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A TEST OF THE CHRONOLOGICAL FEATURES THAT DETERMINE AGE CHANGES ON THE AURICULAR SURFACE OF THE ILIUM AS AN ESTIMATION OF AGE AT

DEATH

A Thesis by

Angie Marie Rabe

Bachelors Degree, Southern Illinois University Carbondale, 2004

Submitted to the Department of Anthropology and the faculty of the Graduate School of

Wichita State University in partial fulfillment of

the requirements for the degree of Master of Arts

August 2009

iii

A TEST OF THE CHRONOLOGICAL FEATURES THAT DETERMINE AGE CHANGES ON THE AURICULAR SURFACE OF THE ILIUM AS AN ESTIMATION OF AGE AT

DEATH

The following faculty members have examined the final copy of this thesis for form and content, and recommend that it be accepted in partial fulfillment of the requirement for the degree of Master of Arts with a major in Anthropology.

______________________________

Peer Moore-Jansen, Committee Chair

______________________________

Robert Lawless, Committee Member

______________________________

JoLynne Campbell, Committee Member

iv

ACKNOWLEDGEMENTS

I would like to thank my advisor, Peer Moore-Jansen, for his guidance and support

throughout my academic career. I would also like to thank the other members of my committee,

Robert Lawless and JoLynne Campbell, for their participation.

I would also like to express my appreciation to Lyman Jellema at the Cleveland Museum

of Natural History for making this research possible. I also want to acknowledge the Nancy

Berner Fund, the Marvin Munsell Anthropology Fellowship, and the Friends of Anthropology

Fellowship from Wichita State University for these generous awards, which have provided

financial support.

I would also like to thank my family for their love and support, because without them this

would not have been possible!!

v

ABSTRACT

The study of age changes in the human pelvis has long been at the core of research in

human osteology. Particularly, studies have focused on joint surfaces as the age during the

lifetime of an individual. This study examines age changes in the posterior ilium, specifically the

auricular surface. The auricular surface is defined as the semi-lunar sacral articulation on the

medial surface of the ilium.

A special focus is placed on the assessment of a previous aging technique applied to the

auricular surface and the posterior ilium (Lovejoy et al. 1985). A second objective addresses the

potential refinement of the proposed age groups defined by Lovejoy et al. (1985). Few studies

have yet to test the use of qualitative scoring system on the auricular surface. This study was

conducted using a sample of 102 Black females from the Hamann-Todd collection at the

Cleveland Museum of Natural History. Both the left and right auricular surfaces were examined

bringing the total number of surfaces recorded to 204.

In addition to qualitative observations of the surfaces six measurements of the auricular

surface were recorded to determine if the size and shape of the surface changes with age. To test

age effects separate t-tests were applied to their right and left size dimensions of the surface to

test for right and left symmetry and size differences between the surfaces of young and old

specimens. The findings presented here suggest that the nature of qualitative morphological

features change with age. As age increases the sacroiliac joint becomes less mobile and

degenerative changes on the auricular surface that include lipping on the apical border increase,

which may affect the shape and size of the auricular surface as age increases. The t-test results

indicate that there are no significant differences between the left and right auricular surfaces.

Age according to the t-test also indicates that there are no significant differences from young to

old age, with the exception of one measurement. The inferior auricular surface length (IFASLT)

vi

is the minimum width of the auricular surface between the apex and the posterior border of the

auricular surface. The difference in this measurement from young to old is affected by the

increase in apical and retro-auricular activity. As retro-auricular activity increases it affects the

posterior border of the auricular surface causing the border to become less pronounced. The

apex is affected by the increase of lipping as age increases. Increasing age causes this

measurement to be slightly higher than in younger individuals, whether as a result of activity or

less clarity in the measurement as age increases is unknown.

The findings presented here suggest that the nature of qualitative morphological features

change with age. To test these findings a chi-square analysis was applied to determine if the

presence and absence of features are determined by age. Results concluded that all features, with

the exception of porosity had significant results. Based on these results a revised age phase

system limited to four phases is presented, which represents a less precise, but more consistently

reliable indicator of age than that of the eight phase system proposed by Lovejoy et al. (1985).

The findings suggest that morphological features are best seen within the decade rather than

within half a decade, suggesting that it is better to include broader age ranges in order to account

for a more accurate age estimation of an individual.

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TABLE OF CONTENTS

Chapter Page

I. BACKGROUND 1

Skeletal Aging Methods 1 Cranial Suture Closure 2

Pubic Symphysis 2 Sternal Rib 3

Auricular Surface 3 Adult Pelvic Girdle 4

Anatomy 5 Pubis 5

Ischium 5 Ilium 6

Ilium of the Auricular Surface 6 Function of the Pelvis 7

Variation of the Os Coxa 7 Sexual Dimorphism 8 Evolutionary Trend of the Adult Human Pelvis 9

Previous Studies 10

II. MATERIAL AND METHODS 17

Introduction 17 Materials 17

Hamann-Todd Collection 17 Recording Data 19

Methods 19 Metric Observations 19

Non-Metric Observations 20 Data Analysis 25

III. RESULTS 27

Summary Statistics 27 Analysis of Frequencies 31 Chi-Square 40 T-Test 43

IV. DISCUSSION 47

Introduction 47 Frequency Analysis and Chi-Square Tests 50 Symmetry 51

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TABLE OF CONTENTS (continued)

Chapter Page

IV. DISCUSSION

Results in Comparison to the Lovejoy et al. (1985) Study 51 Revised Age Phases 53 Preliminary Testing 54 Conclusion 56

REFENENCES 57

APPENDICES 63

Appendix A. (A1-A6) Auricular Surface Measurements 64 Appendix B. Measurements of the Left Auricular Surface 67 Appendix C. Measurements of the Right Auricular Surface 70 Appendix D. Means and Standard Deviations for the Left and Right Auricular Surface 73 Appendix E. Frequencies and Percentages for the Left Auricular Surface 74 Appendix F. Frequencies and Percentages for the Right Auricular Surface 75 Appendix G. Qualitative Scores for the Left Auricular Surface 76 Appendix H. Qualitative Scores for the Right Auricular Surface 79 Appendix I. Hamann-Todd Test Sample used for comparison in Revised Method 82

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LIST OF TABLES

TABLE PAGE

1. Sample Distribution by Age from the Hamann-Todd Collection 18

2. Auricular Surface Measurements 20

3. Summary of Eight Age Phases (Lovejoy et al. 1985) 24

4. Means and Standard Deviations Age 20-24 27







11. Means and Standard Deviations Age 60+ 30

12. Means and Standard Deviations from All Age Groups 30

13. Frequencies and Percentages for the Feature Billows 31

14. Frequencies and Percentages for the Feature Striae 33

15. Frequencies and Percentages for the Feature Fine Granulation 34

16. Frequencies and Percentages for the Feature Coarse Granulation 35

17. Frequencies and Percentages for the Feature Dense 35

18. Frequencies and Percentages for the Feature Microporosity 36

19. Frequencies and Percentages for the Feature Macroporosity 37

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LIST OF TABLES (continued)

TABLE PAGE

20. Frequencies and Percentages for the Feature Apical Activity 38

21. Frequencies and Percentages for the Feature Retro-auricular Activity 39

22. Chi-Square Data for the Left Auricular Surface 40

23. Chi-Square Data for the Right Auricular Surface 41

24. Chi-Square for the Feature Porosity 41

25. Chi-Square Features for young, middle to old, and young to old 42

26. Chi-Square for Retro-auricular activity for young, middle to old, and young to old 43

27. Chi-Square for Apical changes from young, middle to old, and young to old 43

28. t-Test Results for the Left and Right Auricular Surface 44

29. t-Test Results for Age 20-24 to 60+ 45

30. Correct Classification for Revised Method and Lovejoy et al. (1985) 55

xi

LIST OF FIGURES

FIGURE PAGE

1. Pelvic Girdle 4

2. Billows and Striae 21

3. Fine Granulation 21

4. Coarse Granulation and Microporosity 22

5. Subchondral Destruction 22

6. Apex and Retro-auricular Region (Lovejoy et al. 1985) 23

7. Line Graph of Feature Billows and Striae 32

8. Line Graph of Feature Granularity and Density 34

9. Line Graph of Feature Porosity 37

10. Line Graph of Feature Apical Changes 38

11. Line Graph of Retro-auricular Activity 39

1

CHAPTER ONE

BACKGROUND

Introduction

When estimating the age of an individual from skeletal remains alone, it is important to

identify characteristics in the human skeletal anatomy that reflect developmental traits along with

subsequent degenerative change because these effects are all critical to interpret the age at death.

