Early childhood caries epidemiology, aetiology, risk assessment, societal burden, management, education, and policy: Global perspective.

BACKGROUND: This paper is a summary of the proceedings of the International Association of Paediatric Dentistry Bangkok Conference on early childhood caries (ECC) held in 3-4 November 2018. AIM: The paper aims to convey a global perspective of ECC definitions, aetiology, risk factors, societal costs, management, educational curriculum, and policy. DESIGN: This global perspective on ECC is the compilation of the state of science, current concepts, and literature regarding ECC from worldwide experts on ECC. RESULTS: Early childhood caries is related to frequent sugar consumption in an environment of enamel adherent, acid-producing bacteria in a complex biofilm, as well as developmental defects of enamel. The seriousness, societal costs, and impact on quality of life of dental caries in pre-school children are enormous. Worldwide data show that ECC continues to be highly prevalent, yet infrequently treated. Approaches to reduce the prevalence include interventions that start in the first year of a child's life, evidence-based and risk-based management, and reimbursement systems that foster preventive care. CONCLUSIONS: This global perspective on ECC epidemiology, aetiology, risk assessment, global impact, and management is aimed to foster improved worldwide understanding and management of ECC.

A Controlled Study of Pre-Eruptive Intracoronal Resorption and Dental Development.

AIM: To compare the prevalence of PEIR in Australian and Saudi Arabian children and to investigate the relationship of PEIR with dental development. STUDY DESIGN: Panoramic (PAN) radiographs of 842 Australian and 456 Saudi children were screened for PEIR. The dental ages of the children with and without PEIR were assessed from the PAN radiographs using the method of Demirjian and co-workers. RESULTS: The subject prevalence of PEIR was not statistically significant between Australian (2%) and Saudi children (0.6%) (p>0.1). The teeth most commonly affected by PEIR were the mandibular second molars and premolars. Dental impaction was observed in 31% of teeth with PEIR compared to only 0.1% of control teeth (p<0.0001). Children with PEIR showed a mean delay in dental development of 0.54±0.85 years compared with ageand gender-matched controls (p<0.0001). CONCLUSIONS: The present study provides the first evidence that there are no differences in PEIR prevalence between Australian and Saudi populations, and that dental development is significantly delayed in children with PEIR.

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.

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.

Genetic, epigenetic, and environmental influences on dentofacial structures and oral health: ongoing studies of Australian twins and their families.

The Craniofacial Biology Research Group in the School of Dentistry at The University of Adelaide is entering an exciting new phase of its studies of dental development and oral health in twins and their families. Studies of the teeth and faces of Australian twins have been continuing for nearly 30 years, with three major cohorts of twins recruited over that time, and currently we are working with twins aged 2 years old to adults. Cross-sectional data and records relating to teeth and faces of twins are available for around 300 pairs of teenage twins, as well as longitudinal data for 300 pairs of twins examined at three different stages of development, once with primary teeth, once at the mixed dentition stage, and then again when the permanent teeth had emerged. The third cohort of twins comprises over 600 pairs of twins recruited at around birth, together with other family members. The emphasis in this third group of twins has been to record the timing of emergence of the primary teeth and also to sample saliva and dental plaque to establish the timing of colonization of decay-forming bacteria in the mouth. Analyses have confirmed that genetic factors strongly influence variation in timing of primary tooth emergence. The research team is now beginning to carry out clinical examinations of the twins to see whether those who become colonized earlier with decay-forming bacteria develop dental decay at an earlier age. By making comparisons within and between monozygotic (MZ) and dizygotic (DZ) twin pairs and applying modern molecular approaches, we are now teasing out how genetic, epigenetic, and environmental factors interact to influence dental development and also oral health.

A randomised, controlled clinical trial comparing chlorhexidine gel and low-dose fluoride toothpaste to prevent early childhood caries.

OBJECTIVES. This randomised, controlled trial compared the effectiveness of 0.12% chlorhexidine (CHX) gel and 304% fluoride toothpaste to prevent early childhood caries (ECC) in a birth cohort by 24 months. METHODS. The participants were randomised to receive either (i) twice daily toothbrushing with toothpaste and once daily 0.12% CHX gel (n = 110) or (ii) twice daily toothbrushing with toothpaste only (study controls) (n = 89). The primary outcome measured was caries incidence and the secondary outcome was percentage of children with mutans streptococci (MS). All mothers were contacted by telephone at 6, 12, and 18 months. At 24 months, all children were examined at a community dental clinic. RESULTS. At 24 months, the caries prevalence was 5% (3/61) in the CHX and 7% (4/58) in the controls (P = 0.7). There were no differences in percentages of MS-positive children between the CHX and control groups (54%vs 53%). Only 20% applied the CHX gel once daily and 80% less than once daily. CONCLUSIONS. Toothbrushing using 304% fluoride toothpaste with or without the application of chlorhexidine gel (0.12%) reduces ECC from 23% found in the general community to 5-7%. The lack of effect with chlorhexidine is likely to be due to low compliance.

