The Ethical Imperative of Addressing Oral Health Disparities: A Unifying Framework

Health disparities are preventable differences in the burden of disease or opportunities to achieve optimal health that are experienced by socially disadvantaged population groups. Reducing health disparities has been identified as an ethical imperative by the World Health Organization’s Commission on Social Determinants of Health and numerous other national and international bodies. Significant progress has been made over the past years in identifying vulnerable groups, and ‘distal’ factors including political, economic, social, and community characteristics are now considered pivotal. It is thus unsurprising that the remarkable advances in the science and practice of dentistry have not led to notable reductions in oral health disparities. In this review, we summarize recent work and emphasize the need for a solid theoretical framing to guide oral health disparities research. We provide a theoretical framework outlining pathways that operate across the continuum of oral health determinants during the lifecourse and highlight potential areas for intervention. Because oral health disparities emanate from the unequal distribution of social, political, economic, and environmental resources, tangible progress is likely to be realized only by a global movement and concerted efforts by all stakeholders, including policymakers, the civil society, and academic, professional, and scientific bodies

Caregivers’ Health Literacy and Their Young Children’s Oral-health–related Expenditures

Caregivers’ health literacy has emerged as an important determinant of young children’s health care and outcomes. We examined the hypothesis that caregivers’ health literacy influences children’s oral-health-care–related expenditures. This was a prospective cohort study of 1,132 child/caregiver dyads (children’s mean age = 19 months), participating in the Carolina Oral Health Literacy Project. Health literacy was measured by the REALD-30 (word recognition based) and NVS (comprehension based) instruments. Follow-up data included child Medicaid claims for CY2008-10. We quantified expenditures using annualized 2010 fee-adjusted Medicaid-paid dollars for oral-health–related visits involving preventive, restorative, and emergency care. We used descriptive, bivariate, and multivariate statistical methods based on generalized gamma models. Mean oral-health–related annual expenditures totaled $203: preventive—$81, restorative—$99, and emergency care—$22. Among children who received services, mean expenditures were: emergency hospital-based—$1282, preventive—$106, and restorative care—$343. Caregivers’ low literacy in the oral health context was associated with a statistically non-significant increase in total expenditures (average annual difference =$40; 95% confidence interval, -32, 111). Nevertheless, with both instruments, emergency dental care expenditures were consistently elevated among children of low-literacy caregivers. These findings provide initial support for health literacy as an important determinant of the meaningful use and cost of oral health care

Chronic Periodontitis Genome-wide Association Studies: Gene-centric and Gene Set Enrichment Analyses

Recent genome-wide association studies (GWAS) of chronic periodontitis (CP) offer rich data sources for the investigation of candidate genes, functional elements, and pathways. We used GWAS data of CP (n = 4,504) and periodontal pathogen colonization (n = 1,020) from a cohort of adult Americans of European descent participating in the Atherosclerosis Risk in Communities study and employed a MAGENTA approach (i.e., meta-analysis gene set enrichment of variant associations) to obtain gene-centric and gene set association results corrected for gene size, number of single-nucleotide polymorphisms, and local linkage disequilibrium characteristics based on the human genome build 18 (National Center for Biotechnology Information build 36). We used the Gene Ontology, Ingenuity, KEGG, Panther, Reactome, and Biocarta databases for gene set enrichment analyses. Six genes showed evidence of statistically significant association: 4 with severe CP (NIN, p = 1.6 × 10−7; ABHD12B, p = 3.6 × 10−7; WHAMM, p = 1.7 × 10−6; AP3B2, p = 2.2 × 10−6) and 2 with high periodontal pathogen colonization (red complex–KCNK1, p = 3.4 × 10−7; Porphyromonas gingivalis–DAB2IP, p = 1.0 × 10−6). Top-ranked genes for moderate CP were HGD (p = 1.4 × 10−5), ZNF675 (p = 1.5 × 10−5), TNFRSF10C (p = 2.0 × 10−5), and EMR1 (p = 2.0 × 10−5). Loci containing NIN, EMR1, KCNK1, and DAB2IP had showed suggestive evidence of association in the earlier single-nucleotide polymorphism–based analyses, whereas WHAMM and AP2B2 emerged as novel candidates. The top gene sets included severe CP (“endoplasmic reticulum membrane,” “cytochrome P450,” “microsome,” and “oxidation reduction”) and moderate CP (“regulation of gene expression,” “zinc ion binding,” “BMP signaling pathway,” and “ruffle”). Gene-centric analyses offer a promising avenue for efficient interrogation of large-scale GWAS data. These results highlight genes in previously identified loci and new candidate genes and pathways possibly associated with CP, which will need to be validated via replication and mechanistic studies

