Advances in Anthropology
2014. Vol.4, No.1, 1-6
Published Online February 2014 in SciRes (http://www.scirp.org/journal/aa) http://dx.doi.org/10.4236/aa.2014.41001
Sexual Dimorphism and Tooth Size Variation in the Permanent
Dentition of the Uva Bintenna Veddas of Sri Lanka
Thushari H e wapathira na 1, Roshan Peiris1, Deepthi Nanayakkara1,
Malkanthi Chandrasekara2, Eugine Wikramanayake2
1Department of Basic Sciences, Faculty of Dental Sciences, University of Peradeniya, Peradeniya, Sri Lanka
2Department of Anatomy, Faculty of Medicine, University of Peradeniya, Peradeniya, Sri Lanka
Received October 14th, 2013; revised November 16th, 2013; accepted December 13th, 2013
Copyright © 2014 Thushari Hewapathirana et al. This is an open access article distributed under the Creative
Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium,
provided the original work is properly cited. In accordance of the Creative Commons Attribution License all
Copyrights © 2014 are reserved for SCIRP and th e ow n er of th e in tellectual p rop erty Thush ari Hewap ath irana et
al. All Copyright © 2014 are guarded by law and by SCIRP as a guardian.
Forty-eight dental casts (37 males, 11 females) of Uva Bintenna Veddas were the population. Mesiodistal
(MD) and buccolingual (BL) diameters were measured and analyzed for sexual dimorphism and size
variation. In males, MD of maxillary canines and mandibular first molars were significantly greater at p <
0.01 and maxillary first molars and mandibular second molars at p < 0.05. Crown area was significantly
greater at p < 0.01 for maxillary and mandibular first molars. Crown module was significantly greater at p
< 0.01 for mandibular first molars and at p < 0.05 for maxillary first premolars, first molars and mandibu-
lar second molars. Maxillary canines, maxillary first molars and mandibular canines were the most sex
ually dimorphic. First tooth of each tooth class I1, P1, and M1 showed least variability in both arches and
in both sexes. In males, both MD and BL showed high variability in maxillary lateral incisors and man-
dibular second premolars.
Keywords: Uva Bintenna Veddas; Sexual Dimorphism; Size Variation; Crown Diameters; Permanent
Teeth
Introduction
The earliest account of the existence of, habitations, life style,
language and religious ceremonies of the Veddas of Sri Lanka
was by Knox (1681). However, the scientific study of their
physical anthropology had to await the publications of Virchow
and the Sarasins two centuries later in 1886 (Virchow, 1886;
Sarasin & Sarasin, 1886). After a lapse of another fifty years
Osman Hill, Professor of Anatomy, Ceylon Medical College
initiated his studies on personally identified Veddas (Hill,
1932). The somatometry, craniometry and the variations of the
dentition have been reported (Hill, 1945).
Meanwhile, from 1937-1939, the anthropological and anth-
roposcopic data for the Ethnological Survey of Ceylon was
collected by H. R. de la Haule Marett an assistant in Ethnology,
Colombo Museum. The Veddas were identified by their Wa-
riges (clan names). Marett regarded the Veddas with the Sinha-
lese and Tamils as the primary ethnic groups of Sri Lanka. Ma-
rett had included variation in the dentition. After the untimely
death of Marett, the data was analyzed and published as the
Physical Anthropology of Ceylon (Stoudt, 1961). The Vedda
country had been divided geographically into a northern Tam-
mankaduwa and a southern Binntenne, with Binntenne further
subdivided into Uva Binntenne in the west and Wellassa in the
east. The Uva Binntenne Veddas were clustered in Kandegan-
vila and Dambana (Hill, 1941).
Following on the footsteps of Hill, a team of researchers
from the University of Peradeniya commenced a comprehen-
sive longitudinal biometric study of the genetics, somatometry,
nutrition, oral health and dentition of the Uva Binntenne Ved-
das of Kandeganvila from 1971-1973. As these Veddas had
been colonized in 1958, the field studies could be organized at
the level of identified households. For the first time in Vedda
studies, three-generation pedigrees were compiled for the dif-
ferent Wariges. Veddas of Vedda matings of at least three gen-
erations identified from these pedigrees were the research pop-
ulation. The results of the first phase have been published, the
genetics (Ellepola & Wikramanayake, 1986; Hanihara et al.,
1988), secular trends in physical anthropology (Wikrama-
nayake & Wikramanayake, 1992), oral disease patterns and
tooth wear (Pathmanathan & Wikramanayake, 1993), and body
mass index (Wikramanayake et al., 1994). This research was
reviewed later (Wikramanayake, 2002).
