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.

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.

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.

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.

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.

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.

Inequalities in Indigenous Oral Health: Findings from Australia, New Zealand, and Canada

The objective was to compare absolute differences in the prevalence of Indigenous-related inequalities in dental disease experience and self-rated oral health in Australia, Canada, and New Zealand. Data were sourced from national oral health surveys in Australia (2004 to 2006), Canada (2007 to 2009), and New Zealand (2009). Participants were aged ≥18 y. The authors measured age- and sex-adjusted inequalities by estimating absolute prevalence differences and their corresponding 95% confidence intervals (95% CIs). Clinical measures included the prevalence of untreated decayed teeth, missing teeth, and filled teeth; self-reported measures included the prevalence of "fair" or "poor" self-rated oral health. The overall pattern of Indigenous disadvantage was similar across all countries. The summary estimates for the adjusted prevalence differences were as follows: 16.5 (95% CI: 11.1 to 21.9) for decayed teeth (all countries combined), 18.2 (95% CI: 12.5 to 24.0) for missing teeth, 0.8 (95% CI: -1.9 to 3.5) for filled teeth, and 17.5 (95% CI: 11.3 to 23.6) for fair/poor self-rated oral health. The I² estimates were small for each outcome: 0.0% for decayed, missing, and filled teeth and 11.6% for fair/poor self-rated oral health. Irrespective of country, when compared with their non-Indigenous counterparts, Indigenous persons had more untreated dental caries and missing teeth, fewer teeth that had been restored (with the exception of Canada), and a higher proportion reporting fair/poor self-rated oral health. There were no discernible differences among the 3 countries.

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.

Are Stage of Change constructs relevant for subjective oral health in a vulnerable population?

Stage of Change constructs may be proxy markers of psychosocial health which, in turn, are related to oral health.

OBJECTIVE

To determine if Stage of Change constructs were associated with subjective oral health in a population at heightened risk of dental disease.

METHODS

Stage of Change constructs were developed from a validated 18-item scale and categorised into 'Pre-contemplative', 'Contemplative' and 'Active'. A convenience sample of 446 Australian non-Aboriginal women pregnant by an Aboriginal male (age range 14-43 years) provided data to evaluate the outcome variables (self-rated oral health and oral health impairment), the Stage of Change constructs and socio-demographic, behavioural and access-related factors. Factors significant at the p < 0.05 level in bivariate analysis were entered into prevalence regression models.

RESULTS

Approximately 54% of participants had fair/poor self-rated oral health and 34% had oral health impairment. Around 12% were 'Pre-contemplative', 46% 'Contemplative' and 42% 'Active'. Being either 'pre-contemplative' or 'contemplative' was associated with poor self-rated oral health after adjusting for socio-demographic factors. 'Pre-contemplative' ceased being significant after adjusting for dentate status and dental behaviour. 'Pre-contemplative' remained significant when adjusting for dental cost, but not 'Contemplative'. The Stages of Change constructs ceased being associated with self-rated oral health after adjusting for all confounders. Only 'Contemplative' (reference: 'Active') was a risk indicator in the null model for oral health impairment which persisted after adding dentate status, dental behaviour and dental cost variables, but not socio-demographics. When adjusting for all confounders, 'Contemplative' was not a risk indicator for oral health impairment.

CONCLUSIONS

Both the 'Pre-contemplative' and 'Contemplative' Stage of Change constructs were associated with poor self-rated oral health and oral health impairment after adjusting for some, but not all, covariates. When considered as a proxy marker of psychosocial health, Stage of Change constructs may have some relevance for subjective oral health.

Experience of racism and tooth brushing among pregnant Aboriginal Australians: exploring psychosocial mediators

OBJECTIVES

Despite burgeoning evidence regarding the pathways by which experiences of racism influence health outcomes, little attention has been paid to the relationship between racism and oral health-related behaviours in particular. We hypothesised that self-reported racism was associated with tooth brushing, and that this association was mediated by perceived stress and sense of control and moderated by social support.