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.

BACKGROUND: Pregnant 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. METHODS: We 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. RESULTS: There 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). CONCLUSIONS: Our 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.

Enamel hypoplasia in the primary dentition of monozygotic and dizygotic twins compared with singleton controls.

BACKGROUND: The study of enamel hypoplasia (EH) and opacity in twins provides insights into the contribution of genetic and environmental factors in the expression of enamel defects. AIM: This study examined prevalence and site concordance of EH and opacity in the primary dentition of 2- to 4-year-old twins and singleton controls to assess the relative contribution of genetics and the environment to the aetiology of these defects. DESIGN: The study sample consisted of 88 twin children and 40 singletons aged 2-4 years of age. Medical histories were obtained and the children examined for enamel defects. RESULTS: The prevalence of EH by teeth was 21% in monozygotic twins (MZ), 22% in dizygotic twins (DZ), and 15% in singleton controls. Twins showed a higher prevalence of EH compared with singletons (P < 0.05). Factors contributing to increase EH in twins were neonatal complications including intubation. There were no significant differences in site concordance of EH within the MZ twin pairs compared with DZ twin pairs when only presence of EH was considered, whereas a greater concordance was noted between MZ twin pairs compared with DZ twin pairs when both presence and absence of EH were considered. CONCLUSIONS: The results suggest that both genetic and environmental factors contribute to observed variation of EH, although it is likely that environmental factors exert a greater influence.

Comparison of enamel defects in the primary and permanent dentitions of children from a low-fluoride District in Australia.

PURPOSE: The purpose of this study was to compare developmental defects of enamel (DDE) in the primary and permanent dentitions of children from a low-fluoride district. METHODS: A total of 517 healthy schoolchildren were examined using the modified DDE criteria. RESULTS: The prevalence of DDE in the primary and permanent dentition was 25% and 58%, respectively (P<.001). The mean number of teeth with enamel opacity per subject was approximately threefold compared to that affected by enamel hypoplasia (3.1±3.8 vs 0.8±1.4, P<.001 in the primary dentition and 3.6±4.7 vs 1.2±2.2, P<.001 in the permanent dentition). Demarcated opacities (83%) were predominant compared to diffuse opacities (17%), while missing enamel was the most common type of enamel hypoplasia (50%), followed by grooves (31%) and enamel pits (19%) (P=.04). In the permanent dentition, diffuse and demarcated opacities were equally frequent, while enamel grooves were the commonest type of hypoplasia (52%), followed by missing enamel (35%) and enamel pits (5%; P<.001). CONCLUSIONS: In a low-fluoride community, developmental defects of enamel were twice as common in the permanent dentition vs the primary dentition. In the primary dentition, the predominant defects were demarcated opacities and missing enamel, while in the permanent dentition, the defects were more variable.

Congenital aplasia of the major salivary glands: literature review and case report.

Congenital aplasia of the major salivary glands is rare, and there have been few cases of the condition reported to date. In many cases, absence of the salivary glands is associated with syndromes involving the ectodermal tissues. The xerostomia encountered in affected children is usually associated with increased risk for caries and infections of the soft tissues. The purpose of this paper was to describe the case of a 10-year-old boy with bilateral aplasia of the submandibular and parotid salivary glands and the preventive and restorative treatment rendered. This case study demonstrates the importance of timely diagnosis of this condition in order to prevent the serious oral complications from xerostomia.

A controlled study of dental erosion in 2- to 4-year-old twins.