Any studies of documented juveniles, bone growth and dental eruption, particularly with

the development and fusion of ossification centers, provide useful known age sequences in order

to compare individuals of unknown age. In the adult human skeleton this becomes somewhat

more difficult since age related changes become increasingly more variable. Although standards

are currently available for the estimation of adult age at death from several skeletal areas many

fall short of their expected levels of accuracy (Murray and Murray 1991). One probable reason

for this is that the age ranges provided by some methods (e.g., auricular surface (Lovejoy et al.

1985) and sternal rib end techniques (Iscan et al. 1984) do not describe the full range of age

variation at defined stages (Osborne et al. 2004).

Skeletal Aging Methods

In the adult human skeleton the best indicators of age involve two types of methods,

gross and specific analyses. Specific methods include dental thin sectioning and

histomorphometry, which take thin cross sections of bone to be analyzed microscopically. This

gives more accurate results when compared to gross methods, but require more time, equipment,

and knowledge, and necessitate some destruction of the material (Charles et al. 1989, Robling

and Stout 2000).

2

Gross methods on the other hand are faster and do not require destruction. These

methods include age estimation from the morphological changes in the pubic symphysis,

auricular surface, cranial suture closure, sternal rib ends, and degenerative changes in the spine,

joints, and skull, including resorption of cancellous bone, and loss of teeth (Ubelaker 1989).

Degenerative changes in the skeleton can be used as a general indicator of age at death.

As age increases osteophytes, which are boney outgrowths, also increase (Stewart 1976). These

boney outgrowths are common on the rounded center of the vertebra, the ischium, calcaneous,

and sternal ends of the ribs, and where joints occur, developing through the ossification of

cartilage (Stewart 1976).

Cranial Suture Closure

Cranial suture closure, though variable, is also an indicator of age estimation. In

subadults cranial suture lines are clearly visible but as age increases sutures begin to close and in

some older individuals suture lines can even become obliterated. Two common methods for

aging cranial sutures are Acsadi and Nemeskeris (1970) endocranial phases and Meindl and

Lovejoys (1985) ectocranial phases. Meindl and Lovejoys study (1985) found lateral-anterior

sutures to be a better indicator than vault sutures, along with ectocranial suture verses

endocranial sutures.

Pubic Symphysis

Age estimation using the pubic symphysis has become a popular aging method and has

become the standard used to apply to other aging techniques such as the sternal rib ends, and the

auricular surface. A technique which associates surface features of the pubic symphyseal face to

age changes was tested and as a result a six phase analysis of pubic symphysis morphology was

developed (Katz and Suchey 1986). This six phase age analysis was developed as a

3

modification to the ten phase system originally developed by Todd (1920), which was found to

over age individuals and lacked distinct morphological phases leading to inconsistent assignment

to an age range among different observers (Katz and Suchey 1986).

Sternal Rib

Sternal rib ends as an indicator of age estimation was similarly developed to form a phase

system based on morphological changes (Iscan, Loth, and Wright 1984). This included a nine

phase system, which was sex specific. Additional research suggests that age changes are also

population specific (Iscan, Loth, and Wright 1987).

Auricular Surface

In a similar fashion to the pubic symphysis aging method, aging of the auricular surface

of the ilium was developed by Lovejoy et al. (1985). This technique is based on the premise that

age at death of an individual can be estimated by examining morphological features of the

auricular surface of the ilium. This method was developed under the same assumptions of the

pubic symphysis aging method, namely that surface morphology undergoes regular changes as

the result of progressing age.

Advantages of the auricular surface over the pubic symphysis are that qualitative

changes in the auricular surface extend well beyond the age of 50, while they generally do not in

the pubic symphysis (Lovejoy et al. 1985). Also the use of the auricular surface may improve

age estimation in females since this joint is affected by stress during childbirth (Suchey 1979),

whereas the pubic symphysis has been demonstrated to be a less accurate predictor in females

than in males (Lovejoy et al. 1985).

Another advantage of the auricular surface aging technique is that the survival rate of this

region is higher than the pubic symphysis in archaeological populations (Lovejoy et al. 1985). In

4

addition Haglund (1997) reports that the public symphysis, iliac crest, and ischial tuberosity are

the most frequently destroyed portions of the os coxa in cases involving carnivore activity. Also

the ribs are commonly removed by animals as a result of carnivore activity, which is a common

taphonomic agent in many forensic cases.

The Adult Pelvic Girdle

The pelvic girdle is positioned at the base of the spine with the sacrum and coccyx at the

midline. The sacrum articulates posteriorly with the os coxa at the sacro-iliac joint and the two

bones, the os coxae articulate anteriorly at the pubic symphysis, which is illustrated in Figure 1.

The os coxa is made up of three separate bones, the ilium, the ischium, and the pubis. In adults

these bones are fully united at the acetabulum and represent one bone (Scheuer and Black 2000).

The pelvic girdle is supported by abdominal muscles anteriorly, the iliac fossa laterally, and the

fifth lumbar posteriorly (Scheuer and Black 2000). The pelvis also supports and protects the

internal organs such as the bladder, rectum, and internal genitalia (Scheuer and Black 2000).

Figure1. Pelvic Girdle

5

Anatomy

Pubis

The pubis is the most anterior of the three bones of the os coxa. It articulates medially

with the opposite pubis, inferiorly with the ischium, and superiorly at the acetabulum with the

ilium and ischium, with the borders of the pubis forming the obturator foramen (Baker et al.

2005).

The pubis is the last of the pelvis elements to begin ossifying, which ossifies around the

the 5th fetal month (Bass 2005). The narrow, flat inferior ramus of the pubis completes fusion

with its ischial counterpart by 8 years of age (Baker et al. 2005). The pubic symphysis presents

the typical appearance of an epiphyseal surface with its ridges and furrows that characterize it

throughout childhood and early adulthood. The changes associated with aging of the pubic

symphysis are due to secondary ossification that begins around the age of 20 (Baker et al. 2005).

According to Scheuer and Black (2000) by age 20-23 the dorsal margin forms along the

dorsal border of the pubic symphyseal surface, by age 23-27 the epiphysis appears for the pubic

tubercle and delimitation of the upper and lower borders of the symphyseal face commence, by

24-30 there is active ventral rampart formation and obliteration of the ridge and furrow

appearance of the ventral and dorsal aspects of the pubis symphyseal face, and by age 35 the

ventral rampart is complete and the symphyseal rim is mature. These features make the pubis a

reliable indicator for determining age (Scheuer and Black 2000).

Ischium

The ischium is located laterally and inferiorly to both the ilium and the pubis. The

ischium forms the posterior inferior aspect of the os coxa. The ischium contributes to the

formation of the acetabulum and its superior border also forms the lateral and inferior margins of

6

the obturator foramen. The ischium consists of a ramus and a body. The ramus is an extension of

the body and projects anteriorly, while the body projects posteriorly with the posterior aspect of

the ramus bearing a thick and roughened oval known as the ischial tuberosity (Scheuer and Black

2000).

The ischium begins ossification between the 3rd and 5th fetal month from one ossification

center and fuses with the pubis between 4 and 8 years of age (Baker et al. 2005). The ischium

has one secondary ossification center beginning between the ages of 13 and 16 for the epiphysis

of the ischial tuberosity, which begins to fuse between the ages of 16 and 18 and is fully fused by

21 to 23 years (Baker et al. 2005).

