Early Childhood Caries and Primary Caregiver Oral Health Literacy in Western Australia: a Systematic Scoping Review


 Background

Early childhood caries disproportionately affects vulnerable groups and remains a leading cause of preventable hospital admissions for Western Australian children. The Western Australia State Oral Health Plan seeks to improve child oral health through universal and targeted health promotion initiatives with primary caregivers. These initiatives require evidence of primary caregiver health literacy and baseline data on Early childhood caries. The objective of this systematic scoping review is to understand current oral health literacy of primary caregivers of children aged 0 to 4 years, identify influential socioecological determinants, and identify data on Early childhood caries in the Western Australian context.
Methods

A systematic scoping review framework identified articles published between 1980 and 2021, using Scopus, PubMed, Medline, CINAHL, PsycINFO, selected article reference lists, and oral health websites. Articles were screened via author consensus, with eight selected.
Results

Data on early childhood caries in Western Australia is limited; the suggested prevalence of 2.9% based on data over 15 years old, however national data suggests an Early childhood caries prevalence of 3.4–8% of children aged 18 months rising sharply by 36 months of age. Fewer than half the primary caregivers reported following evidence-based oral health recommendations for their young children. Engagement with dentists tended to be reactive. Knowledge of dietary and oral hygiene practices were inconsistent and awareness of the Child Dental Benefit Schedule low. Young children’s oral health status was clearly associated with socioecological factors including socioeconomic status.
Conclusions

Early childhood caries data and primary care-givers’ oral health literacy evidence are unavailable in Western Australia. To realise the Western Australia State Oral Health Plan, research is required to address this knowledge gap.

growing body of evidence that re ects the association between parental oral health literacy and the child's oral health status (Bridges et al., 2014). Primary caregivers' awareness and practice of oral health promoting diets, oral hygiene practices -including brushing teeth -and engagement with preventative dental services provide the foundation for their child's continuing oral health throughout life (Phantumvanit et al., 2018).
A strong link has been established between ECC and frequent sugary food and drink consumption, nocturnal milk bottle use and on demand feeding (Meurman & Pienihäkkinen, 2010;Wigen et al., 2018). Furthermore, irregular brushing habits, not using age-appropriate uoridated toothpaste and limited access to community water uoridation and dental care also signi cantly increase a child's caries risk (Chaffee et al., 2017).
The establishment of a dental home may reduce the prevalence of ECC and improve oral health outcomes among young children; this establishes good preventative practices and enables early detection and intervention to be implemented (Kierce et al., 2016). The Australian guidelines recommend that a child's rst dental visit should be scheduled once their rst tooth erupts, or by the age of one year (Widmer, 2003).
In Australia, dental fees are not covered by Medicare (the free national universal health care service), and dental health is identi ed separately from other categories of physical health. As such nancial barriers and cost of care have been associated with dental attendance patterns while public dental pathways vary among individual states and territories (Chrisopoulos et al., 2013). In WA, the School Dental Service is available to children aged 5 to 16 years and provides routine dental care including examinations, llings, extractions, dental cleaning, radiographs and oral hygiene/tooth brushing instruction (Riordan, 1995).
The service is staffed primarily by dental therapists who are supervised by dentists with more complex procedures requiring referral to specialist services (Riordan, 1995). However, children under ve years of age in WA are not eligible to be seen through the School Dental Service. The Child Dental Bene t Schedule (CDBS) was introduced in 2014 as a supplemental avenue of care for children aged two years to 17 years for families that receive family tax bene ts. The CDBS provides up to $1000 (every 2 years) for basic dental services such as dental examinations, cleaning, llings, extractions, and x-rays (Putri et al., 2019). However, only 10% of eligible WA families access the bene ts of this scheme, compared to around 30% nationally. Moreover, very young children who present with extensive treatment needs requiring treatment under general anaesthesia are not covered by the scheme. While the reasons behind these differences are unclear, they demonstrate a clear inequity of opportunity for WA children.

