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Determination of sex from the hyoid bone.

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AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 143:279–284 (2010)
Determination of Sex From the Hyoid Bone
Sarah C. Kindschuh,1 Tosha L. Dupras,2* and Libby W. Cowgill2
1
2
Department of Anthropology, Binghamton University, State University of New York, Binghamton, NY 13902-6000
Department of Anthropology, University of Central Florida, Orlando, FL 32816
KEY WORDS
sexual dimorphism; discriminate function analysis; forensic anthropology
ABSTRACT
This article explores size differences
related to sex in the hyoid bones from the Robert J.
Terry Anatomical Collection. A series of measurements
were taken from 398 hyoids, both fused and unfused.
The inclusion of unfused hyoids in the study provides
the opportunity to investigate previously unknown size
differences between sexes as well as to determine their
utility in determining sex. Two-way ANOVA was used to
explore differences in hyoid size as related to ancestry
and sex. Discriminant function analysis was employed to
test the ability of the hyoids to be classified by sex. Six
One of the most common uses of the hyoid in a forensic context is as an indicator of traumatic strangulation.
Previous research has shown, however, that the fused
hyoid is in fact a sexually dimorphic bone and therefore
has the ability to aid the physical anthropologist in the
determination of sex (Jelisiejew et al., 1968; Miller et al.,
1998; Reesink et al., 1999; Kim et al., 2006). Male hyoids
are generally larger than female hyoids in almost all
dimensions, but particularly in total hyoid length and
width (Jelisiejew et al., 1968; Miller et al., 1998). The
hyoid body has also been found to be a sexually dimorphic component of the bone (Reesink et al., 1999), suggesting it may also be useful in the determination of sex.
Three previous studies have used discriminant function analysis with varying degrees of success to develop
a function that could be used to classify a hyoid as male
or female (Miller et al., 1998; Reesink et al., 1999; Kim
et al., 2006). Reesink et al. (1999) used three dimensions
of the body to develop an equation that classified their
sample with an overall accuracy of 76%, while Miller et
al. (1998) obtained similar results with a function using
five measurements, achieving an overall accuracy of
approximately 72%. Most recently, Kim et al. (2006)
used three measurements to produce a function that
resulted in an overall accuracy of 88.2%.
Unfortunately, the three previously mentioned studies,
as well as the majority of previous hyoid research,
focused solely on hyoids that had been recovered at the
time of autopsy and whose preparation included leaving
enough soft tissue in place between the hyoid body and
greater cornua to maintain the overall shape of the
bone. However, if a hyoid is found in an archaeological
or forensic setting, unless the greater cornua are
actually fused to the body, the likelihood of finding a
intact hyoid is significantly decreased due to tissue
decomposition. In fact, of the 398 hyoids used in this
study, all derived from the Robert J. Terry Anatomical
Collection, 229 were unfused with either one or neither
of the greater cornua fused to the body. On the basis of
this random sample of the Terry Collection, the likeliC 2010
V
WILEY-LISS, INC.
discriminant function equations ranging in accuracy
from 82% to 85% are provided, each of which is more
accurate than many of the discriminant functions developed in past hyoid research, are simple to use, and can
be used to estimate the sex of a hyoid regardless of its
state of fusion. In addition to providing further information about the morphological form of the hyoid, these
analyses provide a method that can be easily employed
to assess sex of the individual from the hyoid bone. Am
V 2010 Wiley-Liss,
J Phys Anthropol 143:279–284, 2010.
C
Inc.
hood that an unfused skeletonized hyoid will be recovered is greater than 50%, demonstrating the need for
methods of sexing unfused as well as fused hyoids. The
anatomical reasoning behind why some greater cornua
fuse to the body and others do not is still somewhat
unclear: while some studies have suggested that the incidence of fusion increases with age (O’Halloran and
Lundy, 1987), many hyoids remain unfused through old
age, and there is no significant correlation between sex
and bilateral fusion of the greater cornua to the body
(Miller et al., 1998).