Poor oral health affects survival in head and neck cancer

Introduction Poor oral health has emerged as a risk factor for squamous cell carcinoma of the head and neck (HNSCC) but its impact on survival has not been examined. We sought to estimate the impact of oral health indicators on survival in a population-based HNSCC cohort. Materials and methods Cases (n = 1381) and age-, sex- and race-matched controls (n = 1396) were participants in the Carolina Head and Neck Cancer Epidemiologic Study (CHANCE). Vital status was determined via linkage with the National Death Index. Survival was considered at 5 years post-diagnosis or study-enrollment for controls. Oral health was assessed using self-reported indicators including frequency of routine dental exams and tooth brushing. We used Kaplan-Meyer analyses and Cox regression to estimate adjusted hazard ratios (HR) and 95% confidence intervals (CI). Results Routine dental visits during the preceding 10 years were associated with decreased mortality risk (>10 visits: HR = 0.6, 95% CI = 0.4–0.8) after adjusting for confounders. This effect was most pronounced for oral cavity cancer—(e.g., >10 visits: HR = 0.4, 95% CI = 0.2–0.9). Dental visits were also positively associated with survival among controls. No other routine health screening (e.g., eye exams) was associated with survival. Conclusion We found significant associations between markers of oral health and survival among both HNSCC cases and controls. This association was most pronounced for sites closer to the dentition. Oral health may have a direct effect on tumor biology due to the associated immune or inflammatory response. It may also represent a proxy for wellness or unmeasured social determinants of health

Improving Children’s Oral Health: An Interdisciplinary Research Framework

Despite the concerted efforts of research and professional and advocacy stakeholders, recent evidence suggests that improvements in the oral health of young children in the United States has not followed the prevailing trend of oral health improvement in other age groups. In fact, oral health disparities in the youngest children may be widening, yet efforts to translate advances in science and technology into meaningful improvements in populations’ health have had limited success. Nevertheless, the great strides in genomics, biological, behavioral, social, and health services research in the past decade have strengthened the evidence base available to support initiatives and translational efforts. Concerted actions to accelerate this translation and implementation process are warranted; at the same time, policies that can help tackle the upstream determinants of oral health disparities are imperative. This article summarizes the proceedings from the symposium on the interdisciplinary continuum of pediatric oral health that was held during the 43rd annual meeting of the American Association for Dental Research, Charlotte, North Carolina, USA. This report showcases the latest contributions across the interdisciplinary continuum of pediatric oral health research and provides insights into future research priorities and necessary intersectoral synergies. Issues are discussed as related to the overwhelming dominance of social determinants on oral disease and the difficulty of translating science into action

North Carolina Physician-Based Preventive Oral Health Services Improve Access And Use Among Young Medicaid Enrollees

To combat disparities in oral health and access to dental care among infants and toddlers, most state Medicaid programs now reimburse physician-based preventive oral health services, such as fluoride varnish applications. We used geospatial data to examine the distribution of dental and medical Medicaid providers of pediatric oral health services throughout North Carolina to determine if these services have improved access to care for Medicaid enrollees younger than three years old. We then used claims data to examine the association between distance from these practices and use of dental services for a cohort of approximately 1,000 young children. Among 100 counties, four counties had no physician-based preventive oral health services and nine counties had no dental practice. While children who lived further from the nearest dental practice were less likely to make dental visits, distance from physician-based preventive oral health services did not predict use. For young Medicaid enrollees, oral health services provided in medical offices can improve access and increase use

