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An epidemiological study
of
tori
among
667
dental outpatients in
Trinidad
&
Tobago, West lndies
H.F.
Al-Bayaty, P.R. Murti and R. Matthews
St.
Augustine, Trinidad
&
Tobago
P.C. Gupta
Mumbai, India
Aim: To study the prevalence of tori amongst dental outpatients, the
ethnic and sex variations in their distribution, and their clinical features.
Setting: The School of Dentistry, St. Augustine, Trinidad
&
Tobago.
Participants:
667
consecutive dental outpatients representing three differ-
ent ethnic groups of the country. Methods: Clinical examination for and
recording of tori indicating their location, extent and clinical features and the
age, sex and ethnic grouping of the patient. Results: The overall prevalence
of tori was
12.3
per cent. Conclusions: There were no significant differ-
ences in the prevalence among the African, Indian or mixed ethnic groups
of
patients examined. There seemed to be strong link between the co-
existence of palatal and mandibular tori.
Key words: Epidemiology, oral, exostosis, prevalence, tori, palate, mandible
Correspondence to:
Dr.
H.F. Al-Bayaty, School of Dentistry, Faculty
of
Medical Sciences,
The University
of
the West Indies, Uriah Butler Highway, Champs Fleurs, West Indies.
E-
mail: dentalsh@trinidad.net
Tori are mature bony protuberances
of unclear aetiology that occur in
the hard palate, lingual aspect of
the mandible, and in some indi-
viduals,
in
both locations. Whilst
they are mostly asymptomatic need-
ing no treatment, for prosthodontic
purposes surgical intervention may
be required. Several investigations
and reviews from the non-Carib-
bean region reveal that tori are
a
common anomaly with
a
wide
range
of
prevalence rates
(0.1-90.0
per cent) and geographic, sex,
ethnic and clinical variations'-9.
Ogunsalu reported
a
6.6
per cent
prevalence of torus palatinus, torus
mandibularis or both among
958
Jamaican blacks".
Although tori appear to be
common in Trinidad
&
Tobago,
there are no epidemiological stud-
ies of the prevalence of tori,
or
their clinical characteristics in the
multi-ethnic population of the
country. An epidemiological study
of
667
consecutive dental out-
patients was undertaken at the
School of Dentistry to determine:
the prevalence of tori amongst
dental outpatients, the ethnic and
sex variations in their distribution,
and their clinical features.
Material and methods
Geographic considerations
Trinidad
&
Tobago are the
-
0
2001 FDlMlorld Dental Press
0020-6539101 104300-05
301
southernmost of the Caribbean
islands, only about 1 Okm north of
the coast of Venezuela. While
Tobago is situated between
11
"
lati-
tude and 61" longitude, Trinidad
lies between 10" latitude and 61"
longitude. The two islands are 33km
apart and have an area of 4,828
km2 and 300 km', respectively.
While Tobago's 40,000 population
is mainly of African descent, 40
per cent
of
Trinidadian's are of
Indian ethnicity, having come to
the island over 152 years ago
as
indentured labourers, and 43 per
cent are African, having been
brought to the island some 450
years ago by the plantation masters.
The rest constitutes
a
'mixed racial
group'
(a
mixture of African,
Indian, Spanish, European, Medi-
terranean, Chinese) and others,
which include 'Caribs',
a
minuscule
and dwindling community of its
original Amerindian inhabitants.
Calibration
The study was conducted in the
Emergency
&
Oral Medicine Clinic
of the School of Dentistry where
all new patients are examined. Prior
to the commencement of the study,
criteria for the diagnosis and classi-
fication of tori was agreed between
the two (HFA/PRM) examiners.
Inter-observer variation was resolved
by re-examination of cases by both
examiners until standardisation was
achieved. A proforma was devel-
oped for recording lesions that
included site, size, location, and
clinical characteristics. The proforma
was pre-tested and finalised after
incorporating some changes.
