Social Inequities in Access to Dental Care in Australian Adults over Time.

INTRODUCTION: Social inequities in dental caries are reflected by both inequities in the social structures that contribute to disease severity and inequities in the provision of dental care. This study aimed to describe social differentials in the dental caries experience among Australian adults across a 13-y period and to examine if the highest magnitude of oral health inequities persisted across dental caries prevalence (decayed teeth [DT]) or its management (missing teeth [MT], filled teeth [FT]). METHODS: Data were from 2 population-based cross-sectional surveys of Australian adult oral health conducted in 2004-2006 (National Survey of Adult Oral Health-1 [NSAOH-1], n = 5,505) and 2017-2018 (NSAOH-2, n = 5,022). In each survey, representative samples of adults were obtained through a 3-stage, stratified sample design within metropolitan and regional areas in each state/territory. Clinical outcomes included the prevalence and mean of DT, MT, FT, and DMFT. Equivalized household income was grouped into approximately quartiles from low to high. RESULTS: Across all income quartiles, the mean DT and % DT >0 was higher in NSAOH-2 than in NSAOH-1. The increase in prevalence was highest in the third highest income group (prevalence difference [PD] = 8.4, from 24.1 to 32.5). Similarly, % MT >0 was lower in NSAOH-2 than in NSAOH-1 across all income groups, with the decrease most marked for the lowest income group (PD = -6.5, from 74.1 to 67.8). Across all income quartiles, % FT >0 was lower in NSAOH-2 than in NSAOH-1. The decrease was the most marked for the lowest income group (PD = -8.9, from 81.1 to 72.2). CONCLUSION: The findings confirm that although oral health inequities decreased for the most extreme management outcome of dental caries (MT), inequities increased for experience of that disease (DT) and the more conservative management of dental caries (FT). For all D, M, and F components (DMFT), inequities between the lowest and highest household income groups increased from 2004-2006 to 2017-2018. KNOWLEDGE TRANSFER STATEMENT: This study found that social inequities in oral health (experience of untreated dental caries and missing teeth) increased between the most socially advantaged and disadvantaged groups between 2004-2006 and 2017-2018. This suggests that models of dental service provision in Australia are increasingly benefitting those who can afford and access the care and who arguably need the services less than their less socially advantaged counterparts do.

Oral microbiome research - working in partnership with Indigenous Australian communities.

Microbiome research is currently biased towards populations of European descent, with such populations providing a weak basis upon which to understand microbiome-health relationships in under-studied populations, many of whom carry the highest burdens of disease. Most oral microbiome studies to date have been undertaken in industrialized countries. Research involving marginalised populations should be shaped by a number of guiding principles. In the Indigenous Australian context, one useful framework is the Consolidated Criteria for Strengthening Reporting of Health Research involving Indigenous Peoples (CONSIDER) statement. This paper describes how the microbiome research field is having impacts in the Indigenous Australian health space, and describes a particular project involving Indigenous Australians in which the CONSIDER statement is used as the underlying framework.

Oral microbiome research from a public health perspective and implications for oral health.

Advancing oral microbiome research has revealed the association between oral microbiome composition and oral disease. However, much of the research has predominantly focused on comparing health and disease conditions, overlooking the potential dental public health implications. This article examines the evolution of oral microbial research from inception, advancement, and current knowledge of health-associated microbiota. Specifically, we focus on two key aspects: the impact of lifestyle and environmental factors on the oral microbiome and using the oral microbes as a therapeutic modality. The complex interaction of host intrinsic, environmental, and lifestyle factors affects the occurrence and development of the oral microbiota. The article highlights the need for ongoing research that embraces population diversity to promote health equity in oral health research and integrate public health practices into microbiome-based research. The implication of population-level interventions and targeted approaches harnessing the oral microbiome as an intervention, such as oral microbiome transplantation, should be further explored.

Oral microbiome research - a call for equity and inclusion.

