Presence of visible plaque accumulation and reported consumption of sugared drinks were associated with prevalence of caries experience in Flemish preschool children. Severity of disease was associated with gender and with presence of plaque. Results underline the importance of plaque control and diet management from very young age on.

Our findings emphasize the importance of early detection of these oral conditions in order to permit effective and long-term planning, according to the child's individual requirements.

The aim of the present study was to assess indicators shown to be associated with the prevalence of caries in the primary dentition of 7-year-old Flemish schoolchildren. Cross-sectional first year data of the longitudinal Signal-Tandmobiel survey were analysed (n=4468). Gender, age, oral hygiene habits, use of fluorides, dietary habits, geographical factors and parental modelling were the considered predictors. From the multiple logistic regression analysis, including schools as a random effect, and after adjusting for the confounding variables-educational system and province (stratification variables), gender and age-it became clear that the following risk indicators remained significant (at 5% level) for the presence of caries: frequency of toothbrushing (P=0.05) with an OR 1.24 for brushing less than once a day, age at start of brushing (P<0.001) with an OR=1.22 for a delay of 1 year, regular use of fluoride supplements (P<0.001) with an OR=1.54 for no use, daily use of sugar-containing drinks between meals (P<0.001) with an OR=1.38, and number of between-meals snacks (P=0.012) with an OR=1.22 for using more than 2 between-meal snacks. There was a significant difference (P<0.05) in caries experience determined by the geographical spread, with an explicit trend of caries declining from the east to the west. In a model with an ordinal response outcome, the daily use of sugar-containing drinks between meals had a more pronounced effect when caries levels were high. From this study it became obvious that, in Flemish children, an early start of brushing and a brushing frequency of at least once a day need to be encouraged, while the use of sugar-containing drinks and snacks between meals needs to be restricted to a maximum of 2 per day. Geographical differences need to be investigated in more detail.

Zero-inflated models for count data are becoming quite popular nowadays and are found in many application areas, such as medicine, economics, biology, sociology and so on. However, in practice these counts are often prone to measurement error which in this case boils down to misclassification. Methods to deal with misclassification of counts have been suggested recently, but only for the binomial model and the Poisson model. Here we look at a more complex model, that is, the zero-inflated negative binomial, and illustrate how correction for misclassification can be achieved. Our approach is illustrated on the dmft-index which is a popular measure for caries experience in caries research. An extra problem was the fact that several dental examiners were involved in scoring caries experience. Using our example, we illustrate how a non-differential misclassification process for each examiner can lead to differential misclassification overall.

Objectives:The objectives of this cross-sectional survey were to determine the prevalence of secondary caries (SC) in general population, to identify patient-and material-related factors which may affect the prevalence, and to describe some clinical characteristics of SC lesions. Materials and methods:A total of 4036 restorations in 450 patients, who visited university dental clinic for a regular (half-) yearly check-up, were examined clinically (and radiographically) for the presence of SC. Clinical characteristics of the detected SC lesions (size, activity and location) and the planned treatment were recorded. In addition, patients' caries-risk status was assessed according to the modified 'Cariogram' model. Results:In total, 146 restorations were diagnosed with SC, which gives an overall prevalence of 3.6%.Restorative material, restoration class, patient's caries risk and smoking habits, were shown to be important factors, as SC prevalence was significantly higher with composites, class II restorations, high caries risk patients and smokers. Restorations' gingival margins were most frequently affected by SC. The largest number of restorations with SC (72%) was scheduled for the replacement.Conclusions: Prevalence of SC was higher with composite than with amalgam restorations, irrespective of the patient's caries-risk status. Gingival margins of class II, including MOD restorations, seem to be the place of less resistance to SC development. Management of SC seems to place a considerable burden on the health care work force and expenditure.Clinical relevance: Secondary caries (SC) is considered to be the main cause of dental restoration failure and one of the biggest clinical challenges related to dental composites. Nevertheless, its prevalence in daily practice is still not clear, which impedes an accurate estimation of its impact on health care costs.

The dental condition of 626 12-year-old handicapped children with mild mental or moderate to severe mental retardation or learning impairment, being 25% of the population of each of these groups, was examined in Flanders. An evaluation of oral cleanliness showed poor oral hygiene in 31.8% of the children. No significant differences were found in oral cleanliness among types of handicapping conditions. The mean DMFT score was 2.9 (s: 2.6) and DMFS score was 5.4 (s: 5.6). Almost 21% of the children were free of caries or fillings. No significant differences were found among groups of handicapped children. Handicapped children presented a low level of restorative care (restorative index score: 48.7%). Mildly mentally retarded children demonstrated the lowest restorative index (43.9%). The caries experience of first permanent molars represented the largest part of the DMFT score (64.1%). Sealants were present in 7.9% of children examined. A considerable percentage of mildly mentally retarded children and learning impaired children did not brush daily (22.1% and 20.9%) and did not receive help with toothbrushing from their parents or carers (91.0% and 94.7%, respectively).

The aim of the present study was to investigate the timing of emergence of permanent teeth in Flanders (Belgium). Data were obtained in the Signal-Tandmobiel projecta, a longitudinal study in a sample of 4468 Flemish children. Survival analysis with a log-logistic distribution was performed to calculate median (and mean) values and 95% CI's for all permanent teeth. The analysis indicated significantly earlier emergence ages in girls than in boys. The emergence pattern turned out to be symmetric in both sexes. Most mandibular teeth emerged significantly before their antagonists, in boys as well as in girls. These findings are in agreement with other studies on the emergence of permanent teeth.

To establish a reliable screening method for caries prediction and to identify predominant risk factors, this study tested whether a cross–sectional caries risk model assessed at age 7 could be used to predict future caries onset in the permanent first molars at age 10 in 3,303 children born in 1989. As prediction variables, assessing the believed risk, baseline data at age 7 on oral health status, oral hygiene level, oral health behaviour and sociodemographic factors were used. The real risk, based on data collected for the first permanent molars during the follow–up, was assessed by different approaches. Cumulative incidence during the 3–year observation period was 31.6%, ranging from 22.4% in the believed low–risk group to 43.2% in the believed high–risk group. A stepwise logistic regression analysis was performed with net caries increment as outcome measure, adjusted for the real time at risk, using eruption times. Baseline dmfs and occlusal and buccal plaque indices were highly significant for having a high caries increment in permanent first molars with respective odds ratios of 1.07, 1.43 and 1.35. Brushing less than once a day and the daily use of sugar–containing drinks between meals were confirmed as risk factors (OR 2.43 and 1.25, respectively). The logistic regression analysis provided a sensitivity of 59–66% and a specificity of 65.7–72.8%, which indicates that the risk marker did not have an important predictive power. None of the socio–demographic and behavioural variables had enough predictive power at community level to be useful for identifying caries susceptible children. Even the power of dmfs at baseline must be considered modest.