BACKGROUND: Dental erosion (DE) in children is a significant oral health issue and has become a focus for research in clinical paediatric dentistry. AIM: This study investigated DE in the primary dentition of 2- to 4-year-old twin and singleton children with regard to the genetic, medical and dietary factors associated with the condition. DESIGN: The 128 subjects consisted of 88 twin children (31 monozygous, 50 dizygous, 7 unknown zygosity) and singletons (n = 40) aged 2-4 years. Medical, dental, and dietary histories were obtained. The children were examined for DE using a modified index. RESULTS: The prevalence of DE by subject affected was 77% in monozygotic twins (MZ), 74% in dizygotic twins (DZ), and 75% in singleton controls (P > 0.1). Of the teeth scored, 12% had mild, 10% moderate, and 1% severe lesions, and DE was more severe in the older age group (P < 0.05). Concordance rates for erosion lesions in MZ and DZ co-twins were not statistically significant. CONCLUSIONS: The prevalence of DE and the concordance of erosion lesions were similar between MZ and DZ twins and singleton children, suggesting that the contribution of genetic factors to DE is negligible.

A case-control study of dental development in Hypodontic and Hyperdontic children.

PURPOSE: The purpose of this study was to investigate the rate of dental development in children with nonsyndromic hypodontia and nonsyndromic hyperdontia compared to age- and gender-matched controls. METHODS: Dental age assessment was performed using orthopantomograms on 115 children (63 girls, 52 boys) with hypodontia and 61 children (22 girls, 39 boys) with hyperdontia and compared with 176 normal controls, case-matched for gender and age. RESULTS: Both girls and boys with hypodontia showed a significant delay in dental development compared to case controls. The mean differences between dental age and chronological age in hypodontia girls and boys were -0.1+/-1.5 years and -0.1+/-1.2 years, respectively, compared to 1.0+/-1.0 years and 0.8+/-0.8 years in the case controls, respectively (P<.001 for both boys and girls). The delay in dental development was accentuated during puberty. By contrast, no significant differences were observed between hyperdontic children and case controls. CONCLUSIONS: Nonsyndromic hypodontia children experience delayed dental development, whereas nonsyndromic hyperdontia children have similar rotes of dental development compared to normal children. These findings have implications for management of dental growth and development in children with agenesis of the teeth and supernumerary teeth.

Taurodontism in children with hypodontia and supernumerary teeth: a case control study.

PURPOSE: The aim of the present investigation was to compare the prevalence of taurodontism in the permanent mandibular first molars of nonsyndromic children with hypodontia and supernumerary teeth with age- and gender-matched controls. METHODS: The crown-body root ratios of the permanent first molars were determined from orthopantomograms of 83 children with hypodontia (> or =1 missing teeth) and 37 children with supernumerary teeth (> or =1 extra teeth) compared with normal case controls. RESULTS: In children with hypodontia, only girls showed a significantly higher tendency for taurodontism compared to case controls (P=.003), while boys with hypodontia showed a similar prevalence of taurodontism as controls (P=.83). Children with multiple missing teeth were significantly more susceptible to taurodontism than children with a single missing tooth (P=.004). By contrast, the prevalence of taurodontism in children with supernumerary teeth was not significantly different from that of controls. CONCLUSIONS: Compared to normal case controls, children with nonsyndromic hypodontia are more likely to show taurodontism of the permanent first molar teeth whereas children with nonsyndromic supernumerary teeth are not.

Human and mouse enamel phenotypes resulting from mutation or altered expression of AMEL, ENAM, MMP20 and KLK4.

Amelogenesis imperfecta (AI) is caused by AMEL, ENAM, MMP20 and KLK4 gene mutations. Mice lacking expression of the AmelX, Enam and Mmp20 genes have been generated. These mouse models provide tools for understanding enamel formation and AI pathogenesis. This study describes the AI phenotypes and relates them to their mouse model counterparts. Human AI phenotypes were determined in a clinical population of AI families and published cases. Human and murine teeth were evaluated using light and electron microscopy. A total of 463 individuals from 54 families were evaluated and mutations in the AMEL, ENAM and KLK4 genes were identified. The majority of human mutations for genes coding enamel nonproteinase proteins (AMEL and ENAM) resulted in variable hypoplasia ranging from local pitting to a marked, generalized enamel thinning. Specific AMEL mutations were associated with abnormal mineralization and maturation defects. Amel and Enam null murine models displayed marked enamel hypoplasia and a complete loss of prism structure. Human mutations in genes coding for the enamel proteinases (MMP20 and KLK4) cause variable degrees of hypomineralization. The murine Mmp20 null mouse exhibits both hypoplastic and hypomineralized defects. The currently available Amel and Enam mouse models for AI exhibit enamel phenotypes (hypoplastic) that are generally similar to those seen in humans. Mmp20 null mice have a greater degree of hypoplasia than humans with MMP20 mutations. Mice lacking expression of the currently known genes associated with the human AI conditions provide useful models for understanding the pathogenesis of these conditions.

