Dr. Chetan Lavu Karekar
Human dentition of an adult consists of thirty-two teeth, of which some may be missing or malformed or showing manifestations of various environmental events like use of drugs or malnutrition. The distinctive pattern of each individual’s dentition is also due to the wide variety of manipulations being done to the teeth like restoration. With such an extreme array of differences, it is extremely rare to have two similar dentitions. Apart from this, teeth are resistant to postmortem destruction and are one of the most durable parts of our body. These characteristic features make teeth useful in identification of bodies in mass disasters and natural calamities and investigation of various offences by bite marks analysis.
Keiser-Nielsen (1970) have defined forensic odontology as, “a branch of dentistry which deals with the proper handling and examination of dental evidence and with the proper evaluation and presentation of dental findings in the interest of the dentist”.
Some people prefer to use the term forensic odontostomatology for this science as its preview includes the whole of orofacial region. Forensic dentistry is often used interchangeably with forensic odontology.
The positive identification of living or deceased persons using the unique traits and characteristics of teeth and jaws is the corner stone of forensic odontology. Because all humans have an identity in life, compassionate societies require that this identity be recognized after death.
When a person dies, there are many consequences, often financial, that must be dealt with identification of dead person, as a specific individual allows wills to be probated and estates to be settled. Religious services can be completed and family members may start to cope with passing of a loved one.
Significantly in the case of death that is caused by another person, identification of victim as well as perpetrator by forensic dentistry may be useful in solving medico-legal cases.
The field of activity of forensic odontology mainly is the civil, criminal and research areas. The civil class includes malpractice and other aspects of fraud and neglect in which compensation is sought. Identification of dead and living persons also comes under this category. Criminal sector includes identification of bite marks present on the victim, assailant or on some inanimate objects like food items.
Forensic dentists also have significant roles in determining various parameters including age, race, occupation, previous dental history and socioeconomic status of unidentified human beings.
However, it is possible to perform identification through comparing ante mortem and post mortem dental records and to depend on the unique features visible on dental radiographs.
Sassouni has classified the technique of human identification into two groups.
Reconstructive group: Encompasses those cases where there is nothing suggesting the individual’s identity. Attempts are made to elicit age, sex, race, occupation etc leading to a probable identification.
Comparative group: The central dogma of dental identification is that postmortem dental remains can be compared with antemortem dental records, including written notes, study casts, radiographs etc to confirm the identity clearly. Individuals with numerous and complex dental treatments are often easier to identify than those with little or no restorative treatment.
The forensic dentist produces the postmortem record by careful charting and writing the description of dental structures and radiographs.
Once the postmortem record is complete, a comparison between the two records (antemortem and postmortem) can be carried out. A methodical and systematic comparison is required, examining each tooth and the surrounding structures in turn. The similarities and differences should be noted during the comparison process. There may be two types of discrepancies on comparison, i.e. those that can be explained and those that cannot.
Explainable discrepancies normally relate to time elapsed between antemortem and postmortem records e.g. teeth may be extracted or restorations may be placed or carious lesions might have enlarged. If the discrepancy is unexplainable, for example, if a tooth is not present on antemortem record, but present on postmortem records then exclusion must be made.
Estimation of age plays an important part in forensic identification of skeletal remains. The age of an individual is the sign of maturity. It may be described in different ways as chronologic age, radiographic age, dental age, sexual age and mental age.
Historically, age assessment using teeth was first published by Edwin Saunders in 1837, who claimed that teeth provided the most reliable guide to age estimation compared to height, which was a standard method used during that time.
Bite mark analysis is important in criminal cases in which a suspect or a victim has left his or her teeth marks on another person or on an nonliving object such as a candy bar, an apple, cheese, etc. Successful use of bitemarks for identification of a person depends on accurate documentation, correct interpretation and comparison of the bite marks. As truly said by Louis Pasteur, “In the field of observation, chance favors the mind that is prepared scientifically”
Computer-generated dental records are becoming common. The obvious advantage is that it can be easily networked and transferred for routine professional consultation or forensic cases requiring dental records for identiï¬cation.
Likewise a scientifically prepared mind with proper knowledge of dental anatomy, observation of teeth with dental restorations, prosthesis and craniofacial skeleton may help to easily solve medico-legal problems.
Forensic dental identification is at technological cross roads. The incidences of dental restorations which are the mainstay of radiographic dental investigations have declined, whereas molecular biological procedures are rapidly increasing in efficiency and availability.
With the new typing techniques forensic scientists can characterize individuals at the fundamental level of their DNA and the variations between individuals at this level can be used to discriminate between them.
The anatomical location of teeth and the limited extent to which they might suffer environmental changes and provide useful DNA material has propelled forensic odontology to new heights. DNA typing and analysis using teeth has added a new dimension to forensic odontology and will emerge as a powerful tool for person identification in forensic medicine and criminology.
