frequency and severity of dental fluorosis among school children in

Original Article
FREQUENCY AND SEVERITY OF DENTAL FLUOROSIS AMONG SCHOOL
CHILDREN IN GADAP TOWN, KARACHI
ABID MOHSIN, BDS, MPH
SAMAN HAKEEM, BDS, FCPS
3
ABDUL HAKEEM ARAIN, BDS, DPD
4
TAHIR ALI, BDS, MPhil
5
DAUD MIRZA, BDS, MSc
1
2
ABSTRACT
The objective of the study was to determine the prevalence and severity of dental fluorosis among
primary school children. This was a cross-sectional study. Clinical examination was conducted by
calibrated examiners. Dean’s fluorosis index as recommended by WHO (1997) was used to determine
severity of dental fluorosis. The burden of the disease in the community was also calculated through
Community Fluorosis Index. Three hundred fifteen 6- to 15 year-old school children (219 boys and
96 girls) comprised the sample. Some high school age children who were in primary section were also
included in the study. The prevalence of dental fluorosis was found to be 53.33 % in the study sample.
The difference among genders was found which did not increase with age. In males of age groups 6-9,
10-12, 13-15 years CFI values of 1.09, 1.11 and 1.39 were found respectively. Whereas in females of
age groups 6-9, 10-12, 13-15 years lower CFI values of 0.64, 0.43 and 0.55 were recorded respectively.
This study can be taken as a baseline study for a further epidemiological research on dental fluorosis
in this study area. The data can be utilized by public health organizations and dentists to evaluate
risk factors and devise preventive strategies.
Key words: Fluorosis, child, dentition.
INTRODUCTION
Normal growth and development require fluorine
as an essential element. In particular, fluoride’s role in
preventive dentistry is very important since it garners
cariostatic potential.1,2 This cariostatic potential may
be converted into dental and skeletal fluorosis if taken
excessively. Dental fluorosis is a hypo mineralization
of enamel and dentine produced by chronic or excessive ingestion of fluoride during tooth development
process.1,2,3,4
The severity of dental fluorosis depends on the fluoride intake during tooth formation.5,6 The clinical enamel
defects vary from fine white lines to severe chalky or
opaque enamel, which may get discolored and are easily
broken down after eruption. The important problems
Correspondence: Dr Saman Hakeem
Mailing Address: 41-Z/B, Block 6, PECHS, Karachi
E-mail: drshaz80@hotmail.com Cell: +92300-9257062
1
Consultant Dental Surgeon & Assistant Professor, Abdullah Dental
Surgery, Karachi, Pakistan.
2
Assistant Professor & HoD, Deptt. Of Prosthodontics, Bahria
University Medical and Dental College, Karachi, Pakistan.
3
Consultant Dental Surgeon & Associate Professor, Abdullah Dental
Surgery, Karachi, Pakistan.
4
Assistant Professor, Deptt. of Periodontology, Bhittai Dental and
Medical College, Mirpurkhas Pakistan.
5
Assistant Professor, Deptt. of Oral Pathology, Bahria University
Medical and Dental College, Karachi, Pakistan.
Received for Publication:
Accepted:
October 29, 2014
November 26, 2014
Pakistan Oral & Dental Journal Vol 34, No. 4 (December 2014)
due to dental fluorosis are discoloration and the loss of
outermost enamel.7 The enamel discoloration is often
so unsightly that it causes psychological problems in
patients8 whereas the loss of enamel is easily affected
with dental caries. These may have a negative impact
on personal wellbeing.
There are some communities where drinking water
contains high fluoride. This study attempts to determine the prevalence and its severity. This study also
calculated the community fluorosis index (CFI) among
the study sample of primary school children in Gadap
Town, Karachi. This data and statistics regarding dental
fluorosis can be used as baseline for further studies.
It may also help the public health organizations and
community services to plan and devise much needed
preventive strategies.
METHODOLOGY
This was a cross-sectional observational study.
It was conducted in the rural areas of Gadap Town,
Karachi. The sample comprised of 315 school children
aged 6-15 years. The subject’s residency in the study
area since birth was confirmed.
Consent and approval from concerned school authorities were obtained. Consent forms were sent to
prospective subject’s parents to be duly signed before
their inclusion in the study. No dropouts were reported.
Three trained dental surgeons performed oral exam684
Frequency and Severity of Dental Fluorosis
ination using disposable examination sets comprising
of dental mirror, probe and tweezer. The examination
was done in day light on a chair. The operators were
calibrated by a clinical calibration exercise before the
research was undertaken. The presence and severity
of dental fluorosis was documented in the devised
proforma. The severity was scored by Dean’s Fluorosis
index (1942) which follows the WHO (1997) criteria.9
This index gives six degrees of severity starting from
normal, questionable, very mild, mild, moderate to severe. It involved the rating of each tooth in the mouth
according to six categories of Dean’s index. The score
was based on the severest form of dental fluorosis for
two or more teeth in the mouth. The last four categories
of Dean’s index was considered as fluorosis. Community
Fluorosis Index (CFI) index10 was used to calculate
the public health significance of the disease. It was
calculated by summation of scores of dental fluorosis
as recommended by Dean. Then dividing the result by
the total sample size. The public health significance of
CFI is categorized into six value ranges of 0.0-0.4 taken
as negative, 0.4-0.6 as borderline, 0.6-1.0 as slight, 1.02.0 as medium, 2.0-3.0 as marked and finally 3.0-4.0
value range as very marked.
