Question 1 (Part 2): Forensic Dentistry in Identification of Burnt Victims

A body that has been only partially burned can be identified through DNA fingerprinting.

But what if the body has been severely burned?

Fingerprints are not a viable option for identification anymore as the skin has burned!

This is when dental means play a key role in identification of the body.

Among human remains, teeth last longer than any body part, including bone. Even in the most severe burning, it is rare that "some fragments of dental evidence" wouldn't exist.

Comparative Dental Identification
The postmortem (after-death) dental remains can be compared with antemortem (before-death) dental records, including written notes, study casts, radiographs etc. to confirm identity. A presumptive identification usually can be made by using data from the missing persons’ database. Respective antemortem (AM) records are then obtained from the dentists of records.

The forensic dentist produces the postmortem (PM) record by careful charting, written descriptions of the dental structures and radiographs. Then, a methodical, systematic comparison can be done between the PM and AM records. Each tooth and surrounding structures are examined.


       Figure 1: Sample of Postmortem (PM) Odontogram

The following features may give some clues for the identification:
1. filled teeth with restorative material specified
2. missing teeth
3. fixed (crowns and bridges) and removable prosthesis
4. hypodontia, hyperdontia, transposition or retained teeth
5. malocclusions: mesial molar occlusion, frontal open and deep bite > 5mm, cross bite scissors bite, midline displacement, crowding and spacing
6. palatal rugae (able to sustain burns to some extent)

Similarities and discrepancies should be noted during the comparison process. There are two types of discrepancy, those that can be explained and those that cannot. Explainable discrepancies normally relate to the time elapsed between the AM and PM records. If a discrepancy is unexplainable, for example a tooth is not present on the AM record but is present on the PM record then an exclusion must be made.


Figure 2: Explainable discrepancies of AM PM comparison

When reporting dental identification, The American Board of Forensic Odontology recommends that the conclusions should be limited to the following four:
1. Positive identification: The AM and PM data match in sufficient detail, with no unexplainable discrepancies, to establish that they are from the same individual.
2. Possible identification: the AM and PM data have consistent features but, because of the quality of either the PM remains or the AM evidence, it is not possible to establish identity positively.
3. Insufficient evidence: The available information is insufficient to form the basis for a conclusion.
4. Exclusion: the AM and PM data are clearly inconsistent.

Postmortem (PM) dental profiling
In those cases where AM records are not available, and no clues to the possible identity exist, the forensic dentist provides a PM dental profile which suggests characteristics of the individual that helps to narrow the search for the AM materials. A postmortem dental profile will typically provide information on the deceased’s age, ancestry background, sex and socio-economic status. In some instances it is possible to provide additional information regarding occupation, dietary habits, habitual behaviours and occasionally on dental or systemic diseases.

If the PM profile does not elicit the tentative identity of the deceased it may be necessary to reconstruct the individual’s appearance during life. This is the responsibility of forensic artists who use the dental profile to help with the facial reproduction.

☂     References    ☂
1. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3470417/
2. http://edition.cnn.com/2013/02/13/health/burned-body-id/index.html
3. http://voices.yahoo.com/forensic-science-applied-burned-victims-136748.html
4. http://www.forensic-dentistry.info/wp/?page_id=4