Ilium

The first bone of the os coxa to ossify is the ilium. This begins at 2 to 3 fetal months

(Baker et al. 2005). Two epiphyses generally develop for the ilium. A small cap for the anterior

inferior iliac spine begins to ossify around ages 10 to 13, but this center is sometimes linked to

the acetabular epiphysis and is not always found separately (Baker et al. 2005). This epiphysis

fuses completely between the ages of 17 and 20 (Scheuer and Black 2000). A second epiphysis

of the ilium is the iliac crest. This epiphysis begins ossifying from two separate centers around

the age of 12 or 13 in females and 14 to 15 in males (Baker et al. 2000). These separate centers

grow toward the midpoint of the crest and unite to form a single iliac crest epiphysis that begins

to fuse to the blade of the ilium between 17 -20 years and is complete by age 23 (Baker et al.

2005).

Ilium and the Auricular Surface

The ilium is the largest and most superior portion of the os coxa. It is a flat blade like

bone. The superior border of the blade has a long metaphyseal surface called the iliac crest,

7

which changes in thickness throughout its length and is slightly S shaped (Baker et al. 2005). On

the medial and posterior aspect of the blade is an articular surface shaped like an ear, which is

named for its shape (Gray 1995). The auricular surface is the region on the ilium that articulates

with the sacrum to the form the sacroiliac joint.

Function of the Pelvis

The function and shape of the pelvic girdle in modern humans serves to house and protect

viscera, but the female has had to take into account the secondary function of the pelvis, which is

its capability to house a fetus. Pregnancy releases certain hormones, particularly relaxin, which

increases mobility in the sacroiliac joint allowing the joint to expand even further (Sashin 1930).

Therefore the female pelvis is a functional compromise between providing a large enough birth

canal and the necessary framework for attachment of the muscles that facilitate bipedal

locomotion.

Variation of the Os Coxa

The os coxa is highly variable as a result of both genetic and environmental factors.

Reasons for this variation are a result of childbirth, nutritional status, and locomotion. As a

result differences in the os coxa are most visible when comparing males to females.

Up to adolescence, the pelvic girdle is much the same size and shape in boys and girls

(Reynolds 1947). Some authors suggest that the differences in form and morphological

characteristics of the os coxa are a result of the differences in growth rates that are attributed to

the growth hormones that begin in puberty (Coleman 1969). A study by Ellison (1982) and

Worthman (1993) found that age at menarche is best predicted by bi-iliac width, the distance

8

between the iliac crests of the pelvis. They concluded that a median width of 24cm is needed for

menarche. Moerman (1982) also demonstrated a relationship between growth in pelvic size and

reproductive maturation. She found that the crucial variable for a successful first birth is the size

of the pelvic inlet, the bony opening of the birth canal. Her study concluded that in an American

sample of 90 well nourished girls ages 8-18, birth size of the pelvic inlet is reached at 17-18

years of age.

Sexual Dimorphism

Several useful indicators for sexing the os coxa are that in general the male pelvis is more

robust and has more distinct muscle markings, the obturator foramen is larger and oval shaped in

males, whereas it is smaller and more triangular in females, and since the female pelvis is

adapted for childbirth, the pelvic basin is more spacious and less funnel shaped, also the

acetabulum is larger in males to accommodate the larger femoral head (Bass 2005). In general

the female pelvis is longer horizontally and lower vertically than that of the male. Usually the

male iliac blade is higher and narrower that of the female (Straus 1927).

Many of the sex indicators in the os coxa are in response to the areas surrounding the

auricular area (Iscan and Derrick 1984, St.Hoyme 1984). For instance females will have a raised

and narrow iliac auricular surface, and they may have a wide and deep preauricular sulcus. The

sciatic notch is wide and shallow and arthritic changes are more common in older women. In

males the iliac auricular surface may be more depressed and wide with a narrow and shallow

preauricular sulcus. The sciatic notch is deep and narrow and arthritic changes are seen more

rarely (Iscan et al. 1984 and St.Hoyme 1984).

The preauricular sulcus, when present is narrow and more shallow in children and males,

and represents a growth scar, but studies have demonstrated that the preauricular sulcus in

9

females is a result of posterior iliac widening, which is a result of pregnancy (Houghton 1975

and Kelley 1979). As a result of this it is reasonable to expect that the stresses of pregnancy to

enlarge or alter the auricular surface will also affect the area around it, such as the sciatic notch.

A wide sciatic notch, which may widen even further if the sacroiliac joint is mobile, is of

obvious value in childbearing (Cave 1937).

Evolutionary Trends of the Adult Human Pelvis

The morphology of the pelvis is particularly important in the investigation of human

evolution, as it clearly reflects the uniquely bipedal form of locomotion. Humans are the only

primate where the triangular shaped ilium is wider than it is high (Straus 1929). However, the

unique feature of the human ilium is not its great width but its reduced height. Functionally this

brings the sacroiliac joint close to the hip joint thereby reducing the stress on that part of the

ilium that transmits the entire weight of the upper body from the backbone to the hip joint in

bipedal posture (Aiello and Dean 1990).

Another important morphological feature of the human ilium is the orientation of the

blade portion. In humans the blade forms the side of the pelvis resulting in a convex gluteal

surface, a concave iliac fossa, and a very distinctive S-shaped iliac crest (Aiello and Dean 1990).

The location and function of major muscles in the region of the pelvis influence variation in size

and shape of the ilium among different species, and it has been suggested that the human form of

a short, wide, and back bending ilium is a direct reflection of an adaption or selection favoring

habitual bipedalism (Mednick 1955).

The human pelvis is short, squat, and basin shaped (Aiello and Dean 1990). The pelvic

girdle is formed by the articulation of the os coxa as it articulates with sacrum and coccyx. The

10

position of the pelvis between the trunk above and the legs below ensures that it is intimately

involved in the transfer of body weight from the upper body to the ground (Scheuer and Black

2000). In order to have bipedal posture it is essential that the center of gravity of the body

remains directly over the rectangular area formed by supporting the feet (Aiello and Dean 1990).

In adult humans the center of gravity is located in the midline just anterior to the second sacral

vertebra (MacConaill and Basmajian 1969). Body weight is then transmitted to the sacroiliac

joints, acetabulum, and then the femoral heads (Scheuer and Black 2000).

Previous Studies

The sacroiliac joint is influenced by sex-linked factors more than any other part of the

skeleton (Iscan and Kennedy 1989). Sex differences in this joint do not begin to show until

puberty, at which time males progress along lines of strength and females sacrifice strength for

mobility (Brooke 1924). In males the sacral auricular surface is wide and flat, but has a narrow

groove corresponding to the ridged iliac surface. Females on the other hand have a narrow

elevated joint, which Brooke suggests makes the joint more moveable. Brooke (1924) found in

his study that the mobility of the sacroiliac joint could be definitively linked with sex and age.

Results showed that in males, movement of the joint progressively decreases until the fifties,

after which time in most cases complete ankylosis occurs. Ankylosis is the stiffening an

immobility of a joint as the bones begin to fuse, as a result of trauma or disease (Stewart 1976).

However out of a sample of 105 females, not one showed signs of ankylosis (although some

showed signs of arthritic or inflammatory changes).

Ankylosing spondylitis of the sacroiliac joint was examined by Stewart (1976) in various

populations, including American whites and blacks, and the Bantu of South Africa. His findings

11

suggested that ankylosis progressed fairly regularly with age, and occurred more commonly on

the right side, and intensified in the fifth decade. Statistically, almost 90% of cases were male,

and ankylosing was found most frequently in Black Americans, followed by Bantu, then White

Americans (Stewart 1976). More recent studies have confirmed that the tighter post auricular

space between the sacrum and ilium in males probably predisposes them to ankylosis (Iscan and

Derrick 1984).

Distinctive differences in the auricular surface have been observed by examining the

thickness of the cartilage that covers the opposing sacral and iliac surfaces (Schunke 1938).

Schunke (1938) suggested that the sacral cartilage was primarily hyaline with surface cells

arranged in compact, parallel layers, while the cartilage on the iliac portion of the joint was

primarily fibrous with occasional portions of hyaline cartilage, and that after the third decade the

surfaces of the joint became roughened, furred, and frayed (Schunke 1938). These changes to

the auricular surface are attributed to the age related increase in the proportion of fibrocartilage

in the joint (Sashin 1930) rather than as a result of the more typical process of degeneration seen

in other movable joints with synovial cavities (Schunke 1938, Meindl and Lovejoy 1985).

