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Oral health and disease are known to be influenced by complex interactions between environmental (e.g., social and behavioral) factors and innate susceptibility. Although the exact contribution of genomics and other layers of "omics" to oral health is an area of active research, it is well established that the susceptibility to dental caries, periodontal disease, and other oral and craniofacial traits is substantially influenced by the human genome. A comprehensive understanding of these genomic factors is necessary for the realization of precision medicine in the oral health domain. To aid in this direction, the advent and increasing affordability of high-throughput genotyping has enabled the simultaneous interrogation of millions of genetic polymorphisms for association with oral and craniofacial traits. Specifically, genome-wide association studies (GWAS) of dental caries and periodontal disease have provided initial insights into novel loci and biological processes plausibly implicated in these two common, complex, biofilm-mediated diseases. This paper presents a summary of protocols, methods, tools, and pipelines for the conduct of GWAS of dental caries, periodontal disease, and related traits. The protocol begins with the consideration of different traits for both diseases and outlines procedures for genotyping, quality control, adjustment for population stratification, heritability and association analyses, annotation, reporting, and interpretation. Methods and tools available for GWAS are being constantly updated and improved; with this in mind, the presented approaches have been successfully applied in numerous GWAS and meta-analyses among tens of thousands of individuals, including dental traits such as dental caries and periodontal disease. As such, they can serve as a guide or template for future genomic investigations of these and other traits.

The genetic basis of oral health has long been theorized, but little information exists on the heritable variance in common oral and dental disease traits explained by the human genome. We sought to add to the evidence base of heritability of oral and dental traits using high-density genotype data in a well-characterized community-based cohort of middle-age adults. We used genome-wide association (GWAS) data combined with clinical and biomarker information in the Dental Atherosclerosis Risk In Communities (ARIC) cohort. Genotypes comprised SNPs directly typed on the Affymetrix Genome-Wide Human SNP Array 6.0 chip with minor allele frequency of >5% (n = 656,292) or were imputed using HapMap II-CEU (n = 2,104,905). We investigated 30 traits including "global" [e.g., number of natural teeth (NT) and incident tooth loss], clinically defined (e.g., dental caries via the DMFS index, periodontitis via the CDC/AAP and WW17 classifications), and biologically informed (e.g., subgingival pathogen colonization and "complex" traits). Heritability (i.e., variance explained; h 2 ) was calculated using Visscher's Genome-wide Complex Trait Analysis (GCTA), using a random-effects mixed linear model and restricted maximum likelihood (REML) regression adjusting for ancestry (10 principal components), age, and sex. Heritability estimates were modest for clinical traits-NT = 0.11 (se = 0.07), severe chronic periodontitis (CDC/AAP) = 0.22 (se = 0.19), WW17 Stage 4 vs. 1/2 = 0.15 (se = 0.11). "High gingival index" and "high red complex colonization" had h 2  > 0.50, while a periodontal complex trait defined by high IL-1β GCF expression and Aggregatibacter actinomycetemcomitans subgingival colonization had the highest h 2  = 0.72 (se = 0.32). Our results indicate that all GWAS SNPs explain modest levels of the observed variance in clinical oral and dental measures. Subgingival bacterial colonization and complex phenotypes encompassing both bacterial colonization and local inflammatory response had the highest heritability, suggesting that these biologically informed traits capture aspects of the disease process and are promising targets for genomics investigations, according to the notion of precision oral health.

Evidence for a shared genetic basis of association between coronary artery disease (CAD) and periodontitis (PD) exists. To explore the joint genetic basis, we performed a GWAS meta-analysis. In the discovery stage, we used a German aggressive periodontitis sample (AgP-Ger; 680 cases vs 3,973 controls) and the CARDIoGRAMplusC4D CAD meta-analysis dataset (60,801 cases vs 123,504 controls). Two SNPs at the known CAD risk loci ADAMTS7 (rs11634042) and VAMP8 (rs1561198) passed the pre-assigned selection criteria (P AgP-Ger  < 0.05; P CAD  < 5 × 10 -8 ; concordant effect direction) and were replicated in an independent GWAS meta-analysis dataset of PD (4,415 cases vs 5,935 controls). SNP rs1561198 showed significant association (PD[Replication]: P = 0.008 OR = 1.09, 95% CI = [1.02-1.16]; PD [Discovery + Replication]: P = 0.0002, OR = 1.11, 95% CI = [1.05-1.17]). For the associated haplotype block, allele specific cis-effects on VAMP8 expression were reported. Our data adds to the shared genetic basis of CAD and PD and indicate that the observed association of the two disease conditions cannot be solely explained by shared environmental risk factors. We conclude that the molecular pathway shared by CAD and PD involves VAMP8 function, which has a role in membrane vesicular trafficking, and is manipulated by pathogens to corrupt host immune defense.

There is no agnostic GWAS evidence for the genetic control of IL-1β expression in periodontal disease. Here we report a GWAS for "high" gingival crevicular fluid IL-1β expression among 4910 European-American adults and identify association signals in the IL37 locus. rs3811046 at this locus (p = 3.3 × 10 -22 ) is associated with severe chronic periodontitis (OR = 1.50; 95% CI = 1.12-2.00), 10-year incident tooth loss (≥3 teeth: RR = 1.33; 95% CI = 1.09-1.62) and aggressive periodontitis (OR = 1.12; 95% CI = 1.01-1.26) in an independent sample of 4927 German/Dutch adults. The minor allele at rs3811046 is associated with increased expression of IL-1β in periodontal tissue. In RAW macrophages, PBMCs and transgenic mice, the IL37 variant increases expression of IL-1β and IL-6, inducing more severe periodontal disease, while IL-37 protein production is impaired and shows reduced cleavage by caspase-1. A second variant in the IL37 locus (rs2708943, p = 4.2 × 10 -7 ) associates with attenuated IL37 mRNA expression. Overall, we demonstrate that IL37 variants modulate the inflammatory cascade in periodontal disease.