With the declaration of the traditional hunting grounds of the
Uva Binntenne Veddas as a National Park in 1982, the Kande-
ganvila Veddas were relocated in Hennanigala South of the
Mahaweli Irrigation System C. In the second phase of the study
from 1993-1996, it was decided to study the Uva Binntenne
Veddas in the two different locations, those of Kandeganvila in
their relocated households in Hennanigala and those of Dam-
bana in their traditional habitat. Figure 1 gives a map of the
Vedda country with the three locations studied Kandeganvila
(1971-1973) and Hennanigala and Dambana (1993-1996) un-
derlined. At Hennanigala, somatometry, nutrition, oral health
OPEN ACCESS 1

T. HEWAPATHIRANA ET AL.
Figure 1.
The location of Vedda settlements (three locations studied are underlined).
2

T. HEWAPATHIRANA ET AL.
and dentition were repeated. Additionally craniometry and
blood pressure measurements were included. At Dambana,
three-generation pedigrees of the different Wariges were com-
piled. As in the first phase, Veddas identified from these pedi-
grees as those from Vedda matings were the research popula-
tion for the biometry both at Hennanigala and Dambana.
Additionally, at Dambana alginate impressions of the denti-
tion of Veddas were made in the field with informed consent.
The present study based on these dental casts investigates the
sexual dimorphism and tooth size variation of the permanent
dentition of the Uva Bintenne Veddas of Dambana living in
their traditional hunter-gatherer habitat. This is the first report
of the dentition from in Sri Lanka.
Materials and Methods
The forty-eight dental casts, 37 from males (age range 17 -
70 years) and 11 from females were measured and analyzed.
Measurements were done only if teeth were morphologically
normal, fully erupted, and not noticeably affected by attrition or
cavities. The selected teeth of both upper and lower arches of
the left side were measured to the nearest 0.01 mm using a di-
gital caliper. When a tooth on the left side could not be meas-
ured because of absence, abnormality or heavy wear the cor-
responding tooth on the right side was measured. The measure-
ments of the mesiodistal (MD) and buccolingual (BL) crown
diameters were made according to Fujita (1949). For the deter-
mination of measurement errors, thirty casts were selected at
random three months later. Measurements were redone on these
casts and an analysis of error was done according to the method
of Dahlberg (1940). Using the equation, Error = d2/2N (d =
difference between two determinations, N = number of double
determinations). The measurement errors ranged from 0.04 mm
to 0.11 mm. As these were small values compared with the
means, no effect on the statistical analysis was expected. Using
the MD and BL diameters the following indices, crown index,
crown area and crown module were also calculated for the
posterior teeth. Crown index = MD/BL × 100, Crown area =
MD × BL, Crown module = MD + BL/2.
Results
Table 1 gives the results of the MD diameters of the mandi-
bular and maxillary permanent dentition and Table 2 gives the
results of their BL diameter. Both maxillary and mandibular
teeth of males were greater in MD and BL diameters than those
of females except for the MD of the mandibular central incisor
and BL of the mandibular lateral incisor. The differences were
significant at p < 0.01 for MD of maxillary canines and mandi-
bular first molar and at p < 0.05 for MD of maxillary first molar,
maxillary canine, mandibular second molar, BL of maxillary
canine, maxillary first and second molar, and the mandibular
first molar. The coefficients of variation were taken as indica-
tors of trends in the relative variability of tooth size. In each
arch the first molar was the least variable tooth in both MD and
BL diameters. There was no clearly defined pattern of relative
variability in the MD and BL diameters in either sex. In the
males, both MD and BL of the maxillary lateral incisor and
mandibular second premolar showed high variability. In the
females, variability was randomly distributed.
Table 3 gives the crown index, Table 4 the crown area and
Table 5 the crown module of the maxillary and mandibular
premolars and molars (first and second). All the indices were
greater in males. The differences were significant at p < 0.01
Table 1.
Mesiodistal diameters for permanent teeth of mandibular and maxillary teeth of the study.