The goals of this research are twofold. First, while
trends in size sexual dimorphism have been documented
in fused hyoids, it remains unclear if similar patterns of
sex differences exist in the unfused elements. This study
addresses this issue directly, by exploring patterns of
hyoid sexual dimorphism in both fused and unfused
hyoids. Second, given the high frequency with which
unfused hyoid elements are found in skeletal samples, an
equation for predicting sex from unfused hyoids may
prove useful for bioarchaeological and forensic researchers. This research presents several discriminant function
equations which are easy to use, practical, and can be
implemented regardless of the state of fusion of the hyoid.
MATERIALS AND METHODS
Materials
All hyoids utilized in this study are part of the
Robert J. Terry Anatomical Collection, housed at the
*Correspondence to: Dr. Tosha Dupras, Department of Anthropology, University of Central Florida, Orlando, FL 32816.
E-mail: tdupras@mail.ucf.edu
Received 25 July 2009; accepted 8 March 2010
DOI 10.1002/ajpa.21315
Published online 27 May 2010 in Wiley Online Library
(wileyonlinelibrary.com).
280
S.C. KINDSCHUH ET AL.
TABLE 1. Breakdown of sample population
Sex
Condition
Female
Unfused
Fused
Number
103
95
Male
Unfused
Fused
126
74
Total
198
200
TABLE 2. Fused and unfused hyoid dimensions (also see Fig. 1)
Dimension
BL
BH
CWI
CHI
CL
CWS
CHS
THL
THW
WCS
Description
Maximum length of body
Maximum height of body
Width of greater cornu at fusion point with
body (inferior end)
Height of greater cornu at fusion point with
body (inferior end)
Maximum length of greater cornu
Greatest width of superior end of greater cornu
Greatest height of superior end of greater cornu
Total hyoid length – maximum length of hyoid,
from anterior surface of the body to the
superior ends of greater cornua
(fused hyoids only)
Total hyoid width – maximum distance between
the widest points of the greater cornua
(not pictured; fused hyoids only)
Total width between the superior ends of the
right and left greater cornua-taken from lateral
edges (fused hyoids only)
Smithsonian Institute’s National Museum of Natural
History in Washington, D.C. For further information
regarding the history and composition of the Terry Collection, refer to Hunt and Albanese (2005). A total of 398
hyoids, 200 males and 198 females, were selected for
measurement (Table 1). Of these, 169 hyoids were fully
fused with both greater cornua fused to the hyoid body,
and 229 were unfused in which only one or neither of
the greater cornua was fused to the body.
In an attempt to develop a sampling population that
was as uniform as possible, the collection was divided by
age, sex, and ‘‘race.’’ Individuals between the ages of 20
and 79 were broken into groups delineated by 10 year
increments, and within these age groups an attempt was
made to obtain 20 hyoids from both black and white
males and females. Unfortunately, some groups within
the Terry Collection are underrepresented, namely white
females below the age of 40, so that less than 20 hyoids
were recovered from individuals within those ranges.
Two sets of measurements were developed and applied
depending on the state of fusion of each hyoid. Each measurement was chosen due to its use in previous hyoid
research (Jelisiejew et al., 1968; Miller et al., 1998; Reesink
et al., 1999; Lekı̂san et al., 2005; Shimizu et al., 2005; Kim
et al., 2006). These measurements were also selected for
their ability to provide an overall assessment of the size of
each hyoid component. These measurements, outlined in
Table 2 and demonstrated in Figure 1a,b, were taken to the
nearest hundredth of a millimeter using standard digital
calipers. To compensate for potential preservation biases
and to maximize the amount of data available for analysis,
both the right and left sides of each hyoid were measured.
Although some fused hyoids did exhibit very faint lines at
the point of fusion between the body and greater cornua,
the majority of lines were either partially open or clearly
American Journal of Physical Anthropology
discernible. Hyoids in which no fusion point between the
body and greater cornua could be detected were not
included in the study. In addition, some hyoids displayed
sporadic bony growths or spicules which could potentially
interfere with the measurement being taken. When present, these growths were excluded from the measurement.
