Assessing time trend in health and health-related factors is important in monitoring population health and its determinants. The social and economic changes have been at a fast pace in recent times. However, the rate of change is not similar for every population subgroup. There were also different changes in policies and practices related to dental service delivery for children between states and territories. All these differences can have an effect on child oral health.
This chapter presents an analysis of trends between the current Survey and several existing surveys of child oral health in Australia. Australia's previous national survey among children, the National Oral Health Survey of Australia (NOHSA) was conducted in 1987–88. Dental caries experience was collected for samples of children across Australia. The National Survey of Adult Oral Health (NSAOH) 2004-06 collected dental fluorosis experience that allows for analysing time trend of fluorosis by year of birth (Slade et al. 2007).
The other available surveys are a series of the National Dental Telephone Interview Surveys (NDTIS) 1994–2013 and the Child Dental Health Surveys (CDHS) series. Dental service use by Australian children has been routinely collected in the NDTIS. The CDHS series collects administrative data on the oral health status of children attending school dental services in Australian states and territories. Therefore, those surveys covered just a proportion of the child population within each state/territory. This difference should be taken into account in interpreting results of this analysis. The CDHS data have been presented for age groups 6 years and 12 years. The presented data had been collected in Australia for the CDHS series from 1989 to 2010.
Two other oral epidemiological studies conducted among children attending school dental services were the Child Fluoride Study (CFS) Mark I 1992–93 and the Child Fluoride Study Mark II 2002–03. The CFS Mark I was conducted in Queensland and South Australia while the CFS Mark II was conducted in four states: Queensland, South Australia, Victoria and Tasmania. Information on child oral health behaviours was collected.
Trends in oral health status
Trend in dental caries experience
Time trend in dental caries experience was assessed using the NOHSA 1987–88, the CDHS series and the NCOHS 2012–14.
The key challenges in child oral health in Australia are the ongoing population burden of childhood oral diseases for society and the affected individuals and the substantial proportion of children with an unfavourable pattern of use of dental services. There is a need to respond by improving population and individual-level prevention of oral diseases, the organisation and delivery of dental services that put children with better oral health and a favourable pattern of dental care.
The ultimate purpose of this collaborative work is to describe and interpret the findings on oral health and dental behaviours and practices of Australian children so as to stimulate discussion about how to meet the abovementioned challenges. This work is the first national project in Australia since the late 1980s investigating child oral health as well as its associated factors.
The 2012–14 National Child Oral Health Study (NCOHS) was a cross-sectional study of the child population aged 5–14 years in Australia. A total of 24,664 children aged 5 to 14 years from 841 participating schools completed the study. The study sample was selected in a complex multistage, stratified sampling design. Sophisticated weighting procedure was employed to take into account potential variations in probabilities of selection and response rates. Therefore, this report presents estimates as representative of child oral health in Australia.
This collaborative work provides a detailed ‘snapshot’ of child oral health in Australia. In doing so, it describes the levels of dental caries and its components, dental fluorosis and other oral health conditions. It also describes the other protective factors such as toothbrushing and the use of fluoridated toothpastes. The use of dental services by children so as to manage existing oral disease and to contribute to the prevention of dental caries are detailed. Important information of the patterns of dietary intake that might impact on child oral health are presented. The report describes patterns of oral health status and behaviours of a nationally representative sample of Indigenous children. Further, socioeconomic inequalities in child oral health and behaviours are examined. Finally, the report presents information on child oral health using frameworks that emphasise variation by the socioeconomic characteristics of children's households and their reported pattern of dental service use across Australian states and territories.
Health and behaviours are determined above all by social conditions (Sheiham et al. 2014) and for this reason social conditions in which people live have been considered as the cause of causes of diseases and health disorders (Braveman & Gottlieb 2014).
Differences in levels of oral health that disproportionally affect socially disadvantaged members of society and that are avoidable, unfair and unjust are defined as oral health inequalities. It is not only the difference between the rich and the poor but a consistent gradient across the social economic ladder that exists and is universally found (Watt et al. 2016). The huge extent of contemporary health inequalities has led to be termed as the plague of our era (Farmer 2001). Therefore, it is important to document and understand oral health inequalities in order to allow the implementation of the most appropriate oral health interventions.