RESULTS
The sample comprised of 315 schoolchildren attending primary school at Gadap Town, Karachi. Out
of these 315, 219 (69.5%) were boys and 96 (30.5%)
were girls. (Table 1)
The frequency of dental fluorosis in the sample was
found to be 168 with a percentage of 53.33%. It was
more prevalent among boys than girls with 61.64% and
34.38% respectively. Male to female ratio was approximately 4:1. The frequency of dental fluorosis was 78
(49.37%) in 6-9 age group, 54 (55.10%) in 10-12 age group
and 36 (61.01%) in 13-15 age group (Table 2). Most of
the affected subjects had very mild fluorosis that is 81
(25.71%) while only 03 (0.95%) subjects presented with
severe fluorosis. Severity of dental fluorosis according
to age and gender is given in Table 3.
Community Fluorosis index (CFI score) ranged
from borderline (0.43) to slight (0.64) in females while
male presented with medium (1.09-1.39) in different
age groups (Table 2).
DISCUSSION
Fluoride has been used as preventive measure to
control caries in water supplies. According to WHO 1984
report, an optimal level of 0.5 to 1.0 ppm is sufficient
to prevent caries. In Pakistan, Pakistan Council of
Research and Water Resources (PCRWR) conducted a
National Water Quality Monitoring Programme (20012006).11 In this survey fluoride considered as one of the
factors to affect quality of water was found to be 5% in
surface soil and groundwater. Moreover, Karachi was
established as a high fluoride area. Similarly Khan AA
et al (2002)12 also studied the fluoride content in water
sources in Pakistan. The authors concluded that as
a whole, 84% of the water sources have less than 0.7
ppm fluoride content. In Sindh, Thar was identified as
a high risk area with fluorosis as a community health
problem. The effects of level of fluoride in water are
influenced by climatic temperatures as well. According
to Pakistan’s climate which is approximately 84 degrees
TABLE 1: DISTRIBUTION OF SUBJECTS ACCORDING TO AGE AND GENDER
n=315
Age (years)
Male
Female
Total
(n)
%
(n)
%
6-9
109
68.98
49
31.02
158
10-12
70
71.43
28
28.57
98
13-15
40
67.79
19
32.21
59
Total
219
69.52
96
30.47
315
Key: n = no of children
TABLE 2: FREQUENCY OF DENTAL FLUOROSIS AND CFI ACCORDING TO AGE AND GENDER
n = 168
Frequency of fluorosis
Variable
n=168
Age
Groups
CFI score
Percentage: 53.33
Mean: 0.84
M
F
M
F
M
F
6-9
60
18
44.44
54.54
1.09
0.64
10-12
45
9
33.33
27.28
1.11
0.43
13-15
30
6
22.22
18.18
1.39
0.55
135
33
100
100
Total
Key: n = subjects
M = male
F = female
CFI = community fluorosis index
Pakistan Oral & Dental Journal Vol 34, No. 4 (December 2014)
685
Frequency and Severity of Dental Fluorosis
TABLE 3: DISTRIBUTION OF SUBJECTS ACCORDING TO SEVERITY OF DENTAL FLUOROSIS
n = 315
Age
Normal
Questionable
Very mild
Mild
Moderate
Severe
M
F
M
F
M
F
M
F
M
F
M
F
6-9
28
22
21
9
27
9
24
9
9
0
0
0
158
10-12
19
19
6
0
24
6
12
3
9
0
0
0
98
13-15
7
10
3
3
12
3
15
3
0
0
3
0
59
Total
54
51
30
12
63
18
51
15
18
0
3
0
105
42
81
66
18
3
(33.33%)
(13.33%)
(25.71%)
(20.95%)
(5.71%)
(0.95%)
Key: n = no of subjects
M = male
Total
315
F = female
Fahrenheit, WHO recommends 1.5mg/L as a safe level.12
Moreover, high fluoride levels in water is correlated to
high levels of fluoride in blood serum with a positive
dose response.13 Qayyum et al13 studied this aspect and
inferred that, in endemic areas there is greater risk of
fluorosis through water contamination.
Globally, frequency of fluorosis ranges from a
meager 8.53%14 to a staggering high of 69.84%.15 Even
within countries, the prevalence of fluorosis varies between different geographical locations. In India which
is Pakistan’s neighbor with similar geographical and
climatic conditions, the prevalence of fluorosis varies
from 46% in Pradesh16 to 69.84% in Rajasthan.15 Higher
frequencies are seen in endemic areas. Same stands
true for Pakistan. Endemic areas with high fluoride
content of water above 1.5mg/L constitute around 16%
of water sources.12 Gadap Town being an area where
water source is basically groundwater and is considered
an endemic area. This study also proved this notion
because more than half of the subjects presented with
some form of fluorosis. Thereby, these results are
consistent with other studies done in endemic areas
of Pakistan like Mangamandi and Kalat division.11,12
Another study which showed almost the same results
with 60% fluoride affected population was done in
urban population near Quetta.17 It was a case control
study with control group taken from a non-endemic
areas, the peri urban population which had a different
water source. Comparatively, the prevalence was more
in urban population which have groundwater source,
though the results were not statistically significant.