Diagnostic criteria
For diagnosis:
Torus
pakatinus
was
defined
as
an exostosis along the
suture line
of
the hard palate and
Torus nzandibularis
as
an exostosis,
unilaterally or bilaterally situated on
the lingual aspect of the mandible
above the mylohyoid line in the
premolar region. Tori were further
divided into four categories:
Flat torus: occurring
as
a
slightly
convex protuberance with
smooth surface extending sym-
metrically on both sides of the
palate
Spindle torus: present along the
midline ridge along the palatal
raphe area
Nodular torus: occurring as
multiple protuberances each
with individual bases; these
protuberances may coalesce
forming grooves between them
Lobular torus: present as a
pedunculated or sessile lobular
mass that can arise from a
single base.
Study population and
examination
Some 667 unselected, consecutive
patients were included in the study.
After obtaining
a
full medical
history each patient was seated in
a
standard dental chair and exam-
ined by one of the examiners using
mouth mirrors. Whenever tori were
observed all designated features of
the lesion were recorded on
a
proforma indicating their location,
extent and clinical features.
Statistical methods
The age-related prevalence rates
were calculated overall and for each
ethnic sub group (African, Indian,
mixed, and for male or female).
Chi-square analysis to determine the
significance of difference between
two different rates was performed.
Any
difference between two means
was tested by ANOVA.
Results
Figtlre
I
shows the distribution of
the study population (667) accord-
ing to ethnicity, sex and age group-
ings. About 55 per cent of the study
population was African, 32 per cent
Indian and
13
per cent represented
the mixed ethnic group. The major-
ity (502) were between 11-50 years
of age. Women outnumbered men
in
each ethnic group as well
as
over-
all (426).
Table
I
gives the prevalence rates
of tori among the 667 individuals
according to clinical type, ethnicity
and sex. The overall prevalence was
12.3 per cent. The highest preva-
lence was observed in the mixed
ethnic group (men: 17.8 per cent;
women: 16.6 per cent). The differ-
ences in the prevalence rates
between men and women and
ethnic groups, though seemingly
large at times, were not statistically
significant. Among different clini-
cal types, the prevalence of palatal
Distribution
of
the
Study
Population
180
140
P
40
20
41
11-20
21-30
31-40
41-M
51-80
61-70 >70
1
HAfrican
M
fa
African
F
Indian
M
kB
Indian
F
B4
Mixed
M
El
Mixed
F
1
Figure
I.
Distribution
of
the
study population according
to
ethnicity, sex and age groups.
r--_------------
A="pJL
-
-
-_-
___-
i
__
___
___
____-
Al-Bayaty
et
a/.:
Tori in Trinidad
8,
Tobago
302
Table
1
Prevalence of tori among 667 dental outdoor patients at the School of Dentistry, Trinidad according to clinical types,
ethnicity and sex
African Indian Mixed Total Prevalence
M W M
W
M
W
M W
T
Women/Men
Clinical
(n=127) (n=240) (n=86) (n=126) (n=28) (n=60) (n=241) (n=426) (n=667) Quotient
Palate 7 16 4
10
-
7 11 33 44 1.7:l
Mandible 4
5
3 2 4
1
11
8 19 0.4:l
(3%) (2%) (3.5%) (1.6%) (14.3%) (1.6%) (4.5%) (1.8%) (2.8%)
Palate + 3
10
2
1 1
2 6 13 19 1.2:l
Mandible (2.4%) (4%) (2.3%) (0.8%) (3.6%) (3.3%) (2.5%)
(3%)
(2.8%)
Total 14 31 9 13
5
10
28 54 82
Prevalence
11%
13%
10.5%
10.3% 17.8% 16.6% 11.6% 12.6% 12.3%
1.1:1
(5.5%)
(6.7%) (4.7%) (7.9%)
-
(11.6%) (4.5%) (7.7%) (6.6%)
Table 2 Prevalence of difference of forms of tori according to age groups
Age groups Study population All forms
n=667 n=82
up to
10
1
1-20
21-30
31-40
41-50
51-60
61-70
70+
68
98
150
125
129
57
