(FAY) Determining Age From Skeletal Remains Lesson

Determining Age From Skeletal Remains

The age of the decedent at death can usually be approximated by a Forensic Anthropologist once they have examined the remains if a sufficient number of bones and skull are found. Growth and development progresses predictably through several stages that can often be observed in the remains. Forensic Anthropologists look for specific patterns in the bones, teeth and skull sutures to approximate age.

Interactivity: Determining Age From Skeletal Remains

Stature

Stature simply means the height, or how tall an individual is while standing. Forensic Anthropologists can use bone measurements to estimate height when the actual height is unknown. The bone measurements are plugged into standard stature equations and height is estimated from those calculations.

The typical bones that Forensic Anthropologists measure are Ulna, Humerus, Femur, Radius, and the Tibia.

In order to calculate an estimation of height, Forensic Anthropologists plug in the bone measurements (in centimeters) into the following equations:

Bone Measurements

Sex

Tibia Equation

Radius Equation

Femur Equation

Humerus Equation

Female

(Tibia length X 2.90) + 61.53= Height (cm)

(Radius length X 3.87) + 73.50= Height (cm)

(Femur length X 2.6) + 65 = Height (cm)

(Humerus length X 3.06) + 64.26= Height (cm)

Male

(Tibia length X 2.42) + 81.93= Height (cm)

(Radius length X 3.65) + 80.40= Height (cm)

(Femur length X 2.6) + 65 = Height (cm)

(Humerus length X 3.27) + 59.41= Height (cm)

*Tip: When measuring bones, always use a metric ruler. If you must measure in inches, convert the measurement to centimeters by multiplying the inch measurement by 2.54.

Example calculation:

A 40.8 cm male tibia was found in a shallow grave. How tall was this man?

(40.8cm X 2.42) +81.93 = 180.67cm

If you would like to convert the above answer to inches, divide by 2.54.

180.67 cm/2.54= 71.12 inches or about 5 feet 11 inches.

So, in this example, the man was approximately 181 cm or 5'11".

Burial site with markers

Forensic Odontology

Another way to approximate age is through the teeth. Forensic Odontologists can estimate age through tooth eruption patterns as well as tooth wear patterns. Forensic Odontologists specialize in examining bitemarks and dental identification. Their duties include:

-Estimation of the age of the decedent

-Identification of the individual by comparing the teeth with dental records

-Examination of bite marks

-Providing expert testimony in criminal, malpractice and worker's compensation cases in court. In determining age, Forensic Odontologists estimate age based on the tooth eruption pattern in the mouth, as well as the wear patterns on the teeth. In children and adolescents, it is most useful to analyze the eruption patterns as the teeth continue to erupt until the age of about 21 years. The primary teeth, or "baby teeth", are the first set of teeth that a child will have. Forensic Odontologists use the following general patterns and the presence or absence of those teeth to approximate age in younger children.

Forensic Odontologists examine
eruption patterns and wear patterns
to estimate age

Primary Teeth Eruption Patterns

Primary Teeth Eruption Patterns by Age

Tooth Type

Estimated Age

Incisors

6-16 months

Canines

16-23 months

1st Molars

13-19 months

2nd Molars

23-33 months

In later childhood, adolescence and early adulthood, Forensic Odontologists use permanent teeth eruption patterns to estimate age. Forensic Odontologists look to see which of the permanent teeth have already erupted in the mouth and which are still absent in order to approximate the age of the decedent. The permanent teeth age estimates are as follows:

Permanent Teeth Eruption Patterns

Permanent Teeth Eruption Patterns by Age

Tooth Type

Estimated Age

Incisors

6-9 years

Canines

9-11 years

1st Pre-Molar

10-12 years

2nd Pre-Molar

10-12 years

1st Molar

6-7 years

2nd Molar

11-13 years

3rd Molar ("Wisdom Teeth")

17-21 years

In addition to the eruption patterns, Forensic Odontologists also examine the wear patterns of the teeth to estimate age. As people get older, their teeth wear down and show some predictable signs of age. There are various methods for evaluating this and it requires extensive training and experience to estimate age using only dental wear patterns. It is the only method available to estimate age based solely on the teeth in adults older than 21 years old because all teeth have erupted by that age and they are no longer indicative of a particular age. Though it is a more difficult method to employ, tooth wear patterns are commonly used in cases when no other age indicators can be found.

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