Bones & Forensic Anthropology

ctkid

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I am not a Forensic Anthropologist. I am a Radiologic Technologist (X-ray Tech). I worked in the field for 35 years. I have x-rayed many a bone. I have also x-rayed body bags and worked with a coroner. I am going to try to put together some information that would be helpful for our UID Reference section.

http://anthro.palomar.edu/time/time_1.htm

People often think of fossils as being mineralized bones or shells stored in museums. However, they can be any remains or traces of ancient organisms. They even can be footprints, burrows, or casts of bodies with nothing else surviving. Some of the best preserved fossils were rapidly frozen in permafrost soil or ice, dehydrated in dry desert caves, or encased in tree resin that hardened into amber. In any of these three environmental conditions, even soft body parts can be remarkably well preserved indefinitely.

Several wooly mammoths that lived during the last ice age have been excavated from frozen tundra soil in Siberia. Some were still in such good condition, that parts of their bodies were fed to the dogs of the Russian scientists who found them. One small mammoth was even transported intact to Moscow where it is kept in a specially made large freezer that allows it to be displayed for the general public. The oldest frozen human remains were discovered on the edge of a glacier in the Alps of northern Italy in 1991. It was a well preserved body of a man, along with his clothes and tools, who died about 5,300 years ago. Even tattoos on his skin were preserved by the extreme cold.

The mummies of ancient Egypt were preserved by extreme, continuous dehydration. The complicated mummification practices used to prepare the bodies of important people only accelerated the dehydration, but it was not necessary in the dry conditions of Egypt. Mummies from other cultures have been found in deserts around the globe. Some of the best preserved ones were discovered in the Tarim Basin of Western China.

Bodies of people submerged in stagnant swamps or bogs in Denmark and the British Isles thousands of years ago have also been found in remarkably good condition with their soft tissues intact. They were preserved naturally by cold anaerobic environments and by tannins with antibiotic properties released from decaying plants in the swamps. The bodies were essentially tanned like shoe leather. These conditions are hostile for bacteria and other organisms that normally reduce organic matter to basic soil nutrients in a matter of months.

Some of the topic's to be covered. (These might take awhile to cover.)

Differences between male and female skeleton.
How to determine skeletal age.
Epiphysial plate, physis, or growth plate
Arthritis and Disease processes.
Tooth eruption and wear patterns.
Decompositon.
 
What is Forensic Anthropology.

Forensic anthropology - Wikipedia, the free encyclopedia

Forensic anthropology is the application of the science of anthropology in a legal setting—most often physical anthropology and human biology in criminal cases (FBI, CIA and military) where the victim's remains are in the advanced stages of decomposition. A forensic physical anthropologist can assist in the identification of deceased individuals whose remains are decomposed, burned, mutilated or otherwise unrecognizable. The adjective "forensic" refers to the application of this subfield of science to a court of law.

A broad definition of "forensic" anthropology includes forensic cultural anthropology or ethnology, forensic linguistics, and forensic archeology, indeed any and all anthropology applied in judicial settings, both criminal and civil.
 
What is the difference between a male and female skeleton.

The only difference between a male and female human skeleton model is that the female has a more rounded pelvis, but in fact there are many subtle differences between male and female skeletons.

pelvic_cavity_of_males_and_females_(edit)1314760968210.jpg


http://human-skeleton-model-review....erence-between-male-and-female-skeletons.html

Girls mature faster than boys. We have all heard that before. It is not only true about emotional maturity. But bone maturity also.

The bones in a female body complete their development sooner than those in the male body. Female bones complete their development around age 18, while men’s bones continue to mature until around age 21. This is part of the explanation behind the difference in the average size of male and female bones—as the male bones continue to grow and develop longer, they also become larger (on average) and have more pronounced corners. Thus, the relative size of several key features can be used to identify a male vs. female skeleton. In males, the jaw bone is generally larger and more pronounced, and the brow is taller. Male skeletons also generally have longer, thicker bones in the arms, legs and fingers.
 
http://anthropology.si.edu/writteninbone/male_female.html

This table outlines the differences between a male and female pelvis.



Male


narrower, heart-shaped pelvic inlet
◾narrower sciatic notch
◾narrower angle where the two pubic bones meet in front

Female

◾open, circular pelvic inlet
◾broader sciatic notch
◾wider angle where the two pubic bones meet in front
◾more outwardly flared hip bones

Fact:
◾Sex-related skeletal features are not obvious in children's bones. Subtle differences are detectable, but they become more defined following puberty and sexual maturation.
 
Skeletal Age.

