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Comparative study of mesiodistal crown diameters and arch dimensions between indigenous British and Pakistani immigrant populations.

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AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 72:479-483 (1987)
Comparative Study of Mesiodistal Crown Diameters and Arch
Dimensions Between Indigenous British and Pakistani
Immigrant Populations
D. RADNZIC
Orthodonic Department, University of Lee& Dental Hospital,
Leeds, England
KEY WORDS
Arch width, Arch length, Arch perimeter
ABSTRACT
Over the last two decades, the United Kingdom has seen a n
increase in the number of immigrants from the Indian subcontinent, mainly
Pakistan. The amount of information that is available regarding parameters
such as mesiodistal crown diameters and dental arch dimensions is, however,
somewhat limited for this population.
An investigation was carried out to compare corresponding mesiodistal crown
diameters and arch dimensions between samples of the indigenous British
population in Leeds (England) and the Pakistani immigrant population living
in Rochdale (England). Measurements were taken from dental casts.
The results showed that there were no significant differences between the
two ethnic groups in corresponding mesiodistal crown diameters or arch dimensions. Data are provided for the Pakistani immigrant population in Britain.
Differences in mesiodistal crown diameters
and dental arch dimensions between the major ethnic groups (Australoid, Caucasoid,
Mongoloid, and Negroid) have been extensively studied (Moorrees, 1957; Barrett et al.
1963, 1965; Moss et al. 1967; Barrett and
Brown, 1968; Lavelle, 1970, 1972a, b; Grewe,
1970; Lavelle et al., 1970, 1971; Doran and
Freedman, 1973; Mack, 1981). These investigators have shown that there are differences
in corresponding mesiodistal crown diameters and arch dimensions between the various ethnic groups (as measured on dental
casts), but they are of a variable nature and
are often smaller than the differences between the sexes in any one population.
Subgroups, of course, exist within these
major ethnic groups, but these do not appear
to have been investigated as extensively. Although much data are available for certain
ethnic groups such as Australian Aborigines
and Anglo-American Caucasians, less are
available for ethnic groups from the Indian
subcontinent, and none was available for
Pakistani immigrants living in Great Britain.
A large number of Pakistani immigrants
have settled in the United Kingdom over the
previous two decades, principally in the mill
(c)
1987 ALAN R. LISS, INC.
towns of the north. In view of this, it was felt
that a n investigation was necessary to provide information about some aspects of crown
sizes and dental arch dimensions in the Pakistani immigrant population as a n addition
to the literature on comparative odontology.
MATERIALS AND METHODS
A total of 60 pairs of dental casts taken
from indigenous British males in Leeds and
60 pairs of casts taken from Pakistani immigrant males living in Rochdale were measured. Ages ranged from 13 years to 15 years
11 months. The samples were chosen at random from a larger sample in each group that
had met the selection criteria. Ethnic origins
were determined from school records, clinical
(medical) records, and from records used in
previous epidemiological studies. The investigation was limited to male children of the
aforementioned age range for no other rea-
Received August 4, 1986; revision accrpted Octoher 22. I986
This study w as carried out in partial fulfilment of t h e requirements for t h e degree of M.D.Sc while working in t h e Orthodontic Department of t h e Uiiiversity of' Leeds Dental Ilospital.
England.
480
n. RADNZIC
son than availability. The selection criteria
were a s follows:
1. All permanent teeth were present in each
arch (excluding second and third molars) and
in a sufficient state of eruption to permit
measurement of the mesiodistal crown
diameter.
2. There was no previous orthodontic treatment involving the permanent dentition in
either arch.
3. There were no large coronal restorations
that might have altered both coronal shape
and size.
4. Dental casts were undamaged in areas
of measurement.
For each pair of casts, the following parameters were recorded in each arch:
1.Mesiodistal crown diameters
2. Arch widths
3. Arch length
4.Arch perimeter.
The measurements were repeated for each
cast, with a minimum period of 1 week between repeated measurements. The method
of making the measurements will now be
described.
Mesiodistal crown diameter
The greatest distance between interproxima1 contact points was measured for individual teeth in each arch, up to and including
the first permanent molars. Measurements
were made using a vernier gauge (Homer,
West Germany) to the nearest 0.1 mm, with
the blades of the caliper held perpendicular
to the long axis of the crown (Howe et al.,
1983) and parallel to its occlusal and vestibular surfaces.
Arch widths
Two dimensions of arch width were used:
1.Interincisal width, that is, the maximum
distance between distal surfaces of lateral
incisors
2. Mean intermolar width as calculated
from values obtained for buccal and lingual
intermolar widths.
Both buccal and lingual intermolar dimensions were measured from the point of intersection of the gingival margin with a n
extension gingivally of the buccal and lin-
Fig. 1. Points of measurement of arch widths.
gual fissures of the first permanent molars.
Measurements were made using a vernier
caliper (Homer, West Germany) to the nearest 0.1 mm. (Fig. 1).
