|Year : 2016 | Volume
| Issue : 1 | Page : 20-23
Nitai Debnath1, Renu Gupta2, Rajesh Singh Nongthombam1, Preety Chandran3
1 Department of Prosthetic Dentistry, Dental College, RIMS, Imphal, Manipur, India
2 Department of Periodontics, Nair Hospital and Dental College, Mumbai, Maharashtra, India
3 Department of Prosthetic Dentistry, Tamil Nadu Government Dental College and Hospital, Chennai, Tamil Nadu, India
|Date of Web Publication||5-Feb-2016|
Dental College, RIMS, Lamphelpat, Imphal (West), Manipur
Source of Support: None, Conflict of Interest: None
Forensic odontology is a relatively new science that utilizes the dentist's knowledge to serve the judicial system. Forensic odontology deals with human identification based on dental records, bitemarks, lip print, tooth print, and palatal rugae pattern. Human identification heavily relies on the quality of dental records in the office. Dental record includes documents related to the history of present illness, clinical examination, diagnosis, treatment done, and prognosis of treatment. The quality dental records are useful not only in forensic science but also in legal implications such as insurance and consumerism. This article primarily aims at making general practitioners aware about the importance of keeping the various types of dental records and its implication in forensic odontology.
Keywords: Bite marks, Cheiloscopy, Dental records, Palatal rugae, Rugoscopy
|How to cite this article:|
Debnath N, Gupta R, Nongthombam RS, Chandran P. Forensic odontology. J Med Soc 2016;30:20-3
| Introduction|| |
Forensic dentistry is a challenging and fascinating branch of forensic science that involves the application of dental sciences in the identification of deceased individuals through the comparison of ante- and post-mortem records. The term "forensic" implies "court of law."  Forensic odontology is the forensic science that is concerned with dental evidence. Forensic odontology has been defined as that branch of dentistry which (in the interest of justice) deals with the proper handling and examination of dental evidence and with the proper evaluation and presentation of dental findings. 
Forensic odontology has played a key role in the identification of persons in mass disasters (aviation, earthquakes, and tsunamis), in crime investigation, in ethnic studies, and in the identification of decomposed and disfigured bodies such as that of drowned persons, fire victims, and victims of motor vehicle accidents. ,
Dental identification has played a very important role in natural as well as man-made disasters. Identification is based on a comparison between known characteristics of a missing individual with recovered characteristics from an unknown body. When they have no clue about the identity or no antemortem records are present, a detailed postmortem record is compiled for further use, and a forensic anthropologist is used for contributing information such as age, sex, and ancestry of the decreased, which is known as postmortem dental profiling. 
An antemortem dental record will contain written notes, charts, diagrams, dental and medical histories, radiographs, clinical photographs, study models, results of specific tests, prescriptions, and referral letters and other information. Their accuracy and availability have a huge impact on the speed and efficacy of identification. Problems are encountered when the dental records are incomplete, irregular, lost or damaged, and have poor quality radiographs. 
Good quality dental records are an essential part of patient care, a medicolegal requirement, and are necessary for dental identification. A forensic dentist records the postmortem records completely by charting down the dental findings and taking photographs and radiographs. On completion, a comparison between the two is carried out, similarities and discrepancies are noted on the comparison, and a result is established. 
Forensic odontology has three major areas of utilization:
- Diagnostic and therapeutic examination and evaluation of injuries to jaws, teeth, and oral soft tissues.
- The identification of individuals, especially casualties in criminal investigations and mass disasters.
- Identification, examination, and evaluation of bite marks which occur with some frequency in sexual assaults, child abuse cases, and in personal defense situations. 
Identification is based on a comparison between known characteristics of a missing individual with recovered characteristics from an unknown body. 
The dental enamel is the hardest tissue in the body, and would thus withstand peri- and post-mortem damages. Hence, teeth are considered excellent postmortem material for identification with enough concordant points to make a meaningful comparison. For dental identification to be successful, antemortem data need to be available. This relies heavily on dental professionals recording and keeping dental notes, radiographs, study models, clinical photographs, etc. The availability of dental records will allow comparing the dental characteristics of the person during life with those retrieved from the person after death.
Antemortem records are then obtained from the dentist of record.  The use of radiographs, dental casts, prosthetic or dental appliances, type, and number of restorations present may help to identify the victims. Similarities and discrepancies should be noted during the comparison process. There are two types of discrepancy, those that can be explained and those cannot be. Explainable discrepancies normally relate to the time elapsed between the ante- and post-mortem records.  Examples include teeth extracted or restorations placed or enlarged. If a discrepancy is unexplainable, for example, a tooth is not present on the antemortem record but is present on the postmortem record then exclusion must be made. , A range of conclusions can be reached when reporting a dental identification.