HWM (Hand Wrist Method)

http://www.hss.edu/BoneAge.asp
http://www.humankinetics.com/excerpts/excerpts/assessment-of-skeletal-age

CVM (Cervical Vertebral Maturation)

http://www.ncbi.nlm.nih.gov/pubmed/19815140
http://www.moroortodontia.com.br/leitura/cvmseminars.pdf

Epiphysial plate, physis, or growth plate
Epiphyseal plate - Wikipedia, the free encyclopedia

Epiphysial Chart (Ossification)

Femur:
The 3 epiphyses/growth plates at upper end fuse at 18years
The 1 epiphysis/growth plate at lower end fuse at 20 years

Tibia:
Upper end fuses at 16-18 years
Lower end fuses at 15-17 years

Humerus:
Upper end during 20th year
Lower end at about 16 years

Radius:
Upper end during 18th year
Lower end at 20 years
 
As you can see, age determination is not an exact science.
 
As we grow older, our facial bones including our eye sockets, nose and upper jaw continue to change. For example, our eye sockets enlarge, and the angle of the bones beneath our eyebrows decreases which could contribute to the formation of frown lines on our foreheads, "crow's feet" at the corners of our eyes and droopy lower eyelids.
 
Based on the dental evidence, what is the age of the skeleton?

http://anthropology.si.edu/writteninbone/comic/activity/pdf/Identify_the_age.pdf

http://anthropology.si.edu/writteninbone/young_old.html


Analysis of Skeletal Remains - Worksheet

In this activity, skeletons will be examined for how they vary according to the following:


•Gender (based on the pelvis & skull)


•Race (based on the maxilla, and other characteristics of the skull)


•Age (based on general characteristics)


•Height (calculated based on the length of individual bones)

http://shs2.westport.k12.ct.us/forensics/11-forensic_anthropology/skeletal_analysis_worksheet.htm
 
http://shs2.westport.k12.ct.us/forensics/default.htm

The Crime Lab

"Wherever he steps, whatever he touches, whatever he leaves, even unconsciously, will serve as a silent witness against him. Not only his fingerprints or his footprints, but his hair, the fibers from his clothes, the glass he breaks, the tool mark he leaves, the paint he scratches, the blood or semen he deposits or collects. All of these and more, bear mute witness against him. This is evidence that does not forget. It is not confused by the excitement of the moment. It is not absent because human witnesses are. It is factual evidence. Physical evidence cannot be wrong, it cannot perjure itself, it cannot be wholly absent. Only human failure to find it, study and understand it, can diminish its value."
 
http://www.jenjdanna.com/blog/2011/12/6/forensics-101-determining-age-of-a-skeletal-victim.html

◾Pre-pubescent: The skeletons of children and teenagers are in a constant state of flux.1.Infant fontanelles close with the union of cranial bones.
2.Long bones are constantly growing, allowing for increased limb length.
3.The growth plate of long bones is constantly laying down new bone until maturity is reached; at this point, the end of the bone fuses to the shaft, terminating growth.
4.Teeth are lost and new teeth form and erupt in their place.



◾Adult: Due to the lack of growth in the post-pubescent years, age determination of adults is slightly more difficult, but there are several very valuable characteristics.1.The surface of the pubic symphysis (where the two halves of the pelvis meet at the front of the body) changes significantly over time, with those changes continuing into the senior years.
2.Similar changes are seen at the auricular surface of the ilium (the hip bone).
3.The medial rib ends (at the center of the body, where the ribs join with the sternum) also change with age, both the surface of the bone as well as the shape.
4.The sutures in the skull and palate finally fuse, and, with time, become completely obliterated.
 
http://www.pbs.org/opb/historydetectives/technique/learning-from-skeletons/

Wrist

Examine the wrists, as bones often hold clues to the primary work of the decedent. Bony ridges form where the muscles were attached and pulled over the years. A forensic anthropologist might find a bony ridge on the wrist and decide the dead person may have been someone who used their hands for a living, such as a chef or seamstress.

DNA

DNA samples may be taken from any existing hair tissue. As well as positively identifying someone, it can also identify a person's race or tribal origins.

Bugs

When the skeleton is first discovered, take samples from around the remains including any bugs you come across. Insects such as blowflies have a very distinct lifecycle and often plant their eggs on newly deceased bodies. By identifying the stage of the lifecycle, a near-exact time of death can be established. This science is known as forensic entomology.