Age progression in the sacroiliac joint was first pointed out by Brooke (1924) and Sashin

(1930) who noticed regular changes in the sacroiliac joint with increasing age. Then almost 50

years later Lovejoy et al. (1985) introduced a new method for the determination of adult skeletal

age at death based upon chronological changes in the auricular surface of the ilium.

Lovejoy et al. (1985) developed a method that estimated age-at-death by examining

morphological features of the auricular surface. This method was developed under the

assumption that the surface morphology of the auricular surface will undergo regular changes

12

that result from age progression. However, these changes are more difficult to interpret than

those used in pubic symphyseal aging (Lovejoy et al. 1985).

The use of the auricular surface has two advantages over pubic symphyseal aging. The

survival rate of this region is higher than the pubic symphysis in archaeological populations and

qualitative changes in the auricular surface extend well beyond the age of 50, while they

generally do not in the pubic symphysis (Lovejoy et al. 1985).

The study was based on 250 well-preserved auricular surfaces from the Libben

prehistoric collection housed at Kent State University. The authors established that auricular

surface morphology changed with age based on the previous studies of Brooke (1924), Sashin

(1930), and Schunke (1938), which determined degenerative changes in the cartilage of the joint.

From this Lovejoy et al. (1985) determined that these degenerative changes in the joint would

lead to surface changes on the bone as age progresses. Terminology for the description of

surface features was developed by the authors in order to describe these changes. Feature

descriptions are described by billowing, striations, granulation, density, and porosity. From

these feature descriptions based on their study they were able to define eight stages of

morphological changes, which were divided into five and ten year increments, with an age range

spanning 20-60+ years.

In addition to Lovejoy et al. (1985) study other studies have been conducted to test the

accuracy of the auricular surface aging technique. Murray and Murray (1991) undertook a case

by case blind study to examine the use of the auricular surface technique as a single aging factor

and to determine if this technique is equally applicable across race and sex. This study was

tested using a sample of 189 individuals from the Terry Collection, housed at the Smithsonian

Institution. It was concluded that degenerative change does not appear to correlate with race nor

13

sex. The authors did find that the auricular surface technique exhibited a tendency to

overestimate younger individuals and underestimate older individuals (Murray and Murray

1991), thus making this technique less reliable as a single indicator of age.

Igarashi et al. (2002) wanted to revise Lovejoy et al. (1985) study in three ways. First the

authors wanted to identify morphological features by using reference samples. Second they

wanted to link morphological features to chronological age by using reference samples. Third,

they wanted to estimate age of individuals from a target sample. In order to accomplish this

study a total of 13 features of the auricular surface were identified and marked as either present

or absent on a sample of 700 modern Japanese skeletal remains, 438 males and 262 females

(Igarashi et al. 2002).

A revised method was proposed that identified the features typical of younger and older

individuals concluding that Igarashi et al. (2002) age ranges are more effective than other aging

methods. In addition they found that there were not significant differences between the left and

right side of both males and females. They were able to determine statistically, the frequency of

features, based on the absence or presence of nine 9 for a male and 7 for a female, then to

identify modal appearances for each characteristic for older and younger age groups. The

provided scatterplots demonstrate that in both male and female samples, ages of older individuals

were underestimated (Igarashi et al. 2002).

Problems with Lovejoy et al. (1985) age phases are also addressed by Buckberry and

Chamberlain (2002). The separate features of the auricular surface described by Lovejoy et al.

(1985) such as porosity, surface texture, and marginal changes, appear to develop independently

of each other. The age of onset for each stage of different features of the auricular surface

appears to vary, and as a consequence the 5 year age categories of Lovejoy et al. (1985) tend to

14

overlap. Since the age ranges developed by Lovejoy et al. (1985) have overlapping

characteristics of features, it can be difficult to use the method provided by Lovejoy et al. (1985).

The Lovejoy et al. (1985) method can lead to uncertainty and in some cases confusion when

assigning individual auricular surfaces to a particular age stage (Buckberry and Chamberlain

2002). The authors suggested that this issue can be resolved by applying a qualitative scoring

system. This would allow different features of the auricular surface to be examined

independently (Buckberry and Chamberlain 2002). Thereby making this method easier to apply

and also accommodate for the overlap often seen between different stages.

The new method records age-related stages for different features of the auricular surface,

which are then combined to provide a composite score from which an estimate of age at death is

obtained (Buckberry and Chamberlain 2002). Blind tests were conducted on known age skeletal

collections from Christ Church, Spitalfields, London, with statistical tests showing that the age

related changes were not significantly different for males and females. The scores from the

revised method also showed a slightly higher correlation with age than the Suchey-Brooks public

symphysis stages (Buckberry and Chamberlain 2002).

Testing the revised method by Buckberry and Chamberlain (2002) Mulhern and Jones

(2004) examined 309 individuals from the Terry and Huntington Collection. The authors also

used the original method by Lovejoy et al. (1985). While they demonstrated that the revised

method is equally applicable to males and females as well as blacks and whites. They also

concluded that the revised method is less accurate than the original method for individuals

between 20-49 years of age, but more accurate for individuals between 50-69 years of age.

Although the revised method provides a way to age individuals over 60 years, it has greater

15

inaccuracy than in younger ages, which indicated that it should not be used as a single indicator

of age at death in older adults (Mulhern and Jones 2004).

Buckberry and Chamberlains (2002) study was revisited again by Flays, Schutkowski,

and Weston (2006). When documenting a skeletal collection, which spanned from the late 17th to

early 19th century, they suggested that the composite scores of trait expressions as expressed on

the auricular surface correlate, at least in general with age, and show a positive association with

known chronological age. Yet, their conclusions show that when composite scores were

combined to define auricular surface phases, which ultimately assign age estimations, only three

distinct developmental stages, compared with seven suggested by Buckberry and Chamberlain

(2002) could be identified and statistically supported, showing a considerable degree of

individual variation in age (Flays et al. 2006).

Finally, Osborne et al. (2004) reconsiders the auricular surface as an indicator of age at

death and proposes that because of the similarities in the eight phase age system proposed by

Lovejoy et al. (1985) a modified six phase age system would be more accurate for determining

age estimation from the auricular surface.

In their study, the authors provide a more realistic view of the variation associated with

auricular surface morphology and age. Based on examination of 266 individuals of documented

age, sex, and ancestry from the Terry and Bass donated collections (Osborne et al. 2004), each

individual was scored using the standards established by Lovejoy et al. (1985) and it was found

that ancestry and sex had no significant effect on the auricular surface age expression. In order

to assess the variation in age per phase, standard descriptive statistics and error ranges were

calculated, and because the mean ages of some of the eight phases did not differ significantly

16

from one another a six phase age system was presented by the authors, which refined auricular

surface phase descriptions (Osborne et al. 2004).

17

CHAPTER TWO

MATERIALS AND METHODS

Introduction

This study documents the application of the auricular surface technique of age estimation

using eight measurements, two on the os coxa and six to determine if size and shape vary

between the left and right auricular surface. Eight morphological characteristics derived from

Lovejoy et al. (1985) study was adapted into a qualitative scoring system in order to determine if

auricular surface features can be independently used to revise a method of age estimation from

the auricular surface.

Materials

Two samples were used in this research, a cadaver collection housed at Wichita State

University Biological Anthropology Laboratory (WSU-BAL) and the Hamann-Todd Collection

housed at the Natural History Museum in Cleveland, Ohio. The protocol for this method was

designed and tested using the Moore-Jansen Cadaver Collection and the resulting protocol was

then used to collect data on specimens from the Hamann-Todd Collection. The Hamann-Todd

Collection was chosen as a resource due to its state of completeness and accessibility. Results

presented are based on data collection from the Hamann-Todd Collection sample of 102 Black

females.