Objectives Limited information exists on the extent oral health is addressed in the context of prenatal care. This study sought to investigate characteristics of primary care physicians (PCP) who provide oral health counseling to pregnant women. Methods The study relied upon data from the 2013 Survey of PCP on Oral Health. Provision of oral health counseling to pregnant women (sometimes vs. rarely/never) was the primary outcome. Covariates included respondents' demographic and practice characteristics, oral health-related training, knowledge, attitudes, preparedness and clinical behaviors. The analytical strategy included bivariate tests and multivariable Poisson regression modeling, accounting for the survey design; inference was based upon marginal effects estimation. Results Two-thirds of PCP (233 out of 366 respondents) reported providing oral health counseling to pregnant women. In bivariate comparisons, female PCP, PCP with oral health-specific instruction during medical training, favorable oral health-related attitudes, behaviors, preparedness, and knowledge were more likely to provide counseling (p < 0.05). Multivariable analyses confirmed the independent associations of female gender [marginal effect = + 9.7 percentage points (p.p.); 95% confidence interval (CI) = 0.0-19.0], years in practice (- 0.4 p.p. for each added year; 95% CI = - 0.09 to 0.0), oral health continuing education (+ 13.2 p.p.; 95% CI = 2.6-23.8), preparedness (+ 23.0 p.p.; 95% CI = 16.9-29.0) and oral health counseling of adult patients with other conditions (+ 8.8 p.p.; 95% CI = 4.6-13.3) with prenatal oral health counseling. Conclusions for Practice A considerable proportion of PCP nationwide counsel pregnant patients on oral health. Provider attributes including education and preparedness appear as promising targets for interventions aimed to enhance pregnant women's oral health and care.

Unlike zero-inflated Poisson regression, marginalized zero-inflated Poisson (MZIP) models for counts with excess zeros provide estimates with direct interpretations for the overall effects of covariates on the marginal mean. In the presence of missing covariates, MZIP and many other count data models are ordinarily fitted using complete case analysis methods due to lack of appropriate statistical methods and software. This article presents an estimation method for MZIP models with missing covariates. The method, which is applicable to other missing data problems, is illustrated and compared with complete case analysis by using simulations and dental data on the caries preventive effects of a school-based fluoride mouthrinse program., (© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Objective: A genetic component in early childhood caries (ECC) is theorized, but no genome-wide investigations of ECC have been conducted. This pilot study is part of a long-term research program aimed to: (1) determine the proportion of ECC variance attributable to the human genome and (2) identify ECC-associated genetic loci., Methods: The study's community-based sample comprised 212 children (mean age=39 months; range = 30-52 months; males = 55%; Hispanic/Latino = 35%, African-American = 32%; American Academy of Pediatric Dentistry definition of ECC prevalence = 38%). Approximately 2.4 million single nucleotide polymorphisms (SNPs) were genotyped using DNA purified from saliva. A P < 5 × 10 -8 criterion was used for genome-wide significance. SNPs with P < 5 × 10 -5 were followed-up in three independent cohorts of 921 preschool-age children with similar ECC prevalence., Results: SNPs with minor allele frequency ≥5% explained 52% (standard error = 54%) of ECC variance (one-sided P = 0.03). Unsurprisingly, given the pilot's small sample size, no genome-wide significant associations were found. An intergenic locus on 4q32 (rs4690994) displayed the strongest association with ECC [P = 2.3 × 10 -6 ; odds ratio (OR) = 3.5; 95% confidence interval (CI) = 2.1-5.9]. Thirteen loci with suggestive associations were followed-up - none showed evidence of association in the replication samples., Conclusion: This study's findings support a heritable component of ECC and demonstrate the feasibility of conducting genomics studies among preschool-age children., (© 2017 The Authors. International Journal of Paediatric Dentistry published by BSPD, IAPD and John Wiley & Sons Ltd.)

Background: Current periodontal disease taxonomies have limited utility for predicting disease progression and tooth loss; in fact, tooth loss itself can undermine precise person-level periodontal disease classifications. To overcome this limitation, the current group recently introduced a novel patient stratification system using latent class analyses of clinical parameters, including patterns of missing teeth. This investigation sought to determine the clinical utility of the Periodontal Profile Classes and Tooth Profile Classes (PPC/TPC) taxonomy for risk assessment, specifically for predicting periodontal disease progression and incident tooth loss., Methods: The analytic sample comprised 4,682 adult participants of two prospective cohort studies (Dental Atherosclerosis Risk in Communities Study and Piedmont Dental Study) with information on periodontal disease progression and incident tooth loss. The PPC/TPC taxonomy includes seven distinct PPCs (person-level disease pattern and severity) and seven TPCs (tooth-level disease). Logistic regression modeling was used to estimate relative risks (RR) and 95% confidence intervals (CI) for the association of these latent classes with disease progression and incident tooth loss, adjusting for examination center, race, sex, age, diabetes, and smoking. To obtain personalized outcome propensities, risk estimates associated with each participant's PPC and TPC were combined into person-level composite risk scores (Index of Periodontal Risk [IPR])., Results: Individuals in two PPCs (PPC-G: Severe Disease and PPC-D: Tooth Loss) had the highest tooth loss risk (RR = 3.6; 95% CI = 2.6 to 5.0 and RR = 3.8; 95% CI = 2.9 to 5.1, respectively). PPC-G also had the highest risk for periodontitis progression (RR = 5.7; 95% CI = 2.2 to 14.7). Personalized IPR scores were positively associated with both periodontitis progression and tooth loss., Conclusions: These findings, upon additional validation, suggest that the periodontal/tooth profile classes and the derived personalized propensity scores provide clinical periodontal definitions that reflect disease patterns in the population and offer a useful system for patient stratification that is predictive for disease progression and tooth loss., (© 2018 American Academy of Periodontology.)