Over 700 oral bacterial species have been identified in human populations, with ~200 bacterial species identified in any given individual mouth. The relationship between the oral microbiome and health is evidenced in many studies, with dysbiosis (a shift from a healthy to less healthy state of microbial community) associated with dental caries, periodontitis, halitosis and oral cancer. However, oral microbiome research to date has focused primarily on European populations, particularly those in large urban centres housing academic institutions with access to research funding. Key anthropological perspectives examining the sociocultural, epidemiological, genetic and environmental factors that influence the oral microbiome have also been Euro-centric. Very little is known about how the oral microbiome mediates both oral and general disease risks specifically within Indigenous and other vulnerable populations. Undertaking oral microbiome research in under-served communities requires consideration of many issues often unfamiliar in the broader research community, including being acceptable, relevant and of perceived benefit to the communities being studied. Research materials need to be managed respectfully in a culturally safe way, sharing/translating the knowledge obtained. These approaches will likely provide unique insights into the complex connections between environment and biology, people and place, and culture and science in relation to the oral microbiome. The ongoing development of oral microbiome research must facilitate frameworks that are equitable and inclusive to better enable clinical and scientific expertise within marginalised communities.

Commercializing equitable, accessible oral microbiome transplantation therapy.

Chronic oral diseases, such as caries and periodontal disease, may, in future, be treated by oral microbiome transplant (OMT) technology. OMT therapy would involve collecting a donor oral microbiome and transplanting into a recipient to either prevent or treat oral diseases linked to a change (i.e., dysbiosis) in the oral microbiome. Given the great promise of this technology, we must consider the ethical and practical implications of how it is developed to maximise its accessibility and affordability. Here, we examine ways that OMT technology might be commercialized in the context of equity and accessibility in both clinical or do-it-yourself settings. We do this while assuming that the technology can be developed for humans in ways that are safe and effective at the individual and population-levels. We highlight the need for OMT therapy to be 1) cost-effective, 2) understood by end users and clinicians, 3) easy to access even in rural or remote communities, and 4) providing donors equitable compensation for their microbiomes. These key elements will only be achieved through partnerships between scientists, clinicians, investors and stakeholders throughout development. Therefore, proper acknowledgement and equitable evaluation of contributions in this team will also be critical to ensuring that this technology can be globally accessed. While OMT is likely to reshape how we prevent or treat oral disease, consciously guiding its development toward equity and accessibility to all people may significantly aid in improving health for those without access to dental care.

Examining the Effect of Income-Based Inequalities and Dental Service Provision on Dental Service Utilization among Older Australians: A Multiple Mediation Analysis.

INTRODUCTION: Public service provision is one of the keys to reducing inequalities in the utilization of dental services. Given the increase in the aging population, there should be a focus on older adults' oral health. However, this is often overlooked. OBJECTIVES: This study investigates the effectiveness of public services in reducing income-related inequalities in dental service utilization among older South Australians. METHODS: A multiple counterfactual mediation analysis using the ratio of mediator probability weighting approach was used to explore the proposed mediation mechanism using a South Australian population of older adults (≥65 y). The exposure variable in the analysis was income, and the mediators were concession cards and the last dental sector (public or private). The outcome variable was the time of last dental visit. RESULTS: Half of the older adults with high income (≥$40,000) owned a concession card, and 10% of those who attended public dental services belonged to this group. Interestingly, only 16.3% of the study participants had visited the public dental sector at their last dental appointment. Results showed a negligible indirect effect (odds ratio [OR], 0.99; 95% confidence interval [CI], 0.85-1.05) and a significant direct effect (OR, 3.09; 95% CI, 2.24-4.87). By changing the potential outcome distributions to the counterfactual exposure distributions and taking the mediators' distribution as a counterfactual exposure distribution, the odds of dental visits occurring before the past 12 mo approximately tripled for low-income compared to high-income individuals. CONCLUSION: Income inequalities were associated with relatively delayed dental visits in older South Australians, and provision of public services could not improve this pattern. This might happen due to inequitable access to concession cards and public services. A review of policies is required, including addressing income inequalities and implementing short-term approaches to improve service utilization patterns in older South Australians. KNOWLEDGE TRANSFER STATEMENT: The findings of this study can enable policymakers for informed decision-making about the provision of public dental services for older Australians. This study emphasizes the importance of reviewing the current public dental services and subsidies and implementing short-term approaches to reduce income inequalities for older Australians.

