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Sci. & Cult. 76 (3–4) 135-137 (2010) Forensic Odontology: The New Aspects of Forensic Science and Important Role of Dentistry ABSTRACT : Forensic Odontology is a new branch of forensic science associated with maxillofacial pathology which deals with identification of a subject during traumatic tissue injury, postmortem or lack of finger print, bite mark analysis and resolving of legal matters. So dental surgeon has an important role in the collection and preservation of data and to assist the legal authority in the identification of victims and suspects. F orensic dentistry, the application of dentistry to legal structure, is a relative new aspect of forensic science. It may be considered as an art and science of dental medicine as applicable in resolving issue pertaining to law. A classic in the history of forensic Odontology was the Parkman Webster Case in 1849. Prof. Webster of the Harvard Medical School murdered his friend Dr. Parkman and incinerated the body. From charred jaw bones and dental structures Parkman’s dentist identified the murdered man. With the advent of new technology the forensic odontology has become very important part of forensic science. Forensic odontology involves the management, examination, evaluation and presentation of dental evidence in criminal or civil proceeding and research.(2,3) We got so many evidence from forensic odontology like, 1. Identification of teeth as well as person. 2. Presentation of dental data as legal documents. 3. Radiographic examination and comparison and comparison of antemortem with postmortem subject. 4. Age determination based on dental evidence. 5. Bite mark comparison. 6. Mass disaster identification. 7. Trauma of oral tissue and underlying pathology if any, their interpretation of oral injury and its importance in legal matters. 8. Anthropological study and research. VOL. 76, NOS. 3–4 9. Modeling reconstruction of face based on skeletal evidence. 10. To identify dental malpractice and negligence. Dental identification assumes a primary role in the identification of remains when post mortem changes, traumatic tissue injury or lack of finger print record. The main advantage of dental evidence is that, like other hard tissues, it is often preserved after death. Even the status of a) person’s teeth changes throughout life and the combination of decayed, missing and filled teeth is measurable and comparable at any fixed point in time.3,4 Unfortunately dentist often maintain poor records, resulting in poor dental identification.4 In the dental identification the following parameters represents the features of specificity utilized a. number of tooth b) restoration and prosthesis c) decay (caries) d) malposition and malrotation of tooth e) peculiar shapes of teeth f) root canal therapy g) bone pattern seen on intra oral radiograph h) complete denture i) bite relationship etc.1 Dental records as legal documents : The dental record is the legal document owned by the dentist and contains subjective and objective information about patient. Results of the physical examination of the dentition and supportive oral and surrounding structure must be recorded. The results of clinical laboratory test, study cast, photograph and radiograph should be kept for 7 to 10 years. All entries should be signed by recording personnel.7 The antemortem dental data bank available for comparison with the postmortem examination data rests within the records of the attending dentist which includes patient dental chart, dental X-ray films, and models made from impression of the dentition. Computer generated dental records are becoming more common for dental records. Whether dental records are preserved in written form or on a computer database, following the principles of record management ensure that all information is properly maintained and retrievable.3 Radiographic examination : Comparison of the antemortem and postmortem radiograph is the most accurate method of identification. Observation such as shape of restoration, root canal treatment, root pattern, tooth morphology, sinus and jaw bone pattern can be identified by examination of radiographs. Original antemortem dental radiograph are very important for comparison. The best result obtained when the angulations 135 of films to the x-ray tube is the same as that of original films9 Digital dental radiographic superimposition can be used for identification, allowing comparison of the spatial relationship of the root and the supportive structures of the teeth in antemortem and postmortem records.10 Age determination based on dental data : The teeth are most reliable indicators of chronological age from birth to 14 years of age. Human dentition follows a reliable and periodic development sequence starting from 4 months of intra uterine life to the beginning of 3rd decade of life when development of all permanent teeth is completed.