Arch length
The measurement of arch length was accomplished on each cast using a n engineering depth gauge (Moore and Wright,
Sheffield, England), rounding up or down to
the nearest millimeter.
For the present study, arch length was defined as the length of a perpendicular line
from the contact point between the permanent central incisors to a line joining the
distal surfaces of the first permanent molars
(Fig. 2). Incidentally, the point of intersection
of these two lines was found to be within a
range of 2 mm either side of the midline in
all the dental casts used in the study.
Arch perimeter
This was calculated using a modification of
the formula suggested by Mills and Hamilton (1965):
arch perimeter
where x
=
=
J
2 y” -t :4
arch length, but substituting:
Y =
mean intermolar width
2
481
CROWN AND ARCH SIZES IN BRITISH VERSUS PAKISTANIS
crowns rather than their buccal extremities
(Radnzic, 1985).It was felt that this method
was more rapid and capable of giving more
reproducible results than direct measurements on the casts.
In order to minimize random and systematic errors, all measurements were performed by a single observer, as suggested by
Hunter and Priest (1960).All casts were then
remeasured, in a random order, with an intervening period of a t least a week in order
to eliminate any possibility of memory bias.
Random and systematic intraobserver errors
were studied as part of a larger investigation
(Radnzic, 19851, but were not found to be
statistically significant (at P < 0.01).
Fig. 2. Arch length measurement,
RESULTS
Mean values for individual mesiodistal
crown diameters, arch widths, arch lengths,
and arch perimeters together with variances
instead of:
were recorded for maxillary and mandibular
arches in both ethnic groups. Student’s ‘Y’
buccal intermolar width
Y =
tests
were carried out in order to compare
2
the sample means in each group. The results
for maxillary arches are presented in Table
a s suggested by Mills and Hamilton.
1and for mandibular arches in Table 2.
No statistically significant differences beThis gives a value for arch perimeter as tween the groups were observed (at P < 0.01)
the length of a line passing through the buc- in corresponding mesiodistal crown diamecolingual centers and incisal edges of the ters or arch dimensions.
TABLE 1. Comparison
of m e a n values between the two ethnic population
sarnples-maxillary dental arches ( N = 60)
Parameter
Indigenous group
Mean
Variance
(mm)
estimate
I m m i g a n t group
Mean
Variance
(mm)
estimate
“t”
value*
Crown s u e
ti?
15
Li
t3
12
II
I_]
zi
!XI
4-1
ZI
!u
Arch length
Intermolar
arch width
Interincisal
arch width
Arch perimeter
10.69
6.91
7.09
8.04
6.87
8.97
8.98
6.86
8.12
7.13
6.96
10.70
39.07
45.26
0.39
0.21
0.14
0.18
0.31
0.31
0.30
0.37
0.18
0.16
0.21
0.34
12.06
14.19
10.65
6.92
7.24
8.10
7.07
8.86
8.86
7.05
8.12
7.27
6.95
10.63
39.62
44.78
0.37
0.21
0.27
0.20
0.29
0.26
0.29
0.31
0.20
0.29
0.18
0.35
14.51
8.07
0.346 NS’
0.130 NS
1.897 N S
0.679 NS
2.012 NS
1.163 NS
1.197 NS
1.806 N S
0.038 NS
1.607 NS
0.148 NS
0.717 NS
0.826 NS
0.796 NS
27.55
7.14
28.24
7.13
1.417 N S
105.10
44.67
105.08
49.94
1.354 NS
”Level of significance: P < 0.01
INS. not significant.
482
D. RADNZIC
TABLE 2. Comparison of mean values between the two ethnic population samples--mandibular dentul urches
(N = 60)
Parameter
Indigenous group
Mean
Variance
--___
(mm)
estimate
..
Immigrant group
Mean
Variance
(mm)
estimate
“t”
value*
Crown size
6
6
R
B
Iz
ri
il
3
3l
zl
3-l
a
Arch length
Intermolar
arch width
Interincisal
arch width
Arch perimeter
11.23
7.35
7.32
7.25
6.15
5.56
5.53
6.12
7.21
7.31
7.35
11.24
33.75
43.82
0.47
0.19
0.16
0.16
0.13
0.12
0.10
0.11
0.13
0.15
0.18
0.45
7.17
9.04
11.12
7.36
7.34
7.19
6.11
5.55
5.57
6.12
7.18
7.28
7.43
11.08
33.57
43.18
0.30
0.15
0.29
0.25
0.14
0.10
0.11
0.11
0.22
0.23
0.19
0.31
6.89
5.81
1.029 NS’
0.145 NS
0.209 NS
0.666 NS
0.636 NS
0.147 NS
0.572 NS
0.033 NS
0.471 NS
0.361 NS
1.016 NS
1.415 NS
0.378 NS
1.280 NS
21.64
3.92
21.31
2.44
1.014 NS
95.58
31.47
94.12
25.77
1.501 NS
*Level of sipificance: P < 0 01
INS, not significant.