In addition, a random subsample of hyoids was
selected and remeasured in order to quantify intraobserver measurement error. Percent measurement error
for 20 fused and 20 unfused hyoids (equal sex representation in each group) is shown in Table 3. For those
measurements which were taken of both the right and
left sides, the measurements of both sides were pooled
as opposed to calculating the percent error of each individual side. The average amount of error for each measurement was below 5%, suggesting the measurements
can be replicated with a low amount of error.
Statistical methods
A One-Sample Kolmogorov-Smirnov Test confirmed
that the data are distributed normally and therefore
parametric statistical methods were used in this analysis. Box’s M tests were used to test for an equality of covariance among the samples used to develop the discriminant functions. Because Box’s M tests are extremely
sensitive to violations of normality, an alpha level of
0.001 is frequently used (Garson, 2009) and was implemented here. The Box’s M tests did not attain significance, suggesting the covariances are homogeneous, and
that the assumptions of discriminant function analysis
have not been violated.
Several statistical procedures were used to examine
size differences of the hyoids. First, paired samples ttests were used to test for differences in measurements
between the right and left sides of the same hyoid.
Sequentially reductive Bonferroni multiple comparison
tests, which increase the power in detection of more
than one false null hypothesis relative to the standard
Bonferroni technique, were used to adjust the alpha
level in these analyses (Holms, 1979; Rice, 1989).
Second, two-way ANOVA (analysis of variance) was
used to determine the main effects of ancestry and sex
on hyoid form, as it is possible that individuals of European and African ancestry may display different patterns of sexual dimorphism. Therefore, potential interactions between ancestry and sex were explored in order to
determine if separate ancestry-specific discriminant
functions were necessary.
Third, discriminant function analysis was used to develop equations utilizing a combination of measurements
that have the ability to classify a hyoid as either male or
female. Separate functions were developed using both
fused and unfused hyoids. In addition, the likelihood
that an unfused or fragmented hyoid may be recovered
is high, and it is most likely that the body will survive
due to its more dense composition. Therefore, a third
function was developed using the two measurements
taken of the body from unfused hyoids [maximum length
of the body (BL) and maximum height of the body (BH)]
in an attempt to test the usefulness of just the body in
determining sex.
Three sets of discriminant function analyses were performed based on these samples (fused hyoids, unfused
hyoids, and the hyoid body alone). Each analysis was
run twice, once including ancestry as a variable and
once excluding ancestry as a variable, resulting in a
DETERMINING SEX OF THE HYOID
281
Fig. 1. Fused (a) and unfused (b) hyoid measurements. Refer to Table 2 for a description of the measurements that correspond
with each number (total hyoid width (THW) not shown).
TABLE 3. Average percentage of error of fused and unfused
hyoids
Average error
Dimensiona
Fused
Unfused
BL
BH
CWI
CHI
CL
CWS
CHS
THL
THW
WCS
4.72%
2.08%
4.52%
3.01%
2.19%
3.04%
4.44%
1.35%
0.85%
0.40%
0.91%
2.44%
3.58%
3.43%
0.47%
4.70%
4.67%
a
See Table 2 for abbreviations.
total of six discriminant functions. Functions 1–3 include
ancestry as a variable in order to acknowledge and compensate for the potential size differences between ancestries. If the ancestry of the hyoid in question is known,
the coefficient for the ancestry variable is provided
and is simply input into the function. When using
the function to estimate the sex of an individual of
African ancestry a coefficient of 1 is used while the coefficient of 2 is used when estimating the sex of a European individual.
In developing the discriminant functions, the significance of each independent variable in the analysis was
determined using stepwise statistics to find the variables
which set the Wilks’ lambda at a minimum. Once the
stepwise analysis identified which variables were most
valuable in determining sex, a second analysis was performed in which these variables were added independently in addition to ancestry. All statistical tests were
run using SPSS 17.0.
