CHAPTER ONE
1.1 BACKGROUND OF THE STUDY
Roebuck et al noted that anthropometric data varies considerably for individuals within a family or a nation and between nations.
Anthropometry refers to the measurement of living human body dimensions for the purpose of understanding human body physical variation as it plays an important role in plastic surgery, prosthetics, and so on for data collection. Statistical data about the distribution of body dimensions in the population are useful for apparel sizing, forensics, and optimise products.
Many studies have defined human body parts and their proportion to each other morphometrically. In humans, the ear is the defining feature of the face and its structure shows signs of sex and age. The human ear is divided into external, middle and internal part. The pinna and external acoustic meatus forms the external ear. The lateral surface of the pinna is irregularly concave, faces slightly forward and displays numerous eminences and depressions. These structures do not merely act as trumpets; they are the first series of stimulus modifiers in the auditory apparatus.(Standrings, 2008). The importance of anthropometric data was stressed by Abeyshekera and Shahnavaz when they stated that a piece of equipment designed to fit 90% of the male United States population would fit about 90% of Germans, 80% Frenchmen, 65% of Italians, 45% of Japanese, 20% of Thais, and 10% percent of Vietnamese. (Abeyshekera, 1989).
Saha observed that there were differences in anthropometric data of people from different regions of India (Saha, 1985). Similarly in Nigeria different regions of people presents different anthropometric data. Jung and Jung surveyed the dimensions and characteristics of Korean ears and found that age gender and different ethnic populations were determinants of ear dimensions. (Jung et al, 2003). A study carried out in India observed that North-West Indians have smaller ear lobules when compared to Caucasians and Japanese population but similar to those found among the Onge tribe of the Andhra (India) and Newars of Nepalby Sharma et al.
Since anthropometric data should be established for the user population as anthropometric data for Igbinedion University students is scant, the present study attempts to provide anthropometric data for the ear. The study is intended to describe the anatomical height and width of the ear amongst Igbinedion University Students (aged from 16-35years). From these data, it is envisaged that anatomical and morphological differences and changes of the ear in relation to age and sex in our population would be established.
1.2 STATEMENT OF PROBLEM
There is no documented anthropometric data of the ear on an average of 16-35 years of age among Igbinedion university students. This project focuses on documenting the anthropometric data of the ear of Igbinedion University students of the above age and as well as discuss the relevance and uses of anthropometric data in identification and application to forensic science.
1.3 OBJECTIVES OF THE STUDY
The study is based on well-established hypothesis that the human external ear is a highly variable structure. Therefore the main objective is to investigate to what extent this variability exists. It is not possible to undoubtedly prove the theory that all ears are unique, therefore, the null hypothesis is that some human ears are the same. The hypothesis would be accepted, if two ears are found to be exactly alike.
1.3 SCOPE AND SIGNIFICANCE OF THE STUDY
The scope of this project is aimed at investigating the range of variation seen in the anthropometry of the ear among Igbinedion University Okada students between the ages of 16-35 years. The study focused on various components of the external ear and how they vary. A combination of various previous methods as well as some new initiatives was employed. As the variation technique used for the study is through measuring the length and width of the external ear structure.
The significance of the study was aimed to answer the following questions:
- How much variation is displayed in ear size
- Does sexual dimorphism exist in external ear structure?
- What range of variation is seen between the two ears of a single individual?
- How does age affect ear structure?
- Are all ears different?
1.5 DEFINATION OF TERMS
a) ANTHROPOMETRY: Anthropometry can be defined as the scientific study of the measurements and proportions of the human body.
b) DIMORPHISM: Dimorphism isthe existence among animals of same species of two distinct form that differs in one or more characteristics, such as colourization, size, age, shape or sex; Sexual dimorphism on the other hand is a phenotypic differentiation between males and females of the same species
c) MORPHOMETRY: The process of measuring the external shape and dimension of landforms, living organisms or other objects.
d) MORPHOLOGY: The study of the forms of things, in particular; a particular form, shape or structure.
e) OVIA NORTH EAST: This is a local government in Okada town region in the Edo state area of Nigeria containing populations from different tribes.