Primary caregiver oral health literacy
Oral health literacy is de ned as the degree to which individuals have the capacity to obtain, process and understand basic health information and services needed to make appropriate oral health decisions (Dickson-Swift et al., 2014). Therefore, improving oral health literacy is central to reducing existing oral health disparities and enabling sustainable outcomes. Although scarce, a few Australian studies offer some evidence on primary caregiver oral health literacy through research into parental oral health practices and knowledge of cariogenic food and drinks.
Conducted in 2018, a national study of 2000 households indicated low levels of oral health literacy among Australian primary caregivers. This study reported 31% of pre-schoolers had never been taken to a dentist, and 39-50% of children aged 0 to 3 years did not have their teeth cleaned at least twice a day (Rhodes, 2018). This is supported by the results of the National Oral Health Study where only 1 in 5 children aged 2-14 years had never consulted a dentist or dental professional (AIHW, 2020). Around 23% of primary caregiver survey participants indicated a belief that dental services were only accessible for treatment rather than prevention purposes and 77% were not aware their child should be taken to a dentist for their rst visit by the age of 12 months (Rhodes, 2018). Only 50% of participants were aware that uoridated tap water was better for their children's teeth than bottled water; a similar percentage were unaware of the CDBS. Moreover, around 85% did not know the recommended maximum daily intake of free sugars in their children's diet (Rhodes, 2018).
A further study of over 2000 children and primary caregivers in Adelaide, South Australia reported the intake of free sugars among 73% of participants aged 0 to 2 years exceeded WHO recommendations (Devenish et al., 2019). This concerning evidence supports the need for speci c research into WA primary caregivers' oral health literacy.

The Australian National Oral Health Plan
The Australian Government recognises the burden of poor oral health among the Australian population and the disparity in prevention and treatment accessibility for those on low income. The National Oral Health Plan 2015-2024 (Australian Government, 2015) outlines national goals to address these issues through: 1) health promotion (evidence based activities that addresses the social determinants affecting oral health), 2) proportionate universalism (universal services with targeted areas for those priority populations at particular disadvantage), and 3) accessible oral health services and better integration of oral and other health services.
Infancy, childhood and adolescence are acknowledged as key life stages in the National Oral Health Plan requiring universal and targeted health promotion input around tooth-friendly diets, brushing and the use tap water, or approved uoride supplements. The strategic direction of the National plan is aligned with foundation areas, including oral health promotion and improving accessibility of oral health services such as the CDBS. The WA State Oral Health Plan 2016-2020 (WA Department of Health, 2016) re ects the direction of the national plan and sets out objectives to support healthy oral health decisions among priority populations. To achieve optimum oral health outcomes in WA and more broadly in Australia, it is critical to understand primary caregivers' oral health literacy and the associated socioecological determinants. This paper aims to understand primary caregiver oral health literacy and associated socioeconomic factors within the context of ECC in WA. In order to achieve this, a systematic scoping review was conducted with the following objectives: 1) examine the evidence about current ECC patterns and trends among WA children aged 0 to 4 years, 2) review the evidence about primary caregivers' oral health literacy -their awareness and implementation of positive oral health preventative practices, and 3) the associated socioecological determinants.

Methods
The ve-stage systematic scoping review methodological framework described by Arksey and O'Malley (2005) was chosen to guide the systematic scoping review process. The methodology was further checked to ensure it followed the recommendations for a systematic scoping review by Joanna Briggs Institute experts (Peters et al., 2015). Given the scarcity of studies and the heterogeneity of existing studies, a systematic scoping review was deemed to be the most appropriate method to achieve the aim of this study. The evidence from this review is drawn from qualitative and quantitative research as well as publications by state and national health departments and oral health professional bodies.

Stage one: Identi cation of research question
As with any review, the rst stage is to consider the research question and the aspects that are of particular interest (Arksey & O'Malley, 2005). For this review, the areas of interest were: 1) current ECC patterns and trends among WA children aged 0 to 4 years; 2) primary caregivers' oral health literacytheir awareness and implementation of positive oral health preventative practices, and; 3) associated socioecological factors. From this, the scoping review also sought to identify the gaps in evidence requiring further research. The articles considered were published between 2010 and 2021 and written in English. The lack of articles speci c to WA children meant Australian-wide publications were also considered. Inclusion criteria were: rates of ECC for children aged 0 to 4 years, primary caregiver child oral health awareness and practices of tooth brushing, diet, drinks, dentist attendance and awareness of the CDBS. Publications that delineated this information according to sociological factors were also included for consideration.
Systematic and other forms of literature review were excluded, although articles they reviewed were accessed and considered independently. Boolean logic was used, and search terms included synonyms commonly used in literature (Table 1). Several searches were carried out, using the 'population, interest, outcome' method ( Table 2).  This study aimed to explore oral health literacy among the general Australian population. As such studies focusing on previously identi ed high risk groups such as children from refugee or Aboriginal or Torres Strait Islander backgrounds were excluded.