26
14
667
4 (5.9%)
12 (12.2%)
23
(15.3%)
19 (15.2%)
10
(7.8%)
8 (14.0%)
4 (29.0%)
2
(7.9%)
12.3%
Prevalence
%
Palate Mandible Palate + Mandible
n=44 n=l9 n=l9
4 (5.9%)
-
-
8 (8.2%) 3 (3.1%)
1
(1.0%)
12 (8.0%) 3 (2.0%) 8 (5.3%)
10
(8.0%) 6 (4.0%) 3 (2.0%)
5
(3.9%) 3 (2.3%) 2 (1.6%)
1
(3.0%)
-
1
(3.0%)
2 (14.3%)
1
(7.1%)
1
(7.1%)
6.6% 2.8% 2.8%
2 (3.5%) 3 (5.3%) 3 (5.3%)
Table
3
Clinical aspects of tori
Aspects Palatal tori Mandibular tori Palate
+
mandible Total
(n=44) (n=19) (n=19) (n=82)
Age
Range
Mean
SD+
Peak occurrence
Male
Female
Mean size
LXB
Range
Sex
Shape
Flat
Spindle
Nodular
Lobular
Bilateral
6-10 yrs
30.7 yrs
2.3
21-30 yrs (27%)
11
(25%)
33 (75%)
2.1 x 1.8 cm
(L) 0.8-6 cm
(B)
0.2-4 cm
30 (48%)
10
(16%)
8 (13%)
15 (23%)
NA
11-80 yrs
39.2 yrs
3.7
31-40 yrs (32%)
10
(53%)
9 (47%)
1
x 0.9 cm
(L)
0.2-5 cm
(8) 0.2-4 cm
4 (11%)
1
(3%)
23 (61%)
10
(25%)
33 (87%)
12-72 yrs
36.7 yrs
3.5
21-30 yrs (42%)
6 (32%)
13 (68%)
NA
NA
NA
6-72 yrs
34.1 yrs
1.7
21-30 yrs (28%)
27 (33%)
55
(67%)
NA
'34 (34%)
'11
(11%)
'31 (30%)
'25 (25%)
NA
~~
NA: Not applicable as P + M tori computations have been done in each respective group
+:
Cumulative scoring. Total palate 44
+
19; total mandible 19 + 19
=
101
tori was highest
(6.6
per cent). Tori ethnic group. The prevalence of tori in patients under the age of
10
were most common among mandibular tori was significantly years. The prevalence
of
tori peaked
women
of
the mixed ethnic group
(W0.05)
higher in men than among in the age group 21-30 years. There
(prevalence
11.6
per cent). The women. were, however, no signifi,cant
female to male ratio was
1.7:l.
Table
2
shows the prevalence of
(P4.25)
age related differences in
Mandibular
ton
were most common tori according to age groups. There the overall prevalence
of
tori.
(14.3 per cent) in men of the mixed were only 4
(5.9
per cent) cases of
Table
3
shows that tori were
International
Dental
Journal
(2001)
Val.
511No.4
303
observed in
a
wide age range
(6-
72 years). The mean age of 82 indi-
viduals who had all forms of tori
was 34.1 years. There were, how-
ever, some significant differences
(P<O.OOl)
in the mean ages of 44
individuals with palatal tori (30.7),
19 with mandibular tori (39.2 years)
and 19 with tori in both locations
(36.7 years). The mean age (36.7
years) of those individuals who had
tori in both locations was signifi-
cantly (P<0.05) lower compared
to those (39.2 years) who had only
mandibular tori. The mean sizes of
palatal and mandibular tori were
2.1
x
1.8 cm, and
1.0
x 0.9 cm,
respectively. Some 34 per cent of
the tori were flat, 30 per cent nodu-
lar, 25 per cent and
11
per cent
were spindle or nodular in shape.
While palatal tori were predomi-
nantly flat (48 per cent), 61 per
cent of mandibular tori were
nodular.
Discussion
The new findings of
this
study show
the prevalence of all forms of tori
in dental outpatients is higher (12.3
per cent) than that reported
(6.6
per cent) in Jamaican blacks". The
prevalence of tori was also higher
among Afro-Trinidadian men
(1
1
per cent) and women
(13
per cent)
than reported among Jamaican
blacks". While extrapolation of
these findings to the general popu-
lation
in
Trinidad
is
not possible,
our findings demonstrate that tori
are common among dental out-
patients. The present study did not,
however, show any ethnic or sex
differences in the overall preva-
lence of tori, implying perhaps that
ethnically based factors in this study
may be least influential. The preva-
lence of palatal tori among women
(7.7 per cent) was significantly
(Ik0.05)
higher compared to that
of mandibular tori (1.8 per cent).