METHODS

Data from 365 pregnant Aboriginal Australian women were used to evaluate tooth brushing behaviour, sociodemographic factors, psychosocial factors, general health, risk behaviours and racism exposure. Bivariate associations were explored and hierarchical logistic regression models estimated odds ratios (OR) and 95% confidence intervals (CI) for tooth brushing. Perceived stress and sense of control were examined as mediators of the association between self-reported racism and tooth brushing using binary mediation with bootstrapping.

RESULTS

High levels of self-reported racism persisted as a risk indicator for tooth brushing (OR 0.51, 95%CI 0.27,0.98) after controlling for significant covariates. Perceived stress mediated the relationship between self-reported racism and tooth brushing: the direct effect of racism on tooth brushing was attenuated, and the indirect effect on tooth brushing was significant (beta coefficient -0.09; bias-corrected 95%CI -0.166,-0.028; 48.1% of effect mediated). Sense of control was insignificant as a mediator of the relationship between racism and tooth brushing.

CONCLUSIONS

High levels of self-reported racism were associated with non-optimal tooth brushing behaviours, and perceived stress mediated this association among this sample of pregnant Aboriginal women.. Limitations and implications are discussed.

Access, literacy and behavioural correlates of poor self-rated oral health amongst an indigenous south Australian population

OBJECTIVE

To better understand the determinants of self-rated oral health within an Indigenous population by: 1, examining potential individual-level correlates of socio-demographic, health behaviours, dental care access and oral health literacy-related outcomes with self-rated oral health; and, 2, examining the relative contribution of these domains to self-rated oral health in multivariable modelling.

METHODS

We conducted nested logistic regression analyses on self-reported status of 'fair or poor' versus 'better' oral health using data from a convenience sample of rural dwelling Indigenous Australians (n = 468). Data were collected on background characteristics, health behaviours, access to dental care, oral health literacy-related outcome variables and REALD 30, an oral health literacy scale.

RESULTS

Overall 37.0 % of the Indigenous adult population reported fair or poor oral health. In multivariable modelling, risk indicators for fair or poor self-rated oral health that persisted after adjusting for other covariates included being aged 38+ years (OR 2.9, 95%CI 1.9,4.6), holding a Government Health Concession card (OR 2.3, 95%CI 1.1,4.5), avoiding the dentist due to financial constraints (OR 2.3, 95%CI 1.4,3.6), not knowing how to make an emergency dental visit (OR 1.7, 95%CI 1.1,2.7) and poor understanding of the prevention of dental disease (OR 1.7, 95%CI 1.1,2.7).

CONCLUSIONS

In this vulnerable population, risk indicators contributing to poor self-rated oral health included socio-demographic, dental care access and oral health literacy-related factors. Health behaviours were not significant.

Greater inequalities in dental treatment than in disease experience

This study aimed to (1) describe social gradients in dental caries in a population-level survey and (2) examine whether inequalities are greater in disease experience or in its treatment. Using data from Australia's National Survey of Adult Oral Health 2004-2006, we examined absolute and relative income inequalities for DMFT and its separate components (DT, MT, FT) using adjusted proportions, means, and health disparity indices [Slope Index of Inequality (SII) and Relative Index of Inequality (RII)]. Approximately 90% of Australian adults had experienced caries, with prevalence ranging from 89.7% in the highest to 96.6% in the lowest income group. Social gradients in caries were evident across all components of DMFT, but particularly notable in Missing (SII = -15.5, RII = -0.3) and untreated Decay (SII = -23.7, RII = -0.9). Analysis of age- and gender-adjusted data indicated less variation in levels of disease experienced (DMFT) than in the health outcomes of its management (missing teeth). The findings indicate that social gradients for dental caries have a greater effect on how the disease was treated than on lifetime disease experience.