Stage three: Study selection
The process of study selection followed the Preferred Reporting Items for Systematic Reviews and Meta-Analysis In this stage of the process, the selected studies were charted and sorted according to key issues and themes, providing a 'narrative review' (Arksey & O'Malley, 2005) that presents broad information about the study objective, population group, study design/methodology and key ndings ( Table 3). The eight studies that were included in the nal review, re ects the lack of research in this space. Only one was a WA study, three from Victoria and the remaining four had an Australian-wide focus ( organised under the themes: ECC trends, primary caregiver awareness and behaviours, and socioecological indicators. The second theme was divided into diet, dental hygiene practices, dental service engagement and awareness of CDBS. Descriptive, mixedmethod, two-stage approach.
Interviews and a questionnaire with the child's primary caregiver.
Children aged 2 to 3 years were less likely than older children (aged 6 to 7 years) to brush their teeth twice a day (44% compared to 61%) and to have attended a dental health service in the last 12 months (15% compared to 59%).
Only 3% of younger children had parentreported caries, compared to 67% in the older children.
The most socially disadvantaged were associated with higher odds of caries, infrequent toothbrushing and non-use of dental services. Cross-sectionalquantitative.
Children living in areas with limited access to oral health professionals had 65% higher rates of dental hospitalisation.
Children from families of low SES had 57% higher rates of dental hospitalisations.
Children living in areas without water uoridation were on average 59% higher rates of dental hospitalisations.
90% of children were hospitalised because of preventable dental caries. In this stage of the process, the ndings from the selected articles are presented. As a scoping review, the ndings are discussed as a narrative rather than an assessment of the weight of the evidence (Arksey & O'Malley, 2005). Three themes informed this review: i) early childhood caries among WA children; ii) primary caregiver oral health literacy, and iii) socioecological factors (socioeconomic and environmental determinants).

Stage 6: Consultation stage
Consultation was undertaken at this stage with JP, Specialist Paediatric Dentist and Senior Lecturer in Clinical and Paediatric Dentistry. As a quality improvement initiative, JP was invited to read the selected articles and review draft and provide comments and feedback.

Early childhood caries in WA children
Although several studies have assessed the oral health of school-aged children, only one study with a focus on early childhood caries (ECC) data in WA was identi ed (Lucas et al., 2011). In this study, 2006 LSAC data revealed ECC among WA children aged 2 to 3 years in the LSAC cohort was 2.9%, slightly lower than the national average of 3.3%. Only ACT and SA had lower reported rates of ECC at 2.5% and 2.7% respectively. Despite this WA had the highest proportion (89.4%) of children that had not accessed dental services in the last 12 months. Although this study uses a sample considered to be representative of the Australian child population, the oral health data obtained was primarily based on parental reporting rather than clinical examination. The Victorian study conducted by Gussy et al. (2016) provides some evidence of the 'natural history' of caries development among very young Australian children. This cohort study, which followed 467 Victorian children aged 0 to 36 months revealed 8% of participants had caries at the age of 18 months, increasing to 23% by age 36 months. An analysis of national LSAC data by Stormon et al. Both studies associated this increase in rates of ECC with changes in the children's diets, the introduction of sugar-sweetened beverages (SSB) and the recommendations for increased regular tooth brushing during this developmental stage not being followed. All three publications concluded that the prime time for oral health promotion and intervention strategies for young children was between the age of 18 and 36 months. The need for early intervention to halt or slow ECC progression is further supported by additional LSAC data stating that rates of ECC among 6 to 7-year-old children was tenfold that of 2 to 3year-old children (Kilpatrick et al., 2012).

Primary caregiver oral health literacy
The LSAC also provided information on primary caregiver oral health literacy. Kilpatrick and colleagues (2012) revealed that Australia-wide, among the primary caregivers of children aged 2 to 3 years, just 44.4% reported brushing their child's teeth twice a day (increasing to 67% for children aged 6 to7 years).
Only 15.2% of primary care givers had taken their child (aged 2 to 3 years) to a dental health professional in the preceding 12 months, increasing to 59.4% for children aged 6 to 7 years (Kilpatrick et al., 2012). A state by state analysis of tooth brushing behaviour by Lucas et al. (2011) found WA had the highest rate for correct tooth brushing regimes for children aged 6 to 7 years, however, more than half of these children experienced suboptimal toothbrushing at the earlier age of 2 to 3 years.

