1. IMPRESSION OF BITE MARK

2. Bite marks or Bite Patterns Occurs when teeth actively contact and compress softer material such as human flesh, food material such as cheese or an apple, or other inanimate objects such as Styrofoam cups. 3. These bite marks may be one of the physical and biological evidences left by criminals at the site of criminal act. 4. In order to collect evidence from these bite marks, one of the method used by investigators is to establish a good Bite Mark Impression. 5. Bite Mark Impression Plays a very important role in solving the criminal cases. Should be taken only after taking the photographs and swabs of the injury site. 6. Bite Mark Impression Taking Various dental materials have been used (e.g. alginate, silicone) for taking the impressions of the bite marks, but the most commonly used is the Polyvinyl Siloxane. 7. Polyvinyl Siloxanes and one of Alginate 8. The advantage of Polyvinyl Siloxane is that they can be poured numerous times if there is an error. Alginate can also be used for taking the impressions. However the main drawback in using alginate as an impression material is that they have to be poured with one to two hours to prevent contraction. 9. Steps: Bite Mark Impression 1.Prepare the area for impression taking by removing all the hair and area should be washed and dried. 10. 2. A light body impression material is expressed into the injury site with a syringe and is allowed to completely cover the injury. 11. 3.Cotton backing is placed onto the impression material. *The backing material must be contoured to the anatomical contour of the injury site.* 12. 4. Dental plaster is placed onto the cotton packing. *This reinforcement will prevent the inaccuracies being developed in the impressions due to physical distortion. 13. These impressions are then used to create dental stone models. We should make two stone casts. One is used for analysis purpose and the second cast is preserved for presentation in the court. 14. This entire process of impression taking and dental stone model fabrication should be properly photographed. 15. Impressions of the bite mark are not always practical. If the victim is living, normally this procedure Is not performed because the indentions will disappear by the time of examination. 16. Furthermore, if theres an extensive amount of swelling and bleeding in the injury site, the impression procedure may not anymore be practical.