Hamann-Todd Collection

The Hamann-Todd collection was first assembled by the anatomy professor, Dr. Carl

Hamann in 1893 (Cobb 1981). The collection consists of donated dissecting room cadavers that

were collected from individuals born in United States, primarily from the lower socio-economic

18

strata of ethnically White and Black Americans (Todd and Lindala 1928). In 1912 T. Wingate

Todd, followed Dr. Carl Hamann as the Dean of Medicine at the School of Medicine of Western

Reserve (Case Western Reserve University 2009). Specimens for the Hamann-Todd collection

were collected until 1938. Today the collection is housed at the Museum of Natural History in

Cleveland, Ohio and consists of 3,100 modern humans. It is the largest, modern, documented

human skeletal collection in the world. Each cadaver has extensive documentation, which

includes height, weight, age at death, sex, group affiliation, and cause of death, making it one of

the most researched and published collections (Cleveland Museum of Natural History 2009).

Only individuals with a documented age at the time of death were used. This included a

total of 102 Black females. The right and left os coxa of each individual was examined, making

the total sample number 204. This sample represents individuals ranging in age from 20 to 87

(Table 1). The age range was chosen to ensure fully mature specimens and each individual was

selected to include a fairly even distribution of specimens that represented each age range,

represented by Lovejoy et al. (1985).

Table.1 Sample Distribution by Age from the Hamann-Todd Collection Ages 20-24 25-29 30-34 35-39 40-44 45-49 50-59 60+ Left 12 14 11 17 11 10 13 14

Right 12 15 11 17 11 10 12 14

Total 24 29 22 34 22 20 25 28

Measurements and surface features were recorded without the knowledge of the

individuals true age. The left and right surfaces were scored independently using the standards

set forth by Lovejoy et al. (1985) and adapted to the qualitative scoring system developed at

Wichita State Biological Anthropology Laboratory.

19

Recording Data

A data collection form was then created on excel, which consisted of recording spaces for

eight metric and nine non-metric observations as well as demographic information, and any other

applicable information. Data from the Hamann-Todd Collection was entered into the excel data

sheet at the time of collection.

Methods

Measurements were chosen which would best define the shape and size of the auricular

surface. These include measurements that typically characterize size and shape such as breadth

and height. Standard measurements of the os coxa were also included. These include two

measurements that were defined by Moore-Jansen et al. (1994). The other six non-traditional

measurements were developed by the author and Dr. Moore-Jansen. These include the

maximum height and breadth of the auricular surface, along with an inferior and superior

auricular surface breadth and length. All measurements used are listed in Table 2 and are

detailed in Appendix A1-A6. Measurements of the auricular surface were taken with sliding

calipers and were recorded to the nearest millimeter. The two measurements of the os coxa were

taken using spreading calipers and were recorded to the nearest millimeter.

Measurements were chosen in order to quantify the size and shape of the auricular

surface to determine if it is possible to identify changes in size and shape with age. It is expected

that the auricular surface will erode with age and thus get smaller. These measurements were

also selected in order to determine if there are any signs of asymmetry between the left and right

auricular surface.

20

Table 2. Auricular Surface Measurements Measurement Abbreviation Description of the Measurement

MXBR Maximum breadth of the os coxa is the distance from the anterior superior iliac spine to the posterior superior iliac spine.

MXHT Maximum height of the os coxa is the distance from the most superior point of the iliac crest to the most inferior point on the ischial tuberosity.

MXHTAS Maximum height of the auricular surface taken from the most superior to the most inferior border of the auricular surface.

MXBRAS Maximum breadth of the auricular surface is the distance from the most anterior superior point to the most inferior point on the auricular surface.

IFASBR Inferior auricular surface breadth is the minimum width of the auricular surface between points on the anterior and posterior border of the auricular surface.

SPASBR Superior auricular surface breadth is the maximum width of the auricular surface between points on the superior and inferior border of the auricular surface.

IFASLT Inferior auricular surface length is the minimum width of the auricular surface between the apex and the posterior border of the auricular surface.

SPASLT Superior auricular surface length is the maximum width of the auricular surface between the apex and the posterior border of the auricular surface.

Non-metric Observations

Additionally nine non-metric observations were selected to be recorded on each

specimen. Visual assessments were made by examining the different features which Lovejoy et

21

al. (1985) defined. For this study the terminology was based on Lovejoy et al. (1985) study.

These eight morphological characteristics and features defined by Lovejoy et al. (1985) include

billowing, striae, granularity (fine and coarse), densification, porosity (micro and macro),

subchondral destruction, the apex, and the retro auricular region and are defined as follows.

Billowing refers to a series of transverse ridges that tend to cover the entire surface in

younger individuals while slowly disappearing in older individuals. Striae appear after billowing

and are the remnants of the ridges once associated with billowing. Striae differ from billows only

in degree, billows become striae with age. An example of billows and striations is shown in

Figure 2.

Granularity refers to the gross appearance of the surface. Granulation becomes coarser

with increasing age. Fine granulation is an indicator of youth, and is usually associated with

billows and striae. An example of fine granulation is illustrated in Figure 3.

Figure 2. Billows and Striae Figure 3. Fine Granulation (Hamann-Todd Specimen 1969) (Hamann-Todd Specimen 2252)

22

The general sequence, then, is from a fine to coarse condition, with eventual loss to

densification. Coarse granulation can be seen in Figure 4. Densification is another surface

feature, which refers only to the surface appearance and not to the actual amount of bone present.

Dense bone replaces coarse granularity with smooth compact bone.

Porosity is perforations of subchondral bone. Fine porosity is optically visible

perforations also defined as microporosity. An auricular surface displaying microporosity is

shown in Figure 4. Macroporosity is defined as less regular, large, generally oval perforations

ranging from 1 to 10mm in diameter. Subchondral destruction refers to surfaces that are

typically porous and irregular, and is displayed in Figure 5.

Figure 4. Coarse granulation and Microporosity Figure 5. Subchondral Destruction (Hamann-Todd Specimen 2127) (Hamann-Todd Specimen 2278)

The apex is the portion of the auricular surface that meets with the posterior extension of

the arcuate line. The retro-auricular region refers to the area directly posterior to the auricular

surface extending to the posterior inferior iliac crest as shown in Figure 6.

23

Figure 6. Apex and Retro-auricular region (Lovejoy et al. 1985).

In the presented study each feature of the auricular surface was examined independently

and was examined using a revised new qualitative scoring system, which was developed by the

author and Dr. Moore-Jansen, in order to examine the morphological changes on the auricular

surface. The revised system uses a scoring system of 0-3, which ranges from absent, minor,

moderate, and majorly present. The absence, less than 1% of a feature will be scored as a 0.

Minor will be scored as a 1 and represent that 1-25% of the surface is occupied by a particular

feature. Moderate will be scored as a 2 and signify that 25-50% of the surface is occupied by

this feature. The score of a 3 will be given to any feature that is represented as occupying over

50% of the auricular surface.

The only exception to this previous scoring system will be for apical changes. Here the

author will use the scoring system devised by Buckberry and Chamberlain (2002). With 1

representing a sharp and distinct apex with the auricular surface possibly being slightly raised

relative to adjacent bone surface. A score of 2 indicates that some lipping is present at the

24

apex, but the shape of the articular margin is still distinct and smooth. Meaning the shape of the

outline at the surface of the apex is a continuous arc. The score of 3 represents irregularity

occurring in contours of the articular surface, suggesting the shape of the apex is no longer a

smooth arc.

Lovejoy et al. (1985) used these features to develop eight phases that represent age

ranges from age 20 to 60 plus, which portray chronological changes. A summary of each phase

is as listed in Table 3.

Table 3. Summary of Eight Age Phases (Lovejoy et al. 1985) Age 20-24

PHASE I- Surfaces are fine grained with marked transverse organization and pronounced billowing. Neither retro-auricular nor apical activity is present, nor is there evidence of macroporosity. Should any subchondral defects be present they will appear smooth-edged.

Age 25-29

PHASE II- There is slight loss of billowing that is replaced by striae, marked transverse organization and granularity that is only slightly coarser than in Phase I. There is no evidence of macroporosity, apical or retro-auricular activity.

Age 30-34

PHASE III-Reduction of billowing, which are replaced by striae and the loss of transverse organization. The surface exhibits coarser granulation and has no changes at the apex, but has the possibility of slight retro-auricular activity.

Age 35-39

PHASE IV- Exhibits uniform coarse granularity, poorly defined transverse organization and the reduction of striae. There may also be slight retro-auricular activity and minimal apical change.