Male Female Sex difference
N Mean SD Coefficient of variation N Mean SD Coefficient of variation
Maxillary I1 25 8.06 0.65 8.06 12 8.06 0.62 7.69
I2 27 6.61 0.54 8.16 11 6.37 0.39 6.12
C 29 7.50 0.52 6.93 13 6.95 0.46 6.61 **
P1 31 6.81 0.47 6.90 13 6.54 0.65 9.93
P2 31 6.42 0.56 8.72 13 6.11 0.55 9.00
M1 31 10.14 0.52 5.12 13 9.72 0.67 6.89 *
M2 31 9.27 0.70 7.55 13 8.96 0.91 10.47
Mandibular I1 23 5.06 0.46 9.09 11 5.27 1.12 21.25
I2 24 5.73 0.43 7.50 10 5.38 0.69 12.82
C 30 6.58 0.30 4.55 12 6.28 0.61 9.71 *
P1 31 6.71 0.48 7.15 13 6.59 0.32 4.85
P2 31 6.75 0.65 9.62 12 6.61 0.76 11.49
M1 29 10.93 0.58 5.30 12 10.09 0.75 7.43 **
M2 30 10.11 0.71 7.02 12 9.41 0.96 10.20 *
Note: *p < 0.05; **p < 0.01.
OPEN ACCESS 3

T. HEWAPATHIRANA ET AL.
Table 2.
Buccolingual diameters for permanent teeth of mandibular and maxillary teeth of the study.
Male Female Sex difference
N Mean SD Coefficient of variation N Mean SD Coefficient of variation
Maxillary I1 25 7.10 0.66 9.29 12 6.91 0.78 11.28
I2 27 6.45 0.74 11.47 11 6.02 0.52 8.63
C 28 7.86 0.51 6.48 13 7.41 0.57 7.69 *
P1 31 8.76 0.60 6.84 13 8.39 0.57 6.79
P2 31 8.53 0.75 8.79 13 8.45 0.89 10.53
M1 31 10.73 0.67 6.24 13 10.18 0.77 7.56 *
M2 31 10.39 0.78 7.50 13 9.73 1.20 12.33 *
Mandibular I1 25 5.98 0.53 8.86 12 6.02 0.89 14.78
I2 25 6.28 0.62 9.87 10 6.41 0.99 15.44
C 30 7.26 0.52 7.16 12 7.07 1.12 15.84
P1 31 7.49 0.53 7.07 13 7.16 1.00 13.96
P2 31 7.68 0.66 8.59 12 7.39 1.08 14.61
M1 29 10.14 0.49 4.83 12 9.63 0.87 9.03 *
M2 30 9.68 0.63 6.50 12 9.31 1.04 11.17
Note: *p < 0.05; **p < 0.01.
Table 3.
Crown index of the permanent prem olars and molars of the study populat ion.
Male Female
N Mean Standard devi ation Coefficient of variation N Mean Standard deviation Coefficient of variation
Maxillary P1 31 79.01 7.76 9.82 13 78.14 6.52 8.34
P2 31 75.82 5.65 7.45 13 72.65 7.15 9.84
M1 31 94.76 5.82 6.14 13 95.68 6.73 7.03
M2 31 89.81 8.93 9.94 13 93.20 14.19 15.22
Mandibular P1 31 89.40 7.86 8.79 13 92.30 11.31 12.25
P2 31 88.29 9.13 10.34 12 90.88 15.58 17.14
M1 29 107.53 6.02 5.59 12 105.36 8.43 8.00
M2 30 104.49 4.07 3.89 12 101.92 12.1 11.87
for crown area and crown module of mandibular first molar and
at p < 0.05 for crown area and crown module of maxillary first
premolar, maxillary first molar and mandibular second molar.
In both males and females, crown index and crown module of
the first premolar and the first molar were greater than that of
the second premolar and second molar respectively.
In males, in both dentitions the crown index and crown mod-
ule of the first molar was significantly greater than that of the
second in the maxilla at p < 0.01 and mandible at p < 0.05.
Additionally the crown module of the maxillary first premolar
was significantly greater than the second at p < 0.05. The crown
area was greater in the first molar than that of the second molar
in both dentitions with the maxilla at p < 0.01 and the mandible
at p < 0.05. Variability in the indices was not analyzed statisti-
cally in the females.
Discussion
The present study deals with 48 dental casts (37 male and 11
female) of adult contemporary Uva Bintenne Veddas of Sri
Lanka. The subjects were identified from Vedda matings of at
least three generations and had normal occlusion.
The MD and BL crown diameters of both maxillary and
mandibular teeth except the third molars were measured on the
left side. Using the crown diameters the crown index, crown
area and crown module of the premolars and first and second
4

T. HEWAPATHIRANA ET AL.
Table 4.
Crown area of the permanent prem olars and molars of the s tudy population.
