Lenčová et al. BMC Public Health 2012, 12:547
http://www.biomedcentral.com/1471-2458/12/547
RESEARCH ARTICLE
Open Access
Early childhood caries trends and surveillance
shortcomings in the Czech Republic
Erika Lenčová1*, Hynek Pikhart2 and Zdeněk Broukal1
Abstract
Background: Despite the decline in childhood caries prevalence, seen particularly in 1980s, in recent years there
have been reports that the declining trend has stopped or even reversed in some countries. The aim of the study
was to analyse data from previous epidemiological studies on early childhood caries in the Czech Republic,
conduct a secondary analysis of trend in dental caries prevalence, and discuss issues related to national oral health
surveillance.
Methods: Since the 1990s, caries prevalence in preschool children was monitored by two independent bodies:
Institute of Health Information and Statistics (IHIS) that conducted 5 cross-sectional surveys over the period
1994–2006, and Institute of Dental Research (IDR) that conducted 4 studies over the years 1998–2010. Both study
series differed in methods of sample selection and approaches to examiner training. For the assessment of the
caries prevalence trends, regression modelling was used for the following oral-health indicators: caries experience,
mean number of teeth with untreated caries (dt) and percentage of caries-free children.
Results: In both study series, a significant overall trend of declining caries experience and level of untreated caries,
and an increasing trend of percentage of caries-free children was observed (p < 0.05). In IHIS studies, caries
experience reduced from 3.5 to 2.7; dt reduced from 2.2 to 1.5 and a proportion of caries-free children increased
from 23.9 to 42.2%. In IDR studies, caries experience reduced from 3.7 to 2.98; dt reduced from 2.5 to 2.1 and a
proportion of caries-free children increased from 26.7 to 44.9%.
Conclusions: Both study series identified a significant decline of caries prevalence particularly in the 1990s and
early 2000s. By the end of the investigated period, flattening of the caries decline was observed. The positive trend
was observed in the absence of any systematic preventive initiatives on a population level. With respect to the
above the authors assume that in the Czech Republic there still is a potential for further caries reduction in
preschool population. This, however, cannot be expected without any health policy interventions. Oral health
surveillance in the Czech Republic should be promoted by competent regulatory authorities.
Keywords: Early childhood caries, Caries experience, Primary dentition, Oral health surveillance
Background
Dental caries is the most common chronic disease in
childhood. If not managed properly, it may result in significant acute and chronic conditions, the most severe of
which include bacteraemia and impaired development,
not to mention high treatment costs and consequences
to families and communities [1-3]. The American
* Correspondence: lencova@vus.cz
1
Institute of Clinical and Experimental Dental Medicine - 1st Faculty of
Medicine of the Charles University and General Teaching Hospital, Prague,
the Czech Republic
Full list of author information is available at the end of the article
Academy of Pediatric Dentistry (AAPD) classifies early
childhood caries (ECC) in a broad definition as ´the
presence of one or more decayed (non-cavitated or cavitated lesions), missing (due to caries), or filled tooth surfaces in any primary tooth in a child 71-month-old or
younger´[4]. It is complicated to compare global trends
of early childhood caries prevalence mainly due to inconsistencies in the methodology of observational studies in individual countries. Despite the prevailing
declining trend in dental caries, particularly seen in
1980s [5], some authors have reported that such a trend
has stopped or even reversed for the primary dentition
© 2012 Lenčová et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative
Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and
reproduction in any medium, provided the original work is properly cited.
Lenčová et al. BMC Public Health 2012, 12:547
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in recent years, particularly in countries that already had
low caries prevalence in primary dentition [6-9]. It is
well documented that the distribution of ECC in the
population is skewed, with about one third of the examined population bearing most of the disease burden [10].
Cross-sectional epidemiological studies on ECC prevalence that employ standard epidemiologic measures,
such as dmft index (d – number of teeth with untreated
dental caries, m – number of teeth extracted due to dental caries, f – number of teeth with caries treated with a
filling or crown) and a proportion of the population with
intact dentition (dmft = 0) do not reflect the full scope of
ECC´s impact on the society [3]. Nevertheless, they collect elementary data necessary for planning the most appropriate preventive interventions against ECC and for
evaluating their effectiveness. Oral health data for monitoring disease patterns and trends over time represent
an essential component of global oral health information
systems established by WHO [11]. The aim of the study
was to analyse primary data from previous epidemiological studies on the prevalence of early childhood caries in the Czech Republic, conduct a secondary analysis
of trends in dental caries prevalence and discuss national
oral health surveillance issues. The Czech Republic is
also a country undergoing rapid social, economic and
health-care transition and, as such, an interesting place
to assess trends in dental caries in changing social
settings.