However, if the prevalence of
palatal and mandibular tori is
considered, the difference becomes
insignificant.
Although the aetiology of tori is
not clear,
a
combination of dietary,
environmental and genetic factors
were considered to be influential
for their occurrence and variability
in pre~alence~*"-~~. In a Norwegian
study, which demonstrated a higher
women to men ratio for tori, an
x-linked dominant, single gene
mode of inheritance was proposed,
but not established5. These investi-
gators felt that a combination of
genetic and environmental factors
operate in which at least a part of
the genetic determinants of the
liability to tori reside
on
the
x-linked chromosome.
An
earlier
concept of palatal tori hypothesised
that masticating tough food could
trigger pressure towards the median
palatine region thereby leading to
the thickening of the palatal vault
on each side of the palatal suture13.
However, a more recent concept
suggests the role of nutrients upon
the development of bone tissue.
Explaining the higher prevalence
of palatal tori in the Lofoten area
of their study in Norway, Eggen
et
aL5
suggested that saltwater fish
consumption in that area possibly
supplies higher levels of poly-
unsaturated fatty acids and vitamin
D
that is congenial for increased
bone growth. Fish is also an
important food item in Trinidad,
and we feel
this
might influence the
occurrence of tori in Trinidad.
In several reviews and investi-
gations, women with tori out-
numbered males in general, and
more strikingly, in the case of pala-
numbered women in cases of
mandibular t~ri',~,~,'~. Although the
present investigation did not show
any significant sex differences in
the overall prevalence of tori,
unlike in other investigations, the
prevalence of mandibular tori was
significantly
(W0.05)
higher among
men.
The present data also suggests
a
strong association between concomi-
tant palatal and mandibular tori.
This appeared to be stronger for
the occurrence of palatal tori in
those with mandibular tori (50 per
tal
tor-1-5,10-"U2
.
M en however, out-
cent of the 38 individuals with
mandibular tori had palatal tori)
than
vice
versa
(30 per cent of the 63
individuals with palatal tori). Judg-
ing from the age distribution of
prevalence, mean ages and peak
occurrence
(Table
3),
it may be
inferred that formation of palatal
tori (mean 30.7 years) is an earlier
event compared to that of mandibu-
lar tori (mean: 39.2 years).
Interestingly, the mean age (36.7
years) for those with both forms
of tori lies in between. Eggen and
Natvig?? observed a statistically
significant occurrence of mandibu-
lar tori only among women and
explain that such a correlation
is
restricted to women for lyonisation.
Ha~gen?~ observed that the prob-
ability of finding mandibular tori
in a person bearing palatal tori was
more than twice as high as in a
person without this character and
vice versa.
Most individuals in this study
were unaware of the presence of
tori. As observed by other investi-
gator~~,~,~~,~~, flat tori occurred more
frequently, especially in the palate,
whereas nodular tori were most
frequent in the mandible. Rarely
though, tori may be associated with
other forms of exostosis26, and they
are also more likely to be present
when there were fewer unerupted
mandibular canines" possibly due
to the jaw being well-developed
and such individuals carrying
a
greater tendency to develop
mandibular tori. Apart from midline
maxillary diastema in
two
individu-
als,
no
other dental anomalies were
observed in the present cases.
Acknowledgments
We thank Dr. Donald Simeon,
Biostatistician, Faculty of Medical
Sciences for his helpful suggestions
and the secretarial assistance of Ms.
Anisa Baksh
and
Ms. Carol Roberts.
References
1.
I<olas
S,
Halperin
V,
Jefferis
I<,
et
a/.
The
occurrence of torus palatinus and
Al-Bayaty
et
a/.:
Tori in Trinidad
&
Tobago
304
torus mandibularis in
2,478
dental
patients.
Oral
Surg
1953
6:
1134-
1141.
2.
Schauman
B
F,
Peagler
F
D,
Gorlin R
J.
Minor craniofacial anom
a
1'
ies among
negro population.
1.
Prevalence of
cleft uvulas, commissural lip pits,
preauricular pits, torus palatinus and
torus mandibularis.
OralSi{rg
1970
29:
566-575.
3.
Karija M, Alvesalo
L
A. Dental field
investigation in Hailuoto. vi. Torus
palatinus: incidence and some view
points concerning its inheritance.