Male Female
N Mean Standard deviation Coefficient of variation N Mean Standard deviation Coefficient of variation
Maxillary P1 31 60.72* 8.99 14.80 13 55.08 8.09 14.68
P2 31 55.33 8.54 15.43 13 51.98 9.02 17.35
M1 31 108.96* 10.72 9.83 13 99.48 12.80 12.86
M2 31 96.92 12.51 12.90 13 87.73 17.35 19.77
Mandibular P1 31 50.20 6.31 12.56 13 48.05 7.73 16.08
P2 31 52.05 7.91 15.19 12 49.14 10.32 21.00
M1 29 110.78** 9.34 8.43 12 97.66 13.72 14.04
M2 30 98.33* 13.08 13.30 12 88.08 14.92 16.93
Note: Statistica lly significant difference between ma le and fem ale is denot ed by *. *p < 0.05; **p < 0.01.
Table 5.
Crown module of the permanent premolars and molars of the study populat ion.
Male Female
N Mean Standard deviation Coefficient of variation N Mean Standard deviation Coefficient of variation
Maxillary P1 31 7.83* 0.56 7.15 13 7.46 0.54 7.23
P2 31 7.49 0.59 7.87 13 7.28 0.64 8.79
M1 31 10.43* 0.50 4.79 13 9.96 0.65 6.52
M2 31 9.58 0.62 6.47 13 9.34 0.91 9.74
Mandibular P1 31 7.09 0.44 6.20 13 6.93 0.58 8.36
P2 31 7.21 0.55 7.62 12 7.00 0.76 10.85
M1 29 10.52** 0.44 4.18 12 9.86 0.71 7.20
M2 30 9.90* 0.65 6.56 12 9.36 0.83 8.86
Note: Statistica lly significant difference between ma le and fem ale is denot ed by *. *p < 0.05; **p < 0.01.
molars were calculated. The results were analyzed for sexual
dimorphism and size variation of the dentition.
The MD and BL diameters of all teeth except the MD of the
mandibular central incisor and BL of the mandibular lateral
incisor were greater in the males. The differences were signifi-
cant at p < 0.01 for the MD of maxillary canine and mandibular
first molar and at p < 0.05 for the maxillary first molar and
mandibular second molar. The BL of the maxillary canine, first
and second molars and mandibular first molar were signifi-
cantly great er at p < 0.05.
The crown dimension indices were also greater in the males.
However, the crown index was not significantly greater in ei-
ther arch. The crown area was significantly greater at p < 0.01
for the maxillary and mandibular first molars and at p < 0.05
for the maxillary first premolar and mandibular second molar.
The crown module was significantly greater at p < 0.01 for the
mandibular first molar and at p < 0.05 for the maxillary premo-
lar, and first molar and the mandibular second molar.
When the coefficients of variation were taken to indicate rel-
ative variability of tooth size no clearly defined pattern in MD
and BL were observed in either sex. In the males both MD and
BL of the maxillary lateral incisor and mandibular second pre-
molar showed high variability. In the females, variability was
randomly distributed.
Crown index and crown module of the first molar in both
dentitions was significantly greater than that of the second in
the maxilla at p > 0.01 ad mandible at p < 0.05. The crown
module of the maxillary first premolar was significantly greater
than that of the second at p < 0.05 .
With reference to sexual dimorphism the MD identifies the
maxillary canine and mandibular first molar at the higher
probability and the maxillary first molar and mandibular at the
lower. The BL identifies the maxillary canine, first and second
molars and the mandibular first molar at the lower probability.
The crown indices are limited to the posterior teeth. Crwon
index has not been useful in assessing sexual dimorphism.
Crown area identifies the maxillary and mandibular first molars
at the higher probability and the maxillary first premolar and
mandibular second molar at the lower. Crown module identifies
the mandibular first molar at the higher probability and the
OPEN ACCESS 5

T. HEWAPATHIRANA ET AL.
maxillary premolar and first molar and mandibular second mo-
lar at the lower probability.
With reference to relative variability of tooth size, a definite
pattern was not observed in either sex in the MD & BL. The
variability was randomly distributed in the females. In both
sexes in both arches the first tooth of each tooth class (I1, P1,
and M1) showed less variability with the first molar being the
least variable.
Crown area has not been useful in assessing tooth size varia-
bility. Crown index identifies the first molar significantly
greater in the maxilla at the higher probability and the maxillary
first premolar and mandibular second molar at the lower proba-
bility. Crown module identifies the mandibular first molar at
the higher probability and the maxillary premolar and first mo-
lar and mandibular second molar at the lower probability.
The study reveals that MD, crown area and crown module
are more useful in identifying sexual dimorphism. The maxil-
lary teeth are more dimorphic and the maxillary canine and first
molar and mandibular first molar most dimorphic.
