Forensic Dentistry, Second Edition

344 Forensic dentistry

is referred to as the chain of custody. It is important to keep all evidence within

your custody until time of trial and document any transfers or loans of that

material. If you are required to release the material, you must document the

release and return with appropriate chain-of-custody documentation.

Protocols, when followed, help to prevent mistakes. Plan ahead and

be prepared. There is usually no second chance to gather evidence. Have a

prepared list of what you need to take to the facility and bring an assistant,

preferably another odontologist, when possible. The specific and detailed

steps for dental evidence collection from suspects are discussed in the ABFO

Bitemark Analysis Guidelines^35 and Bitemark Evidence.^36

14.3.2 Analysis of Evidence

To properly analyze evidence after it is collected the evidence must be under-

standable and understood. It is dangerous to continue analysis of substan-

dard evidence. Consequently, a standardized method of characterizing and

classifying bitemarks must be developed.

14.3.2.1 Bitemark Injury Classification Systems

14.3.2.1.1 The ABFO Bitemark Scoring Guide In 1981 the Bitemark
Standards Committee of the ABFO developed a system of analyzing and
scoring bitemarks. Beginning in 1982, the scoring guide was published in
the ABFO manual. In 1986, Rawson, Vale, Sperber, Herschaft, and Yfantis
published a statistical analysis of an experimental examination of cases using
the ABFO scoring guide for bite mark analysis.^40 The paper was complex and
controversial. In 1988 the same authors, minus the statistician, published a
letter in the Journal of Forensic Sciences essentially withdrawing their recom-
mendation of the scoring system and stating “the authors believe that fur-
ther research is needed regarding the quantification of bite mark evidence
before precise point counts can be relied upon in court proceedings.”^41 The
scoring system has languished with no further development since that time.
It remained a part of the ABFO manual through 2004 but was deleted from
the 2005 manual and has not reappeared.
The authors believe that a standardized system of classifying and scor-
ing or rating bitemarks should be developed. The system should classify
bitemarks by type and by forensic or evidentiary value. Pretty proposed in
2006 and later published the proposal for a severity and significance scale
that combined both^42 (Chart 14.2). This or a similar scale in concert with the
ABFO scoring system or a derivative would be an excellent starting point
for developing a truly useful method for assisting forensic odontologists to
determine whether a bitemark contains sufficient evidentiary value to war-
rant further analysis. There would still be disagreements among examiners,