There are several individual and area-based measures of socioeconomic position. This chapter presents Australia's child oral health outcomes according to parents’ educational level, household income, Index of Relative Socio-economic Advantage and Disadvantage (IRSAD) and Index of Community Socio-Educational Advantage (ICSEA).
Among several individual measures of socioeconomic position, income and education are most widely used. Education usually results from an individual's schooling until the beginning of the third decade of life, and has little variation from then on. Its impact can occur either in the increase of knowledge and ability to take on healthy habits or in their insertion in the job market, in better positions and with higher incomes (Lynch & Kaplan 2000).
Income is a useful measure of socioeconomic position because it is related directly to the material circumstances that may influence health and health-related behaviours (Lynch & Kaplan 2000).
The IRSAD summarises information about the economic and social conditions of people and households within an area, including both relative advantage and disadvantage measures. The average IRSAD value is 1000. A lower score indicates that an area is relatively disadvantaged compared to an area with a higher score (Australian Bureau of Statistics 2014).
The ICSEA is an index which combines students’ characteristics (such as parental occupation and level of education) and school's area characteristics such as proportion of Indigenous children and geographical location. The lower the ICSEA value, the lower the level of educational advantage of students who attend this school.
Study population and sampling
The target population for the Survey was Australian children aged 5–14 years. To draw a representative sample of children from this target population a stratified two-stage sample design was implemented within each state/territory. In the first stage, schools were selected from a sampling frame of schools located within each jurisdiction. In the second stage, children were sampled from each selected school.
The sampling strategy was designed to derive accurate population estimates of the oral health of Australian children, and to make valid comparisons between the oral health of children across regions within each state. For New South Wales, Victoria and Queensland, the geographical regions were based on Area Health Services/Health Districts, while in the remaining jurisdictions they were based on Capital City/Rest of State. As a consequence, the sampling methodology differed slightly for each jurisdiction.
To sample children across the age range of 5–14 years both primary and secondary schools were in scope of the Survey. A sampling frame of schools was created from a list provided by each jurisdiction which included all public, catholic and independent primary and secondary schools. Information provided on the sampling frame for each school included school code, school name and address, school type, school enrolment and health district.
Schools were excluded from the sampling frame if they were:
• located in very remote locations that would be difficult to access by the mobile dental clinic van
• special schools
• small school enrolment (usually <50 students).
New South Wales
In New South Wales (NSW), there were 2,995 schools that were considered in scope with 2,087 primary only, 567 secondary only and 341 combined primary/secondary schools. Schools on the sampling frame were stratified into 15 regions based on NSW Local Health Districts (LHD). The number of primary and secondary schools selected from each LHD was determined by the region's percentage share of total school enrolment. For primary schools, enrolment was defined as children enrolled in year levels Kindergarten to Year 6. For secondary schools, enrolment was defined as children enrolled in year levels 7–9.
Patterns of dental service use can be described using a range of approaches including measures related to first dental visit, usual dental visit pattern, and the most recent dental visit. First dental visit is considered important as it represents first contact with the dental system. The usual dental visit pattern of children is also of interest as it can reflect long-term attendance patterns. The most recent dental visit is considered important as it reflects current health behaviour.
In this chapter, measures related to first dental visit will be presented for: first making a dental visit before the age of 5 years, having a check-up as the reason for the first dental visit, and reporting having never made a dental visit. Information will also be presented related to usual dental visiting using the measure of irregular usual visit pattern. For the most recent dental visit: making a dental visit within the last 12 months, having a check-up as the reason for last dental visit, attending a private dental clinic at the last dental visit, whether parents or guardians attended with the child at their last dental visit, and rating of the last dental visit by the parent/guardian.