Purpose: The aims of this study were to describe the demographic characteristics of pediatric dentistry patients undergoing dental rehabilitation under general anesthesia (DRGA) at UNC-Chapel Hill during the last 13 years and identify factors associated with multiple (1 versus 2 or more) DRGA visits during that timeframe., Study Design: Administrative claims data were used to identify children and adolescents (age <18 years) who underwent DRGA between 1/1/2002 and 12/31/2014 at the UNC Hospitals system. Information on children's age, sex and all treatment-associated CDT codes were collected. Descriptive statistics and bivariate tests of association were used for data analyses., Results: There were 4,413 DRGAs among 3,973 children (median age=4 years 8 months, males=55%) during the study period. The annual rate of DRGAs increased over time, peaking (n=447) in 2013. Overall, 9% of children had ≥2 visits with repeat rates up to 18%. There was no association between children's sex and receipt of one versus multiple DRGAs; however, craniofacial cases were more likely (p<0.0005) to have multiple DRGAs compared to non-craniofacial ones., Conclusion: DRGAs are on the increase-with the exception of craniofacial and special health care needs patients, multiple DRGAs may be reflective of sub-optimal adherence to preventive and continuing care recommendations.

Aim: The intronic variant rs4252120 in the plasminogen gene (PLG) is known to be associated with aggressive periodontitis (AgP) and atherosclerosis. Here, we examined the chromosomal region spanning PLG for associations with both chronic periodontitis (CP) and AgP., Materials and Methods: The association of PLG candidate rs4252120 was tested in a German case-control sample of 1,419 CP cases using the genotyping assay hCV11225947 and 4,562 controls, genotyped with HumanOmni BeadChips. The German and Dutch sample of AgP cases (N = 851) and controls (N = 6,836) were genotyped with HumanOmni BeadChips. The North American CP sample (N = 2,681 cases, 1,823 controls) was previously genotyped on the Genome-Wide Human SNP Array 6.0. Genotypes were imputed (software Impute v2), and association tests were performed using an additive genetic model adjusting for sex and smoking., Results: Rs4252120 was not associated with CP. However, a haplotype block downstream of PLG and not in linkage disequilibrium with rs4252120 (r 2  = .08) was associated with both AgP (rs1247559; p = .002, odds ratio [OR] = 1.33) and CP (p = .02, OR = 1.15). That locus was also significantly associated with PLG expression in osteoblasts (p = 6.9 × 10 -5 )., Conclusions: Our findings support a role of genetic variants in PLG in the aetiology of periodontitis., (© 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

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 5years 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 10years 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., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Background: This manuscript presents evidence-based guidance on the use of 38 percent silver diamine fluoride (SDF) for dental caries management in children and adolescents, including those with special health care needs. A guideline workgroup formed by the American Academy of Pediatric Dentistry developed guidance and an evidence-based recommendation regarding the application of 38 percent SDF to arrest cavitated caries lesions in primary teeth., Types of Studies Reviewed: The basis of the guideline's recommendation is evidence from an existing systematic review "Clinical trials of silver diamine fluoride in arresting caries among children: A systematic review." (JDR Clin Transl Res 2016;1[3]:201-10). A systematic search was conducted in PubMed®/MEDLINE, Embase®, Cochrane Central Register of Controlled Trials, and gray literature databases to identify randomized controlled trials and systematic reviews reporting on the effect of silver diamine fluoride and address peripheral issues such as adverse effects and cost. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach was used to assess the quality of the evidence and the evidence-to-decision framework was employed to formulate a recommendation., Results: The panel made a conditional recommendation regarding the use of 38 percent SDF for the arrest of cavitated caries lesions in primary teeth as part of a comprehensive caries management program. After taking into consideration the low cost of the treatment and the disease burden of caries, panel members were confident that the benefits of SDF application in the target populations outweigh its possible undesirable effects. Per GRADE, this is a conditional recommendation based on low-quality evidence. Conclusions and practical implications: The guideline intends to inform the clinical practices involving the application of 38 percent SDF to enhance dental caries management outcomes in children and adolescents, including those with special health care needs. These recommended practices are based upon the best available evidence to-date. A 38 percent SDF protocol is included in Appendix II.

Precision medicine is no longer a distant vision; it is becoming part of the rapidly evolving present. Insights from studies of the human genome and microbiome, their associated transcriptomes, proteomes, and metabolomes, and epigenomics and exposomics have reached an unprecedented depth and scale. Much more needs to be done, however, particularly in dentistry.