Age 40-44

PHASE V- There is loss of transverse organization, vague striae, coarse granularity and some densification. Retro-auricular activity is slight to moderate, apical change is slight and macroporosity may be present.

25

Table 3. Summary of Eight Age Phases (Lovejoy et al. 1985) (continued)

Age 45-49

PHASE VI- Displays continued replacement to coarse granularity with dense bone, and the loss of transverse organization and striae. Moderate retro-auricular activity, apical change with irregular margins and macroporosity may also be present.

Age 50-59

PHASE VII- Typically includes surface irregularity, densification, and moderate to severe retro-auricular activity, apical change with irregular margins and macroporosity.

Age 60+

Phase VIII-Features include irregular surface, densification with subchondral destruction, severe retro-auricular activity, and apical change with marginal lipping, as well as the presence of osteophytes and macroporosity.

Each feature was examined independently using the scoring system mentioned above to

determine if the absence or degree of presence of each feature could differentiate when these

morphological features begin to disappear or increase in relation to age. From this a revised age

phase system will be developed.

Data Analysis

The data collected was entered into an Excel spreadsheet. Data was then interpreted

using both descriptive and inferential statistics. Summary statistics were calculated for the

auricular surface measurements this includes the mean and standard deviation for measurements

in each age group. In addition to the summary statistics an independent t-test was performed on

the data collected from the auricular surface measurements to determine difference of means for

each measurement on the left and right auricular surface. An independent t-test was also

26

conducted on the measurements between the youngest and oldest age groups to observe any

differences in size that may be a result of age.

Frequency analyses were calculated on the qualitative scores collected from the

morphological features. In order to test the significance of these scores chi-square analyses were

performed, which examined each feature in relation to age. The age ranges presented by

Lovejoy et al. (1985) are the same age phases used in the results section, which were used to

analyze both the qualitative and quantitative data.

27

CHAPTER THREE

RESULTS

Summary Statistics

An analysis of summary statistics for the measurements taken on the os coxa and the

auricular surface are provided in the tables below. These tables simply summarize the

observations of the eight measurements that were recorded on the os coxa and the auricular

surface. The eight measurements consist of two measurements on the os coxa and six on the

auricular surface. The maximum breadth and maximum height of the os coxa were observed

along with the maximum height, and maximum breadth of the auricular surface. Other

measurements include an inferior and superior auricular surface breadth, with an inferior and

superior auricular surface length; all measurements were recorded to the nearest millimeter. The

mean and standard deviation for each measurement is presented for eight age ranges. Table 4

examines the age group 20-24, which has a mean age of 23.

Table 4. Means and Standard Deviations Age 20-24 (n=12; Mean age= 23, SD 1)

Observations in Table 4 show that the same mean is recorded for all measurements

except two, which are the maximum breadth and height of the os coxa. The maximum breadth

of the os coxa (MXBR) for the left is 146mm and the right is 148mm, both with a standard

deviation of 10. The maximum height of the os coxa (MXHT) has a mean of 189mm for the left

and the right is 190mm. Standard deviations are same for the maximum breadth of the os coxa

(MXBR) and the inferior auricular surface breadth (IFASBR), but vary by one standard deviation

Side MXBR SD MXHT SD MXHTAS SD MXBRAS SD IFASBR SD SPASBR SD IFASLT SD SPASLT SDL 146 10 189 9 45 4 51 7 14 3 17 4 24 5 33 4R 148 10 190 8 45 5 51 6 14 3 17 3 24 4 33 5

28

between the left and right for all other measurements. Means and standard deviations vary

slightly for all measurements between the ages 25-29 for both the left and right, which is shown

in Table 5.

Table 5. Means and Standard Deviations Age 25-29 (Left n=14; Age 27, SD 2/ Right n=13; Age 27, SD 1)

Means and standard deviations are the same for the inferior auricular surface breadth

(IFASBR), although it has increased by 2mm from the previous age range. The superior

auricular surface length (SPASLT) is also the same for the left and right and has a mean of

34mm with a difference of one standard deviation between the left and right (Table 5).

Observations for the means and standard deviation for the ages 30-34 are observed in Table 6.

Table 6. Means and Standard Deviations Age 30-34 (n=11; Mean age=32, SD 2)

The inferior auricular surface length (IFASLT) had a mean of 27mm for the left and right

auricular surface. All other measurements vary by at least one or two millimeters for the ages of

30-34, which has a mean age of 32 (Table 6). The age range of 35-39, exhibits little difference

between means and standard deviations for the left and right auricular surface (Table 7).


Measurements with the same means and standard deviations are the maximum breadth of

the os coxa (MXBR) maximum height of the auricular surface (MXHTAS), and the superior




29

auricular surface breadth (SPASBR). Measurements with the same mean only are the maximum

height of the os coxa (MXHT), which varies by a difference of one standard deviation between

the left and right, and the superior auricular surface length (SPASLT), which differs between 2

standard deviations from the left and right auricular surface (Table 7). Table 8 below examines

the age range of 40-44, which has a mean age of 41, with a standard deviation of 2.


Measurements in Table 8 are similar for both the left and right auricular surface, but only

two measurements have the same mean, which are the maximum breadth of the os coxa at

147mm and the inferior auricular surface length at 24 mm. In Table 9 the mean age observed is

46 for the age range of 45-49.

Table 9. Means and Standard Deviations Age 45-49(n=10, Mean age=46, SD 2)

Standard deviations for the ages 45-49 all differ by one standard deviation in regards to

the left and right, with the exception of the maximum breadth of the os coxa (MXBR) which has

a standard deviation of 9 for both the left and the right. Three measurements the maximum

auricular surface height (MXHTAS), breadth (MXBRAS), and the maximum height of the os

coxa (MXHT) all have the same mean for the left and right (Table 9). The age range of 50-59

had a different sample size for the left and the right, which is shown in Table 10.



30

Table 10. Means and Standard Deviations Age 50-59 (Left n=14; Age 52, SD 2/ Right n=12; Age 53, SD 2)

Results show that the superior auricular surface length (SPASLT) differs by a mean of

7mm from the left and right, besides this measurement there is little variation between the left

and right means and standard deviations which occur at ages 50-59 (Table 10). Means and

standard deviations for specimens ages 60+ are similar to the previous age range of 50-59 (Table

11).

Table 11. Means and Standard Deviations Age 60+ (n=14; Mean Age 68, SD 7)

The inferior auricular surface length mean is the same at 28mm for both the left and right

and all other measurements show little variation between the left and right, with the exception of

one. The superior auricular surface length differs by a mean of 7mm between the left and right

(Table 11). Table 12 is a summary table which examines the differences between the left and

right auricular surface for the total sample.

Table 12. Means and Standard Deviations from All Age Groups (n=102; mean age=41, SD 15)

Results for auricular surface measurements show that they are extremely variable

between the different age groups and Tables 4-11 show that the standard deviations are high

between individual measurements. Yet the means within each age group only show slight

Side MXBR SD MXHT SD MXHTASSD MXBRAS SD IFASBR SD SPASBR SD IFASLT SD SPASLTSDL 149 9 193 9 46 5 52 5 15 3 18 4 25 5 34 4R 150 8 193 9 46 4 52 5 16 3 19 4 26 4 34 4



31

differences, as shown in Table 12, which demonstrates consistency between the left and right. In

order to confirm these results though a t-test must be performed. A t-test on the left and right

will determine if these differences are significant. Another t-test will also be conducted

comparing the age groups to determine if there are significant changes in size and shape of the

auricular surface in correlation with age. Original data collected for each individual on the left

and right auricular surface can be found in Appendix B, Appendix C, and Appendix D.

Analysis of Frequencies

A frequency distribution table for the morphological features of the auricular surface was

organized to show the number of individuals associated with each score that was observed. This

was done for both the left and right auricular surface as shown in Table 13 through Table 21 .

Table 13 shows frequencies and percentages for the left and right auricular surface for

the feature billows collected from the Hamann-Todd collection. Results of billows and striae in

correlation with age in decade and percent displayed of each trait are listed in Figure 7 for the

left auricular surface.