Analysis of the LSAC by Stormon et al. (2019) found mothers' knowledge on dietary practices was
inconsistent: most knew about the cariogenic effect of SSB but few knew about the potential harm associated with night time feeds or the transfer of caries inducing bacteria to their children through poor dental hygiene practices such as kissing children on the lips and sharing feeding utensils.
In Victoria, Virgo-Milton et al. (2016) interviewed the mothers (n = 32) of young children (aged 4 to 12 months) about good oral health, reporting that those with lower oral health literacy may be more likely to delay seeking treatment for their child. Conversely, those who had experienced negative dental experiences during their own childhood, were reported as placing greater impetuous on providing good oral health care for their own children. Australia-wide 2014-2015 Medicare data on children eligible for the CDBS revealed children aged 2 to 4 years were utilising the schedule the least and most primary caregivers who did access the schedule, did so for their children aged 5 to 17 years (Putri et al., 2020). Furthermore, speci c to WA, although 28% of children were eligible for the CDBS only 4% accessed the scheme in 2014, increasing to 6% in 2015.
Socioecological determinants Kilpatrick et al. (2012) reported that for the Australian children in the LSAC study "marked social disparities in oral health appear as early as 2 years of age and remain evident in school-age children" (p. 38). Social indicators for poorer oral health included rural location, English as an additional language and parental income, employment and housing. The authors recommended targeted oral health promotion interventions as early as possible in the child's life to mitigate these disparities.
In WA, records of oral health hospital admissions for children aged 0 to 4 years showed 82.7% from the lowest socioeconomic status quintile had no dental insurance, compared to 32% from the highest quintile and Stormon et al. (2019) reported that children aged 0 to 4 years children living in areas without water uoridation had signi cantly higher rates of dental caries and preventable hospital admissions for oral health issues.

Discussion
Implications for future oral health promotion activities The ndings are interpreted against the systematic scoping review purpose, namely to: 1) examine the evidence about current ECC patterns and trends among WA children aged 0 to 4 years, 2) review the evidence about primary caregivers' oral health literacy -their awareness and implementation of positive oral health preventative practices, and 3) the associated socioecological determinants.

Gaps in existing data
The WA State Oral Health Plan states that research and evaluation is a key strategy to addressing poor oral health: "A structured and coordinated research and evaluation program is required to inform the development of appropriate, effective and sustainable oral health services" (WA Department of Health, 2016, p. 2). Nevertheless, the ndings of this systematic scoping review reveal signi cant gaps in the data required to achieve this goal for WA's young children. Data regarding early childhood caries in WA children are ostensibly absent. The only gures available come from the 2006 LSAC, that reported 2.9% of WA children aged 2 to 3 years had caries (Lucas et al., 2011). Given these gures are over 15 years old, it is impossible to use them to inform current WA patterns and trends in ECC, and as such it is impossible to develop, implement and evaluate effective and meaningful oral health promotion programs and strategies. Other Australian-wide data that indicate a sharp increase in ECC incidence in children between the ages of 18 months and 36 months suggests oral health promotion strategies are required as early as possible in the child's life.