Proc
Fin
Dent
Sot
1973
69:
120-127.
4.
King
D
R, IGng
A
R. Incidence of tori
in three population groups.
J
OralMed
5.
Eggen
S,
Natvig B, Gasmyr
J.
Varia-
tions in torus palatinus prevalence in
Nonvap.
Scand
J
Dent Re5
1991
102:
6.
Axelsson
G,
Hedegaard. Torus
palatinus in Icelandic school children.
An/
J
Hys
Antbrapol
1985
67:
105-
112.
7.
Reichart
P
A, Neuhaus
F,
Sookasem
M.
Prevalence of torus palatinus and
torus mandibularis in Germans and
Thai.
Conniiunig
Dent
Oral
Epideiiiiol
8.
Shah
D
S,
Sanghvi
S J,
Chanda J
D,
et
a/.
Prevalence of torus palatinus and
1981
36:
21-23.
51-59.
1988
16:
61-64.
torus mandibularis in
1000
patients.
Indian
J
Dent Res
1992
3:
107-110.
9.
Gorsky
M,
Raviv M,
Kfir
E,
et
a/.
Prevalence
of
torus
palatinus in a
population of young and adult Israe-
lis.
Arch
Oral
Biol
1996
41:
623-625.
10.
Ogunsalu C
U.
Oral tori
in
Jamaicans
of African origin: a clinical study.
West
Indian
Dent
J
1994
1:
5-7.
11.
IGng
D
R,
More
G
E.
An analysis of
torus palatinus in a transatlantic study.
J
Oral
Med
1976
31:
44-46.
12.
Miller
S
C, Roth
H.
Torus palatinus:
a statistical study.
J
Am
Dent
Assoc
1940 27: 1950-1957.
13.
Hooten
E
A. On certain Eskimoid
characters in Icelandic skulls.
Aut
J
Pbys
Antbrapol
1918
1:
53-76.
14.
Hrdlicka A. Mandibular and maxillary
hyperostosis.
Am
J
PbysAntbalpoll940
15.
Mayhal
J
T.
The effect of culture
change upon the Eskimo dentition.
Arctic Antbrapol
1970
7:
117-121.
16.Axelsson
G,
Hedegaard B.
Torus
mandibularis among Icelanders.
Am
J
Pbys
Antbrapol
1982
54:
383-389.
17.
Eggen
S,
Natvig B. Relationship be-
tween torus mandibularis and number
of present teeth.
Staid
J
Dent Res
1986
94:
233-240.
18.Barbujani
J,
Rolo
M,
Barrai
I,
et
al.
Torus palatinus: a segregation analy-
27:
1-67.
sis.
Hum Hered
J
1986
36:
317-325.
19.
Eggen
S.
Correlated characteristics of
the jaws: association betmeen torus
mandibularis and marginal alveolar
bone height.
Acta
Odontol
Scad
1992
20.
Seah
Y
H.
Torus palatinus and torus
mandibularis: a review
of
literature.
Aust
Dent
J
1995
40:
318-321.
21.
Gorsky
M,
Bukai A, Shohat
M.
Genetic influence on the prevalence
of torus palatinus.
Am
J
bled
Genet
22.Eggen
S,
Natvig B. Concurrence of
torus mandibularis and torus palatinus.
Scand
J
Dent Res
1994
23.
Haugen
L
K. Palatine and mandibular
tori.
A
morphologic study in current
Norweigan population.
Acta
Odontol
Scand
1992
50:
65-67.
24.
Austin
J
E,
Radford
G
H, Banks
S
0,
Jr.
Palatal and mandibular tori in the
Negro.
New
York
Dent
J
1965
31:
187-
191.
25.Bernaba
J
M. Morphology and inci-
dence of torus palatinus and mandib-
ularis in Brazilian Indians.
1
Dent Res
50:
1-6.
1998
75:
138-140.
102:
60-63.
1997
56:
499-501.
26.
Antoniades
D
Z,
Delazi
M,
Papana)
'IOtOU
'
P.
Concurrence of torus palatinus with
palatal and buccal exostosis: a case
report and review of the literature.
Oral
Surg
1998
85:
552-557.
International Dental
Journal
(2001)
Vol.
51/No.4
