W. Kim Seow

Environmental, maternal, and child factors which contribute to early childhood caries: a unifying conceptual model.

OBJECTIVES Although the general pathways connecting the external social environment and child risk factors of early childhood caries (ECC) have been previously identified, the maternal and other links to ECC are not well understood. The aim of this paper is to propose a unifying conceptual model that ties together the broad social environmental, maternal, and child factors that are commonly associated with ECC. METHODS The aetiological factors of ECC are first reviewed individually to demonstrate their connections with ECC risk followed by presentation of the unifying conceptual model. RESULTS In severe ECC cases, there is usually a background of social disadvantage associated with low socioeconomic status, ethnicity or immigrant status, and low maternal educational level. These factors are commonly associated with economic and familial stresses which may in turn result in maternal psychological distress. The distress may be compounded by difficult temperaments of the children and can lead to dysfunctional parenting behaviours that place a child at risk for ECC. CONCLUSIONS The proposed conceptual model provides a framework that connects the social, psychological, and behavioural mediating factors involved in ECC. It demonstrates that the causative pathways involved are best explored using a combination of quantitative and qualitative research.

Oral Streptococcus species in pre‐term and full‐term children – a longitudinal study

BACKGROUND Despite high clinical significance, the microbiology of the dental biofilm in young children remains poorly understood. AIM The aim of this longitudinal study was to investigate five Streptoccocus species commonly found in the oral biofilm of children, namely Streptococcus mutans, Streptococcus sobrinus, Streptococcus mitis, Streptococcus sanguinis, and Streptococcus salivarius to determine their relative numbers in caries-free pre-term children, and age-matched full-term controls. DESIGN Plaque and saliva samples were obtained from 15 pre-term children and 15 age-matched controls at ages 3, 6, 12, 18, and 24 months. A quantitative real-time PCR technique was used to determine the numbers of five species of Streptococcus using probes and primers specific for each bacterial species. RESULTS All species of Streptococcus generally increased from ages 3 to 24 months. The relative ratios of the bacteria remained fairly constant at all ages studied (P > 0.1). There were no significant differences in numbers of all Streptococcus species between pre-term children and full-term controls at all the ages investigated between. CONCLUSION The results show that the relative numbers of S. mutans, S. sobrinus, S. mitis, S. sanguinis, and S. salivarius remain relatively constant from 3 to 24 months of age in caries-free pre- and full-term children.

A controlled, longitudinal study of home visits compared to telephone contacts to prevent early childhood caries

BACKGROUND Home visits (HV) provide excellent opportunities for health promotion. AIM This longitudinal study compared the effects of HV and telephone contacts (TC) in preventing early childhood caries (ECC) and colonisation of mutans streptococci (MS) and lactobacilli (LB) from 0 to 24 months. DESIGN A total of 325 children were recruited from community health centres at mean age of 42 days, and randomly assigned to receive either HV or TC. A total of 188 children completed three, 6 monthly HV, and another 58 had three, 6 monthly TC. An additional 40 age-matched children from childcare facilities served as reference controls (RC). At 24 months, all groups were examined at a community dental clinic. RESULTS At 24 months, three HV children of 188 (1.5%) had caries, compared to four TC of 58 (6.8%) and nine RC of 40 (22.5%) (P < 0.001 for HV versus RC; P = 0.05 for HV versus TC and P = 0.03 for TC versus RC). There were also more children with MS in the TC (47%) and RC (35%) compared to HV (28%) group (P = 0.01 and P = 0.02). CONCLUSIONS Home visits and telephone contacts conducted 6 monthly from birth are effective in reducing ECC prevalence by 24 months.

Increased traffic exposure and negative birth outcomes: a prospective cohort in Australia

BackgroundPregnant women exposed to traffic pollution have an increased risk of negative birth outcomes. We aimed to investigate the size of this risk using a prospective cohort of 970 mothers and newborns in Logan, Queensland.MethodsWe examined two measures of traffic: distance to nearest road and number of roads around the home. To examine the effect of distance we used the number of roads around the home in radii from 50 to 500 metres. We examined three road types: freeways, highways and main roads.ResultsThere were no associations with distance to road. A greater number of freeways and main roads around the home were associated with a shorter gestation time. There were no negative impacts on birth weight, birth length or head circumference after adjusting for gestation. The negative effects on gestation were largely due to main roads within 400 metres of the home. For every 10 extra main roads within 400 metres of the home, gestation time was reduced by 1.1% (95% CI: -1.7, -0.5; p-value = 0.001).ConclusionsOur results add weight to the association between exposure to traffic and reduced gestation time. This effect may be due to the chemical toxins in traffic pollutants, or because of disturbed sleep due to traffic noise.

Cost-effectiveness of a telephone-delivered education programme to prevent early childhood caries in a disadvantaged area: a cohort study

Objectives Early childhood caries is a highly destructive dental disease which is compounded by the need for young children to be treated under general anaesthesia. In Australia, there are long waiting periods for treatment at public hospitals. In this paper, we examined the costs and patient outcomes of a prevention programme for early childhood caries to assess its value for government services. Design Cost-effectiveness analysis using a Markov model. Setting Public dental patients in a low socioeconomic, socially disadvantaged area in the State of Queensland, Australia. Participants Children aged 6 months to 6 years received either a telephone prevention programme or usual care. Primary and secondary outcome measures A mathematical model was used to assess caries incidence and public dental treatment costs for a cohort of children. Healthcare costs, treatment probabilities and caries incidence were modelled from 6 months to 6 years of age based on trial data from mothers and their children who received either a telephone prevention programme or usual care. Sensitivity analyses were used to assess the robustness of the findings to uncertainty in the model estimates. Results By age 6 years, the telephone intervention programme had prevented an estimated 43 carious teeth and saved £69 984 in healthcare costs per 100 children. The results were sensitive to the cost of general anaesthesia (cost-savings range £36 043–£97 298) and the incidence of caries in the prevention group (cost-savings range £59 496–£83 368) and usual care (cost-savings range £46 833–£93 328), but there were cost savings in all scenarios. Conclusions A telephone intervention that aims to prevent early childhood caries is likely to generate considerable and immediate patient benefits and cost savings to the public dental health service in disadvantaged communities.