Oral health behaviours and perceptions reported by Indigenous Australians living in Darwin, Northern Territory

OBJECTIVE

To describe the reported oral health behaviours and perceptions of Indigenous Australians living in Darwin, Northern Territory and to compare those with estimates for Darwin and Australia derived from the National Survey of Adult Oral Health (NSAOH).

PARTICIPANTS

A total of 181 Indigenous Australians aged 22 years and over living in Darwin, participating in screening for a wider randomised clinical trial, were included.

METHOD

Information on socio-demographic characteristics, oral health status including oral health behaviours and perceptions was collected using a questionnaire. Differences between the Darwin study (DS) participants and Australians in NSAOH were made based on non-overlapping 95% confidence intervals.

RESULTS

Almost 72% of DS participants had last seen a dentist over a year earlier, compared to 47% and 39% of NSAOH Darwin and Australian participants, respectively. A higher proportion of DS participants usually visited a dentist because of a problem than NSAOH Darwin and NSAOH Australian participants. A higher proportion of DS participants had avoided or delayed a dental visit because of cost than NSAOH participants. Over three times as many DS participants rated their oral health as fair/poor compared to NSAOH participants. A higher proportion of DS participants had perceived gum disease and one or more symptoms of gum disease than NSAOH participants. A higher proportion of DS participants experienced toothache, felt uncomfortable about appearance of their mouth and avoided eating because of oral problems than NSAOH participants.

CONCLUSIONS

A higher proportion of Indigenous Australians living in Darwin presented with non-optimal oral health behaviours and perceptions compared with both the Darwin and Australian general populations.

Development and psychometric validation of a Health Literacy in Dentistry scale (HeLD)

BACKGROUND

Oral health literacy is emerging as a new public health challenge and poor oral health literacy is increasingly seen as an important predictor of poor oral health outcomes. Within Indigenous populations, there may be benefits to research in using a culturally acceptable, internally consistent and valid instrument to assess oral health literacy. We translated a general health literacy measure, the Health Literacy Management (HeLM) scale to make a dentally relevant scale; Health Literacy in Dentistry (HeLD).

OBJECTIVE

This study describes the development and assessment of the reliability and validity of the HeLD in an Indigenous Australian population.

DESIGN AND METHODS

The 29 item HeLD scale assesses the components of oral health literacy. The reliability and validity of the seven HeLD subscales were evaluated in a convenience sample of 209 Indigenous Australians with mean age 35 years (range 17-81) and of which 139 were female.

RESULTS

The scale was supported by exploratory factor analysis and established seven distinct and internally consistent domains of oral health literacy: Communication, Access, Receptivity, Understanding, Utilisation, Support and Economic Barriers (Cronbach's alpha = 0.91). Discriminative ability was confirmed by HeLD associations with socio-demographic variables and self-reported health ratings in the expected direction. The convergent validity and predictive validity were confirmed by HeLD scores being significantly associated with toothbrush ownership, use of a toothbrush, time since last dental visit and knowledge of the effect of cordial on the teeth.

CONCLUSIONS

The HeLD appears to be an internally valid and reliable instrument and can be used for measuring oral health literacy among rural Indigenous Australian adults.

Ukaipō niho: the place of nurturing for oral health

OBJECTIVES

To report on oral-health-related characteristics, beliefs, and behaviours among participants in a randomised control trial of an intervention to prevent early childhood caries (ECC) among Māori children, and to determine whether there were any systematic differences between the intervention and control groups at baseline.

DESIGN

Baseline measurements from a randomised control trial (involving 222 pregnant Māori women allocated randomly to either Intervention or Delayed groups) which is currently underway.

SETTING

The rohe (tribal area) of Waikato-Tainui.

METHODS

Self-report information collected on sociodemographic characteristics, pregnancy details, self-reported general and oral health and health-related behaviours, and oral health beliefs.