The oral health literacy of primary caregivers in Australia
It is evident that Australia-wide, many primary caregivers have insu cient levels of oral health literacy to effectively achieve optimum oral health outcomes for their very young children. Primary caregiver's behaviours around their children's toothbrushing is suboptimal (Kilpatrick et  An associated issue that requires consideration in any oral health strategy aimed at young children today is the recent exponential growth of the Australian baby food industry (Euromonitor International, 2020).
The market is increasingly ooded with sugar rich infant and toddler products, with the majority of 'pouch foods' increasingly available in the supermarket being predominantly sweet (Moumin et al., 2020).
Although these foods were not discussed in the reviewed articles, perhaps because of their recent establishment in the baby and toddler food market, their sugar content is concerning given the wellestablished links to dental caries (NHMRC, 2012). The smooth texture of these foods also warrant attention as they can encourage persistent and prolonged 'sucking' feeding in which the teeth are bathed for longer periods to this sugar-rich food. One way to reduce the high sugar content in very young children's diets is to provide support and education to primary caregivers around these convenience foods.
Australia-wide evidence of child oral health inequity This systematic scoping review identi ed several socioecological factors that contribute to the inequitable incidence of ECC among very young Australian children, including socioeconomic status and geographic location.
The importance of accessible preventative oral health services in reducing ECC is evident from Government data that reveal children living in areas with limited access to oral health professionals have a 65% higher rate of dental hospitalisation (Australian Government, 2015). Several socioecological factors can in uence primary caregiver engagement with these services. Family nancial status is a strong predictor of dental service accessibility, with the high individual responsibility for the cost of dental treatment (57%) is considerably greater than other health services (11%) (Australian Government, 2015). This reduces dental service accessibility for children in low income families and contributes to the inequitable oral health outcomes across the social divide (Alsharif et al., 2014).
A concerning nding speci c to LSES families in WA is the lack of uptake of the CDBS with only 4 to 6% of eligible children accessing the scheme in 2015 (Putri et al., 2020). Again, socioecological factors come into play here; a lack of available dental health professionals in LSES communities, especially rural areas, reduces primary caregiver awareness of the schedule and limits access to local dental services in general . The reasons for the lack of uptake of the CDBS may be due to negative parent experiences of dental treatment as a child (Hilton et al., 2007) and parents fear of stigmatisation associated with a perceived 'dental neglect' of their children (Muirhead et al., 2013).
This review also revealed that Australian communities without water uoridation experience signi cantly higher rates of dental caries and other oral health associated hospital admissions among young children Stormon et al., 2019). Inadequate tap water uoridation and the increasing reliance on bottled water among the Australian population (Goldstein Market Intelligence, 2020), may have important implications for child oral health. There is evidence to suggest parents believe bottled water is a healthier option for their children, due to a combination of a general 'mistrust' of tap water and persuasive bottled water marketing campaigns (Ragusa & Crampton, 2016). A combination of public health policy action plus primary caregiver oral health promotion activities that target the insu cient exposure of young children to uoride is required.
The need for WA evidence While the primary caregiver oral health literacy evidence provided by this systematic scoping review is enlightening, most is not WA focused. The early childhood caries statistics are dated, inconsistently recorded and tend to be Australia-wide, parent-reported or from 'other' Australian states. Differences exist between states and territories such as population access to public dental health services and efforts made to promote and support community and family oral health (Lucas et al., 2011). Other important differences include levels of family poverty, rural and remote factors, tap water uoride levels and the availability. This heterogeneity of socioecological factors and oral health services mean relying on this evidence in planning WA speci c interventions is problematic.

Recommendations
It is evident that WA speci c research is required to inform universal and targeted intervention strategies that meet the oral health needs of young WA children and their families. Primary caregiver oral health literacy needs to be ascertained, ongoing reliable ECC data need to be gathered and the socioecological factors in uencing the two identi ed.
To achieve the goals and objectives of the WA State Oral Health Plan, policy change is also needed. It can be argued that, to achieve reliable dental caries records for children aged 0 to 4 years, greater access to free public dental services is required, facilitating regular family access to preventative dental services and treatment. The adoption of the WHO recommendation that ECC risk assessments should occur by the time a child is 12 months old and re-evaluated regularly would provide an opportunity for the routine collection of ECC data, which in turn could direct targeted oral health promotion strategies.
At the time of writing this systematic scoping review, the Labour Party manifesto has promised to introduce free dental check-ups for all children aged 6 months to 5 years (WA Labor, 2021). If this eventuates, this may go some way to improve dental service engagement across all social groups and enable more reliable ECC data collection in very young children. This review also argues that further Government action is required in the promotion of the Child Dental Bene t Schedule and the protective bene ts conferred by adequate uoride exposure whether it be through water uoridation or use of uoridated toothpaste for young children.

Conclusions
Oral health related childhood preventable hospitalisations and dental general anaesthetic procedures are increasing among Australian children. The WA State Government has indicated a commitment to reducing this oral health burden, proposing the development of a universal and, where indicated, targeted health promotion approach with children and their families, with a particular focus on the range of socioecological determinants in uencing oral health outcomes for the state's children.
At present, health promotion professionals are disadvantaged by the lack of data on ECC and oral health literacy which limit the ability to inform and evaluate future oral health initiatives. Research with WA primary caregivers is urgently required to inform practice and highlight necessary structural and policy factors that currently disadvantage the oral health outcomes for some WA children.

Declarations
Ethics approval and consent to participate Formal ethical approval is not required as no primary data have been collected. As such, there are no patients involved, so the consent of the patient to participate was not required.

Consent for publication
Not applicable.

Availability of data and materials
All data generated or analyzed during this study are included in this published article. Details of all studies analysed in this scoping review are included in Table 3 in this article.

Competing interests
The authors declare they have no competing interests.

Funding
This scoping review has not been funded by any external body.