Forensic Anthropology and Odontology

Forensic Anthropology

the study of human skeletal remains to determine sex, age, race, and time of death in an effort to identify an individual

Definition has been expanded to include these subtopics:

forensic taphonomy – interpretation of outdoor death scenes

forensic archaeology – recovery of scattered or buried remains

newer topics of facial reconstruction and age progression

“Anthros” is Greek for humankind or man and logos means “the study of.”

Forensic Anthropology

Pictures courtesy of Charles Comer

Determination of Sex

1. Pelvis best

• females have wider subpubic angle

• females have a wider sciatic notch

• females have a broad pelvic inlet

• Females have a larger pelvic brim

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 and Native American decent)

wider cheekbones, concave incisors,

width between eyes greatest

• ‘Black’ (everyone of African and West Indian decent)

more prominent ridges, wider nasal opening

• ‘White’ (Caucasian and Hispanic decent)

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, can use pubic symphysis

• 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

• 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)

1. Obtain skull

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

Facial Reconstruction

Age Progression

Photo of 2.5 year old male abducted by a family member

Age progression drawing using parents and siblings as a guide. It had been 15

years since the abduction so the subject was aged to 18

years of age.

Age Progression

Age progression drawing using parents and siblings as a guide. It had been 15

years since the abduction so the subject was aged to 18

years of age.

Drawing led to tips and identification of the victim

Age Progression

Age progression drawing using parents and siblings as a guide. It had been 15

years since the abduction so the subject was aged to 18

years of age.

Drawing led to tips and identification of the victim

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 MarksPhysical 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 (+/- 4 years)