Biomechanical Factors in Human Dermal Bitemarks in a Cadaver Model*

Abstract

In bitemark analysis, the forensic odontologist must consider how the biomechanical properties of the skin contribute to distortion of the bitemark. In addition, one must consider how the bitemark can be distorted by postural movement of the victim after the bite has occurred. A fundamental review of the architecture and biomechanical properties of the dermis is described and evaluated through bites made on cadavers. In order to assess distortion, 23 bites from a single characterized dentition were made on un-embalmed cadaver skin. Bite indentations were photographed. Following various body manipulations they were re-photographed in different positions. Hollow volume overlays of the biting dentition were constructed, and metric analysis of the dentition and all bitemarks was completed. The overall intercanine, mesial to distal, and angle of rotation distortion was calculated. Of the 23 bites made, none were measurably identical, and in some cases, dramatic distortion was noted.

Forensic odontology, part 4. Human bite marks

“…14 Recently, research from the USA on cadavers has shown that 'no two bites are visibly or measurably identical when dental models were used to inflict bites both parallel and perpendicular to skin tension lines (Langer lines) and with the limbs in different positions. ' 15 However, consistent distortional trends were observed. It was noted that 'when loose elastic tissue is bitten: mesial to distal width increased, there was flattening of the angles of rotation and an elongation of the inter-canine width.…”

Simplified digital infra red photography: an alternative tool in Bite mark forensic investigation

“…Conversely, bitten skin may not have been sufficiently damaged to react at all. 20,25 The Bite mark is not an imprint or impression, but rather a reactive response generated by injured skin that is invariably less precise than a direct recording. 20,26,27 Since Bite mark will fade or changes its color with time, standardized forensic photography should be done as soon as possible.…”

“…In human interactions, biting is known to occur in situations ranging from play to lovemaking and, more malevolently, in violent interchanges, such as fights and frays, and criminal activities from assaults to homicides. 20,24,25 In a pathologist perspective, a patterned injury such as a Bite mark is made visible not by a transfer of material and not often by indentations, but rather by a vital response of the bitten tissue. It may include the superficial scraping of epithelium by the contacting teeth (abrasion), the bleeding within skin by the pressure of the teeth (contusion), or the tearing of skin by teeth (laceration) that renders the Bite mark visible.…”

The Role of Forensic Dentistry for Identification of a Criminal Sexual Assault: A Casework Report

“…The bite marks left on a person may be used to identify the perpetrator. Bite mark identification is based on the individuality of a dentition, which is used to match a bite mark to a suspected person [7]. One can exactly match the bite marks to the accused biter's dentition.…”