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 study of risk factors for enamel hypoplasia in the permanent dentition.

PURPOSE: The purpose of this study was to investigate risk factors for enamel hypoplasia (EH) and enamel opacity (EO) in the permanent teeth of healthy schoolchildren from a nonfluoridated community in Australia. METHODS: Children with EH (N=104) or EO (N=104) were compared with matched controls without enamel defects (N=105). Subjects who previously resided in on optimally fluoridated town provided data on the effects of drinking fluoridated water. RESULTS: The main risk factors for EH were low socioeconomic status (P < .04), respiratory infections (P < .001), exposure to cigarette-smoking (P = .001), asthma (P = .007), otitis media (P = .01), urinary tract infection (UTI; P = .03) and chickenpox (P = .001). Combinations of either chickenpox and UTI or chickenpox and exposure to cigarette-smoking were associated with relatively high numbers of EH. While use of adult toothpaste (1000 ppm) at 0 to 3 years old increased risks for EH, there were less EO in children who used child toothpaste (300 ppm fluoride, 86% vs. 95%; P = .02) or who drank optimally fluoridated water compared to those who did not (4% vs. 29%; P < .001). CONCLUSIONS: Children with low socioeconomic status, histories of respiratory or chickenpox infections, exposure to cigarette-smoking, urinary tract infections, otitis, and use of adult toothpaste are predisposed to enamel hypoplasia. By contrast, drinking optimally fluoridated water at 0 to 3 years old reduces the risk for enamel opacities.

Common dental conditions associated with dental erosion in schoolchildren in Australia.

PURPOSE: The purpose of the investigation was to determine factors associated with dental erosion in a group of schoolchildren in Queensland, Australia. METHODS: Dental examinations were carried out on 714 children aged 5.5 to 14.6 years from 8 randomly selected Australian schools. A total of 3,165 primary and 2,976 permanent teeth were scored for dental erosion using a modified erosion index. Dental caries experience was determined from clinical examination and bitewing radiographs. Enamel defects were recorded using the developmental defects of enamel index. RESULTS: There were 225 children (32%) who exhibited no erosion and 489 (68%) who had erosion of at least one tooth. Erosion was found in 78% of subjects with primary teeth and 25% of subjects with permanent teeth (P<.001). Children with erosion in the primary and permanent dentition were more likely to have: (1) a lower socioeconomic status (primary dentition, P<.001 and permanent dentition (P<.001); (2) enamel hypoplasia in permanent dentition (P=.001); (3) dental caries in the primary dentition (P=.001); and (4) permanent dentition (P=.002). CONCLUSIONS: In Australian schoolchildren, the prevalence of dental erosion in the primary dentition is approximately 3 times greater than in the permanent dentition. Dental erosion is strongly associated with caries experience and enamel hypoplasia.

A longitudinal controlled study of factors associated with mutans streptococci infection and caries lesion initiation in children 21 to 72 months old.

PURPOSE: The purpose of this longitudinal study was to determine factors associated with mutans streptococci (MS) infection and development of caries lesions in a group of children 21 to 72 months old. METHODS: The 63 caries-free children, recruited since birth, were divided into: (1) a study group of 24 children who were colonized with MS; and (2) a control group of 39 children without MS. The children were recalled every 3 months for approximately 24 months, and their social, medical, and dental histories were updated. At each recall, the teeth were checked for presence or absence of plaque, enamel hypoplasia, and caries lesions, and their MS status was assessed using a commercial test kit. RESULTS: MS infection was associated with: (1) visible plaque (P < .01); (2) enamel hypoplasia (P < .05); (3) commencement of tooth-brushing after 12 months of age (P < .05); (4) lack of parental assistance with tooth-brushing (P < .025); and (5) increased hours of child care/school (P < .05). Four children (20%) were colonized at an age range of 21 to 36 months, 9 (45%) at 37 to 48 months, and 7 (35%) at 49 to 72 months (P < .001). Eight children who developed caries lesions: (1) had more hypoplastic teeth (P < .001); (2) ate sugar-containing snacks (P < .05); and (3) did not brush regularly with chlorhexidine gel (P < .01) compared to those who remained free of caries lesions. CONCLUSIONS: Lack of oral hygiene, consumption of sugar-containing snacks, and enamel hypoplasia are significant factors for both MS infection and caries lesion initiation.