Background: The single nucleotide polymorphism (SNP) context of a previously identified periodontitis-associated locus is investigated, and its association with microbial, biologic, and periodontal disease clinical parameters is examined., Methods: A 200-kb spanning region of 1q12 previously highlighted in a genome-wide association scan among 4,766 European American individuals (SNP rs1633266) was annotated. Two haplotype blocks were selected. Association of these polymorphisms with data on microbial plaque composition, gingival crevicular fluid (GCF)-interleukin (IL)-1β levels, and clinical parameters of periodontal disease were examined. Descriptive analysis of IFI16 and AIM2 protein expression in gingival tissues from healthy individuals (n = 2) and individuals with chronic periodontitis (n = 2) was done via immunohistochemistry., Results: The highlighted locus is a 100-kb region containing the interferon γ-inducible protein 16 (IFI16) and absent in melanoma 2 (AIM2) genes. Two haplotype blocks, rs6940 and rs1057028, were significantly associated with increased extent bleeding on probing and levels of microorganisms Porphyromonas gingivalis, Tannerella forsythia, and Campylobacter rectus (P ≤0.05). Haplotype block rs1057028 was also significantly associated with pathogens Fusobacterium nucleatum and Aggregatibacter actinomycetemcomitans, increased GCF-IL-1β levels, and extent of probing depth ≥4 mm (P ≤0.05). Prevalence of severe periodontitis (biofilm-gingival interface P3 classification) was positively associated with haplotype block rs1057028. Similar trends were observed for haplotype block rs1057028. IFI16 and AIM2 protein expression was observed in multiple cell types of gingival tissues, including inflammatory cells., Conclusion: This study found IFI16 and AIM2 SNPs associated with higher levels of periodontal microorganisms and an increased percentage of periodontal disease clinical parameters, suggesting the need for functional studies and additional fine-mapping of variants in the 1q12-locus.

Pediatric oral health is determined by the interaction of environmental factors and genetic influences. This is the case for early childhood caries, the most common disease of childhood. The complexity of exogenous-environmental factors interacting with innate biological predispositions results in a continuum of normal variation, as well as oral health and disease outcomes. Optimal oral health and care or precision dentistry warrants comprehensive understanding of these influences and tools enabling intervention on modifiable factors. This article reviews the current knowledge of the genomic basis of pediatric oral health and highlights known and postulated mechanistic pathways of action relevant to early childhood caries., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Objectives: The authors conducted a systematic review to determine: a) What dental schools and dental hygiene programs are doing to promote knowledge and skills related to addressing childhood obesity and to reduce consumption of sugar-sweetened beverages (SSBs) and b) What else these schools and programs could do to better equip future oral health professionals to address childhood obesity and reduce consumption of SSBs., Methods: The authors searched PubMed, Scopus, Education Full Text (EBSCOHost), and ERIC (EBSCOHost) to identify peer-reviewed publications reporting on obesity or dietetic-related curricula in dental and dental hygiene education within the last 20 years. Three studies met inclusion and exclusion criteria. Outcomes of the identified studies were abstracted and summarized independently by two investigators., Results: The first study describes a 2009 survey of pediatric dentistry residents. Approximately, half had received formal training yet they lacked essential knowledge or skills for managing children who were obese. The second study describes nutrition-related coursework offered in the second year of a predoctoral dental school curriculum in Saudi Arabia, and the third study reports on the development of an "oral health rotation" dietetic internship in a pediatric dentistry clinic, in the context of interprofessional education (IPE)., Conclusions: Evidence of dental schools' and dental hygiene programs' efforts to address obesity and SSB consumption in children in their curricula is scant, while Commission on Dental Accreditation standards make sporadic mentions of diet and nutrition. Opportunities exist to leverage existing resources and innovative, experiential approaches, including IPE, to formally, and effectively address this important issue in predoctoral oral health education., (© 2017 American Association of Public Health Dentistry.)

Purpose: The purpose of this mixed-methods study was to examine pediatric emergency dental trends in two safety net clinics and care-seeking experiences of young children's caregivers., Methods: Administrative data were used to describe and compare emergency first visits of children ages zero to six years in a community-based (CC) and a University-based (UC) safety net clinic from 2010 to 2014. In-person interviews were conducted with 11 caregivers of children ages zero to six presenting for nontrauma-related emergency visits at the UC from January to August 2016. Interviews were transcribed verbatim, coded, and analyzed inductively using Atlas. ti.7.5.9., Results: The UC experienced significantly more emergency first visits (33 percent) than the CC (five percent, P<0.001), and the majority of these UC visits were referrals. Caregivers were dissatisfied with the experienced barriers of access to care and lack of child-centeredness, specifically the referral out of the dental home for emergency dental care., Conclusions: A considerable proportion of children's first visits at dental safety net clinics was emergency related. Children's caregivers voiced issues related to access to care and lack of child-centered care. Discordance was apparent between how professional organizations define the dental home and how caregivers experience it in the context of emergency care.

This study compared the acceptability and relative effectiveness of case-based learning (CBL) versus traditional lecture-based (LB) instruction in a preclinical removable prosthodontics course in the University of North Carolina at Chapel Hill School of Dentistry DDS curriculum. The entire second-year class (N=82) comprised this crossover study's sample. Assessments of baseline comprehension and confidence in removable partial denture (RPD) treatment planning were conducted at the beginning of the course. Near the end of the course, half of the class received CBL and LB instruction in an RPD module in alternating sequence, with students serving as their own control group. Assessments of perceived RPD treatment planning efficacy, comprehension, and instruction method preference were administered directly after students completed the RPD module and six months later. Analyses of variance accounting for period, carryover, and sequence effects were used to determine the relative effects of each approach using a p<0.05 statistical significance threshold. The results showed that the students preferred CBL (81%) over LB instruction (9%), a pattern that remained unchanged after a six-month period. Despite notable period and carryover effects, CBL was also associated with higher gains in RPD treatment planning comprehension (p=0.04) and perceived efficacy (p=0.01) compared to LB instruction. These gains diminished six months after the course-a finding based on a 49% follow-up response rate. Overall, the students overwhelmingly preferred CBL to LB instruction, and the findings suggest small albeit measurable educational benefits associated with CBL. This study's findings support the introduction and further testing of CBL in the preclinical dental curriculum, in anticipation of possible future benefits evident during clinical training.