RESULTS
Paired samples t-tests comparing right and left sides
of fused and unfused males and females showed only one
significant difference (the height of the greater cornu at
the fusion point with the body of fused female hyoids).
Although the difference between the right and left sides
at this point is statistically significant (P 5 0.003), the
difference between the average values of each side is still
relatively small (0.2 mm). Given this, and the fact that
the remainder of the analyses failed to attain significance, it seems probable that hyoids only exhibit low levels of asymmetry. This suggests that although the data
used to develop the functions presented here was
recorded according to side, it is not necessary to discrim-
inate between the right and left sides when using the
functions. Therefore, averages of right and left sides are
used in the following ANOVA and discriminant function
analyses. This will allow the user to utilize the functions
when a partial hyoid is recovered or when it is difficult
to distinguish one side from another.
Measurement means and standard deviations for
males and females of both ancestries are shown in
Table 4. The results of the two-way ANOVAs are shown
in Table 5. Sex is a significant main effect on hyoid metrics for all measurements on fused hyoids, and all but
one measurement on unfused hyoids. Ancestry is a significant main effect for four measurements on fused hyoids
and three of the measurements on unfused hyoids. However, several of the two-way ANOVAs show a significant
interaction effect, indicating that the patterns of sexual
dimorphism in the hyoid may differ between individuals
of different ancestries. In all of the cases where a significant interaction effect was detected, individuals of
African descent show lower levels of sexual dimorphism
in the hyoid than individuals of European descent.
As significant interaction effects between sex and
ancestry were detected in the two-way ANOVA, it is useful to include ancestry as a variable in the discriminant
function analyses. For each analysis that was performed,
each step was statistically significant (P \ 0.001) and
the Wilks’ lambda was significant for each function (P \
0.001), suggesting the function is producing significantly
different discriminant scores for each group. High canonical correlations and eigenvalues close to 1.0 indicate
that the distinction ability of the function is high. Functions 1–3 include ancestry as a variable, and the coefficients of 1 and 2 correspond with individuals of African
and European ancestry, respectively. Functions 4–6 were
developed using pooled ancestries samples, and can be
used if the ancestry of the individual is unknown.
Table 6 shows the functions, the condition of the hyoid
in which they are used, their cutoff points, and overall
accuracies. Function 1, developed using fused hyoids,
utilizes the hyoid’s total length, maximum length of the
body, and height of the greater cornu at its fusion point
with the body (inferior end) in addition to ancestry.
Function 2 was developed using complete unfused hyoids
and the variables needed are maximum length of the
body, maximum height of the body, height of the greater
cornu at its inferior end, and ancestry. Function 3 was
developed using only those measurements taken of the
hyoid body and therefore uses only the maximum length
and height of the body in addition to ancestry. Functions
4–6 use the same variables as Functions 1–3, with the
exception of ancestry, and have very similar accuracies.
Accuracies range between 82% and 85% for all functions.
American Journal of Physical Anthropology
282
S.C. KINDSCHUH ET AL.