The Relations between Systems of Oppression and Oral Care Access in the United States.

We applied a structural intersectionality approach to cross-sectionally examine the relationships between macro-level systems of oppression, their intersections, and access to oral care in the United States. Whether and the extent to which the provision of government-funded dental services attenuates the emerging patterns of associations was also assessed in the study. To accomplish these objectives, individual-level information from over 300,000 respondents of the 2010 US Behavioral Risk Factor Surveillance System was linked with state-level data for 2000 and 2010 on structural racism, structural sexism, and income inequality, as provided by Homan et al. Using multilevel models, we investigated the relationships between systems of oppression and restricted access to oral health services among respondents at the intersections of race, gender, and poverty. The degree to which extended provision of government-funded dental services weakens the observed associations was determined in models stratified by state-level coverage of oral care. Our analyses bring to the fore intersectional groups (e.g., non-Hispanic Black women and men below the poverty line) with the highest odds of not seeing a dentist in the previous year. We also show that residing in states where high levels of structural sexism and income inequality intersect was associated with 1.3 greater odds (95% confidence interval, 1.1-1.5) of not accessing dental services in the 12 mo preceding the survey. Stratified analyses demonstrated that a more extensive provision of government-funded dental services attenuates associations between structural oppressions and restricted access to oral health care. On the basis of these and other findings, we urge researchers and health care planners to increase access to dental services in more effective and inclusive ways. Most important, we show that counteracting structural drivers of inequities in dental services access entails providing dental care for all.

Power, dentistry and oral health inequities; an introduction.

Oral health inequities at a global level persist. This is despite marked advancements in technology, service delivery, training, research and population-level initiatives such as water fluoridation. Although the social determinants of health are frequently cited in the framing, analysis and description of oral health inequities, the explicit role of power is usually omitted. Lukes described power as the capacity of actors to make change, as well as to receive and resist change. An analysis of power thus provides a better understanding of how diverse and conflicting interests of multiple actors can lead to differential oral health norms within communities. An analysis of power also demonstrates the intersectional forms of oral inequities experienced among the socially marginalised; it is not rooted in economic deprivation alone. The training and practice of dentistry itself creates intersectional forms of inequalities through race, gender and class. Dental academic spaces are overwhelmingly White, with the knowledge created thus embedded with Eurocentric values. This needs to be challenged. We aim, in this special issue, to provide an overview of the pluralist and diverse nature of contemporary global society, and to show how attempting to impose singular forms of behaviours, values and knowledge that suppress the cultures of socially marginalised communities enhances oral health inequities. Specifically, this special issue will: (1) present an overview of how power operates generally, using implicit bias examples, with a strong underpinning from the literature; (2) describe what this means for power in dentistry, drawing upon sociological literature with a specific lens on dental organisations; (3) expand understanding of post-colonial theory and how this reinforces power structures in dentistry that further enable the privileged and; (4) examine the power relationship between dentists and patients, using theoretical underpinnings and elaborating on different power paradigms in the Australian vs Asian/Korean context.

Oral health-related self-efficacy and fatalism in a regional South Australian Aboriginal population.

OBJECTIVES: To assess the psychometric properties, including face, content, criterion and known-groups validity and reliability, of scales to measure oral health-related self-efficacy and fatalism in a regional Aboriginal adult population in Australia. METHODS: Four hundred Aboriginal adults (aged 18-82 years, 67% female) completed a self-report questionnaire including items pertaining to oral health-related self-efficacy and fatalism. Structural validity was determined in exploratory factor analysis (EFA) with principal components analysis for each scale. Criterion validity was assessed between the instruments and theoretically related variables. Known-groups validity was investigated by comparing the scores in different population groups according to age, sex, education and employment. Reliability of the scales was assessed through internal consistency. RESULTS: The EFA confirmed a single factor structure for self-efficacy and fatalism scales, with Cronbach's alphas of 0.93 and 0.89 respectively. The two scales were not correlated. Oral health-related self-efficacy was associated with toothbrush ownership and brushing the previous day supporting criterion validity. Oral health-related fatalism was associated with previous extractions and perceived need for extractions also supporting criterion validity. Both measures were associated with social impact of oral health as measured by the OHIP-14, supporting their criterion validity. Mixed findings were observed in terms of known-groups validity. CONCLUSIONS: There was initial evidence that measures of oral health-related self-efficacy and fatalism displayed adequate psychometric properties in this Aboriginal community. These constructs could have implications for approaches for improving oral health among Aboriginal people.