Frequency of dental visits and the reason for dental visits are key aspects related to access to dental care (Roberts-Thomson et al. 1995). Making a recent dental visit is indicative of access to the dental care system while visiting for the reason of a check-up is considered more likely to be associated with better health outcomes than visiting for a dental problem such as relief of pain (Crocombe et al. 2012). Hence, the dental profession tends to advocate a visit pattern of attending for annual dental check-ups to access preventive dental care or allow diagnosis of dental problems at an early stage, which can facilitate treatment before the disease progresses (Riley et al. 2013). For children, there are recommendations in relation to the desirability of making dental visits at an early age (Jones & Tomar 2005). While children who have not made a dental visit or report an irregular dental visit pattern could reflect a lack of perceived need, these measures could also reflect barriers to dental care that inhibit dental visiting or reflect problem-based attendance patterns.
Sample surveys are conducted to make informed inferences about a target population. In order to produce reliable estimates of population parameters a sample should reflect the characteristics of the target population from which it is drawn. This rarely happens in practice as sample designs commonly select participants with unequal probabilities of selection leading to certain groups within the target population being over- or under-represented in the sample. Similarly, survey response rates often vary significantly by sociodemographic status leading to samples that are unrepresentative of the target population and therefore biased population estimates. These concerns can be addressed by the application of survey weights that adjust the sociodemographic composition of the sample to reflect the target population. Consequently, population estimates derived from the weighted sample more closely reflect the true population parameters.
The National Child Oral Health Study (NCOHS) sampled 24,664 children from primary and secondary schools across Australia to estimate the oral health status of children aged 5–14 years. To produce reliable state and territory survey estimates, children from less populated jurisdictions were oversampled and therefore had a higher chance of selection in the Survey. Similarly, children from fluoridated areas of Queensland were oversampled to ensure a sufficient sample size to produce reliable survey estimates by fluoride exposure in that state. As the oral health status of Australian children varies significantly by geographic region (Centre for Oral Health Strategy 2009; Centre for Oral Health Strategy 2013; Do & Spencer 2014; Mejia et al. 2012), it was paramount that the weighting strategy accounted for these differential probabilities of selection.
Furthermore, analysis of the NCOHS sample highlighted differences in response rates by type of school attended and across a range of child, parent and household sociodemographic characteristics. Children from parents with a high level of education were over-represented in the sample. Conversely, Indigenous children and children from single parent families were under-represented. Response rates also varied by geographic region with participation lower in capital cities than other regions. As the association between sociodemographic status and children's oral health is well established (Centre for Oral Health Strategy 2009; Centre for Oral Health Strategy 2013; Do & Spencer 2014; Mejia et al. 2012; Armfield et al. 2006), the weighting strategy was designed to correct for the differential response rates inherent in the Survey.
The genesis of this research was the need to describe and understand contemporary child oral health in Australia. The population study provided an opportunity to collect detailed information on both oral epidemiological and self-reported oral health indicators on a representative sample of the Australian child population. It also provided the opportunity to accompany those indicators with a rich array of individual, family and community characteristics that positioned every child in terms of their social milieu, behavioural risk and preventive factors and use of dental services for both treatment of existing disease and prevention of future disease.
The sampling strategy for the study was built around the capacity for all states and territories to have sufficient confidence in their estimates of child oral health. As a consequence, the study was really eight separate sub-studies then rolled together to constitute a large national oral epidemiological study. The sampling strategy had as its foundation cluster sampling of children from selected schools across all regions of the country. The probability of every child's selection was known, allowing for each child's contribution to the findings of the study to be weighted to reflect equal probabilities of selection in the sample and the population distribution of children with similar characteristics. The outcome of the complex weighting procedures was a data set that showed negligible bias against the population at large. Therefore, there is confidence in unbiased estimates of child oral health.
Every effort was made to collect high quality oral health information through the use of small teams of calibrated dental examiners, well supported with written and visual materials to aid standardised scoring, and with appropriate refresher activities during the fieldwork. The reliability statistics attest the success in this endeavour at least for the more frequently observed oral health indicators.
The accompanying data from a detailed parental questionnaire was strong in its depth. Yet, parents provided complete data with only a few exceptions. Household income was the item for which there was the most missing data, but even here the level of missing data was relatively low and an alternative marker for social position, highest parental education, was very largely complete.