Background: The goal of this study is to use bioinformatics tools to explore identification and definition of distinct periodontal and tooth profile classes (PPCs/TPCs) among a cohort of individuals by using detailed clinical measures at the tooth level, including both periodontal measurements and tooth loss., Methods: Full-mouth clinical periodontal measurements (seven clinical parameters) from 6,793 individuals from the Dental Atherosclerosis Risk in Communities Study (DARIC) were used to identify PPC. A custom latent class analysis (LCA) procedure was developed to identify clinically distinct PPCs and TPCs. Three validation cohorts were used: NHANES (2009 to 2010 and 2011 to 2012) and the Piedmont Study population (7,785 individuals)., Results: The LCA method identified seven distinct periodontal profile classes (PPCs A to G) and seven distinct tooth profile classes (TPCs A to G) ranging from health to severe periodontal disease status. The method enabled identification of classes with common clinical manifestations that are hidden under the current periodontal classification schemas. Class assignment was robust with small misclassification error in the presence of missing data. The PPC algorithm was applied and confirmed in three distinct cohorts., Conclusions: The findings suggest PPC and TPC using LCA can provide robust periodontal clinical definitions that reflect disease patterns in the population at an individual and tooth level. These classifications can potentially be used for patient stratification and thus provide tools for integrating multiple datasets to assess risk for periodontitis progression and tooth loss in dental patients.

Mixture distributions provide flexibility in modeling data collected from populations having unexplained heterogeneity. While interpretations of regression parameters from traditional finite mixture models are specific to unobserved subpopulations or latent classes, investigators are often interested in making inferences about the marginal mean of a count variable in the overall population. Recently, marginal mean regression modeling procedures for zero-inflated count outcomes have been introduced within the framework of maximum likelihood estimation of zero-inflated Poisson and negative binomial regression models. In this article, we propose marginalized mixture regression models based on two-component mixtures of non-degenerate count data distributions that provide directly interpretable estimates of exposure effects on the overall population mean of a count outcome. The models are examined using simulations and applied to two datasets, one from a double-blind dental caries incidence trial, and the other from a horticultural experiment. The finite sample performance of the proposed models are compared with each other and with marginalized zero-inflated count models, as well as ordinary Poisson and negative binomial regression.

Background: Indicators of poor oral health, including smoking, have been associated with increased risk of head and neck squamous cell carcinoma, especially oropharyngeal squamous cell carcinoma (OPSCC), yet few studies have examined whether this association is modified by human papillomavirus (HPV) status., Methods: Data from interviews and tumor HPV status from a large population-based case-control study, the Carolina Head and Neck Cancer Study (CHANCE), were used to estimate the association between oral health indicators and smoking among 102 HPV-positive patients and 145 HPV-negative patients with OPSCC and 1396 controls. HPV status was determined by p16INK4a (p16) immunohistochemistry. Unconditional, multinomial logistic regression was used to estimate odds ratios (ORs) for all oral health indictors adjusting for important covariates., Results: Routine dental examinations were associated with a decreased risk of both HPV-negative OPSCC (OR, 0.52; 95% confidence interval [CI], 0.35-0.76) and HPV-positive OPSCC (OR, 0.55; 95% CI, 0.36-.86). Tooth mobility (a proxy for periodontal disease) increased the risk of HPV-negative disease (OR, 1.70; 95% CI, 1.18-2.43) slightly more than the risk for HPV-positive disease (OR, 1.45; 95% CI, 0.95-2.20). Ten or more pack-years of cigarette smoking were strongly associated with an increased risk of HPV-negative OPSCC (OR, 4.26; 95% CI, 2.85-6.37) and were associated less with an increased risk of HPV-positive OPSCC (OR, 1.62; 95% CI, 1.10-2.38)., Conclusions: Although HPV-positive and HPV-negative HNSCC differ significantly with respect to etiology and tumorigenesis, the current findings suggest a similar pattern of association between poor oral health, frequency of dental examinations, and both HPV-positive and HPV-negative OPSCC. Future research is required to elucidate interactions between poor oral health, tobacco use, and HPV in the development of OPSCC. Cancer 2017;71-80. © 2016 American Cancer Society., Competing Interests: There are no conflicts of interest to disclose., (© 2016 American Cancer Society.)

