The Identity Of Cadavers Revealed By Their Teeth

Ample time must be allowed at the first dental patient visit to judiciously and painstakingly record all the dental findings. Poignant information noted in the past and present medical history is of vital importance to the identification process. Areas of special interest would be a period of hospitalization requiring surgery, emergency room x-rays, and CT or MRI scans.

Many times the forensic dentist leans toward the unusual findings to establish a positive identification. This category will include, to mention a few, areas of dense buccal and gingival pigmentation, palatal and mandibular tori, dento-facial deformities (eg, microgenia), rotated or malposed teeth, and most importantly, any anterior diastemas. In June of 1985, a team of West German and American forensic specialists was called to Brazil to identify the remains of World War II criminal Dr. Josef Mengele, the notorious Angel of Death. Among one of many corroborating features unique to this identification was a prominent, 4-mm diastema located between the upper anterior central incisors. Hospital A/M x-rays taken in 1939 were compared to P/M x-rays of the victim. A titanium pin in the left ankle was a positive match.

Radiographic interpretation will only be as diagnostic as the clarity and contrast of the radiograph taken. Clarity, contrast, and proper angulation will help contribute to the overall identification process. Periapical, bite-wing, occlusal, lateral plates, and A/P Waters views of the skull may all be used to facilitate the identification process. Proper angulation is critical to the radiographic interpretation of root length, bone trabecular pattern, thickness of periodontal membrane and ligament, and overall pulp morphology. The Panorex, though a valuable office adjunct, does not lend itself well to the forensic process due to its lack of anterior contrast and clarity. A body in post-death rigor mortis will exhibit severe facial contraction. This chemical phenomena, together with positional instability, rules out the Panorex as the radiograph of choice.

Loss of facial contour due to decomposition, autolysis and liquefaction, and other chemical changes will rule out a visual identification. When visual, fingerprints, and dental comparison are unavailable for whatever reason, the use of mitochondrial chromatin (DNA) is done.

The role of the orthodontist and prosthodontist must not be overlooked in the forensic picture. The very young (6- to 13-year-old group) and the geriatric population (60- to 90-year-old group) comprise approximately 40% of the unknown and missing persons population. Many times, when radiographs and charts are not available, the use of study models alone will corroborate a positive identification. This was evident when several teenagers were the victims of a raging inferno that swept through Great Adventure amusement park in Jackson, NJ. The orthodontists’ corrective study models contributed to making the final positive identification for all  of the teenagers involved.

When teeth are subjected to prolonged, intense heat,  crowns and roots become brittle and disintegrate. This breakdown occurs at temperatures ranging from 400ºF to 1,796ºF (cremation temperature). Gold fillings, PFM crowns, and gold crowns will melt when subjected to temperatures of 1,832ºF to 2,228ºF. Microscopic examination of the roots at such high temperatures reveals cracking, peeling, and a powdery residue, negating root morphology in the identification process.

Due to very high tem-perature resistance of cast frameworks (eg, chrome cobalt), it would be prudent and invaluable for all removable prostheses—valplast, acrylic, or cast—to be labeled and identified. This should include the patient’s name and/or social security number.

The post mortem examination will proceed to finality using the victim’s ante mortem charts, radiographs, and study models. Very rarely does the ideal situation exist when all 3 modes of identification are available. Whatever is evident must be utilized to the fullest extent. Nothing must be overlooked nor any bits of information be considered too trivial and nonvital to the forensic examination. Every piece of ante mortem evidence is vital to the process of meticulously putting the oral puzzle together. All findings post mortem are assembled, interpreted, reviewed, and recorded. A report can now be filed with reasonable justification and certainty that the comparision finds do coincide and the identification is positive.