Self-rated oral and general health among Aboriginal adults in regional South Australia.

BACKGROUND: In Australia, Aboriginal adults experience higher levels of poor oral and general health than the non-Aboriginal population. This study compared self-rated oral and general health among Aboriginal adults in regional South Australia with participants in the National Survey of Adult Oral Health (NSAOH). METHODS: Data were obtained from the Indigenous Oral Health Literacy Project (IOHLP) based in South Australia. Three sub-populations from the NSAOH were utilised for comparison: National Aboriginal, National non-Aboriginal and South Australian Regional Non-Aboriginal adults. All data were standardised by age group and sex, utilising Census data. RESULTS: Just over 70% of South Australian Regional Aboriginal participants gave a rating of 'excellent, very good or good' for general health, more than 17% lower than each of the other groups. Just over 50% rated their oral health highly, 20% fewer than the proportion for each other group. Stratifying by key socio-demographic factors did not account for all differences. CONCLUSIONS: Proportionally fewer South Australian Regional Aboriginal adults had high ratings of oral and general health than the Aboriginal and non-Aboriginal adults from the national survey, indicating that national-level data might underestimate the proportion of regional Aboriginal Australians with poor oral health.

Inequality and Inequity in the Use of Oral Health Services in Australian Adults.

OBJECTIVE: Social determinants drive disparities in dental visiting. This study aimed to measure inequality and inequity in dental visiting among Australian adults. METHODS: Data were obtained from the National Study of Adult Oral Health (2017 to 2018). Participants were Australian adults aged ≥30 y. The outcome of interest was dental visiting in the last 12 mo. Disparity indicators included education and income. Other sociodemographic characteristics included age, gender, Indigenous status, main language, place of birth, residential location, health card and dental insurance status, and individual's self-rated and impaired oral health. To characterize inequality in dental service use, we examined bivariate relationships using indices of inequality: the absolute and relative concentration indexes and the slope and relative indexes of inequality. Inequalities were depicted through concentration curves. Indirect standardization with a nonlinear model was used to measure inequity. RESULTS: A total of 9,919 Australian adults were included. Bivariate analysis showed a gradient by education and income on dental visiting, with 48% of those with lowest educational attainment/income having not visited a dentist in the last 12 mo. The concentration curves showed pro-low education and pro-poor income inequalities. All measures of absolute and relative indices were negative, indicating that from the bottom to the top of the socioeconomic ladder (education and income), the prevalence of no dental visiting decreased: absolute and relative concentration index estimates were approximately 2.5% and 5.0%, while the slope and relative indexes of inequality estimates were 14% to 18% and 0.4%, respectively. After need standardization, the group with the highest education or income had almost 1.5-times less probability of not having a dental visit in the previous year than those with the lowest education or income. CONCLUSION: The use of oral health services exhibited socioeconomic inequalities and inequities, disproportionately burdening disadvantaged Australian adults. KNOWLEDGE TRANSFER STATEMENT: The results of this study can be used by policy makers when planning a dental labor force in relation to the capacity of supply dental services to 1) reduce the inequality and inequity in the use of oral health services and 2) meet identified oral health needs across the Australian population, which is important for preventive dental care.

Racism and oral health inequities; an introduction.

