DETERMINATION OF STATURE FROM BONES
- Long bone length (femur, humerus) is proportional to height.
- There are sex, race, nutrition and personal variations to consider
- By karl pearson formula.
Humerus = 18% of stature
Femur = 25% of stature
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Determination of postmortem interval from bone.
- postmortem interval (PMI) : period () death & examination.
- Are they ancient or modern bones?
(i.e. greater or less than 50 years )
-Rate of skeletonisation is highly variable.
- In the tropics a body can be reduced to a skeleton in 3 weeks.
- Remarkable preservation of body is seen in acidic peaty soil
Thus, environmental conditions have to be taken into account.
-Naked eye appearance is unreliable:
- Tags of soft tissue, periosteum, ligaments etc, indicate less than 5 years old.
- Soapy texture of surface indicates age less than a few decades.
- Light, crumbling bones are likely to be a century or more old.
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Individualizing skeletal features
Individualizing skeletal features
- Bone disease (Paget's disease, tumours) Previous injury to bone (fracture callus, prosthesis, metallic fragments).
- Comparison of trabecular pattern of bone.
- Pattern of skull's frontal air sinuses ,Outline is unique and comparisons with antemortem X-rays are useful.
- Skull can be scanned into a computer and "fleshed" by computer reconstruction to give likely facial appearance in life.
- Unfortunately eye colour, hair colour and lips are independent of bony structure.
- Laboratory tests –
1.precipitin test : Immunological reaction between bone extract and anti human serum ceases within months of death.
2.If blood pigments are present bones are usually less than 10 years old.
3.Up to 20 amino acids may be identified in bones less than a century old.
4.Fluorescence of freshly sawn bone surface under UV light diminishes after 100 years.
5.New bones contain 4.0 - 4.5 gms% nitrogen; 2.5 gms% indicates approximately 350 years.
6.Radioactive carbon dating indicates which century.