Patterns of toothbrushing practices
Brushing teeth with toothpaste is a widely adopted oral health behaviour in Australia (Slade et al. 2006). There is evidence that more than 90% of Australian children brush their teeth at least once a day (McLellan et al. 1999; Armfield & Spencer 2012) and that almost all children do so with a toothpaste containing fluoride (Armfield & Spencer 2012; Slade et al. 1995). Toothbrushes and fluoride toothpaste are readily available throughout the country and dental and other health authorities recommend brushing.
A great deal of evidence over a number of decades has found that regularly brushing children's teeth with fluoridated toothpaste reduces the risk of dental decay (Marinho et al. 2003a; Walsh et al. 2010). Toothbrushing not only removes plaque, which consists mostly of bacteria and is a risk factor for oral disease, but can be used to apply fluoride to the teeth via the application of toothpaste.
Australia's fluoride guidelines advise that brushing with fluoridated toothpaste commence from the age of 18 months (Australian Research Centre for Population Oral Health 2012). Table 7-1 shows the percentages of children who indicated that they had commenced brushing their teeth before the age of 18 months, by both the child's current age and various demographic and socioeconomic characteristics. The data are based on the recollection of the reporting parent, so parents of older children were having to recall the age of first brushing from further in their past than were parents of younger children. Overall, just over one-third of children commenced brushing with toothpaste before 18 months of age. There was little variation in reported early brushing commencement by child age at the time of the study.
Children were more likely to brush with toothpaste prior to 18 months if their parents were Australian born (36.0%) compared to those with an overseas-born parent (30.3%). In addition, the percentage of children brushing early was higher for those children whose parents had vocational (37.1%) or tertiary education (35.5%) than for those whose parents had no schooling beyond high school (29.2%). There was an income gradient in early-child toothbrushing. The lowest percentage was shown for children from the lowest household incomes (28.7%), followed by children from a medium household income (35.6%), with the highest percentage for children from families with a high household income (38.3%).
Dental caries is the most common chronic infectious disease in childhood, caused by a complex interaction over time between acid-producing bacteria and fermentable carbohydrates (sugars and other carbohydrates from food and drink that can be fermented by bacteria), as well as many host factors including teeth condition and saliva (Fejerskov 2004; Fisher-Owens et al. 2007). Dental caries is characterised by the loss of mineral ions from the tooth (demineralisation), stimulated largely by the presence of bacteria and their by-products. Remineralisation occurs when partly dissolved crystals are induced to grow by the redepositing of minerals via saliva. The demineralisation of the tooth surface can be limited by the use of fluorides. Normally, a balance occurs between the demineralisation and remineralisation of the tooth surface (enamel). However, this balance is disturbed under some conditions, and the subsequent chronic demineralisation leads to the formation of holes or cavities in the tooth surface. In its early stages the damage can be reversed with the use of fluoride. Cavitation (a hole in the tooth) beyond the outer enamel covering of the tooth into the tissues can lead to a bacterial infection, which may cause considerable pain and require surgery or the removal of the tooth. Once the cavity has formed a filling is needed to restore the form and function of the tooth. Childhood caries is a serious public health problem in both developing and industrialised countries (Casamassimo et al. 2009).
At about the age of 5 or 6 years, children start losing their primary (deciduous/baby) teeth, which are replaced by their permanent teeth. Most children have lost all their primary teeth and have gained their permanent teeth (with the exception of wisdom teeth, which may erupt several years, or even decades, later) by the age of 12 years. Therefore, analyses of dental caries in adolescents only report the level of disease in permanent teeth. Younger children generally have a mixture of primary and permanent teeth, from ages 5 to 12 years. The convention is to report on these two sets of teeth separately.
Dental caries experience and other oral conditions were collected through oral epidemiological examinations. Didactic and clinical training for the examination teams was conducted. Frequent refresher sessions were also provided. Examinations were held in fixed or mobile dental clinics under standardised conditions.