TABLE 4. Dimension means (mm) and standard deviations for males and females of both ancestries
Fused
Dimensiona
BL
Sex
Mean
Std. deviation
N
Mean
Std. deviation
N
Black
F
M
F
M
F
M
F
M
F
M
F
M
F
M
F
M
F
M
F
M
F
M
F
M
F
M
F
M
F
M
F
M
F
M
F
M
F
M
F
M
F
M
F
M
F
M
F
M
F
M
F
M
F
M
F
M
F
M
F
M
20.29
23.93
22.17
24.55
20.86
24.12
10.79
12.13
10.56
12.11
10.72
12.13
4.02
4.32
4.33
5.01
4.12
4.54
6.73
7.49
6.58
8.35
6.68
7.75
27.23
30.34
26.46
31.27
27.05
30.65
3.21
3.24
2.98
3.55
3.16
3.34
4.20
4.37
4.07
4.90
4.17
4.55
33.51
37.47
31.63
37.87
33.02
37.60
37.21
41.48
41.09
43.97
38.33
42.25
37.84
42.45
42.45
44.51
39.11
43.15
2.47
2.16
2.21
2.69
2.54
2.34
1.31
1.16
1.07
1.21
1.24
1.17
0.69
0.47
0.70
1.05
0.70
0.77
0.99
0.70
0.92
1.17
0.97
0.95
3.24
3.16
3.14
3.30
3.21
3.20
0.56
0.57
0.44
0.74
0.54
0.64
0.85
0.76
0.52
0.91
0.79
0.85
3.58
3.75
3.45
3.40
3.62
3.62
4.06
3.68
4.75
5.28
4.60
4.36
5.42
4.80
6.14
5.88
5.96
5.23
65
51
28
23
93
74
66
51
29
23
95
74
66
51
28
23
94
74
66
51
28
23
94
74
47
33
14
17
61
50
49
35
13
17
62
52
49
35
13
18
62
53
63
48
22
23
85
71
64
49
26
22
90
71
47
35
18
18
65
53
20.30
23.40
21.04
25.11
20.55
24.17
10.87
12.63
10.46
12.25
10.73
12.46
3.78
4.06
3.65
4.59
3.74
4.29
5.95
7.05
5.71
7.18
5.87
7.11
27.55
31.27
28.10
31.37
27.68
31.31
3.15
3.15
3.03
3.21
3.12
3.18
4.19
4.45
4.14
4.46
4.18
4.45
1.90
2.44
1.72
2.02
1.87
2.41
1.09
1.24
1.03
1.12
1.08
1.20
0.58
0.65
0.47
0.74
0.55
0.74
0.76
0.85
0.58
0.81
0.71
0.83
3.01
2.58
2.68
3.17
2.93
2.84
0.46
0.63
0.42
0.79
0.45
0.70
0.66
0.87
0.57
0.90
0.64
0.88
N/A
68
68
35
56
103
124
68
69
35
56
103
125
62
68
30
52
92
120
62
67
30
52
92
119
55
46
17
37
72
83
55
48
18
38
73
86
56
48
18
37
74
85
White
Total
BH
Black
White
Total
CWI
Black
White
Total
CHI
Black
White
Total
CL
Black
White
Total
CWS
Black
White
Total
CHS
Black
White
Total
THL
Black
White
Total
THW
Black
White
Total
WCS
Black
White
Total
a
Unfused
Ancestry
N/A
N/A
See Table 2 for abbreviations.
DISCUSSION
Results from the analysis of the two-way ANOVA reveal
several interesting patterns regarding how hyoid metrics
vary in relation to both ancestry and sex. First, ancestry
was found to be a significant main effect on four measureAmerican Journal of Physical Anthropology
ments taken of fused hyoids and two measurements taken
of unfused hyoids. Among these variables, hyoids of individuals of European ancestry are generally larger than
those of African ancestries. Second, three of the analyses
show significant interactions between ancestry and sex. In
general, hyoids of individuals of African descent display
283
DETERMINING SEX OF THE HYOID
lower levels of sexual dimorphism than hyoids of European
descent. This suggests that whenever possible, ancestry
should be included as a variable when determining sex
based on hyoid morphology. However, as is displayed in
Table 6, the overall accuracy of the functions, which is the
average of the accuracy at which males and females are
correctly classified, changes very little, if at all, when
ancestry is included as a variable. This may be due to the
fact that only one measurement utilized in the functions
(CHI) displays a significant interaction between ancestry
and sex and that this variable actually contributes very little to the sex estimation. When comparing the standarTABLE 5. Results of 2-way ANOVA showing the effects of
ancestry and sex on hyoid measurements
Fused
Dimensiona
BL
BH
CWI
