Flashcards in Forensic Anthropology Deck (42)
What is forensic osteology?
Study of topics such as facial superimposition, facial reconstruction, forensic odontology, bone pathology, and archaeology
What is the forensic osteologist asked to provide?
Information that may confirm, or assist in determining the identity of an individual from their skeletal remains
More recently become members of teams investigating war graves
What is the first question asked by police/coroner/ procutator fiscal/ forensic pathologist?
Are the bones human or animal
What are some examples of bones that can't show whether a bone belongs to a human or animal?
The shaft of a long bone or a fragment of rib is difficult to distinguish from animal remains, especially those of pig or sheep
What can be used to distinguish if the bone is human or animal?
Sometimes the smell on heating bone gives a clear indication if it's an animal
What is the second question asked?
Whether the remains are of forensic or archaeological provenance i.e. bones older than 70 years its unlikely guilty party can be brought to justice
Why is it difficult to determine the time since death?
As there are many different factors that alter the composition of the bone
What factors can affect the decomposition of a body?
Physical conditions and the activities of humans. These can include temperature, pH of soil, level of the water table, the growth and metabo- lism of bacteria and vegetation and disturbance by animals. Skeletonization can take place in hot, dry conditions in as little as 2 weeks or may take centuries as witnessed by the bog-men and the ice-man
What is taphonomy?
The study of the way in which elements of a dead body are scattered and degraded
What chemical indicators can indicate the time since death?
14C (Taylor et al., 1989) and 90Sr levels (MacLaughlin-Black et al., 1992; Neis et al., 1999), equilibrium between 210Po and 210Pb levels (Swift, 1998), ultraviolet fluorescence and anal- ysis of nitrogen content by various means (Knight and Lauder, 1967, 1969).
What are the issues with chemical indicators?
Some of these methods are complex, time consuming procedures that require a specialist laboratory and none give a very satisfactory answer within the forensic time frame.
What often is the issue for the bone specialist in examining the samples?
Often presented in the mortuary or laboratory with a bag of bones that have been retrieved by persons not specialised in the excavation or examination of a skeleton.
What type of grave is usually of forensic importance
Shallow graves, especially if accompanied by the remnants of a blanket, carpet or plastic sheet
What are the 4 main attributes of biological identity that most forensic osteologists hope to determine?
What is the first task once you have found remains?
Allocate skeletal elements to specific individuals e.g. 2 right radii are found there must be at least 2 individuals
What factors can identify whether you have a bone belonging to the same or different person?
Size of bones
Robusticity of bones
How does identifying the sex help in an investigation?
Halves the people you are looking for off a missing persons list
What are the two main differences in male and female bones?
First, male bones are generally bigger and more robust than female bones. Second, the male pelvis is primarily adapted to bipedal striding whereas the female pelvis displays size and shape differences that reflect the compromise between efficient locomotion and the modifications necessary for the safe passage of a large fetal head through the birth canal.
What does the reliability of sex determination rely on?
Depends on the completeness of the remains and the degree of sexual dimorphism inherent in the population
What two bones are most sexually dimorphic?
The pelvis and the skull
What is the shape of the male pelvis?
High and narrow
What is the shape of the female pelvis?
Wider and shal- lower and has a larger outlet
What bones in the pelivs can show these differences?
These differences are reflected in the shapes of both of the greater sciatic notch and the subpubic angle and in the relative proportions of the body and alae of the sacrum
What can the sciatic notch identify?
The sex of the person. A wide, shallow greater sciatic notch is considered to be a female characteristic as is the greater width of the ala of the sacrum compared to the width of the body.
The pubic bone is probably the element of the skeleton that can offer the most reliable indication of sex
What are the 3 features characteristics of the female pubic bone?
A subpubic concavity; a ventral arc that is an elevated bony ridge extending from the pubic crest to the pubic ramus on the ventral surface of the bone; and a ridged medial border to the inferior pubic ramus
What are other indicators of sex in the pelvis?
The greater sciatic notch and the acetabular index and the morphology of the sacro-iliac joint
Sexing pelvis was based on large sample sizes what does this mean?
1 in every 7 individuals would be incorrectly assigned
How does the sacrum differ in sexes?
Ala is narrower in the body of S1= male
Ala is of similar body to the S1= female
How does the pubic arch differ between sexes?
90 degres or less (acute) likely to be male, if its obtuse likely to be female
How does the body of the pubic bone differ between sexes?
Looks like a triangle- male, looks like a square- female
How does under the pubic symphis-inferior pubic differ between sexes?
Male broad and flat, female- sharp and concave
How can you estimate age in juveniles?
Dentition and skeletal development
How can dental age be determined in juveniles?
From the eruption or degree of mineralization of the teeth.
How can skeletal age be determined in juveniles?
Developmental state of centers of ossification and the size and length of the long bones
Does skeletal age or dental age give a better indication of chronological age?
What factors can estimate age in adults over 30?
- Arthritic change
- Pubic symphysis
- Sacroiliac joint
- 4th right rib
- Tooth attrition
After what age is it more difficult to age an individual?
How can you age someone over 40?
Looking at degenerative features as opposed to developmental features
Look for arthritis
Lip on bone (osteophyte)
Osteophytes characteristic of osteoarthritis (tends to effect vertebrae first)
Person with osteophytes likely to be over the age of 40
40-44 osteoarthritis and pubic symphis
Pubic symphis and sacral
Aim to get it into a decade
End of the 4th right rib (careful its not chipped)
How CANT you age someone over 40?
What tends to be broken if an individual is strangled?
What features are sometimes seen in ethnic groups?
• Prominent cheek bones in Chinese
• Larger noses- black people