RESULTS

Other than those in the Delayed group being slightly older, on average, there were no significant differences between the two groups. Some 37.0% were expecting their first child. Most reported good health; 43.6% were current smokers, and 26.4% had never smoked. Only 8.2% were current users of alcohol. Almost all were dentate, and 57.7% described their oral health as fair or poor. One in six had had toothache in the previous year; 33.8% reported being uncomfortable about the appearance of their teeth, and 27.7% reported difficulty in eating. Dental service-use was relatively low and symptom-related; 78.9% needed to see a dentist. Overall, most of the sample believed that it was important to avoid sweet foods, visit dentists and to brush the teeth, while about half thought that using fluoride toothpaste and using floss were important. Some 38.2% felt that drinking fluoridated water was important. Oral-health-related fatalism was apparent, with 74.2% believing that most people usually get dental problems, 58.6% believing that most people will need extractions at some stage, and that most children eventually get dental caries.

CONCLUSIONS

Mothers' important role in nurturing the well-being of the young child includes the protection and maintenance of the growing child's oral health (or ukaipo niho). The findings provide important insights into Māori mothers' oral health knowledge, beliefs and practices.

Associations between oral health and height in an indigenous Australian birth cohort

OBJECTIVE

Evidence suggests that taller individuals have better health than their shorter counterparts. This study aimed to test the hypothesis that shorter participants in wave-3 of the Aboriginal Birth Cohort (ABC) study, a prospective longitudinal investigation of Indigenous Australian individuals born 1987-1990 at an Australian regional hospital, would have more caries and periodontal disease experience than their taller counterparts.

METHODS

Data were collected through oral clinical examinations, anthropometric measures and self-report questionnaires. The outcome variables were participants' caries (mean DMFT) and periodontal disease experience (moderate or severe periodontal disease as defined by the Centre for Disease Control), with height as an explanatory variable. Antecedent anthropometric, socio-demographic, sugar consumption frequency, dental behaviour and substance use variables were used as possible confounders. Linear regression was used in the analysis of caries experience, while adjusted prevalence ratios were used for prevalence of moderate or severe periodontal disease.

RESULTS

Higher DMFT was found among participants in the shortest tertile (B=1.02, 95% CI=0.02-2.02) and those who consumed sweets every day or a few days a week (B=1.08, 95% CI=0.11-2.05), while lower DMFT was found among those owning a toothbrush (B=0.80, 95% CI=-0.22-1.82). Periodontal disease was positively associated with the shortest tertile (adjusted PR=1.39, 95% CI=0.96-1.82) and negatively associated with toothbrush ownership (adjusted PR=0.50, 95% CI=0.34-0.66).

CONCLUSION

The hypothesis that shorter participants in wave-3 of the ABC study would have higher levels of caries and periodontal disease was confirmed.

Oral health literacy comparisons between Indigenous Australians and American Indians

OBJECTIVES

To compare oral health literacy (OHL) levels between two profoundly disadvantaged groups, Indigenous Australians and American Indians, and to explore differences in socio-demographic, dental service utilisation, self-reported oral health indicators, and oral health-related quality of life (OHRQoL) correlates of OHL among the above.

METHODS

OHL was measured using REALD-30 among convenience samples of 468 Indigenous Australians (aged 17-72 years, 63% female) and 254 female American Indians (aged 18-57 years). Covariates included socio-demography, dental utilisation, self-reported oral health status (OHS), perceived treatment needs and OHRQoL (prevalence, severity and extent of OHIP-14 'impacts'). Descriptive and bivariate methods were used for data presentation and analysis, and between-sample comparisons relied upon empirical contrasts of sample-specific estimates and correlation coefficients.

RESULTS

OHL scores were: Indigenous Australians - 15.0 (95% CL=14.2, 15.8) and American Indians--13.7 (95% CL=13.1, 14.4). In both populations, OHL strongly correlated with educational attainment, and was lower among participants with infrequent dental attendance and perceived restorative treatment needs. A significant inverse association between OHL and prevalence of OHRQoL impacts was found among American Indians (rho=-0.23; 95% CL = -0.34, -0.12) but not among Indigenous Australians.