CHI
CL
CWS
CHS
THL
THW
WCS
Sex
Ancestry
Sex-Ancestry
Sex
Ancestry
Sex-Ancestry
Sex
Ancestry
Sex-Ancestry
Sex
Ancestry
Sex-Ancestry
Sex
Ancestry
Sex-Ancestry
Sex
Ancestry
Sex-Ancestry
Sex
Ancestry
Sex-Ancestry
Sex
Ancestry
Sex-Ancestry
Sex
Ancestry
Sex-Ancestry
Sex
Ancestry
Sex-Ancestry
Unfused
F
P
F
56.47
9.77
2.49
50.24
0.38
0.28
17.39
17.95
2.71
65.29
5.06
10.52
33.36
0.01
1.54
5.87
0.09
4.60
8.53
1.37
3.71
64.12
1.35
3.20
23.60
18.64
0.89
9.36
9.39
1.38
\0.001*
0.002*
0.117
\0.001*
0.540
0.597
\0.001*
\0.001*
0.102
\0.001*
0.026*
0.001*
\0.001*
0.909
0.217
0.017*
0.759
0.034*
0.004*
0.245
0.057
\0.001*
0.248
0.076
\0.001*
\0.001*
0.346
0.003*
0.003*
0.243
156.32
18.39
2.90
128.78
6.50
0.02
44.27
4.80
13.49
129.99
0.20
2.69
46.32
0.40
0.19
0.77
0.08
0.74
4.43
0.02
0.05
a
See Table 2 for abbreviations.
* Statistically significant results.
P
\0.001*
\0.001*
0.090
\0.001*
0.011*
0.901
\0.001*
0.030*
\0.001*
\0.001*
0.658
0.103
\0.001*
0.529
0.664
0.383
0.780
0.390
0.037*
0.879
0.830
N/A
N/A
N/A
dized canonical discriminant function coefficients, which
are used to assess each variable’s contribution to the discriminant function, only ancestry (when used) has a lower
input than CHI. For example, in Function 1 CHI has a
standardized coefficient of 0.410 as compared to 0.480 for
total hyoid length and 0.537 for body length. Similar differences are seen in the standardized coefficients of Function
2 and when the ancestry variable is removed in Functions
4 and 5 the distance between CHI and the other variables
increases. This also suggests that while knowing the ancestry of the individual may be helpful it is not particularly
necessary in order to estimate sex.
The discriminant functions also display an interesting
pattern when the accuracies for each sex are compared.
Overall the two functions developed for use on fused hyoids
classify males with higher accuracy than females, while
those functions developed for use on unfused hyoids classify females with higher accuracy than males. Both functions using the hyoid body classify females better than
males. It is possible that in the case of fused hyoids it is easier to classify larger hyoids, which tend to be male. In contrast, the functions developed for unfused hyoids perform
better on smaller elements, which tend to be female.
One of the most important aspects of this research is
that it presents four discriminant functions that were
developed specifically to be used if an unfused hyoid is
recovered. In the past, similar research has primarily
used cadaveric hyoids which were held together with
soft tissue, simulating a fused hyoid regardless of
whether the greater cornua were actually fused to the
hyoid body. While this would provide an idea of the size
and shape of the hyoid while in anatomical position, a
hyoid recovered in a bioarchaeological or forensic context
may be skeletonized or lacking enough tissue to hold the
greater cornua to the body. In this case, formulae developed from fused hyoids that use measurements such as
total length or width of the bone cannot be used and the
ideal method of sex estimation would be to use formulae
developed specifically for use on unfused hyoids. In addition, each of the four functions to be used solely on
unfused hyoids has an overall accuracy of greater than
80% which is significantly higher than the majority of
previously developed discriminant functions.