DISCUSSION
The mean values obtained for the indigenous British population sample were in
agreement with other workers (Lavelle, 1970,
1972a,b; Lavelle et al., 1970, 1971; Mack,
1981).There were no previous data available
for the Pakistani immigrant population living in the United Kingdom; therefore, it can
only be assumed, until proven otherwise, that
the present findings are representative of
Pakistani male children in Britain.
The results showed no statistically significant differences in corresponding mesiodistal
crown diameters or arch dimensions between
the Asian and non-Asian groups. This was
not entirely unexpected, as the indigenous
British and Pakistanis are essentially of the
same ethnic root stock. Also, one cannot entirely discount the possibility of influences
such as racial interbreeding and environmental factors such as diet (Moore et al. 1968)
in accounting for the similarities, although
there was no direct evidence for this in the
present study.
Racial interbreeding is unlikely among the
Pakistanis in view of the strict customary
attitudes towards mixed marriages. There is,
however, a greater likelihood of racial intermixing in the indigenous British population
due to changing attitudes and the advent of
the multicultural society.
Regarding diet, there is no firm evidence
to suggest that the dietary backgrounds of
the two samples studied were in any way
different. One may argue that if any Pakistani immigrants used in the sample had
come from the poorer rural areas of Pakistan,
then they might have existed on coarser,
more abrasive diets, which would consequently have led to greater dental attrition,
particularly affecting the occlusal and interproximal surfaces of the teeth and leading to
a reduction in their mesiodistal crown diameters. The results of the present investigation do not support this, although it is a
situation that is frequently seen in human
skulls imported from the Indian subcontinent for use by medical students.
Incidentally, no significant differences were
observed in either ethnic group in tooth sizes
between left and right sides of the dental
arches. These findings accord with those of
Lavelle and Plant (1969) but not with Ballard (1944).
ACKNOWLEDGMENTS
I am most grateful to Mr. J.F. Gravely,
senior lecturer in Orthodontics, University
of Leeds Dental Hospital, for his advice and
CROWN AND ARCH SIZES IN BRITISH VERSUS PAKISTANIS
guidance during the investigation, and also
to Mr. A.J. Doyle, district dental officer,
Rochdale District Health Authority, for provision of materials and facilities.
LITERATURE CITED
Ballard, ML (1944) Asymmetry in tooth size: A factor in
the etiology, diagnosis and treatment of malocclusion.
Angle Orthod. 14:67-70.
Barrett, MJ, Brown, T, and MacDonald, MR (1963) Dental observations on Australian Aborigines: Mesiodistal
crown diameters of permanent teeth. Aust. Dent. J.
8:150-155.
Barrett, MJ, Brown, T, and MacDonald, MR (1965) Size
of dental arches in a tribe of Central Australian Aborigines. J. Dent. Res. 44t912-920.
Barrett, MJ, and Brown, T. (1968)Relations between the
breadth and depth of dental arches in a tribe of Central
Australian Aborigines. Aust. Dent. J. 13:381-386.
Doran, GA, and Freedman, L (1973) Metrical features of
the arches and dentition of populations from Goroka
and Lufa, Papua New Guinea. J. Anat. 116:482.
Grewe, JiV(1970)Intercanine width variability in American Indian children. Angle Orthod. 40:353-358.
Howe, RP, McNamara, JA, and O’Connor, KA (1983) An
examination of dental crowding and its relationship to
tooth size and arch dimension. Am. J. Orthod. 83:363373.
Hunter, WS, and Priest, WR (1960) Errors and discrcpancies in measurement of tooth size. J. Dent. Res.
39:405-414.
Lavelle, CLB, and Plant, CG (1969) Comparison between
the right and left sides of the dental arch. J. Dent. Res.
48:971.
483
Lavelle, CLB (1970) Crowding and spacing within the
human dental arch of different racial groups. Arch.
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Lavelle, CLB, Flinn, RM, Foster, TD, and Hamilton, MC
(1970) Differences in growth of the dental arch in some
“races” of man. J. Anat. 107:182-183.
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arches in various ethnic groups. Angle Orthod. 41:293299.
Lavelle, CLB (1972a) Secular trends in different racial
groups. Angle Orthod. 4219-25.
Lavelle, CLB (1972b) Maxillary and mandibular tooth
size in different racial groups and in different occlusal
categories. Am. J. Orthod. 61:29-37.
Mack. PJ (1981) Maxillarv arch and central incisor dimensions in a Nigerian and British population sample.
J. Dent. 9:67-70.
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studies of malalignment, a method of computing dental arch circumference. Angle Orthod. 35:244-248.
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study of dental characteristics in an Eskimoid people.
Cambridge, Massachusetts: Harvard University Press
p. 257.
Moss, ML, Chase, PS, and Howes, RI (1967)Comparative
odontometry of the permanent postcanine dentition of
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University (England).
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