CONCLUSIONS

Our findings indicate that OHL levels were comparable between the two groups and lower compared to previously reported estimates among diverse populations. Although the patterns of association of OHL with most examined domains of correlates were similar between the two groups, this study found evidence of heterogeneity in the domains of self-reported OHS and OHRQoL.

Associations between area-level disadvantage and DMFT among a birth cohort of Indigenous Australians

BACKGROUND

Individual-level factors influence DMFT, but little is known about the influence of community environment. This study examined associations between community-level influences and DMFT among a birth cohort of Indigenous Australians aged 16-20 years.

METHODS

Data were collected as part of Wave 3 of the Aboriginal Birth Cohort study. Fifteen community areas were established and the sample comprised 442 individuals. The outcome variable was mean DMFT with explanatory variables including diet and community disadvantage (access to services, infrastructure and communications). Data were analysed using multilevel regression modelling.

RESULTS

In a null model, 13.8% of the total variance in mean DMFT was between community areas, which increased to 14.3% after adjusting for gender, age and diet. Addition of the community disadvantage variable decreased the variance between areas by 4.8%, indicating that community disadvantage explained one-third of the area-level variance. Residents of under-resourced communities had significantly higher mean DMFT (β = 3.86, 95% CI 0.02, 7.70) after adjusting for gender, age and diet.

CONCLUSIONS

Living in under-resourced communities was associated with greater DMFT among this disadvantaged population, indicating that policies aiming to reduce oral health-related inequalities among vulnerable groups may benefit from taking into account factors external to individual-level influences.

Self-reported oral health of a metropolitan homeless population in Australia: comparisons with population-level data

BACKGROUND

There is limited information on self-perceived oral health of homeless populations. This study quantified self-reported oral health among a metropolitan homeless adult population and compared against a representative sample of the metropolitan adult population obtained from the National Survey of Adult Oral Health.

METHODS

A total of 248 homeless participants (age range 17-78 years, 79% male) completed a self-report questionnaire. Data for an age-matched, representative sample of metropolitan-dwelling adults were obtained from Australia's second National Survey of Adult Oral Health. Percentage responses and 95% confidence intervals were calculated, with non-overlapping 95% confidence intervals used to identify statistically significant differences between the two groups.

RESULTS

Homeless adults reported poorer oral health than their age-matched general population counterparts. Twice as many homeless adults reported visiting a dentist more than a year ago and that their usual reason for dental attendance was for a dental problem. The proportion of homeless adults with a perceived need for fillings or extractions was also twice that of their age-matched general population counterparts. Three times as many homeless adults rated their oral health as 'fair' or 'poor'.

CONCLUSIONS

A significantly greater proportion of homeless adults in an Australian metropolitan location reported poorer oral health compared with the general metropolitan adult population.

Oral health-related quality of life among rural-dwelling indigenous Australians

BACKGROUND

There is limited information on the impact of poor oral health on Indigenous Australian quality of life. This study aimed to determine the prevalence, extent and severity of, and to calculate risk indicators for, poor oral health-related quality of life among a convenience sample of rural-dwelling Indigenous Australians.

METHODS

Participants (n = 468) completed a questionnaire that included socio-demographic, lifestyle, dental service utilization, dental self-care and oral health-related quality of life (OHIP-14) factors.

RESULTS

The prevalence of having experienced one or more of OHIP-14 items 'fairly often' or 'very often' was 34.8%. The extent of OHIP-14 scores was 1.88, while the severity was 15.0. Risk indicators for having experienced one or more of OHIP-14 items 'fairly often' or 'very often' included problem-based dental attendance, avoiding dental care because of cost, difficulty paying a $100 dental bill and non-ownership of a toothbrush. An additional risk indicator for OHIP-14 extent was healthcare card ownership, while additional indicators for OHIP-14 severity were healthcare card ownership and having had 5+ teeth extracted.