Methods
After political changes in the Czech Republic in 1989,
data on caries experience of 5-year-olds were collected
by two independent bodies: Institute of Health Information and Statistics (IHIS) and Institute of Dental Research (IDR). Data from the study series conducted by
those two bodies were analyzed in the presented study.
IHIS studies
In the years 1994, 1997, 2000, 2003 and 2006, five
cross-sectional national surveys of caries experience in
5-year-olds were conducted by IHIS. The studies were
supported by the Czech Ministry of Health as a part of
national health monitoring programme. In each study,
all general dental practitioners in the country were
asked to collect caries experience data of all 5-year-old
patients that would come for a dental appointment
within one calendar month (April). To prevent doubling of the data in the case of repeated visits, each subject was included only once. With respect to the fact
that providing the data was made mandatory by legislation, the response rate in each of the IHIS studies
was almost 100%. No calibration exercise was performed and methodology was described in a brochure
distributed to all examiners. Dental examinations were
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performed in dental offices under standard clinical
conditions, x-ray examinations were not included.
Dental caries detection threshold was a cavitated carious lesion as recommended by WHO [12]. Caries experience, as measured by the dmft index, was recorded
in a standard WHO form distributed with the methodology leaflet. Completed forms were sent back to IHIS
and processed centrally. Data analysis involved dmft
descriptive statistics.
IDR studies
IDR conducted national cross-sectional surveys on caries
experience of 5-year olds in the years 1998, 2001, 2005
and 2010 as part of oral epidemiological research projects. In each study, a representative geographically
stratified national sample of children in preschool nurseries aged more than 5 and less than 6 years was
selected in compliance with the WHO manual for Oral
health surveys [12]. The children were included in the
study after their parents signed informed consent forms
(ICF) agreeing to participation in the study. All studies
were approved by the Institutional Ethics Committee.
Dental examinations were conducted in nurseries using
dental mirror, rounded probe and headlight. In each of
the IDR studies, calibration exercise was carried out and
a high inter-examiner reliability (Kappa values >0.80)
was achieved. Dental caries was detected at the level of a
cavitated lesion, and caries experience was recorded in
the form of dmft index.
Present study
For the assessment of caries prevalence trends observed
by IHIS and IDR studies, regression modelling was used
for each of the above described caries indicators, i.e.
mean dmft per child, mean dt per child, and percentage
of subjects with dmft = 0, separately in each group of
studies (IDR and ECC). The significance threshold was
set at p < 0.05.
Results
Table 1 shows total number of study subjects, mean
dmft value per child, mean number of teeth with untreated caries per child (dt value) and proportion of
Table 1 IHIS studies: sample sizes and main results
1994
1997
2000
2003
Total number of study subjects
3383
3578
3186
3337
2006
3561
Mean dmft per child
3.5
3.6
3.4
2.6
2.7
SE
0.06
0.06
0.06
0.06
0.06
Mean dt per child
2.2
2.2
1.8
1.5
1.5
SE
0.05
0.05
0.05
0.04
0.04
% of children with dmft =0
23.9
24.7
29.8
41.6
42.2
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children with intact dentition (dmft = 0) for each wave of
IHIS surveillance.
Table 2 shows total number of study subjects, overall
response rate, mean dmft value per child, mean number
of teeth with untreated caries per child (dt value) and
percentage of subjects with dmft = 0 for each IDR study.
The respective regression lines together with R2 and
respective p-values are shown in Figures 1 and 2. In a
series of IHIS studies conducted over years 1994–2006,
a significant trend of declining mean dmft and mean dt
value per child and increasing trend of percentage of
caries-free children was observed (p < 0.05). Mean dmft
value reduced from 3.5 to 2.7; mean dt values reduced
from 2.2 to 1.5 and a proportion of caries-free children
increased from 23.9 to 42.2%. In the IDR studies conducted over the years 1998–2010, a significant trend of
declining mean dmft, mean dt value per child and increasing trend of percentage of caries-free children was
observed (p < 0.05). Mean dmft value reduced from 3.7
to 2.98; mean dt values reduced from 2.5 to 2.1 and a
proportion of caries-free children increased from 26.7 to
44.9%.
Discussion
A positive trend of caries prevalence over a period
1994–2010 was observed both for national monitoring
and smaller epidemiological studies. The two study
series employed different methods of study sample selection (dental patients vs. subjects from a stratified national sample) and a different approach to examiner
training (non-calibrated vs. calibrated examiners).
