and D. Sweet, 2001. A Look at Forensic Dentistry- Part 1: The Role of Teeth in the Identification of Human Identity. British Dental Journal, 2001. Volume 190, No. 7, Pages 359-366 Tsang A & D. Sweet, 1999. Detecting child abuse and neglect - Are dentists doing enough J Can Dent Assoc 1999; 65: 387-391. Read More