CONCLUSIONS

Risk indicators for poor oral health-related quality of life among this marginalized population included socio-economic factors, dentate status factors, dental service utilization patterns, financial factors and dental self-care factors.

Factors associated with restoration and extraction receipt among New Zealand children

OBJECTIVES

To assess the relative contribution of demographic socioeconomic, physical/lifestyles, dietary, food security and dental factors to self-reported restoration or extraction receipt among New Zealand children.

BASIC RESEARCH DESIGN

Cross-sectional study of nationally representation data using a two-stage random clustered sampling procedure and complex sampling analysis.

PARTICIPANTS

Mäori, Pacific and New Zealand European or Other (NZEO) children aged 5-14 years.

RESULTS

Of the 3,275 participants 37.4% were Mäori, 32.3% Pacific and 30.3% NZEO. Mäori children had higher odds of having received a restoration than NZEO children after adjusting for age, gender and length of time lived in New Zealand (OR: 1.87) and with addition of household SES (OR: 1.58), lifestyle (OR: 1.92), dietary (OR: 1.64), food security (OR: 1.79) or dental factors (OR: 1.89). By contrast, Pacific children had higher odds of having received an extraction than NZEO children when age, gender and length of time lived in New Zealand were taken into account (OR: 1.69), and with addition of household SES (OR: 1.48), lifestyle (OR: 1.71), dietary (OR: 1.52), food security (OR: 1.21) or other dental factors (OR: 1.93).

CONCLUSIONS

Mäori children were more likely to have received a restoration, and Pacific children more likely to experience an extraction, than NZEO children after adjusting for behavioural and material factors. Household SES contributed to most of the variance in Mäori child restoration receipt, while food security items explained most of the variance in Pacific child experience of extraction.

Dental caries trends among indigenous and non-indigenous Australian children

OBJECTIVE

To examine trends in dental caries among indigenous and non-indigenous children in an Australian territory.

BASIC RESEARCH DESIGN

Routinely-collected data from a random selection of 6- and 12-year-old indigenous and non-indigenous children enrolled in the Northern Territory School Dental Service from 1989-2000 were obtained. The association of indigenous status with caries prevalence (percent dmft or DMFT>0 and percent dmft>3 or DMFT>1), caries severity (mean dmft or DMFT) and treatment need (percent d/dmft or D/DMFT) was examined.

RESULTS

Results were obtained for 10,687 6- and 12-year old indigenous children and 21,777 6- and 12-year-old non-indigenous children from 1989-2000. Across all years, indigenous 6-year-olds had higher caries prevalence in the deciduous dentition, greater mean dmft and percent d/dmft, and indigenous 12-year-olds had greater percent D/DMFT than their non-indigenous counterparts (p<0.05). From 1996-2000 the mean dmft and percent d/dmft for indigenous 6-year-olds and mean DMFT and percent D/DMFT for indigenous 12-year-olds increased, yet remained relatively constant for their non-indigenous counterparts (p<0.05). From 1997-2000, the percent dmft>3 for 6-year-old indigenous children was more than double that of non-indigenous children, while across the period 1994-2000, indigenous 6-year-old mean dmft was more than double that of their non-indigenous counterparts (p<0.05).

CONCLUSIONS

Indigenous children in our study experienced consistently poorer oral health than non-indigenous children. The severity of dental caries among indigenous children, particularly in the deciduous dentition, appears to be increasing while that of non-indigenous children has remained constant. Our findings suggest that indigenous children carry a disproportionate amount of the dental caries burden among Northern Territory 6- and 12-year-olds.

Indigenous children and receipt of hospital dental care in Australia

OBJECTIVE

The aim of this study was to investigate dental procedures received under hospital general anaesthetic by indigenous and non-indigenous Australian children in 2002-2003.

METHODS

Separation data from 1297 public and private hospitals were obtained from the Australian Institute of Health and Welfare National Hospital Morbidity Database for 2002-2003. The dependant variable was the admission rate of children receiving four categories of dental care (i.e. extraction, pulpal, restoration or other). The explanatory variables included sex, age group, indigenous status and location (i.e. major city, regional or remote). Rates were calculated using estimated resident population counts.