Genome-wide Association Study of Periodontal Pathogen Colonization

Pathological shifts of the human microbiome are characteristic of many diseases, including chronic periodontitis. To date, there is limited evidence on host genetic risk loci associated with periodontal pathogen colonization. We conducted a genome-wide association (GWA) study among 1,020 white participants of the Atherosclerosis Risk in Communities Study, whose periodontal diagnosis ranged from healthy to severe chronic periodontitis, and for whom “checkerboard” DNA-DNA hybridization quantification of 8 periodontal pathogens was performed. We examined 3 traits: “high red” and “high orange” bacterial complexes, and “high” Aggregatibacter actinomycetemcomitans (Aa) colonization. Genotyping was performed on the Affymetrix 6.0 platform. Imputation to 2.5 million markers was based on HapMap II-CEU, and a multiple-test correction was applied (genome-wide threshold of p < 5 × 10−8). We detected no genome-wide significant signals. However, 13 loci, including KCNK1, FBXO38, UHRF2, IL33, RUNX2, TRPS1, CAMTA1, and VAMP3, provided suggestive evidence (p < 5 × 10−6) of association. All associations reported for “red” and “orange” complex microbiota, but not for Aa, had the same effect direction in a second sample of 123 African-American participants. None of these polymorphisms was associated with periodontitis diagnosis. Investigations replicating these findings may lead to an improved understanding of the complex nature of host-microbiome interactions that characterizes states of health and disease

Distinct Microbial Signatures between Periodontal Profile Classes

Precise classification of periodontal disease has been the objective of concerted efforts and has led to the introduction of new consensus-based and data-driven classifications. The purpose of this study was to characterize the microbiological signatures of a latent class analysis (LCA)–derived periodontal stratification system, the Periodontal Profile Class (PPC) taxonomy. We used demographic, microbial (subgingival biofilm composition), and immunological data (serum IgG antibody levels, obtained with checkerboard immunoblotting technique) for 1,450 adult participants of the Dental Atherosclerosis Risk in Communities (ARIC) study, with already generated PPC classifications. Analyses relied on t tests and generalized linear models with Bonferroni correction. Men and African Americans had higher systemic antibody levels against most microorganisms compared to women and Caucasians (P < 0.05). Healthy individuals (PPC-I) had low levels of biofilm bacteria and serum IgG levels against most periodontal pathogens (P < 0.05). Subjects with mild to moderate disease (PPC-II to PPC-III) showed mild/moderate colonization of multiple biofilm pathogens. Individuals with severe disease (PPC-IV) had moderate/high levels of biofilm pathogens and antibody levels for orange/red complexes. High gingival index individuals (PPC-V) showed moderate/high levels of biofilm Campylobacter rectus and Aggregatibacter actinomycetemcomitans. Biofilm composition in individuals with reduced periodontium (PPC-VI) was similar to health but showed moderate to high antibody responses. Those with severe tooth loss (PPC-VII) had significantly high levels of multiple biofilm pathogens, while the systemic antibody response to these microorganisms was comparable to health. The results support a biologic basis for elevated risk for periodontal disease in men and African Americans. Periodontally healthy individuals showed a low biofilm pathogen and low systemic antibody burden. In the presence of PPC disease, a microbial-host imbalance characterized by higher microbial biofilm colonization and/or systemic IgG responses was identified. These results support the notion that subgroups identified by the PPC system present distinct microbial profiles and may be useful in designing future precise biological treatment interventions

Influence of Caregivers and Children's Entry Into the Dental Care System

Early preventive dental visits are essential in improving children’s oral health, especially young children at high risk for dental caries. However, there is scant information on how these children enter the dental care system. Our objectives were as follows: (1) to describe how a population-based cohort of young Medicaid-enrolled children entered dental care; and (2) to investigate the influence of caregiver characteristics on their children’s dental care–seeking patterns