RADIOGRAPHIC DETERMINATION OF SEX DIFFERENCES IN ISCHIOPUBIC MEASUREMENT

The study was carried out to determine and compare the pubic length, ischial length and ischiopubic indices among the people of Enugu State of Nigeria. Anterioposterior radiographs of 94 adult pelvis (of age range, 18-70 years) were evaluated. Ninety four of the radiographs (50 males and 44 females) were those from Enugu state of Nigeria. The morphological   measurements were pubic length, ischial length and ischiopubic index. The mean values of pubic length, ischial length and ischiopubic index of males of Enugu were 71.0mm, 84.4mm, 84.0 respectively while those of their females were 85.0mm, 83.0mm and 105.6 respectively. The mean pubic length was significantly longer in females in the population (p<0.05). The mean ischial length was significantly higher in males than females in the population (p<0.05). Using the radiographs, sex could be assigned to 89% of Enugu males and 91% of Enugu females. Comparison with other population of the world showed that Nigerian population differed from most populations of the world previously studied. The accurate determination of sex and race are important tools to forensic scientists and physical Anthropologists. Thus this study is important as it has provided the necessary data for the Nigeria population under investigation. The data is recommended to obstetricians, physical anthropologists and forensic scientist, especially in the developing countries while more sophisticated methods are awaited. 

Key words: Ischiopubic index, pelvic bone, Morphology, Cephalometry, Radiography.

Table 1: Values of Pubic Length of Males obtained in this work.----------24

Table 2: Values of Ischial Length of Males obtained in this work--------31 

Table 3: Values of Pubic Length of Females obtained in this work----------34

Table 4: Values of Ischial Length of Females obtained in this work. --------36

Table 5: Values of the Ischiopubic  Index of Males from measured Values of Males Pubic and Ischial Lengths using the Formula(IP)= AB/AC X 100 -----39

Table 6: Values of the Ischiopubic Index of Females from Measured Pubic and Ischial Lengths----42

Table 7: Mean and Standard Deviation of the Measurements of People of Enugu State of Nigeria.-------45

Table 8: Ranges, Means and Demarking Points of Ischiopubic 

Index of Enugu of Nigeria.-----46

Table 9: Comparative Analysis of Mean Ischiopubic Indices of  

Various Populations.------48

Fig.Ia &Ib.  Diagram of Measurement of the Width and Height Of Sacrum.-----             6

Fig. II. Ischiopubic Pain in a Patient with Paget’s disease With Larger Lytic Image on The Left Ischium.--19

Fig.III.Pelvic Radiograph, Showing Measurement of the Pubic and Ischial Lengths.-----25

Histograms to show Mean and Standard Deviation Values

Fig.IV Mean and Standard Deviation for pubic Length-----                             46

Fig.V Mean and Standard Deviation for ischial Length-----                            47

Fig.VI. Mean and Standard Deviation for ischiopubic index-----                                    47

Title Page ----------i

Certification--------- ii

Approval page -------iii

Dedication----------iv

Acknowledgements--------v

Abstract----------vi

List of table ---------vii

Table of Figure---------vii

Table of Content ---------x

CHAPTER ONE-Introduction

1.1 Background of the Study-------1

1.2 Statement of Problem-------4

1.3 Objective of Study--------4

1.4 Significance of Study-------4

1.5 Scope of Study---------5

1.6 Limitation of Study--------6

1.7 Literature Review---------6

CHAPTER TWO-Anatomy and Radiography of the Pelvis

2.1 Anatomy of the Pelvis-------12

2.1.1 The Ilium---------12

2.1.2 The Pubic Bone--------12

2.1.3 The Ischium---------13

2.1.4 The Sacrum--------14

2.1.5 The Coccyx ---------13

2.2 Radiology of the Pelvic Ring ------14

2.3 Overview of Arteries, Veins and Nerves----14

2.3.1 Internal Iliac Artery---------15

2.3.2 Radiological Point of Interest------16

2.3.3 External Iliac Artery-------16

2.3.4 The Iliac Veins--------17

2.3.5 Important Nerves of the Pelvis------17

2.4 Some Specific Pathologies and Abnormalities of the Pelvis-19

2.5 Clinical Uses of Radiographic Sex Determination Index.--20

CHAPTER THREE

3.1 Research Methodology-------22

3.2 Target Population--------22

3.3 The Study Centres-------22

3.4 Collection of Radiographs (Raw Data)----23

3.5 Processing of Data and Collection-----23

3.6 Measuring Instruments/Materials-----24

3.7 Parameters of Measurement------24       

               