Objective: A systematic review was conducted to summarize the epidemiological evidence on environmental tobacco smoke (ETS) exposure and prevalent periodontitis endpoints among nonsmokers., Methods: We searched PubMed, EMBASE, Web of Science, Pro-Quest dissertations, and conference proceedings of a dental research association. We included studies from which prevalence odds ratios (POR) could be extracted for periodontitis determined by examiner measurements of clinical attachment level (CAL) and/or probing pocket depth (PD) or self-report of missing teeth. Studies determined ETS exposure by self-report or biomarker (cotinine) levels., Results: For studies reporting CAL and/or PD (n = 6), associations were stronger with cotinine-measured exposure (n = 3; random effects POR [95% prediction interval] = 1.63 (0.90, 2.96)) than self-reported exposure (n = 3; random effects POR = 1.15 (0.68, 1.96)). There was no meaningful difference in summary estimate for studies reporting CAL and/or PD endpoint (n = 6; random effects POR = 1.34 (0.93, 1.94)) as opposed to tooth loss (n = 2; random effects POR = 1.33 (0.52, 3.40))., Conclusions: There appears to be a positive association between exposure to ETS and prevalent periodontitis endpoints among nonsmokers, the magnitude of which depended mostly on the method of ETS assessment., Implications: The notoriety of ETS is often discussed in terms of its associations with cancer, chronic conditions like cardiovascular diseases, and respiratory illnesses in children. However, very little attention is paid to its association with oral diseases, especially periodontitis. Periodontitis affects a large proportion of the population and is a major cause of tooth loss. This study summarized the epidemiologic association between exposure to ETS and periodontitis among nonsmokers. Although the findings are consistent with a positive association, methodological weaknesses relating to study design, assessment of ETS, periodontitis, and adjustment covariates were highlighted and recommendations for improvement in future studies provided., (© The Author 2016. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Objective: This study examined young, preschool children's oral health-related quality of life (OHRQoL) among a community-based cohort of English and Spanish-speaking parent-child dyads in North Carolina, and sought to quantify the association of parent/caregiver characteristics, including spoken language, with OHRQoL impacts., Methods: Data from structured interviews with 1,111 parents of children aged 6-23 months enrolled in the Zero-Out Early Childhood Caries study in 2010-2012 were used. OHRQoL was measured using the overall score (range: 0-52) of the Early Childhood Oral Health Impact Scale (ECOHIS). We examined associations with parents' sociodemographic characteristics, spoken language, self-reported oral and general health, oral health knowledge, children's dental attendance, and dental care needs. Analyses included descriptive, bivariate, and multivariate methods based upon zero-inflated negative binomial regression. To determine differences between English and Spanish speakers, language-stratified model estimates were contrasted using homogeneity χ 2 tests., Results: The mean overall ECOHIS score was 3.9 [95% confidence interval (CI) = 3.6-4.2]; 4.7 among English-speakers and 1.5 among Spanish speakers. In multivariate analyses, caregivers' education showed a positive association with OHRQoL impacts among Spanish speakers [prevalence ratio (PR) = 1.12 (95% CI = 1.03-1.22), for every added year of schooling], whereas caregivers' fair/poor oral health showed a positive association among English speakers (PR = 1.20; 95% CI = 1.02-1.41)., Conclusions: The overall severity of ECOHIS impacts was low among this population-based sample of young, preschool children, and substantially lower among Spanish versus English speakers. Further studies are warranted to identify sources of these differences in - actual or reported - OHRQoL impacts., (© 2016 American Association of Public Health Dentistry.)

Background and Objectives: Despite the widespread acknowledgement of the importance of childhood oral health, little progress has been made in preventing early childhood caries. Limited information exists regarding specific daily-life and community-related factors that impede optimal oral hygiene, diet, care, and ultimately oral health for children. We sought to understand what parents of young children consider important and potentially modifiable factors and resources influencing their children's oral health, within the contexts of the family and the community., Methods: This qualitative study employed Photovoice among 10 English-speaking parents of infants and toddlers who were clients of an urban WIC clinic in North Carolina. The primary research question was: "What do you consider as important behaviors, as well as family and community resources to prevent cavities among young children?" Five group sessions were conducted and they were recorded, transcribed verbatim and analyzed using qualitative research methodology. Inductive analyses were based on analytical summaries, double-coding, and summary matrices and were done using Atlas.ti.7.5.9 software., Findings: Good oral health was associated with avoidance of problems or restorations for the participants. Financial constraints affected healthy food and beverage choices, as well as access to oral health care. Time constraints and occasional frustration related to children's oral hygiene emerged as additional barriers. Establishment of rules/routines and commitment to them was a successful strategy to promote their children's oral health, as well as modeling of older siblings, cooperation among caregivers and peer support. Community programs and organizations, social hubs including playgrounds, grocery stores and social media emerged as promising avenues for gaining support and sharing resources., Conclusions: Low-income parents of young children are faced with daily life struggles that interfere with oral health and care. Financial constraints are pervasive, but parents identified several strategies involving home care and community agents that can be helpful. Future interventions aimed to improve children's oral health must take into consideration the role of families and the communities in which they live., Competing Interests: The authors have declared that no competing interests exist.

Ameloblastoma is a locally invasive benign neoplasm derived from odontogenic epithelium and presents with diverse phenotypes yet to be characterized molecularly. High recurrence rates of 50-80% with conservative treatment in some sub-types warrants radical surgical resections resulting in high morbidity. The objective of the study was to characterize the transcriptome of ameloblastoma and identify relevant genes and molecular pathways using normal odontogenic tissue (human "dentome") for comparison. Laser capture microdissection was used to obtain neoplastic epithelial tissue from 17 tumors which were examined using the Agilent 44 k whole genome microarray. Ameloblastoma separated into 2 distinct molecular clusters that were associated with pre-secretory ameloblast and odontoblast. Within the pre-secretory cluster, 9/10 of samples were of the follicular type while 6/7 of the samples in the odontoblast cluster were of the plexiform type (p < 0.05). Common pathways altered in both clusters included cell-cycle regulation, inflammatory and MAPkinase pathways, specifically known cancer-driving genes such as TP53 and members of the MAPkinase pathways. The pre-secretory ameloblast cluster exhibited higher activation of inflammatory pathways while the odontoblast cluster showed greater disturbances in transcription regulators. Our results are suggestive of underlying inter-tumor molecular heterogeneity of ameloblastoma sub-types and have implications for the use of tailored treatment.