Consistency observed in trends of individual parameters
enhances the validity of the observed results. As it is evident from the data shown in Tables 1 and 2, the differences between the IHIS and IDR study results are
generally small and they can be explained by methodological factors, e.g. by the differences between “patients”
and “study subjects”. The study subjects recruited in the
nurseries had higher proportion of intact teeth, but at
the same time higher mean dmft and dt scores than
patients examined in dental practices. This is probably
related to the fact that the patients sought dental care
Table 2 IDR studies: sample sizes and main results
1998
2001
2005
2010
Total number of study subjects
435
297
285
583
Overall response rate (%)
84.9
69.1
73.8
80.2
Mean dmft per child
3.7
3.3
2.8
2.9
SE
0.25
0.21
0.22
0.20
Mean dt per child
2.5
2.3
2.0
2.2
SE
0.19
0.18
0.19
0.15
% of children with dmft =0
26.7
31.30
51.2
44.9
predominantly not for preventive reasons, but because
they were in need of dental treatment.
Detailed inspection of caries prevalence data shown in
Tables 1 and 2 reveals that the decline in caries prevalence happened mainly in 1990s and early 2000s. By the
end of the investigated period, both series of studies suggest possible flattening of the trend. This observation is
consistent with reports showing stopping or reversal of
this declining trend in childhood caries in some other
countries [6-9]. Therefore, further surveys in the next
few years would be needed to confirm whether this is a
long-term trend or whether this was one-off event.
We can speculate on the reasons for the positive
trend in caries experience. Over the recent years, there
have been no systematic preventive initiatives against
childhood caries implemented in the Czech Republic
on a country- or regional level. Only isolated oral
health programmes have been conducted in a few nurseries (such as oral hygiene training organized by dental students or programmes sponsored by dental
companies). Dental prevention in preschool children
has been conducted mostly only on individual level.
Currently it has been a responsibility of parents to
bring their child for dental check-up after the eruption
of their first tooth; however, many of them neglect this
responsibility. The underlying factors that might have
influenced caries prevalence include children’s access to
dental care and the availability of fluoride-containing
products. These factors remained generally unchanged
over the investigated period. As for the social and educational determinants influencing oral health, the
standard of living (expressed by Gross Domestic Product per capita) and educational attainment of the
Czech population (referring to the number of students
in university education) were increasing steadily over
this period, see Table 3 [13,14].
Oral hearth surveillance issues
In 2006, due to a political decision, national oral health
monitoring was terminated. The decision was probably
guided by the cost-saving efforts of the government. In
addition to that, at present, due to significant financial
constraints on new research projects in the Czech Republic, no extensive regular oral health surveys can be
planned. These factors significantly negatively influence
national oral health surveillance.
The two presented study series both collected oral
health data in a consistent way for more than a decade.
Therefore they were chosen for the analysis of caries
prevalence trend. Nevertheless, several potential sources
of bias might have influenced their findings. IHIS studies
recruited the subjects from patients who were actively
seeking dental care. They involved non-calibrated examiners, but this was partially compensated by the fact that
Lenčová et al. BMC Public Health 2012, 12:547
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Figure 1 Regression trends of individual dental caries experience indicators, IHIS studies.
dental caries detection threshold was a cavitated lesion,
and by large sample sizes. Nevertheless, limitations
related to sample selection and non-calibrated examiners
should not have influenced trends observed in the analysis, as the methods remained unchanged in all IHIS
surveys; and thus the results from all 5 rounds were
comparable with each other.
Inclusion of IDR study subjects based on parental
informed consents interferes with random sample selection procedures. However, similarity of the results from
both IHIS and IDR study series to some extent limits a
possibility of differential bias related to response rates in
IDR studies because response rates in IHIS were almost
100%.
In both IHIS and IDR studies, dental caries was
detected using visual-tactile method at a cavity level as
recommended by WHO. Choosing a cavitated carious
lesion, i.e. a stricter criterion for the disease detection,
reduces the incidence of false positive findings. However,
it is currently generally accepted that such a detection
threshold results in an increased number of false
negative findings [15]. In case oral health surveillance
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Figure 2 Regression trends of individual dental caries experience indicators, IDR studies.
