NCJ Number
52891
Journal
Canadian Society of Forensic Science Journal Volume: 11 Issue: 3 Dated: (SEPTEMBER 1978) Pages: 203-210
Date Published
1978
Length
8 pages
Annotation
THE RESULTS OF A SCANNING ELECTRON MICROSCOPIC STUDY OF INCINERATED HUMAN DENTAL TISSUES INDICATE THAT THE EFFECT OF EXTREME HEAT IS TO REMOVE UNMINERALIZED OR POORLY MINERALIZED MATERIAL.
Abstract
THE PRACTICAL FORENSIC APPLICATIONS OF SCANNING ELECTRON MICROSCOPIC (SEM) OBSERVATION OF INCINERATED HUMAN DENTAL TISSUES REMAIN HYPOTHETICAL, BUT IT IS EVIDENT THAT MINERALIZED DENTAL TISSUES CAN BE IDENTIFIED USING THE SEM SYSTEM, EVEN THOUGH SUCH TISSUES HAVE BEEN EXPOSED TO THE HEAT OF AN AUTOMOBILE FIRE. IT IS ALSO INDICATED THAT SUCH TISSUES CAN BE PREPARED FOR SEM OBSERVATION WITH A MINIMUM OF TECHNICAL PREPARATION. TO OBTAIN VISUAL DOCUMENTATION OF THE CHANGES WHICH OCCUR IN DENTAL TISSUES UPON EXPOSURE TO HEAT, SAMPLE TISSUES WERE OBTAINED FROM TWO VICTIMS, AGED 18 AND 21, OF A MOTOR VEHICLE ACCIDENT. WHICH OF THE VICTIMS THE STUDIED TOOTH FRAGMENTS CAME FROM COULD NOT BE DETERMINED WITH CERTAINTY. THESE TISSUES EXHIBITED GREY-BLACK COLORATION AND WERE EXTREMELY FRIABLE; THE TOOTH ROOTS EXHIBITED NORMAL GROSS MORPHOLOGY, BUT COULD BE FRACTURED WITH FINGER PRESSURE. PREPARATION OF THE TISSUES INCLUDED DEHYDRATION IN ABSOLUTE ALCOHOL AND AIR DRYING PRIOR TO COATING WITH CARBON AND GOLD. OBSERVATIONS WERE MADE OF THE ENAMEL, DENTIN-PULP, AND CEMENTUM OF THE SPECIMENS. EXAMINATION OF THE FRACTURED ENAMEL SURFACE REVEALED THE PRESENCE OF IDENTIFIABLE ENAMEL RODS AND FINE CRACKS IN THE ENAMEL. CEMENTUM WAS THE MOST DIFFICULT DENTAL TISSUE TO IDENTIFY ON THE BASIS OF MORPHOLOGY; THE FINDING OF COARSE FIBER BUNDLES CORRESPONDING TO SHARPEY'S FIBERS DID ALLOW TISSUE IDENTIFICATION. THE COMPLETE ABSENCE OF PULP TISSUE AND THE ABSENCE OF ODONTOBLAST PROCESS REMNANTS SUGGESTS THAT ONE EFFECT OF HEAT ON DENTIN IS THE REMOVAL OF ORGANIC MATERIAL FROM THIS TISSUE. OBSERVATIONS OF THE DENTINAL TUBULES CONFLICT WITH THEORIES RELATING TO THE MINERALIZED PERITUBULAR DENTIN MORPHOLOGY, AND SUGGESTS THAT THE EFFECT OF HEAT IS TO REMOVE THE ORGANIC MATRIX MATERIAL AND LEAVE BEHIND A SKELETON OF MINERALIZED MATRIX COMPONENTS. REFERENCES AND PHOTOGRAPHS ARE INCLUDED. (TWK).