Forensic Dentistry, Second Edition

334 Forensic dentistry

on the fist or other object. Teeth marks may be found on the inner aspect

of a victim’s upper and lower lips after an attack. Pressure applied to the

lips, which are consequently pressed against the teeth, leaves the teeth marks,

patterned injuries that may indicate asphyxiation by force. Teeth mark inju-

ries have not been widely discussed in the literature separate from bitemarks.

The teeth marks left in different locations during motor vehicular accidents

may be used to help distinguish passengers from drivers. Teeth marks have

been found on exterior parts of vehicles during hit-and-run accidents. Teeth

marks left on fists or hands as when striking a victim in the mouth can be

crucial evidence placing a subject at a scene and showing that there was a

violent interaction. These may be particularly helpful when a victim’s body

may have been severely affected by trauma or fire. Teeth marks on the hand

or arm of a police officer or other law enforcement official may be used to

support or disprove conflicting testimony in a police custody scenario, for

example, a policeman’s claim that the detainee bit him versus the prisoner

stating, “He had me in a strangle hold and his forearm was forced into my

mouth.” It is important to note the nature of the patterned injury and the

location of the teeth marks to determine which scenario is more likely. Teeth

marks, unlike a bitemark, are more often single arch in nature. Bitemarks, on

the other hand, more often show multiple teeth from both arches.

14.2.3 Class Characteristics

The definition above includes descriptions of both class and individual char-
acteristics of bitemarks. The ABFO manual describes a class characteristic as
“a feature, trait, or pattern that distinguishes a bitemark from other patterned
injuries. Thus, a bitemark class characteristic identifies the group from which
it originates: human, animal, fish, or other species.”^35 Class characteristics
include the characteristic arch forms of the biter and allow distinguishing
between the upper and lower arch forms in a bitemark. Confirming the pres-
ence of class characteristics should be the first step in evaluating a bitemark.
If unable to distinguish upper from lower arches, the evidence should not be
considered to be of sufficient quality for comparison analysis. Obviously, ever y
curved pattern injury was not caused by teeth. Misinterpretations of injuries
that look similar to dental arches have led to errors in evaluation. It must
be emphasized that, if unable to distinguish between upper and lower dental
arches in a patterned injury, or to be able to identify which marks were made
by specific individual teeth, forensic dentists should not attempt to compare
the injury to suspect information unless that pattern contains one or more
unique individual characteristics that may also be seen in a suspect biter’s
tooth or teeth. In some cases it may be possible to exclude individuals based
on lower quality bite pattern information (Figures 14.27 to 14.29). An example
would be a contusion pattern that exhibited a gap or gaps and a suspect that