RESULTS

The sample included 24 874 children aged from 2 to 14 years. Some 4.3% were indigenous (n = 1062). Admission rates for indigenous and non-indigenous children were similar, with indigenous males having 1.2 times the admission rate of indigenous females (P < 0.05). Indigenous children aged < 5 years had 1.4 times the admission rate of similarly aged non-indigenous children (P < 0.001) and 5.0 times the admission rate of 10-14-year-old indigenous children (P < 0.001). Remote-living indigenous children had 1.5 times the admission rate of their counterparts in major cities or regional areas (P < 0.001), and 1.4 times the admission rate of remote-living non-indigenous children (P < 0.01). The extraction rate of indigenous males was 1.3 times that of non-indigenous males (P < 0.01), and 1.2 times that of indigenous females (P < 0.05). Pre-school indigenous children had 2.2 times the extraction rate of similarly aged non-indigenous children (P < 0.001), and 5.3 times that of indigenous 10-14-year-olds (P < 0.001). The extraction rate of remotely located indigenous children was 1.5 times that of indigenous children in major cities (P < 0.01), and 1.8 times that of remote-living non-indigenous children (P < 0.001).

CONCLUSIONS

In certain strata - particularly males, the very young and those in remote locations - indigenous children experienced higher rates of extractions than non-indigenous children when undergoing care in a hospital dental general anaesthetic setting.

Using qualitative methodology to elucidate themes for a traditional tooth gauging education tool for use in a remote Ugandan community

The gauging of unerupted deciduous canine teeth occurs in approximately one in three children in some areas of Uganda. It is believed that such teeth are 'maggots' that cause fever, diarrohea and vomiting. Traditional healers use knitting needles, bicycle spokes, scissors or broken glass to extract the teeth. Post-ebino extraction complications include septicaemia, anaemia, difficulties in feeding and pain. Some children require hospitalization. Health is further compromised when multiple ebino extractions occur at one time, increasing the risk of human immunodeficiency virus/acquired immunodeficiency syndrome transmission. An ebino education initiative was developed in the southwest Ugandan province of Rukungiri, based on the findings of five community-based focus group discussions. The initiative involved role-plays, didactic presentations and discussion/debate workshops to 23 women's groups in 15 communities (total number of women exposed = 1874). After 1.5 years of the programme's inception, community awareness of the scientific causes and alternatives to ebino extractions had increased (as gauged by follow-up focus group discussion findings) and the number of hospital admissions for traditional tooth extraction complications had reduced. The appropriateness of the model in exploring and addressing ebino extraction beliefs and attitudes is discussed, as are implications of the strategy in its implementation in other communities where ebino extractions are prevalent.

Caries prevalence and severity in urban Fijian school children

OBJECTIVES

To determine the prevalence and severity of dental caries in a sample of urban Fijian school children.

DESIGN

Cross-sectional.

SAMPLE AND METHODS

Children aged between 6 and 8 years who attended one of four primary schools in different localities of Suva completed self-report questionnaires and were examined for dental caries.

RESULTS

A total of 704 children (response rate = 72.4%) returned questionnaires and were examined dentally. The prevalence of dental caries in the primary dentition was 87.6% and in the permanent dentition, 46.7%. The mean dfs and mean DFS were 8.43 (SD 7.82) and 2.38 (SD 1.37), respectively. High caries prevalence and severity were associated with infrequent brushing, snacking on sugar-containing foods, having seen a dentist before, and having last visited a dentist because of pain.

CONCLUSIONS

The caries prevalence of the sample was comparable with findings from a national oral health survey conducted in 1985/86, but the caries severity was greater. As in other developing countries, this may be due to an increased availability of refined sugar products without a concurrent rise in oral health awareness. The study findings contribute to the overall picture of Fijian school children's dental health.