Genome-wide association studies (GWAS) of chronic periodontitis (CP) defined by clinical criteria alone have had modest success to-date. Here, we refine the CP phenotype by supplementing clinical data with biological intermediates of microbial burden (levels of eight periodontal pathogens) and local inflammatory response (gingival crevicular fluid IL-1β) and derive periodontal complex traits (PCTs) via principal component analysis. PCTs were carried forward to GWAS (∼2.5 million markers) to identify PCT-associated loci among 975 European American adult participants of the Dental ARIC study. We sought to validate these findings for CP in the larger ARIC cohort (n = 821 participants with severe CP, 2031-moderate CP, 1914-healthy/mild disease) and an independent German sample including 717 aggressive periodontitis cases and 4210 controls. We identified six PCTs with distinct microbial community/IL-1β structures, although with overlapping clinical presentations. PCT1 was characterized by a uniformly high pathogen load, whereas PCT3 and PCT5 were dominated by Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis, respectively. We detected genome-wide significant signals for PCT1 (CLEC19A, TRA, GGTA2P, TM9SF2, IFI16, RBMS3), PCT4 (HPVC1) and PCT5 (SLC15A4, PKP2, SNRPN). Overall, the highlighted loci included genes associated with immune response and epithelial barrier function. With the exception of associations of BEGAIN with severe and UBE3D with moderate CP, no other loci were associated with CP in ARIC or aggressive periodontitis in the German sample. Although not associated with current clinically determined periodontal disease taxonomies, upon replication and mechanistic validation these candidate loci may highlight dysbiotic microbial community structures and altered inflammatory/immune responses underlying biological sub-types of CP., (© The Author 2016. Published by Oxford University Press.)

The zero-inflated negative binomial regression model (ZINB) is often employed in diverse fields such as dentistry, health care utilization, highway safety, and medicine to examine relationships between exposures of interest and overdispersed count outcomes exhibiting many zeros. The regression coefficients of ZINB have latent class interpretations for a susceptible subpopulation at risk for the disease/condition under study with counts generated from a negative binomial distribution and for a non-susceptible subpopulation that provides only zero counts. The ZINB parameters, however, are not well-suited for estimating overall exposure effects, specifically, in quantifying the effect of an explanatory variable in the overall mixture population. In this paper, a marginalized zero-inflated negative binomial regression (MZINB) model for independent responses is proposed to model the population marginal mean count directly, providing straightforward inference for overall exposure effects based on maximum likelihood estimation. Through simulation studies, the finite sample performance of MZINB is compared with marginalized zero-inflated Poisson, Poisson, and negative binomial regression. The MZINB model is applied in the evaluation of a school-based fluoride mouthrinse program on dental caries in 677 children., (Copyright © 2015 John Wiley & Sons, Ltd.)

Keratocystic Odontogenic Tumor (KCOT) is a locally aggressive developmental cystic neoplasm thought to arise from the odontogenic epithelium. A high recurrence rate of up to 30% has been found following conservative treatment. Aggressive tumor resection can lead to the need for extensive reconstructive surgery, resulting in significant morbidity and impacting quality of life. Most research has focused on candidate-genes with a handful of studies employing whole transcriptome approaches. There is also the question of which reference tissue is most biologically-relevant. This study characterizes the transcriptome of KCOT using whole genome microarray and compare it with gene expression of different odontogenic tissues ("dentome"). Laser capture microdissection was used to isolate the neoplastic epithelial tissue in 20 cases. KCOT gene expression was compared with the "dentome" and relevant pathways were examined. Cluster analysis revealed 2 distinct molecular subtypes of KCOT. Several inflammatory pathways were activated in both subtypes. The AKT pathway was activated in one subtype while MAP kinase pathway was activated in the other. Additionally, PTCH1 expression was downregulated in both clusters suggesting involvement in KCOT tumorigenesis. In conclusion, this study provides new insights into the transcriptome of KCOT and highlights pathways that could be of diagnostic and prognostic value.

The postdoctoral application and matching process in dental education is a high-stakes and resource-intensive process for all involved. While programs seek the most qualified candidates, applicants strive to be competitive to increase their likelihood of being accepted to a desirable program. There are limited data regarding either subjective or objective factors underlying the complex interplay between programs and applicants. This qualitative study sought to provide insight into the stakeholders' experiences and views on the matching process. Telephone and in-person interviews were conducted with ten pediatric dentistry program directors and ten recent applicants to pediatric dentistry programs in the United States in 2013-14. Participants were selected to represent the geographic (five districts of the American Academy of Pediatric Dentistry) and institutional (hospital- or university-based) diversity of pediatric dentistry programs. Interviews were recorded and transcribed verbatim. Veracity and need for more information were the themes most often articulated by both groups. The program directors most valued teachability and self-motivation as desirable applicant characteristics. The applicants relied primarily on subjective sources to gather information about programs and prioritized location and financial factors as pivotal for their rankings. Both groups appreciated the uniformity of the current application process and highlighted several weaknesses and areas for improvement. These results shed light on the postdoctoral matching process in pediatric dentistry via a qualitative description of stakeholders' experiences and viewpoints. These insights can serve as a basis for improving and refining the matching process.

Introduction: Elucidating the microbial ecology of endodontic infections (EIs) is a necessary step in developing effective intracanal antimicrobials. The aim of the present study was to investigate the bacterial composition of symptomatic and asymptomatic primary and persistent infections in a Greek population using high-throughput sequencing methods., Methods: 16S amplicon pyrosequencing of 48 root canal bacterial samples was conducted, and sequencing data were analyzed using an oral microbiome-specific and a generic (Greengenes) database. Bacterial abundance and diversity were examined by EI type (primary or persistent), and statistical analysis was performed by using non-parametric and parametric tests accounting for clustered data., Results: Bacteroidetes was the most abundant phylum in both infection groups. Significant, albeit weak associations of bacterial diversity were found, as measured by UniFrac distances with infection type (analyses of similarity, R = 0.087, P = .005) and symptoms (analyses of similarity, R = 0.055, P = .047). Persistent infections were significantly enriched for Proteobacteria and Tenericutes compared with primary ones; at the genus level, significant differences were noted for 14 taxa, including increased enrichment of persistent infections for Lactobacillus, Streptococcus, and Sphingomonas. More but less abundant phyla were identified using the Greengenes database; among those, Cyanobacteria (0.018%) and Acidobacteria (0.007%) were significantly enriched among persistent infections. Persistent infections showed higher phylogenetic diversity (PD) (asymptomatic: PD = 9.2, standard error [SE] = 1.3; symptomatic: PD = 8.2, SE = 0.7) compared with primary infections (asymptomatic: PD = 5.9, SE = 0.8; symptomatic: PD = 7.4, SE = 1.0)., Conclusions: The present study revealed a high bacterial diversity of EI and suggests that persistent infections may have more diverse bacterial communities than primary infections., (Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