(The coroner that I knew talked about measuring maggots, to help determine how long a person had been dead)

images
 
The housefly life cycle closely mirrors that of most insects: a basic cycle that begins with an egg, then develops through a larva phase, a pupa phase, and finally, into an adult. During a warm summer -- optimal conditions for a housefly -- the cycle, from fertilized egg to adult, spans a mere seven to 10 days.
 
http://www.arthritis.org/conditions-treatments/disease-center/women/

The term "arthritis" encompasses more than 100 diseases and conditions that affect joints, the surrounding tissues and other connective tissues. Arthritis can cause mild to severe pain in the joints, as well as joint tenderness and swelling. More than 50 million Americans have some type of arthritis or related condition.

The various forms of arthritis and related conditions can affect anyone, no matter what your race, gender or age. However, it is especially important for women to be educated about these diseases since they affect women at a much higher rate than men. Sixty percent of all people who have arthritis are female, and several of the more common forms are more prevalent in women.

Osteoarthritis, also known as degenerative joint disease or OA, is the most common form of arthritis. Of the nearly 27 million Americans who have osteoarthritis approximately 16 million are women. Women usually develop OA after age 40. It causes damage to cartilage and bones, causing joint pain, swelling, stiffness and loss of function.

Rheumatoid arthritis (RA) usually strikes women between the ages of 25 to 50, but can occur in children. RA is a systemic disease that can affect the entire body. An abnormality in the body's immune system causes it to work improperly, leading to inflammation in the lining of the joints and other internal organs. Chronic inflammation can lead to deterioration, pain and limited movement. Approximately 1.5 million American adults have RA, with women outnumbering men 2.5-to-1. Learn more about RA. Learn about how to live with RA from the editors of Arthritis Today.

Lupus (systemic lupus erythematosus) is an inflammatory disease that may affect the joints, skin, kidneys and other parts of the body. Almost 240,000 Americans -- 90 percent of whom are women -- have this arthritis-related condition. It usually affects women of childbearing age and is more common among African American women than Caucasian women. Some studies indicate that it may also be more common among Asian and Latino populations.
 
http://foil.ucsc.edu/WhatWeDo.htm

Age: In adults, the most accurate indicators of age-at-death are the pubic symphysis of the pubic bone, the auricular surface of the ilium, and the sternal end of the fourth rib. . In addition, the general condition of the skeleton, such as presence of arthritis, lipping of the vertebral bodies or osteoporosis can be used for general age estimates. In young adults and teenagers, the pattern of epiphyseal fusion of the skeleton and eruption of the teeth are used to estimate age. In the fetus, infants and children, dental development, epiphyseal fusion, ossification patterns and length of the long bones are used to determine age.



Stature: Stature in adults is estimated by measuring long bone length and extrapolating the measurements to estimate living height. Fragmentary bones may also be used to approximate living stature. In teenagers and children (who are not fully grown) stature estimates are not accurate. Stature estimates are sex and population specific. Estimates are given as an interval.



Ancestry: Ancestry is difficult to access from skeletal remains. There are no “pure” races and bureaucratic assessments of ancestry or cultural identification may not reflect biology. Characteristics of the teeth, facial skeleton, cranium, and femur are most useful for determination of ancestry. Measurements of adult skeletons can also be used to estimate ancestry.
 
Tooth wear models and calculation for age

http://onlinelibrary.wiley.com/doi/10.1111/j.1834-7819.2003.tb00041.x/pdf

attrition (i.e., tooth-to-tooth contact), erosion (due to
action of exogenous or regurgitated acids), abrasion by
consumed or environmental substances, or by some
combination of these factors. Furthermore, there is a
need for easily-applied, age-specific standards that can
assist clinicians to decide whether the extent of tooth
reduction observed in a given patient at a specific age is
physiological or whether, in the absence of any
intervention, the process is likely to progress to become
a problem in later life.
The aim of this paper is to present a simple
mathematical model of occlusal and incisal tooth
reduction as a means for accurately predicting the
progress of tooth wear in individuals over time.
 
http://bonesdontlie.wordpress.com/2...-remains/?wc=GQhrGA9+BnRABwpyBggdFBAMThUFHA==

Estimating age at death in dental remains is based on a number of variables. Dental wear is often used in adult populations where the teeth have stopped developing. Based on comparisons within a population between the wear ratios on different teeth, the age of individuals can be estimated. This is very particular to cultures and regions based on diet and the use of teeth as tools. However, in sub-adults, you can look at the development of teeth in order to determine age. From before birth to one’s mid-20′s, teeth are developing, resorbing and emerging. Emergence and loss of the deciduous teeth are one of the primary ways of assessing age at death in dentition. For more detail, radiographs of the jaw can be made to look at the development of adult teeth below the deciduous ones, formation of the roots, cusp or crown, and the resorption of the deciduous roots before they fall out. By looking at the developmental stage of all the teeth available, the age can be determine fairly accurately.
 

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