Being orally healthy means that people can eat, speak and socialise without discomfort or embarrassment and without active disease in their mouth which affects their overall wellbeing (UK Department of Health 1994). Australians of all ages have an expectation of being orally healthy, but this is particularly relevant to children. Children constitute a special population group requiring attention and consideration because of the importance of maximising the opportunities of childhood as a key developmental stage and the foreshadowing of later adult oral health and wellbeing.
There are two highly prevalent oral diseases and disorders affecting the teeth and their supporting tissues: dental caries (decay) and periodontal diseases (gum disease). There are a number of less frequently occurring but nonetheless important oral diseases of the oral mucosa as well as disorders such as developmental defects, dental impactions, malocclusions, tooth wear, jaw joint dysfunction and dental and oral trauma (AHMAC, Steering Committee for National Planning for Oral Health 2001). Among children, dental caries, early stage periodontal disease (gingivitis), and developmental defects like dental fluorosis, oral mucosal lesions and trauma, are the most frequent and impacting oral diseases and disorders. These conditions severally and collectively cause pain and discomfort, eating difficulties, speech and cognition dysfunction, embarrassment and social marginalisation. These impacts are no different to the impacts of many other diseases and ill-health. Just as the mouth is an integral part of the body, oral health is an essential component of overall child health and quality of life.
Risks and prevention of dental caries
Among children, dental caries is the leading oral disease. It has high prevalence and associated high impact on children and their families. Its presence dominates the need for dental services and the cost of them both to families and society.
Historically, Australian children have experienced a high level of oral disease. In the immediate post-WW2 period, Australian children had one of the highest levels of dental caries among comparable developed countries (Barnard 1956). By the 1990 decade Australia's child oral health surveillance had reported a marked improvement in experience of dental caries. However, in the last two decades, the improvement in oral health of Australian children has ceased or even reversed (Armfield et al. 2010).
This Survey gathered information from a representative sample of the Australian child population aged 5–14 years to describe the oral health status of the population and factors related to use of dental services and dental behaviours, as well as associated individual, family, and community factors such as the sociodemographic characteristics of the child's household.
Surveys provide a means of measuring a population's characteristics, self-reported and observed behaviour, and needs. Unlike a census, where all members of a population are studied, sample surveys gather information from only a portion of a population of interest. In a statistically valid survey, the sample is objectively chosen so that each member of the population will have a known non-zero chance of selection. Only then can the results be reliably projected from the sample to the population.
Surveys, however, are not exempt of errors (or bias), which can occur when some segments of the population do not participate in the survey. As not all Australian children were included in this Survey, there is potential that the sample does not accurately represent the population of interest.
Errors due to sampling depend on the sample selection strategy and can be measured statistically. Variability inherent to the sampling process is expressed using the 95% confidence interval. On the other hand, non-sampling error or bias is more problematic because it is more difficult to measure and control. Bias due to non-participation occurs when the participants differ from the non-participants or the targeted population in one or more characteristics. The potential for bias due to non-participation or non-response can be explored by examining key sociodemographic characteristics of the Survey sample, and comparing them with known characteristics of the target population.
As outlined in Chapter 3, this Survey employed rigorous sampling procedures to achieve a representative sample of the Australian child population aged 5–14 years. The procedures used to derive survey weights for this Survey reflect the standards of best practice for weighting complex survey data, and are procedures used by leading statistical agencies. Procedures used to derive survey weights ensure valid estimates and inferences of the target child population can be made. The methodologies employed in the Survey will minimise any potential bias, which will be assessed in this chapter.