Table 3 Selected social and educational determinants in the Czech Republic over the investigated period
1994
1997
2000
2003
2006
2009
Gross Domestic Product per capita in USD
n/a
5 543
5 552
8 949
13 882
18 135
Number of students in university education
136 566
177 723
209 298
243 801
316 367
389 231
Lenčová et al. BMC Public Health 2012, 12:547
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is re-initiated in the Czech Republic, dental caries should
be recorded at a pre-cavitation level as has been a common practice in epidemiological studies lately [16-19]. A
geographically stratified national random sample used in
IDR studies should be preferred to the sample recruited
from dental patients.
In order to validly compare the ECC´s burden in different countries, it should be determined which definition better reflects the typical disease pattern, its
severity and impacts. AAPD definition of ECC is significantly broad and sets no parameters for the disease severity. However, there is also a definition of severe ECC
(S-ECC): ´in children younger than 3 years of age, any
sign of smooth-surface caries is indicative of severe early
childhood caries. From ages 3 through 5, 1 or more cavitated, missing (due to caries), or filled smooth surfaces
in primary maxillary anterior teeth or a decayed, missing, or filled score of ≥4 (age 3), ≥5 (age 4), or ≥6 (age 5)
surfaces constitutes S-ECC [20]´. This definition probably better reflects typical clinical picture of rampant
caries. Another issue that should be addressed is a reference age group, representative for the population suffering from this disease and well accessible for surveying.
The disease impact is particularly severe in children aged
less than 3 years, therefore ECC data on this age group
would be especially valuable. Nevertheless, in the Czech
Republic, children attending nurseries (which generally
admit children from the age of 3 to 6 years) are best accessible for the oral health surveys. Collecting caries
prevalence data in dental patients aged less than 3 years
by calibrated general dental professionals is another option. However, even though it is generally recommended
that regular dental check-ups should be established with
the eruption of the first primary tooth, only a small proportion of parents, most likely non-representative, bring
their children to the dentist at that age. Therefore, creating a nationally representative sample of children aged
less than 3 years seems to be an issue.
Conclusions
The consistency observed in trends of individual parameters enhances the validity of the results in both sets
of studies. Despite the observed decreasing trend of caries experience indicators in the examined cohorts, caries
prevalence in Czech 5-year olds reported in this paper is
still considerably higher than in other European countries [6,8]. It is also considerably higher than the targets
set by WHO within the Health21 policy framework. Target 8.5 of this policy, related to the reducing of noncommunicable diseases, stipulates that by the year 2020,
at least 80% of children aged 6 years should be free of
caries [21]. Therefore, the authors of this paper assume
that in countries such as the Czech Republic, where the
caries prevalence is still relatively high, there still seems
Page 6 of 7
to be a potential for caries reduction. This is documented by significant reduction in dental caries prevalence
in the absence of any systematic preventive initiatives on
a population level.
Further improvement of oral health of preschool population, however, cannot be expected without any health
policy interventions. For the development and implementation of effective community preventive measures
adequate to meet the needs of this population group,
long-term monitoring of ECC trends is essential. National oral health data is required to assess oral health
needs of the population, monitor oral health; plan effective intervention community programs and health policies; and evaluate the progress toward health objectives.
Thus, systematic oral health surveillance in the Czech
Republic should be promoted by competent regulatory
authorities. This would help the policymakers obtain
support for public oral preventive programs in an environment, which is highly competitive in terms of getting
public resources [22], and to enable further long-term
monitoring of childhood caries. Unfortunately, oral surveillance initiatives still remain a challenge in the Czech
Republic.
Abbreviations
AAPD: American academy of pediatric dentistry; ECC: Early childhood caries;
dmft index: d – number of teeth with untreated dental caries, m – number
of teeth extracted due to dental caries, f – number of teeth with caries
treated with a filling or crown; dt: Number of teeth with untreated dental
caries; WHO: World Health Organization; IHIS: Institute of health information
and statistics; IDR: Institute of dental research; ICF: Informed consent form;
S-ECC: Severe early childhood caries; GDP: Gross domestic product; USD: The
United States dollar; n/a: Not available; SE: Standard error.
Competing interests
The authors declare that they have no competing interests.
Authors’ contributions
ZB and EL performed and/or collected data from the studies reported in the
manuscript and processed the data. HP performed the statistical analysis. All
authors contributed in writing the paper and approved the final draft.
Acknowledgements
The project was supported by the Internal Grant Agency of the Ministry of
Health of the Czech Republic, projects No. NS/10599-3 and NS/10353-3 and
project PRVOUK-P28/LF1/6.
Author details
1
Institute of Clinical and Experimental Dental Medicine - 1st Faculty of
Medicine of the Charles University and General Teaching Hospital, Prague,
the Czech Republic. 2Department of Epidemiology and Public Health,
University College London, London, UK.
