Personal Identification Technique and their Importance in determination of Age and Sex

Introduction

The metric (anthropometry) and morphological (Anthroposcopy) assessment of the characteristics of living and skeletal remains are two of the most often used methods in forensic anthropology. These methods date back to the seventeenth century, when there was a lot of curiosity in human variation, particularly among individuals who had recently been ‚Äėfound‚Äô by colonizing European nations. The word anthropometry has been derived from Greek words Anthropos which means man, and metron which means to measure. The literal definition of anthropometry could be rightly stated as the discipline that deals with bodily measurements like body size, shape, strength, and working capacity. Anthropometry is the systematic measuring of the human body‚Äôs physical dimensions. Earlier, it was used for personal identification, to understand the physical variation between human beings, and also, to relate the physical traits of a person to particular racial or psychological horizons.

Forensic Significance

Anthropometric attributes have a direct association with the sex, shape, and form of an individual, and these variables are personally connected and are resultant of the various internal structures and tissue parts that are impacted by ecological and hereditary variables. Anthropometric information is accepted to possess objectivity and they permit the forensic expert to go past subjective appraisals, for example, ‚Äúcomparable‚ÄĚ or ‚Äėdistinctive‚Äô. With this anthropometric information, the expert can evaluate the level of contrast or likeness and the certainty with which this information can be interpreted.

The objective of anthropometrists working in a pharmaceutical /medico-legal division, working with unknown variables, was to depict the remaining parts in such terms so that one can accomplish the objective of assessing age at the time of death, sex, stock/race/ family/ethnicity, stature, body weight/body fabricate, subtle elements of individualizing qualities such as amputations, fractures, deformities, and bone pathologies and to some extent, the cause of death is reflected in the remains/bones. The target is to empower the law authorization organizations to accomplish a definitive objective of individual distinguishing proof.

Identification Techniques

Forensic anthropologists employ various techniques or methods for identification:

Osteometry

Osteometry is the study and measurement of human or animal skeletons, especially in an anthropological or archaeological context. The major purpose of osteometry in zooarchaeology is taxonomic determination and, to a lesser extent, sex determination. Because it is often difficult to distinguish between species belonging to the same genus or family (for example, South American camelids), statistical study of osteometric data is highly beneficial.

Osteometry is particularly valuable in bioarchaeology for solving many anthropological difficulties about previous human populations, such as determining family, sex, the degree of sex dimorphism (which can be used to answer questions about lack of nutrition), and ethnicity. There are numerous issues with interpreting Osteometric data, including measurement replicability problems, problems with phenotypic variance between subpopulations of one species, and so on.

It incorporates the estimations of the skeleton and its parts i.e. the estimations of the bones including the skull. It is characterized as a system to take measurements of skeletal remains. Through this procedure, a researcher can examine the variety in skeletons of distinctive populations of the world. The study has been effectively utilized as a part of the estimation of stature, age, sex, and race in legal and legitimate sciences. These four parameters i.e. age; sex, race, and stature are considered as the ‚ÄúHuge Fours‚ÄĚ of measurable human sciences. Different studies have been led and are in advancement in numerous parts of the world in such manner.

Somatometry

Somatometry means the measurements of the living body including the head and face. It is necessary to keep a record of the subject itself before collecting the Somatometric measurements so that the findings of measurement can be analyzed at any time, in comparison to other findings. Many methods exist for forensic ancestry attribution. Metric statistical methods generally require that a prescribed set of measurements be made and plugged into a formula for discriminant function analysis. For example, the Gill method assesses mid-facial flatness utilizing a specialized coordinate caliper called a seismometer.

It takes various upper-face measurements and generates a numeric result that falls on either side of a sectioning point, indicating which of two populations is being compared. Although most ancestry assessment focuses on the skull, particularly the face, several procedures for specific postcranial bones have been established. Observations of nonmetric qualities can also be employed.

For example, Western European ancestry is typically associated with face morphology that includes a pinched nasal bridge and a narrow nasal opening, whereas the nasal bridge is more likely to be flattened and the nasal aperture wider in Asian and Native American groups. Carabelli’s cusp, a small additional cusp or pit on the maxillary molar teeth.

It is not unusual in Europeans but is rarely seen in Asians or Africans. However, no single feature should ever be utilized to make an ancestry determination. Rather, the complete set of characteristics and measures should be evaluated. The forensic anthropologist’s level of experience with the geographical community in which he or she practices is crucial.

Method of Taking Somatometric Measurements

When the forensic anthropologist examines an unidentified body, the first task is to take out a profile of biological and morphological characteristics from the details of the skeletal shape and size. The goal is to reduce the possibilities for group membership (age group, sex, or population) to increase the chances for identification. It is an exercise in statistics, sociocultural context, and judgment, and not at all exact.

Since the goal is to place an individual within a modern sociocultural matrix, the methods should utilize comparable reference populations. To have a comparative study, one needs to have pre-collected data. Below is a brief idea about how these measurements are taken which later helps to establish identity.

  • Maximum Head Length

It is the straight distance from glabella (g) to opisthocranion (op). The opisthocranion is thought to be the most prominent point of the occipital bone, which is positioned on the upper surface of the head in the mid-sagittal plane.

  • ¬†Maximum Head Breadth

This measurement displays the straight distance between the two eurya (EU), i.e. euryon to euryon. To have an accurate result, measurement should be taken at right angles to the mid-sagittal plane.

  • Auricular Height of head or Head Height

This measurement demonstrates the projective distance between tragion (t) and vertex (v).

  • Minimum Frontal Breadth

This measurement tells about the straight distance between the two front-temporal(ft). It is in reality the linear distance from frontotemporal to frontotemporal.

