Transcript Forensic Anthropology and Odontology

Forensic Anthropology and
Odontology
Forensic Anthropology
-study of human skeletal remains to determine sex, age,
race, and time of death in an effort to identify an
individual
- includes newer topics of facial reconstruction and age
progression
- “anthros” is Greek for humankind or man, logos
means “the study of”
Determination of Sex
1. Pelvis best
•
females have wider subpubic angle
•
females have a wider sciatic notch
•
females have a broad pelvic inlet
Determination of Sex
1. Pelvis best
•
females have wider subpubic angle
•
females have a wider sciatic notch
•
females have a broad pelvic inlet
Determination of Sex
2. Cranium second best
• Crests and ridges more
pronounced in males (A,
B, C)
• Chin significantly more
square in males (E)
• Jaw (I, E), mastoid
process wide and robust
in males
• Forehead slopes more in
males (F)
Determination of Sex
Other bones are not usually as good an indicator
regarding sex
Determination of Race
The cranium is the only reliable bone and, even
then, can only tell general category as below:
• Mongoloid (all of Asian decent and Native
American decent)
wider cheekbones, concave incisors,
width between eyes greatest
• Negro (everyone of African decent and West
Indian decent)
more prominent ridges, wider nasal opening
• Caucasian (all ‘white’ individuals)
narrow everything
Determination of Age from Bones
• Ages 0-5: teeth are best – forensic odontology
• Ages 6-25: epiphyseal fusion – fusion of bone
ends to bone shaft
epiphyseal fusion varies with sex and is typically
complete by age 25
• Ages 25-40: very hard
• Ages 40+: periodontal disease, arthritis,
breakdown of pelvis, occupational stress,
unique clues
Determination of Age from Bones
Occupational stress wears
bones at joints
Surgeries or healed wounds
aid in identification
Determination of Stature from Bones
Long bone length (femur, tibia, humerus) is
proportional to height
There are tables that forensic anthropologists use.
For example:
Femur length
Predicted Height
41 cm
167 cm (5’6”)
50 cm
186 cm (6’1’)
Males: (1.88 x femur length in inches) + 32.01
Females: (1.945 x femur length in inches) + 28.70
Dating Human Skeletal Remains
Under the right conditions, bodies can be reduced
to a skeleton in as little as three weeks
Laboratory Tests
• Immunology tests can indicate if body is a few
months old or less
• Blood pigments last less than 10 years
• Identification of amino acids possible if less
than 100 yrs old (fluorescence)
• Percentage of nitrogen in bones (new is about
4.5%) – bones lose about 0.006% a year
• Carbon dating for bones centuries old
Facial Reconstruction
1. Obtain skull
• Determine demographic information
(female, Caucasian, early 40s)
• Note unique features
(had lost all back teeth on
upper and lower jaw)
• Anything known about this individual?
(came to U.S. by boat in 1710
from Europe, died and buried in
NY around 1733)
Facial Reconstruction
2. Add tissue depth markers
•
Based on largely on sex and race
3. Begin to add common fat deposits
and underlying muscles
Facial Reconstruction
4. Add muscle to average
depth for race
5. Add skin, nose, ears
6. Add features related to age and
race (wrinkles, eye and hair color)
Facial Reconstruction
7. Add clothing etc appropriate for the
time period, religious affiliations, etc
Forensic Odontology
• identification of bite marks on victims
• comparison of bite marks with teeth of a suspect
• identification of unknown bodies through dental
records
• age estimations of skeletal remains
• victim identification through DNA analysis
Normal Adult Human Teeth
Forensic Odontology – Bite Marks
Physical Characteristics
• distance from cuspid to cuspid
• tooth alignment
• teeth width, thickness, spacing
• missing teeth
• wear patterns including chips and grinding
• dental history including fillings, crowns, etc.
Forensic Odontology – Age Determination
Neonatal Line – allows forensic
odontologists to determine if a child was
alive at birth
• Ratio of L-aspartic acid to D-aspartic acid (+/- 1.5 years)
(L-aspartic acid  D-aspartic acid with time)
• Gustafson’s Method – six signs of wear including dentin
density and transparency