Received: 1 February 2012 Accepted: 24 July 2012
Published: 24 July 2012
References
1. Kagihara LE, Niederhauser VP, Stark M: Assessment, management, and
prevention of early childhood caries. J Am Acad Nurse Pract 2009, 21:1–10.
2. Benzian H, Monse B, Heinrich-Weltzien R, Hobdell M, Mulder J, van
Palenstein Helderman W: Untreated severe dental decay: a neglected
determinant of low Body Mass Index in 12-year-old Filipino children.
BMC Public Health 2011, 11:558.
Lenčová et al. BMC Public Health 2012, 12:547
http://www.biomedcentral.com/1471-2458/12/547
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
Page 7 of 7
Casamassimo PS, Thikkurissy S, Edelstein BL, Maiorini E: Beyond the dmft:
the human and economic cost of early childhood caries. J Am Dent Assoc
2009, 140:650–657.
American Academy on Pediatric Dentistry, American Academy of Pediatrics:
Policy on Early Childhood Caries (ECC): Classifications, Consequences,
and Preventive Strategies. Pediatr Dent 2008-2009, 30:40–43.
Marthaler TM: Changes in dental caries 1953–2003. Caries Res 2004,
38:173–181.
Pitts NB, Chestnutt IG, Evans D, White D, Chadwick B, Steele JG: The
dentinal caries experience of children in the United Kingdom, 2003.
Br Dent J 2006, 200:313–320.
Speechley M, Johnston DW: Some evidence from Ontario, Canada, of a
reversal in the dental caries decline. Caries Res 1996, 30:423–427.
Haugejorden O, Birkeland JM: Evidence for reversal of the caries decline
among Norwegian children. Int J Paediatr Dent 2002, 12:306–315.
Dye BA, Thornton-Evans G: Trends in oral health by poverty status as
measured by Healthy People 2010 objectives. Public Health Rep 2010,
125:817–830.
Gao XL, Hsu CY, Xu Y, Hwarng HB, Loh T, Koh D: Building caries risk
assessment models for children. J Dent Res, 89:637–643.
Petersen PE, Bourgeois D, Bratthall D, Ogawa H: Oral health information
systems–towards measuring progress in oral health promotion and
disease prevention. Bull World Health Organ 2005, 83:686–693.
Oral health surveys: Basic methods. 4th edition. Geneva: World Health
Organization; 1997.
Czech statistical office: GDP and other macroeconomic indicators in the Czech
Republic over the period 1989–2009: http://www.czso.cz/csu/2011edicniplan.
nsf/t/76003C705F/$File/1420110303.pdf.
Czech statistical office: Education in the Czech Republic over the period 1989–2009:
http://www.czso.cz/csu/2011edicniplan.nsf/t/76005209C3/$File/1420111702.pdf.
Rimmer PA, Pitts NB: Effects of diagnostic threshold and overlapped
approximal surfaces on reported caries status. Community Dent Oral
Epidemiol 1991, 19:205–212.
Whelton H: Overview of the impact of changing global patterns of
dental caries experience on caries clinical trials. J Dent Res 2004,
83(Spec No C):C29–C34.
Ismail AI, Sohn W, Tellez M, Amaya A, Sen A, Hasson H, Pitts NB: The
International Caries Detection and Assessment System (ICDAS): an
integrated system for measuring dental caries. Community Dent Oral
Epidemiol 2007, 35:170–178.
Finlayson TL, Siefert K, Ismail AI, Sohn W: Psychosocial factors and early
childhood caries among low-income African-American children in
Detroit. Community Dent Oral Epidemiol 2007, 35:439–448.
Cadavid AS, Lince CM, Jaramillo MC: Dental caries in the primary dentition
of a Colombian population according to the ICDAS criteria. Braz Oral Res
2010, 24:211–216.
Policy on early childhood caries (ECC): classifications, consequences, and
preventive strategies. Pediatr Dent 2008, 30:40–43.
HEALTH21: An introduction to the health for all policy framework for the WHO
European Region. Copenhagen: WHO Regional Office for Europe; 1998.
Beltran-Aguilar ED, Malvitz DM, Lockwood SA, Rozier RG, Tomar SL: Oral
health surveillance: past, present, and future challenges. J Public Health
Dent 2003, 63:141–149.
doi:10.1186/1471-2458-12-547
Cite this article as: Lenčová et al.: Early childhood caries trends and
surveillance shortcomings in the Czech Republic. BMC Public Health 2012
12:547.
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