Forensic Odontology

1
Forensic Odontology

• Teeth and Bite Mark Evidence

2
What is a Forensic Odontologist?

• Most forensic odontologists are practicing
  dentists.
• However, they have gone through specialized
  training to understand how to apply forensic
  science to dentistry.
• Most are members of a
• professional organization.

3
The Importance of Forensic Odontology

• A forensic investigation of teeth will help to
  determine
• -Individual Identification
• -Mass Disaster Identification
• -Bite mark analysis
• Child Abuse
• Dental Malpractice

4
An Understanding of Teeth

• Teeth begin to appear at 6 months of age and all
  should have emerged by age 3.
• Humans have 20 deciduous (baby) teeth.
• Between the ages of 7-21 years all of the
  deciduous teeth should have been replaced with
  permanent teeth.
• Adults have 32 permanent teeth. This includes the
  four wisdom teeth.
• Teeth are the hardest substance in the body.

5
Age Chart for Deciduous and Permanent teeth
6
Teeth Numbering System

• Teeth are numbered from 1 to 32 starting from the
  upper right (1), to upper left (16), down to
  lower left (17) to lower right (32).

7
The 4 types of the Teeth

• The 4 types of teeth
• Incisors
• Canines
• Premolars
• Molars

8
The 5 Surfaces of the Teeth

• Each tooth has 5 surfaces
• M mesial (front)
• D - distal (backside)
• O - occlusal (biting surface)
• F facial (cheek side)
• L - lingual (tongue side)

9
Tooth Composition
10
Identification using Teeth

• Many times identity of a skeleton can be
  determined by comparing the teeth features in the
  skull to dental records.
• Unusual features including the number and types
  of teeth and fillings, the spacing of the teeth,
  and/or special dental work (bridges, false teeth,
  root canals) help to make a positive
  identification.
• 70-80 of Americans have received dental care so
  use of dental records is common

11
Example of a Dental Record

• Today, most people have a dental record.
• Dental records have information about the
  condition of each tooth and this information is
  compared to the postmortem report.

12
Dental Work That Makes Teeth Unique
Dental Crown
Dental Fillings
13
Dental Work That Makes Teeth Unique (cont)
Dental Extraction
Dental Bridge
14
Postmortem Dental Information will include any
unique dental features
15
Lifestyle Effect on Teeth will also help to
identify the body

• First, the antemortem (before death) and
  postmortem (after death) X-rays are compared.
• Next, the investigator will look for other
  lifestyle indications from the teeth. For
  example, smoking.

16
Example of X-ray comparison.
17
Example of X-ray Comparison
18
Lifestyles and Teeth

• Mouth of a smoker

• Mouth of a Meth user

19
(No Transcript)
20
(No Transcript)
21
(No Transcript)
22
(No Transcript)
23
Dentures

• There are cases where the victim no longer had
  teeth and wore dentures.
• Records are also kept for dentures so this dental
  appliance is a very good source.

24
Cases of Identification using Teeth

• The first case Roman Emperor Claudius to
  recognize his beheaded mistress.
• First U.S. Court case- in 1849 the incinerated
  remains of George Parkman were identified using a
  partial denture.
• First case using dental records- identified the
  victims of the Vienna Opera House fire in 1878.

25
Cases of Identification using Teeth

• In more recent times, teeth identification has
  been used in mass disasters such as plane
  crashes, fires and bombings.
• Approximately half of the victims from the
  September 11, 2001attack on the
• World Trade Center
• were identified using
• DNA, jewelry and
• dental records.

26
Bite Mark Evidence

• Forensic odontologists will also work on cases
  that involve bite mark evidence.
• Bite marks are found when teeth are used as
  weapons.

27
Bitemarks may be found on

• Victims
• Suspects
• Trash
• Chewing Gum
• Food Items

28
Class Patterns of Tooth Types

• Incisors Rectangles
• Canines Triangles with some variations
• Premolars Single or dual triangles, diamonds
  with some variations
• Molars Rarely leave marks

29
The First Steps

• The area will be swabbed for saliva
• Bruising around the bite indicates a current bite
• Photographs taken
• Impressions made
• Measurements taken
• Skin preserved if needed

30
Bite Mark Evidence

• Bite mark evidence is controversial because skin
  is elastic and distortable.
• The accuracy of this evidence is often questioned
  by the court.
• Many bite mark cases are overturned.
• However, this evidence is very helpful in
  excluding suspects.
• Many times the saliva on the bite mark allows DNA
  analysis.

31
Ted Bundy

• The Ted Bundy Case is a very famous bite mark
  case. Bundy had a very unusual bite and was
  convicted on this evidence.
• The dentist forgot about mirror image of
  transparency and used overlay incorrectly

32
Ted Bundy and his teeth configuration that
caused the unusual bite