Estimating Age at Death and Stature

Flashcards on estimating age at death and stature using the skeleton.

How should continuous variables like age at death and stature be reported?

Continuous variables should be reported with standard errors.

What does plus or minus one standard error indicate?

There is a 68% chance the actual estimate lies within that range.

What does adding and subtracting two standard errors indicate?

There is a 95% chance the actual estimate lies within the range.

What is a key assumption when applying age estimation methods?

Assuming that the method's population or sample is appropriate for the individual.

Why is age estimation more accurate in immature individuals?

Developmental processes and growth occur at predictable rates in young individuals.

What are the primary methods for age estimation in immature individuals?

Bone growth, epiphyseal fusion, dental development, and tooth eruption.

How do sexes differ in developmental rates?

Females generally develop faster than males, by about two to three years in The US.

What environmental influences affect development?

Access to nutrition and general health.

How does high altitude affect maturation times?

Populations at high altitude tend to have slower maturation times.

When do deciduous teeth typically begin to erupt?

The deciduous teeth begin to erupt into the mouth at about nine months of age.

When is the complete deciduous dentition typically present?

Around age three.

When does the permanent tooth (molar) typically begin to erupt?

Around six years of age.

What does a standard dental eruption chart show?

A typical pattern of tooth formation, root development, and eruption.

Why are dental tissues with growth increments very accurate for age estimation?

A specialist can find a marker that tells them roughly when birth is.

What is the prominent stria of Retzius in the enamel of teeth referred to as?

The neonatal line.

What are the primary drawbacks of using dental tissue analysis for age estimation?

It is destructive and time-consuming.

Besides dental methods, what other method is used for age estimation in immature individuals?

Epiphyseal fusion or synostosis.

How does epiphyseal fusion aid in age estimation?

The epiphyses unite with their diaphyses in a predictable order and timing.

Where do epiphyses around particular joints tend to fuse at about the same time?

Around the elbow, knee, or ankle.

What does each line on an epiphyseal fusion chart represent?

The age range during which the epiphysis is undergoing the unification process.

How is epiphyseal fusion helpful for individuals in the 15-23 age range?

A particularly helpful method for coming up with an age estimate.

What is the last epiphysis to unite with its diaphysis?

The medial end of the clavicle.

What is the last synchondrosis in the base of the skull to synostose?

The spheno-occipital synchondrosis.

What is a helpful method in younger subadults, for age estimation?

The total length of the diaphysis.

For whom is the total length of the diaphysis the most accurate method?

For neonates and young children.

When are age indicators exhausted?

After the wisdom teeth have fully erupted and the medial clavicular epiphysis has united with its diaphysis.

What characterizes age estimation in adults?

More gradual changes resulting in less precise age estimates.

What is a widely used technique for osteological estimation of age at death in adults?

The pubic symphysis.

What characterizes the earlier stages of the pubic symphysis?

A smooth billowy surface with horizontal ridges and grooves.

What occurs with age in the pubic symphysis?

Formation of a rim around that begins with the smoother dorsal surface as well as little ossified nodules.

What occurs in phase six of pubic symphysis aging?

Breakdown of the rim and a more erratic pattern of ossification of the pubic face.

Which area undergoes changes fairly similar to those observed in the pubic symphysis?

The auricular surface of the ileum.

How are the imprecisely obtained age estimates useful?

They are useful and can provide really important information like this is a younger adult, this is an older adult, and when combined with some of the other techniques can give important clues.

What is another widely used technique for age estimation?

The sternal end of the ribs.

What represents morphological changes that occur in the sternal end of the ribs?

It transitions from bone to cartilage.

What are the phases of morphological changes at the sternal end of the ribs?

Smooth, billowy surface, formation of a rim, depression of the center with a more porous pattern of ossification, and eventual breakdown of the edge.

How are sternal ends of the ribs useful?

The morphology of the sternal ends of the ribs can be useful indicators of young adulthood, middle adulthood and later adulthood.

What approach in the skull is important for age estimation?

Synostosis of some of the cranial sutures.

How are sutures ranked for synostosis?

Fully patent sutures to completely synostosed.

How do you calculate an age estimate based on cranial suture closure?

By summing the scores and looking up the total in a table.

