Reporting Data from Caries Epidemiological Surveys
The manner in which results are reported is important. Documents that describe epidemiological surveys are not restricted to dental professionals. Policy makers, medical practitioners, politicians, and the public have access to such documents, which requires clear reporting and should be straightforward and supported with easily understandable tables and figures. To make caries epidemiological reports easy to read a few typical dental inherited approaches from the past need to be changed, such as the use of the dmf/DMF index, which dates back to 1938 and contains a number of deficiencies.
Table 1. The validated CAST characteristics, codes and descriptions
An inherent deficiency is its use in calculating the prevalence of dental caries. By definition, the presence of carious lesions into dentine, restored dentine lesions, and missing teeth due to dental caries (D3MFT) make up the prevalence of dental caries. If required, the code for enamel carious lesion(s) can be included in the prevalence calculation, but this has to be clearly stated (D1MFT or D2MFT). The present definition covers not only actual disease but also past disease (restored and missing teeth). The advantage of considering teeth restored and teeth lost due to dental caries not diseased anymore is that dental caries prevalence is calculated on the bases of the actual presence of the disease in the individual. This reasoning was one of the cornerstones of the development of CAST. It holds the advantage of depicting the state of the disease and monitoring its changes over time in society more reliably. For example, successful interventions cannot be evidenced by a lower prevalence score [27].
In principle, studies that use CAST do not report the results in dmf/DMF counts but a dmf/DMF count can be calculated using CAST codes [23]. CAST uses frequency distributions per caries code or for maximum CAST code, depending on the aim of the survey (Fig. 1, 2). The severity of caries-related conditions within an individual or group after using CAST is calculated according to a mathematical formula in which the CAST codes have been assigned a weighted coefficient of severity [28]. Those wishing to know more about how to apply CAST and how to report data are referred to the CAST manual [29].
Global Epidemiology of Dental Caries
A recent publication reported on the global epidemiology of dental caries [30]. The paper was based on a systematic review of systematic reviews on the prevalence and incidence of dental caries. As only one systematic review was retrieved covering 1990–2010, and this review had limited background variables [31], the WHO Data Bank at Malmö University Dental School [32] was used to obtain more detailed information. The Data Bank contains dental caries-related data, covers several decades of studies, and is periodically updated. The country dental caries prevalence and the dmf/DMF and d/D-component data from the recommended WHO age groups were used as outcome measures for the period from 2000 to 2016. These data were related to the countries’ gross national income [33], developed by the World Bank, according to high-, upper-middle-, lower-middle-, and low-income countries.
Fig. 1. Maximum CAST score per subject and type of dentition based on hypothetical results. Modified from Leal et al. [57].
Fig. 2. Severity of dental caries based on the maximum CAST score per subject. Modified from Leal et al. [57].
The publication also reported trend studies that had covered a period of at least 20 years, from 1999 to 2016. The caries assessment criterion developed by the WHO (1971) was used most frequently.
Global Burden of Untreated Cavitated Dentine Carious Lesions
The systematic review dealt with the global burden of untreated cavitated dentine carious lesions and covered 187 countries [31]. The age-standardised prevalence of untreated dentine carious lesions in the primary dentition in the global population did not change during the 2 decades and constituted the 10th most prevalent health condition, affecting 621 million children worldwide. There were no significant differences between boys and girls.
Table 2. Median prevalence of cavitated dentine carious lesions in 5- and 6-year-olds, median of mean dmft scores and range interval, and proportion of d-component and range interval by category of country income, using WHO Data Bank data from 2000 to 2015 (data from Frencken et al. [30])
The global age-standardised prevalence of untreated dentine carious lesions in the permanent dentition did not change between 1990 and 2010 and reached a peak at age 25 years, with a second peak at around 70 years of age. There were no significant differences between gender. The authors concluded that untreated cavitated dentine carious lesions in permanent teeth remained the most prevalent health condition across the globe in 2010, affecting 2.4 billion people [31].
Prevalence and Extent of Carious Lesions in Infants and Young Children
It is technically and behaviourally possible to keep healthy primary teeth healthy. Unfortunately, this is not the reality in many world communities. Frencken [34] reported that “(severe) early childhood caries ([S-]ECC) is prevalent in many countries with large populations in deprivation. Epidemiological surveys from Brazil, Canada, Vietnam, China, Switzerland, and Thailand show alarming results. High prevalence figures for S-ECC for 38% (Canada) and 44.1% (Thailand) of 3-year olds have been reported while the prevalence of ECC was 24.8% in Switzerland and 74.4% in Vietnam among 1- to 6-year olds. The mean dmft-score for 1- to 6-year olds was 3.6 in China and 3.9 in Canada” [31]. The heterogeneity of data collection methods between these studies notwithstanding, these figures show that something is drastically wrong in many world communities despite some improvements achieved over the last 3 decades in other countries and communities [27].
One of the risk indicators for developing dental caries is the level of deprivation.