Survey manager Amanda Blyton-Patterson
Co-ordinator Amanda Blyton-Patterson
Dental examiners Ruth Vosseler, Elizabeth Doyle, Patricia Mason, Heather Pinder
Dental recorders Karen Harmsworth, Jenny Wardrobe, Brooke Morris, Kristin Alsemgeest, Danielle Pearce
Survey manager Tanya Schinkewitsch
Co-ordinator Tanya Schinkewitsch
Dental examiners Leonie Green, Lynne Brissett, Katherine Price, Debbie McGibbon, Brianne Bartos, Julie Kelpsa, Angela Rankin, Jenny Lang, Sharyn James, Joanne Johnson, Hollie Day, Karen Kennedy, Helen Lee, Sharon Stuhl
Dental recorders Michele Tait – Kerr, Beth Rieger, Leeona Harrison, Annette Dix, Elizabeth Di Meco, Sung Yang, Katherine Price, Natalie Jaksic, Cheryl Bedford, Lia Pagdanganan, Karen O'Grady.
Survey manager Patricia Slocum
Co-ordinator Maria Ciarla
Dental examiners Sally Finlay, Debbie Beldham, Lorrae Beckett, Imogen Hoppmann, Joanne Nelson, Melody Foh, Shavaya Huskinson
Dental recorders Leanne Rigby, Pollyanna Walker, Tiffany Ammenhauser, Sarah Jones, Karen MacGregor, Khayla De Aussen
Survey manager Ben Stute, Rhys Thomas
Co-ordinator Zoe Johnson
Dental team members Sue Batterham, Kym Baxter, Lauren Bonar, Susan Brain, Jo-Anne Bunyan, Kathy Burns, Michelle Campbell, Jillian Clyde, Amanda Corbett, Tonia Danes, Kathyrn Davis, Elizabeth De Silva, Wendy Doyle, Sue Douglass, Catherine Draney, Diana Hill, Colleen Hull, Maria Jones, Kerry Keene, Donna Knowles, Amanda Liddell, Gail Masters, Louise McGlinchey, Terri McIntosh, Cheryl McMahon, Margaret Moore, Kerrie O'Shea, Rebecca Osmond, Amanda Philp, Judith Plahn, Melissa Plath, Rhonda Roan, Jennifer Roberts, Terri Roser, Jenny Romagnolo, Lisa Rush, Tracy Sharp, Shelley Sinclair, Allison Smallwood, Kirrilea Smyth, Casey Soper, Christine Southall, Lauren Stockham, Deb Tector, Louise, Thompson, Lesley Toomey, Maria Turpie, Cathy Vaughan, Donna Weaver, Jane Yorkston
Oral health is an integral part of general health and shares a number of common determinants with general health. Those common determinants are mostly related to diet. General health behaviours that affect child oral health centre largely on consumption of water and of drinks and foods containing sugar.
Water consumption can affect oral health in two ways. First, water is a ‘tooth friendly’ drink. Water contains no decay-causing sugar and is generally in the range of acidity that is safe for teeth. Second, water is the main way in which fluoride is accessible to the whole community, irrespective of their individual oral hygiene behaviours. Multiple studies from more than 20 countries have shown that fluoridation reduces dental caries (National Health and Medical Research Council 2007; Rugg-Gunn and Do 2012; Iheozor- Ejiofor et al. 2015), which explains the high priority given to water fluoridation by public health authorities. Water fluoridation provides the greatest benefit to those who can least afford professional dental care (Slade et al. 1995b; Burt 2002). This chapter examines children's consumption of mains and tap water as well as bottled water to assess the extent to which children are likely to receive the benefits to their oral health than can be gained from the fluoridation of reticulated water.
Consumption of sugar is a key risk factor for dental caries (Moynihan and Kelly 2014; Sheiham and James 2014). The impact of sugar on oral health depends in large part on the type, quantity and pattern of consumption. For oral health purposes, sugar that does not occur naturally in milk or in whole fruit or vegetables can contribute to a child's risk of experiencing tooth decay. These sugars are known as ‘free sugars’ and are defined as ‘monosaccharides and disaccharides added to foods and beverages by the manufacturer, cook or consumer, and sugars naturally present in honey, syrups, fruit juices and fruit juice concentrates’ (Rosenberg et al. 2005). Dietary guidelines for Australia recommend that Australians ‘Limit intake of foods and drinks containing added sugars such as confectionary, sugar-sweetened soft drinks and cordials, fruit drinks, vitamin waters, energy and sports drinks’ (National Health and Medical Research Council 2013).
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