Early childhood caries trends and surveillance shortcomings in the Czech Republic

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 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 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.

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.

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 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%.

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 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].

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 non-communicable 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 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.