Table 13. Frequencies and Percentages for the Feature Billows

Age 20-24 Age 25-29 Age 30-34 Age 35-39 Age 40-44 Age 45-49 Age 50-59 Age 60+ LEFT

Score (n) % (n) % (n) % (n) % (n) % (n) % (n) % (n) % Totals (n=102) (0) Absent 3 25 9 64 9 82 17 100 11 100 10 100 13 100 14 100 86(1) Minor 8 67 5 36 2 18 0 0 0 0 0 0 0 0 0 0 15(2) Moderate 1 8 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1(3) Major 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

102Age 20-24 Age 25-29 Age 30-34 Age 35-39 Age 40-44 Age 45-49 Age 50-59 Age 60+

RIGHTScore (n) % (n) % (n) % (n) % (n) % (n) % (n) % (n) % Totals (n=102)

(0) Absent 7 58 5 33 9 82 16 94 11 100 10 100 12 100 14 100 84(1) Minor 5 42 9 60 2 18 1 6 0 0 0 0 0 0 0 0 17(2) Moderate 0 0 1 7 0 0 0 0 0 0 0 0 0 0 0 0 1(3) Major 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

102

(n=10) (n=13) (n=14)

(n=12) (n=15) (n=11) (n=17) (n=11) (n=10) (n=12) (n=14)

(n=12) (n=14) (n= 11) (n=17) (n=11)

32

The left auricular surface indicates that the highest percentage for the presence of billows

is in the age range 20-24, which has a percentage of 67%. After the age of 34 the feature billows

is absent. The right auricular surface indicates that the feature billows has the highest percentage

between the ages 25-29 where 60% of billows present are minor. Billows on the left and right

auricular surface decrease with age and decrease considerably after the age of 34 and are absent

on both after the age of 40. Figure 7 illustrates a decrease in billows and striae as age increases.

Striation results for frequencies and percentages collected on the left and right auricular surface

are located in Table 14.

Figure7. Billowing and Striae for Left Auricular Surface

0 10 20 30 40 50 60 70 80 90

100

20 30 40 50 60

% billowsstriae

Age in Years

%

33

Table 14. Frequencies and Percentages for the Feature Striae

Striae can also be seen to decrease with age but is more prevalent in all ages with the

exception of 60+. Table 14 shows that for the left auricular surface striae were only absent from

the age range of 60 and over, but had more than 50% present ranging from minor to majorly

present between the ages of 20-34. After the age 34 there is a decrease from moderate and major

to only minor present, which continues as age increases to the age of 50-60+ to the absence of

striae. The right auricular surface for striae exhibits that it is present in all of the age ranges but

decreases to less than 50% present, and from moderate to minor present after the age of 40.

Fine granulation is exhibited in Table 15, which shows the left and right auricular surface

frequencies and percentages. The left auricular surface shows that the percentage of fine

granulation seemed to decrease as age increased, but it was only absent after the age of 50.

Figure 8 shows fine, coarse granulation, and dense bone in correlation with age for the left

auricular surface.

Age 30-34 Age 35-39 Age 40-44 Age 45-49 Age 50-59 Age 60+ LEFT

Score (n) % (n) % (n) % (n) % (n) % (n) % (n) % (n) % Totals (n=102) (0) Absent 0 0 3 21 4 36.5 9 53 8 73 6 60 10 77 14 100 54(1) Minor 5 42 4 29 4 36.5 7 41 2 18 4 40 3 23 0 0 29(2) Moderate 6 50 5 36 3 27 1 6 1 9 0 0 0 0 0 0 16(3) Major 1 8 2 14 0 0 0 0 0 0 0 0 0 0 0 0 3

102

Age 20-24 Age 25-29 Age 30-34 Age 35-39 Age 40-44 Age 45-49 Age 50-59 Age 60+ RIGHTScore (n) % (n) % (n) % (n) % (n) % (n) % (n) % (n) % Totals (n=102)

(0) Absent 3 25 3 20 5 45.5 8 47 7 64 5 50 10 83 12 86 53(1) Minor 5 42 8 53 5 45.5 8 47 4 36 4 40 2 17 2 14 38(2) Moderate 3 25 1 7 0 0 1 6 0 0 1 10 0 0 0 0 6(3) Major 1 8 3 20 1 9 0 0 0 0 0 0 0 0 0 0 5

102

Age 20-24 Age 25-29 (n=13) (n=14)

(n=12) (n=15) (n=11) (n=17) (n=11) (n=10) (n=12) (n=14)

(n=12) (n=14) (n= 11) (n=17) (n=11) (n=10)

34

Table 15. Frequencies and Percentages for the Feature Fine Granulation

Figure 8. Fine grain, Coarse grain, and Dense bone for the Left Auricular Surface

Fine granulation appears to decrease as age increases and is replaced with coarse grain,

which takes over faster than fine grain disappears. Frequencies and percentages for coarse

granulation are shown in Table 16.

0102030405060708090

100

20 30 40 50 60

%

fine graincoarse graindense

Age in Years

%

Age 20-24 Age 25-29 Age 30-34 Age 35-39 Age 40-44 Age 45-49 Age 50-59 Age 60+ LEFT

Score (n) % (n) % (n) % (n) % (n) % (n) % (n) % (n) % Totals (n=102) (0) Absent 1 8 3 21 4 36 12 71 9 82 7 70 13 100 14 100 63(1) Minor 3 25 5 36 5 46 2 11.5 1 9 1 10 0 0 0 0 17(2) Moderate 4 33.5 5 36 2 18 2 11.5 1 9 0 0 0 0 0 0 14(3) Major 4 33.5 1 7 0 0 1 6 0 0 2 20 0 0 0 0 8



(0) Absent 3 25 1 7 6 55 8 47 9 82 7 70 11 92 13 93 58(1) Minor 3 25 8 53 2 18 4 23.5 0 0 1 10 1 8 0 0 19(2) Moderate 2 17 5 33 2 18 4 23.5 2 18 0 0 0 0 1 7 16(3) Major 4 33 1 7 1 9 1 6 0 0 2 20 0 0 0 0 9

102

(n=12) (n=14)(n=12) (n=15) (n= 11) (n=17) (n=11) (n=10)

(n=13) (n=14)(n=12) (n=14) (n= 11) (n=17) (n=11) (n=10)

35

Table 16. Frequencies and Percentages for the Feature Coarse Granulation

Age 20-24 Age 25-29 Age 30-34 Age 35-39 Age 40-44 Age 45-49 Age 50-59 Age 60+LEFTScore (n) % (n) % (n) % (n) % (n) % (n) % (n) % (n) % Totals (n=102)

(0) Absent 7 59 2 14.5 1 9 1 6 0 0 1 10 1 8 2 14 15(1) Minor 4 33 3 21 3 27 5 29 0 0 2 20 2 15 5 36 24(2) Moderate 1 8 7 50 2 18 4 24 3 27 1 10 6 46 3 21 27(3) Major 0 0 2 14.5 5 46 7 41 8 73 6 60 4 31 4 29 36

102

Age 20-24 Age 25-29 Age 30-34 Age 35-39 Age 40-44 Age 45-49 Age 50-59 Age 60+ RIGHTScore (n) % (n) % (n) % (n) % (n) % (n) % (n) % (n) % Totals (n=102)

(0) Absent 6 50 4 27 2 18 1 6 0 0 1 10 0 0 0 0 14(1) Minor 4 33 5 33 2 18 5 29 0 0 2 20 4 33 7 50 29(2) Moderate 2 17 5 33 2 18 4 24 5 45.5 3 30 3 25 2 14 26(3) Major 0 0 1 7 5 46 7 41 6 54.5 4 40 5 42 5 36 33

102

(n=12) (n=14)(n=12) (n=15) (n=12) (n=17) (n=11) (n=10)

(n=12) (n=14) (n=11) (n=17) (n=11) (n=10) (n=13) (n=14)

The left auricular surface appears to have coarse granulation present in all age ranges but

has the strongest percentage in individuals aged 40-44, where 73% of fine granulation was

majorly present on the auricular surface. Both the left and right show a decrease from minor

present to an increase in moderate to major present after the age of 40. Figure 8 confirms that

dense bone increases as age increases. Frequency and percentage results for the feature dense

bone are shown in Table 17 for the left and right auricular surface.