With reference to variability of tooth size in the MD and BL
diameters the first tooth of each class (I1, P1, and M1) in both
arches with the first molar being the least variable in both sexes.
In the males both MD and BL of the maxillary lateral incisor
and mandibular second premolar showed high variability. The
variability in MD and BL were randomly distributed in the
females.
With reference to the crown indices in both arches in the
males, the crown index and crown module of the first molar
was significantly greater than that of the second in the maxilla
at the higher probability in the maxilla and in the mandible at
the lower. The crown module of the maxillary first premolar
was significantly greater than that of the second at the lower
probability.
In this study, the MD and BL diameters have not been in-
formative of relative variability of tooth size in the dentition.
The crown area too was not informative. However in the males
both crown index and crown module have identified tooth size
variation between the first and second molars at the higher
probability in the maxillary teeth. Crown module has also iden-
tified variation between the maxillary first premolar and second
at the lower probability. The first tooth of each tooth class I1, P1,
and M1 in both arches in both sexes showed less variability
with the first molar being the least variable. In the males both
MD and BL showed high variability in the maxillary lateral
incisor and mandibular second molar. Differences in the crown
dimension indices crown index, crown area and crown module
are expected to show variability in the shape, robustness and
bulkiness of the teeth respectively (Townsend & Brown, 1979).
In this study crown index was not informative on sexual di-
morphism and crown area on relative variability while crown
module was informative of both. Further studies are necessary
to confirm the relevance of these indices in the dentition.
Conclusion
In conclusion, this study is the first on dental casts of any
population group in Sri Lanka establishing the sexual dimor-
phism and tooth size variation in the permanent dentition of the
contemporary Uva Bintenne Veddas.
REFERENCES
Dahlberg, G. (1940). Statistical methods for medical and biological
students. London: George Allen and Unwin, Ltd.
Ellepola, S. B., & Wirka manayake, E. R. (1986). A genetic study of the
Veddas and Sinhalese. Ceylon Journal of Medical Science, 29, 1-21.
Fujita, T. (1949). On the standard of the measurement of teeth. The
Journal of the Anthropological Soc iety of Nippon, 61, 27-32.
http://dx.doi.org/10.1537/ase1911.61.27
Hanihara, S., Saitou, N., Hirai, M., Gojobori, T., Park, K. S., Misawa,
S., Ellepola, S. B., Ishida, T., & Omoto, K. (1988). Mitochondrial
DNA polymorphism among five Asian populations. American Jour-
nal of Human Genetics, 43, 134-143.
Hill, W. C. O. (1932). Anthropology of Veddas. Nature, 130, 891-892.
http://dx.doi.org/10.1038/130891b0
Hill, W. C. O. (1941). The physical anthropology of the existing Ved-
das in Ceylon Part I. Ceylon Journal of Science, 3, 37-38.
Hill, W. C. O. (1945). Veddahs—A living relic of primitive man. Loris,
201-206.
Knox, R. (1981). An historical relation of Ceylon (pp. 194-199).
Dehiwela: Tisara Prakasakayo Ltd.
Pathmanathan, R. S., and Wikramanayake, E. R. (1993). Oral disease
patterns and tooth wear in the Veddas. Ceylon Journal of Medical
Science, 36, 43-49.
Sarasin, C. F., and Sarasin, P. B. (1886). Outline of tw o years research
in Ceylon. Journal of the Royal Asiatic Society (Ceylon Branch), 9,
289-305.
Stoudt, H. W. (1961). The physical anthropology of Ceylon. Ceyl on N a-
tional Museum Ethnographic Series 2 (pp. 149-154). Sri Lanka: Co-
lombo National Museum.
Townsend, G. C., and Brown, T. (1979). Tooth size characteristics of
Australian Aborigines (pp. 17-38). Ocaational papers in human biol-
ogy. Australian Institute of Aboriginal Studies, Canberra.
Virchow, R. (1886). The Vedda of Ceylon and their relation to neigh-
boring tribes. Journal of the Royal Asiatic Society (Ceylon Branch),
9, 349-495.
Wikramanayake, E. (2002). Twenty five years research on the Ved-
das—A review. Journ al Royal Asiatic Society of Sri Lan ka, 46, 105-
114.
Wikramanayak e, E. R., Wikramanaayke, T. W., & Chan drasekera, M.
S. (1994). Body mass index of kandeganvila Veddas. Ceylon Journal
of Medical Science, 37, 13-17.
Wikramanayake, T. W., & Wikramanayake, E. R. (1992). Secular
trends in the physical anthropology of the Veddas of Sri Lanka. Cey-
lon Journal of Medical Science, 35, 23-28.
6