Transcript 5_Odontology - bloodhounds Incorporated

Medico-legal Investigation
Skeletalization &Forensic
Odontology
Skeletalization
environment is more
important than the time in this
• The
•
•
•
•
process.
12-18 months: bone and tendon tags
After 3 yrs: bare bone.
In temperate zones the bones will
remain solid & heavy with the
preservation of bone marrow in long
bones for a number of years.
After 40-50 years :
– Surface of the bone becomes dry & brittle
– Marrow cavity will be empty.
The individual was recovered in a home with
rats. Post-mortem bite marks are yellow,
bloodless defects with scalloped edges.
Post-mortem Gnaw
Marks on the Bone
Post-mortem vulture activity on a woman
discovered in a wooded area. The tendon is
visible through the hole while much of the
muscle is absent. The yellow discoloration
around the hole is consistent with beak marks
The skeleton is that of an adult male who was
missing 1.5 months during late fall in the
southeastern US. He was found in a wooded
area. Gnaw marks are evident on several ribs.
Forensic Odontology
An Introduction to Forensic Dentistry
FORENSIC ODONTOLOGY
Forensic Odontology is the application of
dentistry in legal proceedings deriving from
ANY evidence that pertains to teeth.
TEETH
Hardest part of body attached to jaws.
Teeth serves to help digest food, act as
a defense mechanism, etc.
Teeth Basics
• Tooth consists of
–
–
–
–
Root
Root canal
Dentin
Enamel
Types of teeth.
Left to right: Incisor, Canine, Premolar,
molar.
Forensic Odontology
• Human Dentition and Dental Anatomy
– Enamel is the hardest substance in the
human body
– Full compliment of adult dentition of 32
teeth
– Each tooth presents 5 surfaces in a
visual examination for a total of 160
surfaces
– Arranged in 2 Dental Sets called “arches”
• One Upper Arch = Maxillary Jaw
• One Lower Arch = Mandibular Jaw
Odontology
Odontology
Forensic Odontology
• Human Dentition and Dental
Anatomy
– Dental Arches are Symmetrical
– Each Quadrant contains the same
“number and type” of teeth
Teeth through the years
Childhood
•
Primary teeth sprout from milk
buds and are temporary. Once they
fall out, permanent teeth as seen on
the other side appear.
Adulthood
 Permanent adult teeth come in
when primary teeth fall out; they are
permanent because they establish
roots inside the gums. Third molars
come in around the mid teenage
years.
Forensic Odontology
• The Human has the
following:
– 2 Incisors = sharp,
flat, wide teeth for
cutting
– Cuspid = tearing,
ripping and gripping
– 2 Premolar = 2
cusps for biting and
crushing
– 3 Molar = 3-5 cusps
(wide biting area)
– Third molar =
Wisdom (last tooth
in arch)
Forensic Odontology
• Key to Dental Anatomy
is:
– Orientation
– Tooth Surface
– Landmarks and
Structures
•
•
•
•
•
M = mesial
O = occlusal
D = distal
L = lingual
B = buccal
distal ←, mesial →, coronal ↑, apical ↓.
Forensic Odontology
Individual Characteristics






Size of tooth
Shape of tooth
Shape of root
Placement of tooth
Quantity of teeth
Combinations of
dental work done:
 Crowns
 Extractions
 Bridge
 Fillings
 Root canals
Various dental work
Analyzing Teeth
• The Universal System
1. Teeth are given a
specific number.
(Primary teeth are
given specific capital
letter)
2. Any dental work done
on surface is noted
3. Sheets kept on dental
file forever. When
person is missing, files
are transferred to the
missing person’s office
Various Teeth Found
Why Teeth?
 Every human body ages in a similar manner, the teeth also
follow a semi-standardized pattern. These quantitative
measurements help establish relative age of person.
 Each human has an individual set of teeth which can be traced
back to established dental records to find missing individuals.
 Teeth are made of enamel (hardest tissue of the body) so they
can withstand trauma (decomposition, heat degradation, water
immersion, and desiccation) better than other tissues in body.
 Teeth are a source of DNA: dental pulp or a crushed tooth can
provide nuclear or mitochondrial DNA to help identify a person.
Dental X-rays
Forensic Odontology
– Scope of FO is the
following:
• Identification of unknown
decedents by analyzing
dentition (teeth), jaw
structure, craniofacial
bones, maxillofacial bones
• Bite mark investigation
• Examination of oral-facial
trauma involving
person/child abuse
• Medico-legal jurisprudence
and expert witness
testimony
Who practices Forensic Odontology
and what do they do?
 Forensic
Odontologists
 Must have DDS degree
 Should have specialized
training in the field
through lectures (not
required)
 Forensic dentists help:
Top: Forensic Odontologist
analyzing animal teeth for
comparison.
Side: Seal for American Board of
Forensic Odontology.
 Identify human remains
(individual and mass)
 Analyze bite marks
 Bite marks are compared
to known teeth molds to
find origin of bite injuries
 Estimate age of the
victim and perpetrator
 Trace dental
malpractice
History
• The earliest known
identification from teeth is in
1775 by Paul Revere.
• Paul Revere made a silver bridge
for one man. The man was
killed in the Revolutionary War.
• Body was in a mass grave and
identified by his silver dental
work and hippo tusk.
History of Forensic Odontology
• 66AD – First body identified using
teeth
– Lollia Paulina
• 1849 – Mass deaths at Vienna
Opera House Fire
– Dental evidence is first admitted
into court system in US
Organizations of Forensic
Odontology
• Bureau of Legal Dentistry
(BOLD)
• American Board of Forensic
Odontology (ABFO)
• International Organization
for Forensic OdontoStomatology (IOFOS)
Forensic Odontology
• Postmortem dental
examination should
include examination of:
– Missing, unerupted or
extracted teeth
– Restorations and
prosthesis
– Decay and broken
teeth
– Malposition,
overlapping, crowding
and spacing
• Identifying
factors such
as cavities,
tooth pattern,
and general
dental health
neglect
Forensic Odontology
•
•
•
•
Peculiar shapes of teeth
Root canal on x-ray
Bone pattern on x-ray
Bite patterns
Odontology
BITE MARKS
Impressions from teeth found on
skin or items left at a scene.
Usually outline teeth placement.
Forensic Odontology
• Forensic
Odontology may
include the
study of bite
mark patterns
on the victim.
– Digital overlay is
used to make a
comparison.
Ted Bundy
List of Skull Bones for
You to Know
•
•
•
•
•
•
•
•
Frontal
Parietal
Occipital
Temporal
Zygomatic (and arch)
Orbit
Maxilla
Mandible