As opposed to this, a study conducted in a teaching
hospital in Lahore found only 12% fluorosis.18 The authors claimed that most of the patient pool was from
adjoining areas including Patoki, Kasur, Mangamandi
and Kot Radha Kishan. The reason for such a less frequency may be due to sampling technique, the patient
pool being not representative of the population. Then
there are studies in literature which have cited a very
high prevalence of fluorosis around 85% to 98% in
Mianwali and Mardan respectively.19 Apart from the high
fluoride value in groundwater in these areas, the authors also cited greater tea consumption to be a possible
Pakistan Oral & Dental Journal Vol 34, No. 4 (December 2014)
risk factor for this very high fluorosis prevalence even
for any endemic area in Pakistan. This study may
have under estimated fluorosis since only one school
was examined. Further studies with a better study
design and sampling technique may provide more accurate results. Albeit, this study has identified Gadap
town to have a significant dental health problem in the
form of fluorosis which not only impacts the aesthetics
but also the self-esteem of an individual especially for
children who may undergo embarrassment and peer
pressure.20
The results of this study are also consistent with
studies done in primary school children of rural areas
of Haryana21 and Tamil Nadu.22 The mild differences
in prevalence is due to different levels of fluoride in
different areas. Other possible reasons may be the
differences in climate, dietary habits, usage of fluoride
dentrifices, dust and fumes from adjoining aluminium
industry19 if applicable which have not been considered
in any of the above mentioned studies.
This study reported greater prevalence of fluorosis
in males than females. Marwat et al20 also found the
same results. Most of the studies recorded no gender
difference like in Haryana21 and Tamil Nadu22, as well
as in rural Tanzania.22 In contrast, a study conducted
in Kerala23 and Lahore18 showed greater prevalence
in girls than boys. The difference in the results may
be due to lesser number of girls in schools than boys.
Since the current study was conducted in a school, it
may have missed the fairer sex in the sampling pool.
Still, literature does not cite any established reason
for greater prevalence in males.22
Many studies have shown increasing frequency of
fluorosis with increasing age. A study conducted in rural
communities of Brazil24 cited that greater exposure to
fluoride with age leads to increase in risk of fluorosis.
Saravanan et al22 deliberated it in the light of enamel
developmental stage. He considered that the enamel of
permanent teeth are exposed to fluoride for a greater
time period in the womb since it is thicker than primary
teeth. The present study didn’t give a clear predilection
of fluorosis with increasing age, albeit, all the cases of
severe fluorosis were recorded in 13 to 15 years age
686
Frequency and Severity of Dental Fluorosis
group. Most of the cases presented with very mild fluorosis according to Dean’s Fluorosis Index. The severity
may have been underestimated since this study was
primarily done in mixed dentition and a lesser sample size of 13 to 15 age group. However, the reasons
need to be identified in a different study assessing the
permanent dentition as well. Furthermore, severity of
fluorosis needs to be associated with fluoride level in
water source which was not done in this study. However, the results of this study are consistent with other
studies done globally in Brazil24, India22 and Mexico25
which also revealed lesser cases of objectional fluorosis.
This study reported a CFI score in the category
of borderline except for slight for females in 6-9 age
group. This can be inferred as a significant public health
problem in the researched area. According to Lamson
and Galagan26 public health significance is directly
related to fluoride level in water. Only three cases out
of 168 had severe fluorosis in 12-15 age group, thus the
CFI score in the category of borderline. The severity of
fluorosis may have been underestimated since 12 – 15
year olds in this sample were very few. Therefore, this
age group was not represented properly in the sample.
Further studies need to be done in adolescents
and teenagers which may reveal increased severity
of fluorosis in population of Gadap Town. Thereby,
the burden of the disease may be greater in this area.
Moreover, the fluoride level in water also needs to be
analysed with other risk factors of fluorosis.
However, this study is an attempt to provide a
platform for identifying further research questions in
the area. This data can be utilized as a preliminary
record for a well-designed epidemiological study in this
endemic area.
7
Franzolin SB, Goncalves A, Padovani CR, Francischone LA,
Marta SN. Epidemiology of fluorosis and dental caries according
to different types of water supplies. Ciencia & Saude Coletiva
2010;15:1841-47.
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9
World Health Organization. Oral health surveys: Basic methods.
4th ed. World Health Organization: Geneva;1997.
CONCLUSION
Within the limitations of the study, it can be concluded that Gadap Town has a significant burden of
dental fluorosis with more than half of the population
having this disease. Most cases were of very mild category.
19 Siddiq K, Dost S, Naseem A, Arshad A, Attaullah. Prevalence of
dental fluorosis in Mianwali and Mardan. JCDSA 2011;1:106-09.
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