Contemporary evidence shows that: (i) racial minorities often bear the greatest burden of oral diseases; (ii) there are notable differences between socially advantaged and disadvantaged racial groups and; (iii) racial inequities in oral health persist over time and across space. In the four papers that follow, we seek to contribute to the discourse around oral health and racial inequities through recognition that racism has a structural basis and is embedded in long-standing social policy in almost every developed (and developing) nation. The papers formed the basis of a symposium entitled 'Racism and oral health inequities' at the 99th General Session of the International Association of Dental Research held July 2021 in Boston, United States. The authors responded to the international Black Lives Matter movement that gained momentum in 2019, responding in many calls to arms for greater exposure to the insidious impacts on racism on all facets of health and wellbeing, and the regulatory regimes in which they operate. The papers provide an overview of the history of racism in oral health inequities at an international level, with a specific focus on the implications of addressing (or not addressing) racism in population oral health at an international level. This includes the role of advocacy and engaging with health policymakers to both minimize racism and to increase comprehension of its residual effects that may lead to misinformed policy.

Making science and doing justice: The need to reframe research on racial inequities in oral health.

This article combines a review of dental studies on race with sociological insights into systemic racism to advance a counter-narrative on the root causes of racial oral health inequities. Taking racism as a form of oppression that cuts across institutional, cultural, and behavioral dimensions of social life, we ask: How pervasive are racial inequities in the occurrence of adverse oral health outcomes? What is the direction and magnitude of racial inequities in oral health? Does the inequitable distribution of negative outcomes persist over time? How can sociological frameworks on systemic racism inform initiatives to effectively reduce racial oral health inequities? The first three questions are addressed by reviewing dental studies conducted in the past few years around the globe. The fourth question is addressed by framing racial oral health inequities around sociological scholarship on racism as a systemic feature of contemporary societies. The paper concludes with a set of practical recommendations on how to eliminate racial oral health inequities, which include engaging with a strong anti-racist narrative and actively dismantling the race discrimination system. Amid the few attempts at moving the field towards improved racial justice, this paper should be followed by research on interventions against racial oral health inequities, including the conditions under which they succeed.

Random and Systematic Bias in Population Oral Health Research: an introduction.

Bias in population oral health research is a form of systematic error that can affect scientific investigations and distort inference (i.e under or over confidence in an estimate). A biased study loses validity in relation to the degree of the bias. While some study designs are more prone to bias, its presence is universal. It is difficult to completely eliminate bias; in the process of attempting to do so, new bias may be introduced or a study may be rendered less generalizable. The goals are to therefore minimize bias and for investigators and readers to comprehend its residual effects, limiting misinterpretation and misuse of data. In the four papers that follow, we seek to contribute to the discourse around random and systematic bias in population oral health research through the lens of case controlled studies, longitudinal studies and genomics re search. The papers formed the basis of a symposium entitled 'Random and Systematic Bias in Population Oral Health Research' at the 98th General Session of the International Association of Dental Research held March 2020 in Washington DC, United States.

Challenges and Solutions for Improved Oral Health: Examples from Motivational Interviewing Trials.

KNOWLEDGE TRANSFER STATEMENT: Irrespective of country, socially disadvantaged children experience greater levels of preventable dental disease than their more socially advantaged peers. Motivational interviewing (MI) is recognized as a potential intervention tool for reducing prevalence of child dental disease. The challenges of implementing MI in 4 trials involving socially vulnerable children are highlighted in this commentary, with some potential solutions offered.

Effects of racism on the socio-emotional wellbeing of Aboriginal Australian children.