(11) The use of radiograph is characteristic of technique that involve observation of morphologically distinct stages of mineralization. Such determinations are based on root and Gustafson’s Ranking of Structural Changes in Age Determination: Changes Ranking & Details Attrition=A A=0 No attrition A=1 Attrition lying within enamel A=2 Attrition reaching dentin A=3 Attrition reaching pulp Periodontosis=P P=0 No periodontosis P=1 Periodontosis just begun P=2 Periodontosis along first 1/3 rd of root P=3 Periodontosis along first 2/3 rd of root Secondary Dentin=S S=0 No deposition of secondary dentin in pulp cavity S=1 Secondary dentin starts depositing at upper part of the cavity S=2 About half of pulp cavity being occupied by secondary dentin S=3 Almost whole of cavity is filled by secondary dentin Cementum Apposition=C C=0 Normal C=1 A layer little greater than normal C=2 A thick layer C=3 A heavy layer Root Resorption=R R=0 No visible resorption R=1 Resorption isolated spots only on small R=2 Greater loss of substance R=3 More cementum and dentin affected Root Transparency=T T=0 Transparency not present T=1 Transparency just noticeable T=2 Transparency over apical 1/3rd of root T=3Transparency over apical of root 136 2/3 rd crown formation, closure of apical foramen, the stages of calcification, eruption pattern.12 In elderly patient age can be estimated by application of Gustafson’s formula (based on aging and decaying changes in teeth).13 After about 20 years of age, following changes occur in the teeth and based upon the changes allotted score such as 0,1,2,3 etc. given. Bite mark Bvidence : Comparison of bite mark represents dentistry’s vital contribution to forensic science. The mark pattern is compared with the dental characteristics of the dentition of suspect. Depending upon the situation bite mark analysis done.5,6 In cases of family and domestic violence, physical or sexual abuse, biting can represent a form of expression that occurs when verbal communication fails.7 Non human biting injuries are found on victims are usually distinguished from human bite injuries by differences in arch alignments and specific tooth morphology. Animal bites often cause shear rather than impact injuries, producing open wounds.8 In general bite mark analysis is concerned with a comparison of a life size photographic reproduction of the bitten area with the dental model of the suspect .The first step in the bite mark examination is the swabbing of involved skin surface to detect the possible presence of secretor antigens which may serve to implicate or eliminate a particular suspect .The second step involves bite registration from the victim or bitten object. Such registration is done by photographic and impression method. Microscopic examination of the bitten tissue very effective for pathologist to establish proximity to the time of death .Third, registration of the suspects dentition is accomplished by means of impression and subsequent stone model of the tooth. In this manner examiner should reach on a conclusion about bite mark evidence. Mass disaster identification : In situation like transport accident, fire or severe trauma where bodies are often destroyed but tooth structure are heavily calcified, so they can resist fire or huge traumas. Therefore dental examination very important for identification. Teeth and restoration are resistance to heat so preservation is possible in most cases.4 The forensic odontologist has an important role as a team member along with pathologist and other specialist in this type of mass disaster.2 Anthropologic examination : Forensic anthropologist and forensic odontologist may work together for identification .The bones and teeth of craniofacial complex SCIENCE AND CULTURE, MARCH-APRIL, 2010 remain identification for the forensic odontologist which are distinguished one person from others and one population from another and use to determine the race, age and sex of a person.9 Tooth size, shape, cusp of Carabelli, enamel pearls, and dental pulp shape are the important features for the racial determination. American, Indian tend to be large toothed with wide crowns and American Blacks tend to have large crowns. The anatomic material can be used for identification when the skull and facial bones are used as a foundation for the reconstruction of facial soft tissues .With the help of different anthropologic parameter, measurements face can be reconstructed with sculpting clay and features can sometimes be digitized on a computer screen. Computer is a very sophisticated tool for checking accuracy and facial superimposition .The generated data can be stored and reproduced for comparison.14 Conclusion : Forensic odontology is a new scientific armamentarium in the field of forensic science. Proper understanding of this new responsibility and implication through proper record preservation and analysis to make legally acceptable document and assist legal authorities in the identification of victims and suspects. S R.G.Kar Medical College and Hospital Kolkata Received : 22 June, 2009 Revised : 31 December, 2009 1 I. M. Sopher, Forensic Dentistry, (1976) Springfield, III: Charles C.Thomas. 2 J. M. Cameron and B. G. Sims Forensic Dentistry. (1974) Edinburg: Churchill Livingstone. 3 B. Neville, D. Douglas, C. M. Allen and J. Bouquot Forensic dentistry. P 763-783 (2002). In Oral & maxillofascial pathology. 2nd ed. Philadelphia(PA) : W. B. Saudenrs Co.. 4 W. U. Spitz Spitz & Fisher’s medicolegal investigation of death: guidelines for the application of pathology of crime investigation. Springerfield, III: Charles C.Thomas; (1993). 5 D. G. MacDonald J. Forensic Sci 14(3) : 229-33 (1974). 6 M. M. Aksu and J. P. Gobetti. Am J. Forensic Med. Pathol 17(2) : 136-40 (1996). 7 Sylvie Louise Avon. J. Can. Dent. Assoc; 70(7) : 453-8, (2004) 8 J. Epstein Am. J. Dent. ; 14(3) : 152-7 (1992). 9 L. Luntz Dent Clin. North Am; 21(1) : 7-17 (1977). 10 R. E. Wood, N. J. Kirk and D. J. Sweet J. Forensic Sci; 44(5) : 910-6 (1999). 11 D K. Whittaker Quintessence Int., 25(10) : 723-30 (1994). 12 T. D. Stewart, J. Dent. Res. 42 : 264, (1963). 13 G. Gustafsons Am. Dent. Assoc., 41: 45-52 (1950). 14 R. E. Wood, B. Clark, S. E. Brooks and B. Blenkinshop, Can Soc Forensic Sci. J. ; 29(4) : 195-203 (1996). SHYAMAL BAR* AND SURAJIT BOSE VOL. 76, NOS. 3–4 137