Which histological method is used for age estimation?

Counting osteons.

How are complete and partial osteons used in age estimation?

They are tallied and then placed into formulas with a standard error.

How is counting cementum annulations useful?

Is not particularly precise, but provides information if one only has teeth.

When estimating size for the biological profile in human osteology, what do we usually focus on?

Stature.

What's a quick rule of thumb for estimating body length?

Body length is roughly five times the length of the humerus.

What happens if you have more than one bones when estimating stature?

They can be combined to produce more precise estimates.

How is stature estimation done based on the entire skeleton?

Dividing the skeleton into different segments.

What is the 95% confidence range for a stature estimate in osteology?

Approximately four inches.

How are lengths of bones measured when estimating stature?

With an osteometric board

For a single bone, which is the best for estimating stature?

The femur is the best individual bone for estimating stature.

When estimating stature which long bones are superior?

Any long bone from the lower limb is superior to long bones from the upper limb.

Why might secular trend affect stature estimates?

Many of our reference populations are from 100 ago (from the early century).

How do you estimate stature from incomplete elements?

Measure the length of a sub segment of a bone.

How can postural changes affect stature with age?

Vertebral bodies collapse a little bit with age, which can shorten overall stature.

What stature is usually provided on driver's licenses?

Slightly taller stature.

What are the key takeaways regarding age and stature estimation?

Report continuous variables, understand standard errors, and know the assumptions of methods used.

Among immature individuals, what is the most important technique to use?

Dental eruption schedules.

What are development parameters affected by?

Access to nutrition and general health.

Why is the total length of the diaphysis helpful in younger sub adults?

Because there aren't even epiphyses present in younger individuals.

What is really challenging to estimate regarding stature.

Individual weight.

Besides pubic symphysis and cranial sutures, what are other methods that have been applied, though are not particularly precise?

Dental wear, cementum annulations, and osteon counting.

How does stature change over time?

Postural changes, vertebral collapse, and bone shrinkage occur with age.

What is the key to accuracy when using standard error?

Plus or minus one standard error gives us about two thirds accuracy or 68% chance.

What can be applied if you know the age when dividing the skeleton into different segments?

If age is known, an adjustment can be applied for age as well.

When are age estimates useful?

When combined with other clues such as is the individual a younger or older adult.

Where would you measure the length of a sub segment on the humerous?

From the humeral head to the olecranon fossa.

Why is total length used rather than a functional length?

For simplicity.

How do you use the different parts of the body in correlation to synostosis closures? (composite scores)

Average of say thirty nine years, and a range from twenty seven to 43.

Why and how is counting osteons important?

The number of complete and then partial osteons are tallied, and then these are placed into formulas with a standard error, and that can yield age estimates.

What should you be aware of?

The sample upon which you are applying these methods when using this data.

What does the amount of wears allow you to do?

The amount of exposed dentin on different teeth and come up with an age estimate in a particular population.

Why would one focus on stature when estimating size for the biological profile?

Since stature can vary relatively little throughout an individual's life.

When are peoples stature overall reported taller?

Those given on driver's licenses

When are heights of the bodies measured?

To produce a relatively accurate stature estimation.

What does this method say when estimating assuming the the method population or sample is relevant to the individual?

That the individual is middle aged.

When aren't there any kinds of age indicators left for estimating the age of an individual?

After the last tooth erupts into the mouth.

What happens when you have to bear in mind that there's error in each step of this process when estimating stature in human osteology?

You actually have to multiply them together.

Why is it problematic that standard age estimates have not been generated for any other rib other than the rib?

Can be problematic and how to adjust the age depending on different ribs is not understood.

What should you bear in mind when looking at some of these formulae in human osteology?

Because of our own society the way it is, sometimes people over report their stature.

How do you apply the standard formula for the femur?

2.38 times the length of the femur plus 61.41 and that gives you a height in centimeters and then the standard error is provided there.

What has growth increments in them?

Dental tissues.

What are the lengths to the bones that are measured to produce a realitivity accurate stature estimation?

The femur, tibia and the talus plus calcaneus.

How are the cranial sutures when synostosed?

These aren't necessarily much more precise than what you would get looking at the pubic symphysis or other techniques like this.