Bite Marks

1. BITE MARKS
AS
FORENSIC EVIDENCE
PREPARED BY:
TEJASVI BHATIA

2. CONTENTS
 What are bite marks?
 Forensic significance
 Locations.
 Types.
 Sequence of events in a bite mark investigation.
 Limitations
 References

3. What are Bite Marks?
 It is defined as physical alteration in or on a
medium caused by the contact of the teeth.
 It represents the pattern left in an object or tissue
by the dental structure of an animal or human.

4. FORENSIC significance
 Narrows down the investigation.
 It places the assailant with close proximity of the
victim.
 Individualization.

5.  In Sexual assault:
 Females exhibit bite marks on breasts,
nipples ,abdomen, thighs and pubis.
 Males receive bite marks on back shoulders and
pubic areas.
 Defensive bite marks:
 Can receive bite marks on forearms and hands.
• Found on other substances such as leather and
foodstuffs.
location

6. BITE MARKS ON BACK AND
SHOULDER

7. TYPES
Cutaneous bite marks
An injury in skin caused by contacting teeth (with
or without the lips or tongue) which shows the
representational pattern of the oral structures.
 Single bite
 Double bite- a “bite within a bite”
 Weave patterns of interposed clothing

8.  Partial bite marks
• One arched”(half bites)
 One or few teeth
 Unilateral(one sided marks due to incomplete
dentition or uneven pressure)

9.  Indistinct or faded bite mark
 Fused arch
 Closed arch
 Multiple bites.

10. Multiple bite marks Indistinct bite marks

11. SEQUENCE OF EVENTS IN A BITE MARK
INVESTIGATION
 Recognition.
 Whether it is a bite mark or not?
 Could human teeth can cause that?
 Does the area allow swabbing for saliva?
 Do the teeth marks present in the evidence
possess information sufficient to identify one
person?

12.  Documentation
 Photography of the bite site before and after
taking impressions.
 Markings on the backing of the impression.
 Notes

13. •Collection of evidence from the victim
 It should first be determined whether bite mark
has been affected by washing and contamination.
 The following steps are followed while collecting
the evidence:
1. Photography
 Location photograph should be taken to show
where on the body the mark is found.
 Close up photography should be done with an
attempt to reposition the bite marks in the
manner it was inflicted with labeled dimensional
standards of ABFO.

14.  Photographs of the marks should be taken with
and without a scale in place.
 When the scale is used, it should be on the same
plane and adjacent to the bite mark.
In case of living victim, it may be beneficial to
obtain serial photographs of the bite marks.

15. Photography with the use of scales

16. 2.Salivary swabbing
 Whenever possible, salivary trace evidence
should be collected.
 The bite mark is swabbed with a sterile swab that
is analyzed for traces of saliva and another for
DNA.

17. 3.Impressions
 Skin surface impressions are very useful in either
living or dead individuals with bite marks.
 one thing that is missing in photographic
representation of a bite mark is that of a normal
curvature present.
 Impression materials used is vinylpolysiloxane
(VPS).

18.  Collection of evidence from suspect
1. History
2. Photography
3. Impressions
4. Sample bite
5. Study cast

19. SAMPLE BITE ON CHEWING
GUM

20. •Comparison
 Class characteristics
A feature ,trait or pattern preferentially seen in ,or
reflective of ,a given group.
 Individual characteristics.
A feature ,trait or pattern that represents an
individual variation rather than an expected
finding within a group

21.  Comparison produces either:
 Common link
 No link
 Inability to determine because of poor quality of
evidence.

22. LIMITATIONS
 Skin being poor surface to clearly capture the
shapes of teeth.
 The common appearance and shape of human
teeth.
 It is time limiting.

23. references
 Stimson P.G and Mertz C.A :Forensic
dentistry(pg 137- 159)
 Nordby J.J and James S.H: An introduction to
scientific and investigative techniques(pg 70- 73)
 Bowers C.M:Forensic dental evidence(pg 67-
115)
 www.forensicdentistryonline.org
 www.forensicscience.uwa.edu

24. THANK YOU