CHAPTER FOUR- Data Presentation and Analysis 

4.1. Results from Measurements.------27

4.1.2 Analysis of   Result-------44

4.1. 3 Summary of Finding --------47

CHAPTER FIVE-Discussion and Conclusion

5.1 Discussion ----------49 

5.2 Recommendation and Conclusion-----50

REFERENCES

The sexual differences noticed in the pelvis are of interest to anatomist, gynaecologist, and even anthropologist.  The extent of sex determination is so important to females with narrow cavity which find it more difficult to deliver babies naturally than those with wide pelvic cavity.  The growth of the pelvis is in the width resulting to wide pelvic inlets as such, study will determine the sex difference using the ischiopubic measurement (index) of patients’ radiograph with no pathological abnormalities and fractures.

The ischiopubic  index is the measurement of the distance between the triradiate cartilage (acetabulum) and the pubic tubercle of the pelvic bone divided by the distance between the triradiate cartilage (acetabulum) and the ischial tuberosity of the pelvic bone, multiplied by hundred according to (Shultz A.H. and Adolph H(24).).  The function of the bony pelvic is to transfer the weight of the upper body from the axial to the lower appendicular skeleton and to withstand compression and other forces resulting from its support of body weight, and it also provides attachments for powerful muscles, such as, the levator ani muscles which consist of the iliococcygeus,pubococcygeus and coccygeus muscles.

The importance of ischiopubic index in obstetrics can not be over emphasized.  It has been observed that the size of the ischiopubic index determines the size of the birth canal, which is an important criterion in vaginal delivery.

However, most of the techniques for sexing pelvic bones currently in use in forensic osteology were developed on large sample sizes of archeological provenance where accuracy in sexing of about 85% was considered reasonable.  This means that about one in every seven individuals would be incorrectly assigned which, in a forensic situation, is not acceptable.

Other commonly used pelvic indicators of sex are the so called “scars of parturition” thought to be indications that an individual was female and had borne children.  Some authors even went as far as declaring that the number of pubic pits could reflect the parity of the individual.  They include the presence of a deep pre-ocular sulcus, pitting on the dorsal aspect of the pubic body and extension of the pubic tubercle.  All these factors have been extensively investigated, and whilst their presence is more common in females, they are not as sex definitive as first claimed.  In fact, it was reported that pubic pitting was more likely to be associated with age at death than obstetric event, and as such obstetricians would find it more easier by using radiographs which appear more accurate in estimation of sex differences rather than the use of adult skeleton in sex determination and subsequent methods for age and stature estimation are sex-dependent.

But the reliability of sex determination depends on the completeness of the remains of skeleton and the degree of sexual dimorphism inherent in the population, but it is generally accepted that the two most sexually dimorphic elements of the skeletal structure are the pelvis and the skull. The sacroiliac joint and surrounding area have been found to exhibit sexual dimorphism mainly due to it’s role in locomotion, weight bearing, and transfer capabilities(Ali and Maclanghlin(1).

Nevertheless, this project which is a retrospective study is carried out by taking measurements of ischiopubic length index from dry x-ray films of both males and females, taken with conventional radiography at University of Nigeria Teaching Hospital (UNTH) Enugu, the Enugu State University Teaching Hospital, Parklane Enugu, and the National Orthopedics Hospital, Enugu.  The measurements obtained are antero-posterior (AP) films.  The accurate determination of sex and race are important to forensic scientists and physical anthropologists.  Thus, this study is important as it has provided the necessary data for the Nigerian populations under investigation.

This research project consists of five chapters.  Chapter one states the background of study, statement of  problem, objective of study, significance of study, scope of study, and review of related literatures. While chapter two entails the anatomy of the pelvis and radiographic conditions.  And chapter three presents the research methodology with. Chapter four entails data presentation and analysis, while chapter five deals on summary of findings, discussion and conclusion.