Effects of Water Fluoridation on Caries Experience in the Primary Dentition in a High Caries Risk Community in Queensland, Australia

Objectives: In December 2008, artificial water fluoridation was introduced for the first time to the Logan-Beaudesert district in the state of Queensland, Australia. The aim of this study was to evaluate the effects of water fluoridation in the primary dentition in this community after a period of 36 months. Methods: Children aged 4-9 years with clinical examinations and bitewing radiographs (BWs) taken before water fluoridation (pre-F) were randomly selected as comparison controls for age matched children who had been exposed to a mean period of 36 months of water fluoridation (post-F). A total of 201 sets of pre-F BWs from children (mean age 6.95 ± 1.05 years) and 256 sets of post-F BWs from children (mean age 7.19 ± 1.23 years) attending schools in the district were randomly selected. Caries experience in the primary dentition was determined as decayed, missing or filled teeth/surfaces (dmft/dmfs). Results: The caries prevalence for the pre-F group was 87% compared to 75% in the post-F group (Odds ratio (OR): 0.44, 95% CI: 0.27-0.72). Overall, there was a 19 percent reduction of mean dmft from 4.54 in the pre-F group to 3.66 in the post-F group (p = 0.005). After fluoridation, the dmfs was reduced from 6.68 to 5.17 (p = 0.0056). The distal surfaces of maxillary first primary molars experienced the greatest reduction (26%) in caries experience after water fluoridation (p < 0.001). Conclusions: After only 36 months of water fluoridation there was a significant drop in caries prevalence from 87 to 75% and a 19% reduction in caries experience in a community with one of the highest caries rates in Australia.

New approaches to dental anthropology based on the study of twins

Studies of twins carried out over the past 25 years by the Craniofacial Biology Research Group at the University of Adelaide have provided insights into the roles of genetic, environmental and epigenetic influences on human dento-facial growth and development. The aim of this paper is to review some of the main findings of these studies and to highlight the value of using different twin models, including the monozygotic (MZ) co-twin design. We also introduce the concept of ‘dental phenomics’ whereby modern 2D and 3D imaging systems are now enabling biologically meaningful, dental phenotypes to be quantified in order to provide detailed descriptions of the size and shape of teeth. We propose that developments in the field of ‘dental phenomics’, with linking of the data generated to large-scale genome sequencing approaches, should enable us to further unravel the mysteries of how genetic, environmental and epigenetic factors interact to produce the extensive range of morphological variations evident within the human dentition and face.

Association of erosion with timing of detection and selected risk factors in primary dentition: a longitudinal study

OBJECTIVE The aims of this study were to determine the prevalence of erosion in a birth cohort at 24, 36, and 48 months and to investigate risk factors for erosion. METHODS One hundred and fifty-four children from a birth cohort were followed at 24, 36, and 48 months of age. RESULTS Of the 154 children examined, 0% (0/154), 7% (11/154), and 28% (40/154) had erosion detected for the first time at 24, 36, and 48 months, respectively (P < 0.001). A cumulative total of 51 (33%) children and 256 (8%) teeth had erosion by the age of 48 months. There were no significant associations between erosive lesions first detected at 36 months and oral hygiene behaviour, medical conditions, or dietary habits reported at the 24- or 36-month examinations (all P > 0.05). In contrast, erosive lesion first detected at 48 months was positively associated with the use of a feeding bottle reported at the 36-month examination (P = 0.026). CONCLUSIONS The prevalence of dental erosion in young children increased with age, with clinically detectable lesions forming between 24 and 36 months of age. Erosive lesions first detected at 48 months were positively associated with the use of a feeding bottle reported at 36 months.

Bacterial colonization, enamel defects and dental caries in 4-6-year-old mono- and dizygotic twins.

BACKGROUND Knowledge of the genetic and environmental influences in caries aetiology has relevance for preventive dentistry. AIMS This classical twin study compared concordance of mutans streptococci (MS) and lactobacilli (LB) colonization, enamel defects, and caries in a cohort of 4-6-year-old mono- (MZ) and dizygotic (DZ) twin pairs. DESIGN The twins were examined for prevalence and concordance of enamel opacities and hypoplasia, oral counts of MS and LB, and dental caries. Bacterial counts were assessed using a commercial microbiological kit. RESULTS Thirty-four MZ and 50 DZ twins (mean gestational age 35.0 ± 2.4 weeks, and birthweight 2.4 ± 0.6 kg) were examined. There were no statistically significant differences between MZ and DZ twins in the prevalence of MS, LB, and enamel hypoplasia. Concordance rates for MS and LB presence and prevalence of enamel defects within MZ and DZ twin pairs were not significantly different. There were more children with caries in DZ compared with MZ twins (18% vs 3%, P = 0.0029), most likely due to increased daily frequency of sugar consumption and less toothbrushing. CONCLUSIONS Concordance data from MZ and DZ twins did not demonstrate any statistically significant difference in susceptibility for enamel defects and colonization of MS and LB.