Oral and craniofacial research in the Generation R study: an executive summary.

OBJECTIVES: Oral conditions are of high prevalence and chronic character within the general population. Identifying the risk factors and determinants of oral disease is important, not only to reduce the burden of oral diseases, but also to improve (equal access to) oral health care systems, and to develop effective oral health promotion programs. Longitudinal population-based (birth-)cohort studies are very suitable to study risk factors on common oral diseases and have the potential to emphasize the importance of a healthy start for oral health. In this paper, we provide an overview of the comprehensive oral and craniofacial dataset that has been collected in the Generation R study: a population-based prospective birth cohort in the Netherlands that was designed to identify causes of health from fetal life until adulthood. METHODS: Within the multidisciplinary context of the Generation R study, oral and craniofacial data has been collected from the age of 3 years onwards, and continued at the age of six, nine, and thirteen. Data collection is continuing in 17-year-old participants. RESEARCH OUTCOMES: In total, the cohort population comprised 9749 children at birth, and 7405 eligible participants at the age of seventeen. Based on questionnaires, the dataset contains information on oral hygiene, dental visits, oral habits, oral health-related quality of life, orthodontic treatment, and obstructive sleep apnea. Based on direct measurements, the dataset contains information on dental caries, developmental defects of enamel, objective orthodontic treatment need, dental development, craniofacial characteristics, mandibular cortical thickness, and 3D facial measurements. CONCLUSIONS: Several research lines have been set up using the oral and craniofacial data linked with the extensive data collection that exists within the Generation R study. CLINICAL RELEVANCE: Being embedded in a multidisciplinary and longitudinal birth cohort study allows researchers to study several determinants of oral and craniofacial health, and to provide answers and insight into unknown etiologies and oral health problems in the general population.

Adherence to dietary guidelines and dental caries among children: a longitudinal cohort study.

BACKGROUND: Even though dietary sugars are the most important nutrient for caries development, the disease process is dependent on other dietary practices. The intake of individual nutrient components cannot be evaluated separately from the overall diet which includes other nutrients, foods and habits. Therefore, the aim of this study was to investigate the association between adherence to dietary guidelines and dental caries. METHODS: This study was embedded in the Generation R Study, conducted in Rotterdam, the Netherlands. In total, 2911 children were included in the present analyses. Dietary intake at the age of 8 years was assessed using food-frequency questionnaires. Diet quality scores were estimated, reflecting adherence to Dutch dietary guidelines. Dental caries was assessed at the age of 13 years using intra-oral photographs. Associations were estimated using multinomial logistic regression analyses, adjusted for sociodemographic characteristics and oral hygiene practices. RESULTS: The prevalence of dental caries at the age of 13 years was 33% (n = 969). Better diet quality was associated with a lower occurrence of severe dental caries after adjustments for sociodemographic factors [e.g. highest vs. lowest quartile of diet quality: odds ratio (OR) 0.62, 95% confidence interval (CI) 0.39-0.98]. After additional adjustments for oral hygiene practices, this association was not statistically significant (OR 0.65, 95% CI 0.41-1.03). CONCLUSION: Adherence to dietary guidelines has the potential to reduce dental caries in children; however, with proper oral hygiene practices, this relationship might be attenuated. To understand the role of dietary patterns and dental caries, the contributing role of daily eating occasions needs to be studied further.

Breastfeeding and Childhood Dental Caries: Results from a Socially Diverse Birth Cohort Study.

Previous studies showed that prolonged breastfeeding increases the risk of caries. However, the observed associations were mainly based on non-European populations, and important confounding and mediating factors like socioeconomic position (SEP) and diet were often neglected. The aim of this study was to investigate the role of breastfeeding and bottle-feeding practices on dental caries during childhood while accounting for SEP, ethnic background, and sugar intake. This study was part of the Generation R Study, a prospective multiethnic cohort study conducted in Rotterdam, The Netherlands. In total, 4,146 children were included in the analyses. Information about feeding practices was derived from delivery reports and questionnaires during infancy. Caries was measured via intraoral photographs at the age of 6 years and defined as decayed, missing, and filled teeth (dmft). Negative binomial hurdle regression analyses were used to study the associations between several infant feeding practices and childhood caries. The prevalence of dental caries at the age of 6 years was 27.9% (n = 1,158). Prolonged breastfeeding (for >12 months) was associated with dental caries (OR 1.35, 95% CI 1.04-1.74) and the number of teeth affected by dental caries (RR 1.27, 95% CI 1.03-1.56). Furthermore, nocturnal bottle-feeding was associated with dental caries (OR 1.52, 95% CI 1.20-1.93). All associations were independent of family SEP, ethnic background, and sugar intake. Results from this Dutch cohort study confirmed the previously observed associations between prolonged breastfeeding and nocturnal bottle-feeding and the increased risk of childhood dental caries, even after proper adjustments for indicators of SEP, ethnic background, and sugar intake. Future studies are encouraged to elaborate further on possible explanations for the observed relationships. Healthcare professionals should be aware and advise caregivers about the potential risk of prolonged breastfeeding on caries development by applying the current recommendations on breastfeeding, oral hygiene, and feeding frequency.

Neighbourhood characteristics and children's oral health: a multilevel population-based cohort study.

BACKGROUND: To understand determinants of oral health inequalities, multilevel modelling is a useful manner to study contextual factors in relation to individual oral health. Several studies outside Europe have been performed so far, however, contextual variables used are diverse and results conflicting. Therefore, this study investigated whether neighbourhood level differences in oral health exist, and whether any of the neighbourhood characteristics used were associated with oral health. METHODS: This study is embedded in The Generation R Study, a prospective cohort study conducted in The Netherlands. In total, 5 960 6-year-old children, representing 158 neighbourhoods in the area of Rotterdam, were included. Data on individual and neighbourhood characteristics were derived from questionnaires, and via open data resources. Caries was assessed via intraoral photographs, and defined as decayed, missing and filled teeth (dmft). RESULTS: Differences between neighbourhoods explained 13.3% of the risk of getting severe caries, and 2% of the chance of visiting the dentist yearly. After adjustments for neighbourhood and individual characteristics, neighbourhood deprivation was significantly associated with severe dental caries (OR: 1.48, 95% CI: 1.02-2.15), and suggestive of a low odds of visiting the dentist yearly (OR: 0.81, 95% CI: 0.56-1.18). CONCLUSIONS: Childhood caries and use of dental services differs between neighbourhoods and living in a deprived neighbourhood is associated with increased dental caries and decreased yearly use of dental services. This highlights the importance of neighbourhoods for understanding differences in children's oral health, and for targeted policies and interventions to improve the oral health of children living in deprived neighbourhoods.