While differing sample sizes and the use of only complete hyoids may have had some influence on the accuracies of the functions developed in the research previously
mentioned in the introduction, it is also likely that the
method of measurement played a role. For example,
TABLE 6. Discriminant functions for determining sex from unfused and fused hyoids
Function
number
Hyoid
condition
Function 1
Fused
Function 2
Unfused
Function 3
Body only
Function 4
Fused
Function 5
Unfused
Function 6
Body only
Discriminant functions 1–6
D 5 (0.133)(THL) 1 (0.219)(BL) 1 (0.444)(CHI)
1 (20.107)(A) – 12.598
D 5 (0.210)(BL) 1 (0.416)(BH) 1 (0.498)(CHI)
1 (0.118)(A) – 13.047
D 5 (0.311)(BL) 1 (0.498)(BH) 1 (0.027)(A)
– 12.850
D 5 (0.153)(THL) 1 (0.220)(BL) 1 (0.395)(CHI)
– 13.123
D 5 (0.240)(BL) 1 (0.413)(BH) 1 (0.430)(CHI)
– 13.006
D 5 (0.313)(BL) 1 (0.495)(BH) – 12.827
Total
function
accuracy
Accuracy of sexes
84.4%
M: 87.3%; F: 81.9%
20.13
84.3%
M: 80.5%; F: 89.1%
20.092
82.8%
M: 80.6%; F: 85.4%
0.0640
84.4%
M: 87.3%; F: 81.9%
20.0765
85.2%
M: 82.2%; F: 89.1%
20.092
82.8%
M: 80.6%; F: 85.4%
Cutoff
point
0.0715
See Table 2 and Figure 1 for dimensions. ‘‘A’’ refers to ancestry (African 5 1, European 5 2). Values above cutoff points are males,
values below are females.
American Journal of Physical Anthropology
284
S.C. KINDSCHUH ET AL.
Miller et al. (1998) and Reesink et al. (1999) radiographed
each hyoid and then took measurements from the images,
while Kim and colleagues (2006) digitally photographed
each bone and then took measurements from the photograph. Taking measurements from a radiograph or photograph can be problematic due to dimensional distortion
resulting from the angle at which the photograph was
taken, the presence of soft tissue, and the bone density of
each hyoid (Lekı̂san et al., 2005). Because these studies
were performed using cadaveric sample populations in
which tissue was removed from the bone before the image
was taken, there is the possibility that a small amount of
remaining tissue could alter the measurement taken from
the image. Similarly, differences in bone density may alter
the measurement if some portions of the bone do not show
up on the radiograph.
In addition, the use of imagery to take measurements
has led to the taking of measurements which are not
readily available to one without the use of this technology. For example, the discriminant function developed by
Kim and colleagues (2006) utilizes three measurements,
one of which is the ‘‘distance from the narrowest segment of the greater horn to a point equidistant between
the distal and proximal ends of the greater horn, measured through the central axis of the greater horn on the
right’’ (981). Unfortunately this would be a very difficult
and time consuming measurement to take, particularly
if the only equipment available was a set of calipers.
Because a physical anthropologist attempting to determine sex from a hyoid will likely not have the resources
or time, especially if they are in the field, to radiograph
or photograph the bone and take measurements from
the image, it is important to use methods that can be
easily replicable whether in a lab or field setting. In light
of these concerns, the simplest and likely most accurate
method of data collection is that used in this study.
One possible limitation of this study is the representa_can, 1983), and the hyoids used
tiveness of the sample (Is
to develop the discriminant functions in this analysis may
not be comparable in size and shape to those in modern
populations. This issue of representativeness is one that is
common in metric studies based on the Terry Collection
and as such the user of the discriminant functions should
be aware of possible discrepancies between the size and
shape of the individual in question and those remains in
the Terry Collection. The functions presented here should
be used in conjunction with other methods of sexing whenever possible. However, studies such as Albanese et al.
(2008) have achieved success in developing metric methods of determining sex using the Terry Collection and testing those methods on independent samples outside the
collection. Although the functions presented here have not
been tested on an outside population so that their ability
to classify hyoids outside the Terry Collection is still
unknown, it is believed that the functions can be useful in
both modern and archaeological contexts. While the exact
frequency of hyoid recovery is unknown and is strongly
dependent upon numerous taphonomic factors, should a
hyoid be recovered it is believed that these functions can
contribute to the sex estimation of the individual.