BACKGROUND: Racism is a pervasive experience in the life of Aboriginal Australians that begins in childhood. As a psychosocial stressor, racism compromises wellbeing and impacts developmental trajectories. The purpose of the present study was to estimate the effect of racism on indicators of Australian Aboriginal child socio-emotional wellbeing (SEWB) at one to two years after exposure. Age-related differences in the onset of symptoms were explored. METHODS: Data from the B- and K-cohorts of the Longitudinal Study of Indigenous Children were used (aged 6 to 12 years). Racism, confounding variables, and the Strengths and Difficulties Questionnaire (a measure of SEWB) were collected by questionnaires and guided interviews with each child's main caregiver. Adjusted Poisson regression was used to estimate the relative risk (RRa) effects of racism on SEWB for both cohorts separately. RRa were pooled in a random effects meta-analysis. RESULTS: Exposure to racism was associated with an adjusted point estimate indicating a 41% increased risk for total emotional and behavioural difficulties, although the confidence intervals were wide (pooled RRa 1.41, 95% CI 0.75, 2.07). Analyses by cohort showed younger children had higher RRa for total difficulties (RRa 1.72, 95% CI 1.16, 2.54), whilst older children had higher RRa for hyperactive behaviour (RRa 1.66, 95% CI 1.01, 2.73). CONCLUSIONS: The effects observed contributes to our understanding of the impact of racism on Aboriginal Australian children. Support for emotional and behavioural difficulties, and hyperactive behaviour, for Aboriginal children might help counteract the effects of racism. Future longitudinal research and policies aimed at reducing racism in Australian society are necessary.

Transnational corporations and oral health inequalities; an introduction.

In an increasingly globalised world, Trans-National Corporations (TNCs) wield considerable social, economic and political influence, both in the international market economy and within individual countries. The practices of TNCs can have positive or adverse effects on population health through production methods and products, shaping social determinants of health, or influencing the regulatory structures governing their activities. TNCs can contribute to health inequities if the health consequences arising from their practices have disproportionate adverse impacts on vulnerable populations or positive benefits for less vulnerable groups. Despite growing recognition of the implications for health, including oral health, arising from TNC practices, little research has sought to systematically assess the oral health and/or oral health equity impacts of TNCs. In the four papers that follow, we contribute to the discourse around oral health-related inequalities through the lens of power, human agency and TNCs. The papers formed the basis of a symposium entitled 'Transnational Corporations and oral health inequalities' at the 97th General Session of the International Association of Dental Research held June 2019 in Vancouver, British Columbia. The authors responded to the 2014 Lancet-University of Oslo Commission on Global Governance for Health call for greater attention to the health effects of TNC practices and the regulatory regimes in which they operate. The papers overview the role of TNCs in oral health inequalities at an international level, with a specific focus on illuminating their far-reaching influence on our everyday lives, from both epidemiological and sociological perspectives, and the multi-faceted positive or adverse effects on oral health this might have. Key TNC examples are provided by way of the sugar and the tobacco industries, with their impact on dental caries, periodontal diseases and head and neck cancers.

Periodontal therapy and glycaemic control among individuals with type 2 diabetes: reflections from the PerioCardio study.

OBJECTIVES: Diabetes mellitus and periodontal disease are highly prevalent among Indigenous Australian adults. Untreated periodontitis impacts glycaemic control in people with diabetes. The aim of this study was to report on the effect of periodontal therapy on glycaemic control among people with obesity. METHODS: This subgroup analysis is limited to 62 participants with diabetes from the original 273 Aboriginal Australian adults enrolled into the PerioCardio study. Intervention participants received full-mouth non-surgical periodontal scaling during a single, untimed session while controls were untreated. Endpoints of interest included change in glycated haemoglobin (HbA1c), C-reactive protein (CRP) and periodontal status at 3 months post-intervention. RESULTS: There were more females randomized to the treatment group (n = 17) than control (n = 10) while the control group had a higher overall body mass index (BMI) [mean (SD)] 33.1 (9.7 kg m-2 ) versus 29.9 (6.0 kg m-2 ). A greater proportion of males were followed up at 3 months compared to females, P = 0.05. Periodontal therapy did not significantly reduce HbA1c: ancova difference in means 0.22 mmol mol-1 (95% CI -6.25 to 6.69), CRP: ancova difference in means 0.64 (95% CI -1.08, 2.37) or periodontal status at 3 months. CONCLUSIONS: Non-surgical periodontal therapy did not significantly reduce glycated haemoglobin in participants with type 2 diabetes. Reasons are likely to be multifactorial and may be influenced by persistent periodontal inflammation at the follow-up appointments. Alternatively, the BMI of study participants may impact glycaemic control via alternative mechanisms involving the interplay between inflammation and adiposity meaning HbA1c may not be amenable to periodontal therapy in these individuals.