The American Board of Forensic Odontology recommends that these be limited to the following four conclusions: ,,,
- Positive identification: The antemortem and postmortem data match in sufficient detail, with no unexplainable discrepancies, to establish that they are from the same individual.
- Possible identification: The antemortem and postmortem data have consistent features but, because of the quality of either the postmortem remains or the antemortem evidence, it is not possible to establish identity positively.
- Insufficient evidence: The available information is insufficient to form the basis for a conclusion.
- Exclusion: The antemortem and postmortem data are clearly inconsistent.
| Dental Profiling|| |
When dental records are unavailable, and other methods also become impossible, a picture of the general features of the individual is produced, and this is known as postmortem dental profiling which includes information on the age, sex, socioeconomic status, and ancestry background of the deceased. Additional information such as habits, dietary pattern, and occupation may also be provided.
| Other Methods Used for Identification|| |
The external surface of the lip has numerous elevations and depressions that form a characteristic pattern, referred to as lip prints.  Lip prints can be obtained at the crime scene from clothing, cups, glasses, cigarettes, windows, and doors. Using lip prints for personal identification in forensic odontology is an accepted method in the criminal justice system worldwide. Impressions are made from the middle portion of the lower lip, an area always visible in any trace made, and the characteristic patterns are studied. The various patterns identified include vertical, intersected, branched, reticular, and undetermined.
The anatomical landmarks of the lip include chelion (the lateral most point in mouth opening), stomion (the contact of upper and lower lips in the midsagittal plane), and labrale superius and labrale inferius (the highest and lowest points of upper and lower lip margins in the midsagittal plane, respectively). ,
Various factors can alter lip print recording. Lip prints have to be obtained within 24 h of the time of death to prevent erroneous data that would result from postmortem alterations of the lip. 
Although lip prints are unique to an individual, when the lines are not clear, individual identification based on this trace is extremely difficult unless the trace contains more individual characteristics like scars, clefts, etc.
Palatal rugae comprise about 3-7 ridges radiating out tangentially from the incisive papilla. These ridges can be classified as curved, straight, wavy, and branched. The pattern of these rugae is considered unique to an individual. In instances where postmortem dental identification is not possible, as in edentulous mouths, palatal rugae can be used as a supplement.
The shortcomings in applying rugoscopy as a definitive tool in forensic odontology are many.
- Postmortem identification is not possible without the antemortem records.
- Complex rugae patterns (patterns that cannot be classified under one particular group) can cause intra- or inter-observer errors.
Kapali et al. have observed that denture wear, tooth malposition, and palatal pathology can cause alterations in rugae patterns. 
In a situation involving fire, palatal rugae are often destroyed, and also since decomposition and skeletonization can occur in <6 weeks in summer and 4 months in winter, rugoscopy does not have application after this stipulated period. 
Bite mark is vital evidence in the case of crime and abuse. Recording, comparing, and determining whether the mark is truly a result of biting is important for a forensic odontologist. Knowledge on the arch alignments and specific tooth morphology of animals is also required for a forensic odontologist to distinguish human bites from nonhuman.
| Tooth Prints (Ameloglyphics)|| |
Ameloblasts lay down the enamel rods in an undulating and intertwining path. This is reflected on the outer surface of the enamel as patterns of the ends of a series of adjacent enamel rods. This study of the enamel rod end patterns is termed as ameloglyphics by Manjunath et al. and could aid as an identification tool in decomposed or burned bodies as enamel can resist decomposition. 
| Role of DNA in Dental Identifications|| |
Because of the resistant nature of dental tissues to environmental assaults, such as incineration, immersion, trauma, mutilation, and decomposition, teeth represent an excellent source of DNA material. 
PCR-based analysis produces a DNA profile that can be compared with known antemortem samples (stored blood, hairbrush, clothing, cervical smear, biopsy, etc.,) or paternal DNA. Besides, this technique may also help criminal investigators to link victims to crime scenes once the body has been removed and incinerated. ,
Genomic DNA is found in the nucleus of each cell and represents the DNA source for most forensic applications. When body tissues have decomposed, the structures of the enamel, dentine, and pulp complex persist. DNA can be extracted from calcified tissues of teeth even in cases of root canal treated teeth. 
| Conclusion|| |
Forensic dentistry plays a major role in the identification of those individuals who cannot be identified visually or by other means. Greater knowledge and awareness of forensic odontology among dental practitioners would be required in the growing field of medicine. The unique nature of our dental anatomy and the placement of custom restorations ensure accuracy when the techniques are correctly employed. Dental practitioners should be aware of the forensic application of dentistry. Dental records that are used to provide patients with optimal dental service could also be very beneficial to legal authorities during an identification process. Therefore, all forms of dental treatments should be recorded and kept properly.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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