Chapter 14 Anthropology and Odontology PDF

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Chapter 14 notes from Crime and Forensics taught by Professor Forsthoff. ...

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Introduction ○ Anthropology i s the study of the human race, and emcompasses the cultural study of humans as well as the biological study of humans. ○ Forensic Anthropology i s a specialty within physical anthropology. ○ It involves applications of osteology  and skeletal  identification to matters involving the law and the public. ○ Osteology is the study of bone. ○ Forensic anthropologists work with skeletal remains and try to determine the identity of the deceased. ○ A forensic anthropologist identifies these characteristics in skeletal remains and compared them to a  ntemortem e  vidence. ○ Forensic anthropologists help with facial and body recognition of people in crowds and even analyze characteristics such as gait  as a means of identification. Human Skeleton ○ The central focus of the work of forensic anthropologists is the human skeleton. ○ The basic unit of the skeleton is the bone. ○ There are 206 bones in the normal human skeleton. ○ Bones are living functioning entities and the skeleton is considered to be an organ system. Bones grow and change over time, altering and repairing themselves as needed. ○ The interior of many larger bones contains marrow,  which, among other things, is responsible for the production of red blood cells. ○ Bones have a number of functions in the body. ○ First, they provide support for the other organs and tissues. ○ Muscles attach at bones and their contractions make motion possible. ○ Bones also serve a protective function for some of the more delicate soft tissues. ○ The rib cage protects the heart and lungs. ○ The skull protects the brain from shock. ○ Bones are also the center for growth. ○ Growth of bones begins at birth and continues until early adulthood. ○ Bone Structure ■ The outermost layer is called c ompact bone. ■ It is hard and smooth. ■ In long bones, there is an internal layer called t rabecullar bone, which is light and spongy. ■ It adds strength to bone without adding much weight. ■ The bone marrow is contained in long bones in the center in a medullary cavity. ■ There are special growth units in bone called o  steons. ■ They are deposited in layers and eventually from chambers.

The chambers have canals where blood vessels travel to reach each cell in the bone. ■ This network of canals is called the H  aversian System. ■ The individual cells in the bone are called osteocytes  and make up most of the compact bone. ■ Osteocytes are connected by a microscopic canal system called the canaliculi. Identification of Skeletal Remains ○ The ultimate goal of the identification of skeletal remains is to determine the identity of the bones. ○ This process requires that there be some individual features of the bones that aid in identification. ○ Individual features include antemortem injuries or trauma to the bone and any unusual shapes or features in the bone. ○ Before the biological profile and individual characteristics are determined, three questions must be answered regarding submitted specimen: ■ Is the material bone? ■ If so, is it human? ■ Does the age of the bone make it useful for forensic purpose? ○ Is the specimen bone? ■ In cases where there are whole bones or large pieces of bone present, identification is usually straightforward. ○ Is the specimen human bone? ■ Depending upon the size and condition of the bone, the species may be determined macroscopically by comparing its features to those of various animal species. ○ Significance of Age ■ Other than radiocarbon dating there are no reliable methods for dating skeletal remains. ■ If the skeletal remains are determined to be more than 50 years old, then its value forensically is limited. ○ Biological Profile ■ First, class characteristics are established as part of a biological profile. ■ Then, if possible, individual characteristics are determined that could lead to absolute identification. ■ The more common class  characteristics that are determined as part of a biological profile are age,  gender, race, and stature.  ○ Determination of Age ■ Once they have reached maturity, the bones will not grow except for repairs and reactions to aging. ○ Using dentition to determine age ■

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One of the most reliable ways of determining the age of a sub-adult is by assessing the formation of teeth and their eruption through the gums. ■ In most cases, temporary teeth are formed and then permanent teeth form and erupt in a fairly predictable time period. Using bone development to determine age ■ When the long bones start to grow, they consist of the shaft or diaphysis a  nd the end(s) or e  piphysis. ■ As the individual develops, these two fuse together at the growth area, called the m  etaphysis. ■ Within the metaphysis is the epiphyseal  plate or growth plate which lengthens as the immature bones grow. ■ When the union is complete, growth ceases, and what remains is a thin line where the growth area was located called the e  piphyseal line. Using pubic and rib bones to determine age ■ The main areas in the body where age determinations are made in adults are the pubic  bones and rib  bones. Pubic symphysis ■ In adults, there are several ways of determining age at death. ■ One of the most common methods is the macroscopic observation of the condition of the p  ubic symphysis. ■ The left and right hip (pelvic_ bones join at the p  elvis. ■ Where these join, there is a symphysis or space that has a small amount of cartilage. ■ When the cartilage is removed and the bones are separated, the shape and surface texture on the medial surfaces can be examined. Determination of Gender ■ In general, human males are larger than females, but this is more obvious when the person is alive. ■ The pelvis is the most obvious place to determine gender. ■ This is largely due to the pelvis having different functions in males and females. ■ In females, the pelvic region must support a fetus throughout development and delivery. ■ The male pelvis is generally larger than the female while the female pelvis is broader. ■ The most obvious locations on the pelvis where gender differences can be seen is the greater  sciatic notch and the area below the pubic symphysis that forms the s ub pubic angle. ■ In females, the notch is quite broad with an angle greater than 60 degrees, whereas in males, the angle is much smaller. ■