CONCLUSION
The analysis of hyoid morphology presented here supports previous findings of sexual dimorphism in fused
hyoids. In addition, this study has established the presence of sexual dimorphism in unfused hyoids. Although
American Journal of Physical Anthropology
recovering a hyoid in multiple elements does not allow for
an idea of the overall size of the bone, size differences
between males and females of the individual elements are
significant enough to allow for differentiation between the
two sexes. The development of four discriminant functions
that can be used to sex an unfused hyoid, will allow for
sex estimations to be performed on an unfused hyoid,
even if the only available element is the body.
Sex determination of an individual is often performed
using a limited collection of skeletal elements, particularly
within a bioarchaeological setting, prompting the development of methods to determine the sex of bones that may
not normally be considered as useful in the process of
developing a biological profile. The hyoid is rarely if ever
considered to be a bone that can aid in sex estimation.
However, this study has determined the presence of considerable sexual dimorphism in both fused and unfused
hyoids and has produced six discriminant functions that
can be used within multiple scenarios and which utilize
measurements that can be quickly and easily reproduced.
This will provide the physical anthropologist with the opportunity to make use of every skeletal element present
when assessing the sex of an individual.
ACKNOWLEDGMENTS
The authors thank Dr. David Hunt and the Smithsonian’s National Museum of Natural History for allowing
access to the hyoids of the Terry Collection. Special thanks
also to Dr. Chris Ruff and the anonymous reviewers who
helped to make this a stronger manuscript.
LITERATURE CITED
Albanese J, Eklics G, Tuck A. 2008. A metric method for sex
determination using the proximal femur and fragmentary hipbone. J Forensic Sci 53:1283–1288.
Garson, DG. 2009. Multivariate GLM, MANOVA, and MANCOVA, from Statnotes: Topics in Multivariate Analysis.
Retrieved on 10/09/2009 from http://faculty.chass.ncsu.edu/
garson/pa765/statnote.htm.
Holms S. 1979. A simple sequentially reductive multiple test
procedure. Scand J Stat 6:65–70.
Hunt DR, Albanese J. 2005. History and demographic composition of the Robert J. Terry Anatomical Collection. Am J Phys
Anthropol 127:406–417.
_can Y. 1983. Assessment of race from the pelvis. Am J Phys
Is
Anthropol 62:205–208.
Jelisiejew T, Jaroslaw S, Kuduk I. 1968. Morphologic studies on
the hyoid bone in man. Folia Morphol 27:172–182.
Kim D-I, Lee U-Y, Park D-K, Kim Y-S, Han K-H, Kim K-H, Han
S-H. 2006. Morphometrics of the hyoid bone for human sex
determination from digital photographs. J Forensic Sci
51:979–984.
Lekı̂san I, Marcikić M, Nikolić V, Radić R, Selthofer R. 2005.
Morphological classification and sexual dimorphism of hyoid
bone: new approach. Coll Antropol 29:237–242.
Miller KWP, Walker PL, O’Halloran RL. 1998. Age and sexrelated variation in hyoid bone morphology. J Forensic Sci
43:1138–1143.
O’Halloran RL, Lundy JK. 1987. Age and ossification of the hyoid
bone: forensic implications. J Forensic Sci 32:1655–1659.
Reesink EM, Van Immerseel AAH, Brand R, Bruintjes TJD.
1999. Sexual dimorphism of the hyoid bone? Int J Osteoarchaeol 9:357–360.
Rice WR. 1989. Analyzing tables of statistical tests. Evolution
43:223–225.
Shimizu Y, Kanetaka H, Kim Y, Okayama K, Kano M, Kikuchi
M. 2005. Age-related morphological changes in the human
hyoid bone. Cells Tissues Organs 180:185–192.
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