Table 17. Frequencies and Percentages for Dense Bone

Age 20-24 Age 25-29 Age 30-34 Age 35-39 Age 40-44 Age 45-49 Age 50-59 Age 60+ LEFTScore (n) % (n) % (n) % (n) % (n) % (n) % (n) % (n) % Totals (n=102)

(0) Absent 12 100 14 100 8 73 11 65 8 73 6 60 5 38.5 1 7 65(1) Minor 0 0 0 0 2 18 6 35 2 18 2 20 5 38.5 8 57 25(2) Moderate 0 0 0 0 0 0 0 0 1 9 2 20 1 8 3 22 7(3) Major 0 0 0 0 1 9 0 0 0 0 0 0 2 15 2 14 5

102

Age 20-24 Age 25-29 Age 30-34 Age 35-39 Age 40-44 Age 45-49 Age 50-59 Age 60+RIGHTScore (n) % (n) % (n) % (n) % (n) % (n) % (n) % (n) % Totals (n=102)

(0) Absent 11 92 15 100 7 64 13 76 5 46 6 60 5 42 2 14 64(1) Minor 1 8 0 0 3 27 3 18 4 36 1 10 3 25 6 43 21(2) Moderate 0 0 0 0 0 0 1 6 2 18 3 30 2 16.5 3 22 11(3) Major 0 0 0 0 1 9 0 0 0 0 0 0 2 16.5 3 22 6

102

(n=12) (n=14)(n=12) (n=15) (n=12) (n=17) (n=11) (n=10)

(n=12) (n=14) (n=11) (n=17) (n=11) (n=10) (n=13) (n=14)

36

Dense bone does not appear to be present on the left auricular surface until the age range

30-34, where it is minor. The feature then appears to increase from minor to major as age

increases. The right auricular surface shows it increasing from minor to moderate after age 40

and from moderate to major after age 50.

Table 18 shows frequencies and percentages for the left and right auricular surface for the

feature microporosity that was collected from the Hamann-Todd collection. Porosity results in

correlation with age in decade are illustrated in Figure 9 for the left auricular surface.

Table 18. Frequencies and Percentages for Microporosity

Age 20-24 Age 25-29 Age 30-34 Age 35-39 Age 40-44 Age 45-49 Age 50-59 Age 60+LEFT

Score (n) % (n) % (n) % (n) % (n) % (n) % (n) % (n) % Totals (n=102) (0) Absent 7 58 8 57 4 36 4 23 7 64 5 50 6 46 8 57 49(1) Minor 5 42 6 43 6 55 10 59 4 36 5 50 5 39 5 36 46(2) Moderate 0 0 0 0 0 0 2 12 0 0 0 0 2 15 1 7 5(3) Major 0 0 0 0 1 9 1 6 0 0 0 0 0 0 0 0 2



(0) Absent 7 58 10 67 6 55 7 41 4 36 6 60 2 17 5 36 47(1) Minor 5 42 5 33 4 36 9 53 7 64 4 40 10 83 7 50 51(2) Moderate 0 0 0 0 1 9 0 0 0 0 0 0 0 0 2 14 3(3) Major 0 0 0 0 0 0 1 6 0 0 0 0 0 0 0 0 1

102

(n=12) (n=14)(n=12) (n=15) (n=11) (n=17) (n=11) (n=10)

(n=12) (n=14) (n=11) (n=17) (n=11) (n=10) (n=13) (n=14)

37

Figure 9. Porosity for the Left Auricular Surface

The left auricular surface has the highest presence of microporosity between ages 35-39.

The right auricular surface has the highest percentage of microporosity between the ages of 50-

59 with 83% as minor present. There appears to be no trend in microporosity, although Figure 9

shows that macroporosity has a steady trend of increasing with age. Table 19 exhibits results for

macroporosity from left and right auricular surfaces.

Table 19. Frequencies and Percentages for Macroporosity Age 20-24 Age 25-29 Age 30-34 Age 35-39 Age 40-44 Age 45-49 Age 50-59 Age 60+

LEFTScore (n) % (n) % (n) % (n) % (n) % (n) % (n) % (n) % Totals (n=102)

(0) Absent 9 75 13 93 9 82 13 76 7 64 8 80 7 54 3 22 69(1) Minor 2 17 1 7 2 18 3 18 3 27 2 20 4 31 6 43 23(2) Moderate 1 8 0 0 0 0 1 6 1 9 0 0 1 7.5 3 22 7(3) Major 0 0 0 0 0 0 0 0 0 0 0 0 1 7.5 2 14 3



(0) Absent 10 83 14 93 9 82 12 71 6 54.5 6 60 5 41.5 4 29 66(1) Minor 2 17 1 7 2 18 5 29 5 45.5 3 30 5 41.5 8 57 31(2) Moderate 0 0 0 0 0 0 0 0 0 0 1 10 1 8.5 1 7 3(3) Major 0 0 0 0 0 0 0 0 0 0 0 0 1 8.5 1 7 2

102

(n=12) (n=14)(n=12) (n=15) (n= 11) (n=17) (n=11) (n=10)

(n=12) (n=14) (n= 11) (n=17) (n=11) (n=10) (n=13) (n=14)

010 20 30 40 50 6070 80 90

20 30 40 50 60

% micromacro

Age in Years

%

38

The highest percentage of macroporosity present is from age 60 and over where at least a

total of 80% of individuals exhibit this feature. A distinct trend does not exist for either the left

or right auricular surface, but shows that macroporosity becomes more prominent after the age

50.

Results of frequencies and percentages for apical changes for the left and right auricular

surfaces are shown in Table 20. Apical changes with correlation to age are illustrated in Figure

10, which indicates that there is a distinct trend showing that from the age of 30+ there is a

decrease in a distinct apical border, with an increase in lipping. After the age of 20 there is a

steady increase in some lipping at the apex. Age 40 is the peak age at which some lipping

occurs, but there remains a steady trend in some lipping to the age of 60+.

Table. 20 Frequencies and Percentages for Apical changes

Age 20-24 Age 25-29 Age 30-34 Age 35-39 Age 40-44 Age 45-49 Age 50-59 Age 60+LEFT

Score (n) % (n) % (n) % (n) % (n) % (n) % (n) % (n) % Totals (n=102)(1) distinct 10 83 11 79 3 27 4 23 2 18 1 10 1 8 0 0 32(2) some lipping 2 17 3 21 8 73 10 59 7 64 8 80 7 54 6 43 51(3) major changes 0 0 0 0 0 0 3 18 2 18 1 10 5 38 8 57 19


RIGHTScore (n) % (n) % (n) % (n) % (n) % (n) % (n) % (n) % Totals (n=102)(1) distinct 10 83 12 80 2 18 3 17.5 1 9 1 10 0 0 0 0 29(2) some lipping 1 8.5 3 20 9 82 11 65 6 55 7 70 7 58 8 57 52(3) major changes 1 8.5 0 0 0 0 3 17.5 4 36 2 20 5 42 6 43 21

102

(n=13) (n=14)

(n=12) (n=15) (n=11) (n=17) (n=12) (n=10) (n=12) (n=14)

(n=12) (n=14) (n=11) (n=17) (n=12) (n=10)

39

Figure 10. Apical changes for the Left Auricular Surface

The left auricular surface shows that a distinct and sharp apex is present in about 80% of

individuals between the ages 20-29. From the age of 30 there is an increase in lipping at the

apex although the articular margin has a distinct shape. The right auricular surface shows that a

distinct and sharp apex is present in 75-87 % of individuals between the ages 20-29.

Table 21 has results of frequencies and percentages for the retro-auricular activity from

the left and right auricular surfaces. Figure 11 shows correlations of retro-auricular activity with

age.

0 102030405060708090

20 30 40 50 60

%

distinct

some lipping

major lipping or irregular border

Age in Years

%

40

Table 21. Frequencies and Percentages for Retro-auricular Activity

Figure 11. Retro-auricular activity for the Left Auricular Surface

Both the left and right auricular surfaces show that the retro-auricular area exhibits signs

of minor activity from the age of 20-29

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