  • Breadth of Bizygomatic Arch

This measurement demonstrates the straight distance in the middle of the two zygia (zy), i.e. the distance from zygion (zy) to zygion (zy). The region is the most lateral point on the zygomatic arch and the first finger and is applied on the zygomatic arches.

  • Bi‚ÄďGonial Breadth

This measurement shows the straight distance between the two gonia (go) which are present in the mandible (lower jaw) as the lateral most prominent part.

  • Morphological Facial Height or Total Facial Height

It is the case where the measurement signifies the straight distance between nasion (n) and gnathion (gn).

  • Morphological Upper Facial Height

This measurement displays the straight distance in between the points- nasion (n) and prosthion (pr). In this case, the blunt end of the fixed cross-bar is positioned on the nasion.

  • Nasal Height

It is the measurement that discloses the straight distance between nasion (n) and subnasale (sn). A sliding caliper is used to take this measurement by holding it by right hand where the lower cross-bar coups on the subnasal point, at the lower border of the nasal septum. Then the upper cross-bar is made stable against the nation.

To have an accurate measurement, the Calliper has to be held in reserve sideways, leaving the middle line of the nasal bridge.

  • Nasal Breadth

This measurement displays the straight area between the two malaria (al). It is thought to be the most laterally placed point on the nasal wings. This measurement is taken with the help of a sliding caliper where the upper cross-bar is positioned against the right alare of the nose and the movable cross-bar is adjusted on the other alare. While taking the measurement we should remember that for getting accurate measurement even slight pressure on the nasal wings must be avoided. 

  • Nasal Depth

Nasal depth is thought to be the measurement which is the projective straight distance from the tip of the nose or let us say pronase to the hind-most point of the nasal septum.

  • Ear Breadth or Physiognomic Ear Breadth

The result of this measurement is the straight distance in-between the two most lateral points of the ear; where one point lies at the base of the ear and the other point lies at the posterior border of the ear cartilage. It is measured with the help of a sliding Calliper using flat arms.

A fixed cross-bar of the measuring instrument is initially placed at the base of the ear and then the movable crossbar is sliding until it touches the most prominent point present on the ear cartilage.

  • Circumference of the Head or Horizontal Circumference of the Head

This measurement shows the maximum circumference of the head in a horizontal position. One end of the steel tape is held on glabella (g) by the left hand. The other end is held with the right hand and taken round following the opisthocranion (op), and again taken back to glabella (g). The tape around the head (g‚Äďop‚Äďg) should be kept in the same plane and opisthocranion is to be located beforehand. One should be very careful at the time of measuring as there is a fair chance to get the tape dislocated.

  • Height of Integumental Lips

This measurement is the straight distance between the labral superior (Is) and labral inferior (li). In this case, the mouth of the person to be measured should be closed and the arms of the sliding caliper are very cautiously placed in such a manner that they intersect the margins of the integumental lips tangentially while the Calliper position is vertical.

  • Lip Length

This measurement reveals the straight distance between two chelation (ch). This is mouth breadth or distance between two comers of the mouth. The Calliper need to be placed firmly on the jaws of the subject which must be closed and the facial muscles must be relaxed at the time of taking the measurement.

Indices

A mathematically defined relationship between the measurements is referred to as an index. So different measurements can be compared and expressed as various features of shape and dimension. E.g. the maximum length and breadth of the head give a length‚Äďbreadth index; so are the length and breadth of the nose, etc. In this way, we find different types of variations in the measurements which can produce the ratio of certain forms and features. The measurement ratio is known as an index. To find out an index, the shorter measurement is arranged as the numerator and the longer as the denominator. This gives rise to a fraction that has to be multiplied by 100.

Somatoscopy

Somatoscopy is a Systematic method for evaluating human body features that employs descriptive characterization. It is one of the fundamental methods for studying human biological variability.

In other words, Somatoscopy is the systematic visual observation of physical features of various parts of the human body in order to provide accurate descriptions that are qualitative in nature and thus descriptive in approach. The following are generally regarded to be used in the Somatoscopic method:

  • Skin colour
  • Hair colour and form
  • Eyes
  • Ear
  • Nose
  • Lips
  • Mouth
  • Teeth
  • Body Posture
  • Head Forms
  • Face, etc.
Facial Forms
Fisher & Saller Hair Colour Chart
Source: http://savepic.ru/5828530.jpg
Head Forms

Craniometry

Craniometry is a method of determining the size of the cranium (the main section of the skull), which is usually the human cranium. It is a subset of cephalometry, or head measurement, which is a subset of anthropometry, or body measuring, in humans. It differs from phrenology, a pseudoscience that attempted to relate personality and character to head shape, and physiognomy, which attempted to link face features to personality and character. These fields, on the other hand, have all claimed to be able to predict qualities or intellect. It was originally widely used in anthropology, particularly in physical anthropology, during the nineteenth and early twentieth centuries. At this time, theories attempting to scientifically justify racial segregation became popular, with one of the most prominent figures being Georges Vacher de Lapouge (1854‚Äď1936), who divided humanity into various, hierarchized ‚Äúraces,‚ÄĚ ranging from the ‚ÄúAryan white race, dolichocephalic‚ÄĚ (from the Ancient Greek kephal√™, head, and Dolichos, long and thin) to the ‚Äúbrachycephalic‚ÄĚ (short and broad-headed) On the other hand, craniometry was used by Franz Boas, who used the cephalic index to demonstrate the influence of environmental variables, as proof against the existence of a ‚ÄúNordic race.‚ÄĚ To prove his hypothesis of evolution, Charles Darwin used craniometry and the study of skeletons.

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