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A number of bones in the skull have traits that differ between males and females. ■ These include the prominence of brow  ridges, the shape of the mastoid process of the temporal bone, t he absence or presence of the external occipital protuberance, a  nd the shape of the forehead. ○ Determination of Race ■ A typical scheme is used by the United States Department of Commerce in its census that is done every 10 years. ■ The categories used are Caucasian, Blacks, Asians, Native Americans, Hispanics, and others. ■ The most reliable means of determining race in the skeleton are centered on the skull and can be based on either gross morphological examination or by mathematical analysis of various morphological features. ■ The femur in the leg also exhibits racial characteristics, specifically the curvature of the diaphysis that varies from straight in Black people to curved in persons with Caucasian ancestry. Individualization of Human Bone ○ Bone Trauma and Individual Features ■ If a bone is broken, then it will show signs of the break as it heals. ■ These signs will usually remain throughout life and will show up in x-rays. ■ A postmortem x-ray can be compared with the antemortem x-ray, and this may provide positive evidence of the identity of the person. ○ Analysis of Skulls ■ If all or most of a skull is recovered, there are at least two ways that identifications may be made. ■ The most reliable method is p  hotographic superimposition. ■ This involves the comparison of the skull with a photograph of the suspected owner. ■ One of the newer methods of accomplishing the comparison is to use video cameras to capture the image of the skull and of the actual photo and then super-impose the two. ■ Videography has the advantage of permitting manipulations of the images including fading and using various sizes and angles. ■ When a skull is recovered and no identification is made, investigators can use a sculpture to recreate a face. ■ A three-dimensional reconstruction of the soft tissues of a face are built up onto the skull. ■ Compilations of tissue thicknesses for various parts of the face have been compiled for various races of males and females. ■

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Some guesswork is involved in choosing lips, the nose, eyebrows, etc. ■ Prosthetic eyes and wigs are also used. ■ This method is not used for identification of a particular individual. Collection of Bones ○ Collection of bone evidence from an outdoor crime scene is somewhat like an archaeological dig. ○ The perimeters of the scene are located and marked. ○ Depending upon its size, the scene may be divided into quadrants to organize the search. Forensic Odontology ○ Forensic odontology is a part of forensic medicine. ○ It deals with the examination of dental evidence including teeth, mouth, and jaws, and the presentation of expert evidence in a court of law. ○ There are a number of aspects of forensic odontology. ○ They include: ■ Identification of human remains in crimes and mass disasters. ■ Estimation of the age of a person living or dead. ■ Analysis of bite marks found on victims of an attack and in objects such as foods or other substances including wood and leather. ■ Examination of the dentition and face of a person suspected to be the victim of abuse. ○ Structure and Development of Teeth ■ Teeth are unique in the human anatomy for a number of reasons. ■ First, the outer part of a tooth is made of a substance called enamel. ■ This is the hardest substance that is produced by the human body. ■ Because of this, it can leave impressions in a wide variety of materials from wood to flesh. ■ Teeth also interact directly with a person’s environment and thus their condition may reflect elements of that individual’s lifestyle and experiences. ■ Each tooth is made up of three parts: the  crown, the body and the  root. ■ Teeth are also oriented by their sides. ■ The chewing surface of the tooth is the o  cclusal s  urface. ■ Humans develop two sets of teeth as they grow. ■ The first set is the “baby” teeth. ■ Dentists refer to this set as the d  eciduous t eeth. ■ They are gradually replaced by the p  ermanent t eeth. ■ Different teeth develop at different rates. ■

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Dentists can estimate the age of a person by the development of various teeth. Identification of Dental Remains ■ Although there is usually sufficient evidence to identify a dead body, sometimes dentition is the only way of achieving a positive identification. ■ Cases aided by dental record checks include burning, drowning, fire or explosion, and decompisition. ■

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