The aim of the present study was to evaluate the effects of storage media on the longitudinal hardness changes of tissue conditioning materials. Four tissue-conditioning materials were used for fabrication of 80 disc-shaped specimens and divided in four groups, stored in four storage media. The specimens underwent artificial ageing corresponding to 30 nights of extra-oral storage. Hardness measurements were obtained at nine intervals between 8 and 240 hours after specimen fabrication. To test the effects of storage media on hardness we employed multivariate modelling (Bonferroni correction; α = 0.05). The materials exhibited varying hardness changes, most pronounced when stored in ambient air.

Aim: This nested case-control study sought to determine whether an accelerated rate of leukocyte telomere length (LTL) shortening over 6 years was associated with chronic periodontitis., Materials and Methods: We sampled cases (n = 178) with severe chronic periodontitis and controls (n = 178) with no/mild chronic periodontitis from the Atherosclerosis Risk in Communities study. Controls were frequency-matched to cases by study site, age, sex and race. Age ranged from 53 to 73 years. Severe chronic periodontitis was defined using the CDC-AAP case classification. LTL was measured from DNA collected at two time points, 6 years apart, with quantitative polymerase chain reaction relative to a single-copy control gene. Multiple linear regression evaluated associations between LTL measured at baseline, follow-up and change scores with severe chronic periodontitis, adjusting for potential confounders., Results: Cases had shorter LTL than controls at baseline (p = 0.03) and follow-up (p = 0.04) after adjusting for confounding. Overall there was a net reduction in LTL over time (p = 0.02). The rate of LTL did not differ between cases and controls (p = 0.80)., Conclusions: Leukocyte telomere length shortening occurred at the same rate among adults with and without severe chronic periodontitis. This suggests that LTL shortening may have occurred earlier in the life course., (© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

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 age three. 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 one hundred counties, four counties had no physician-based preventive oral health services, and nine counties had no dental practice. While children who lived farther from the nearest dental practice were less likely to make dental visits, distance from physician-based preventive oral health services did not predict utilization. For young Medicaid enrollees, oral health services provided in medical offices can improve access and increase utilization., (Project HOPE—The People-to-People Health Foundation, Inc.)

Background and Objectives: Recent evidence supports a link between caregivers' health literacy and their children's health and use of health services. Disruptions in children's health insurance coverage have been linked to poor health care and outcomes. We examined young children's Medicaid enrollment patterns in a well-characterized cohort of child/caregivers dyads and investigated the association of caregivers' low health literacy with the incidence of enrollment gaps., Methods: We relied upon Medicaid enrollment data for 1208 children (mean age = 19 months) enrolled in the Carolina Oral Health Literacy project during 2008-09. The median follow-up was 25 months. Health literacy was measured using the Newest Vital Sign (NVS). Analyses relied on descriptive, bivariate, and multivariate methods based on Poisson modeling., Findings: One-third of children experienced one or more enrollment gaps; most were short in duration (median = 5 months). The risk of gaps was inversely associated with caregivers' age, with a 2% relative risk decrease for each added year. Low health literacy was associated with a modestly elevated risk increase [Incidence Rate Ratio (IRR) = 1.17 (95% confidence interval (CI) 0.88-1.57)] for enrollment disruptions; however, this estimate was substantially elevated among caregivers with less than a high school education [IRR = 1.52 (95% CI 0.99-2.35); homogeneity p<0.2]., Conclusions: Our findings provide initial support for a possible role of caregivers' health literacy as a determinant of children's Medicaid enrollment gaps. Although the association between health literacy and enrollment gaps was not confirmed statistically, we found that it was markedly stronger among caregivers with low educational attainment. This population, as well as young caregivers, may be the most vulnerable to the negative effects of low health literacy.

Objectives: 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., Methods: We relied on Medicaid claims and interview data of caregiver-child dyads who were enrolled in the Carolina Oral Health Literacy study during 2007-2008. The analytical cohort comprised 1000 children who had no dental visits before enrollment. Additional information was collected on sociodemographic characteristics, oral health status, health literacy, dental neglect, and access to care barriers. Our analyses relied on descriptive, bivariate, and multivariate methods., Results: During the 25-month median follow-up period, 39% of the children (mean baseline age: 16 months) entered the dental care system, and 13% of their first encounters were for emergency care. Caregivers' dental neglect emerged as a significant predictor of nonentrance. Children with reported oral health problems at baseline were more likely to enter the dental care system compared with children with better oral health, but they were also more likely to require emergency care., Conclusions: Caregivers have a pivotal role in children's oral health and care. Interventions aimed at improving children's oral health should involve community outreach to engage caregivers in a culturally appropriate manner when their children are infants or toddlers., (Copyright © 2014 by the American Academy of Pediatrics.)

Background: Dental caries, the most common childhood chronic disease, disproportionately affects vulnerable parts of the population and confers substantial impacts to children, families, and health systems. Because efforts directed toward oral health promotion and disease prevention are fundamentally superior to dental rehabilitation secondary to disease development, early preventive dental visits (EPDVs) are widely advocated by professional and academic stakeholders. The aim of this comprehensive review was to critically review and summarize available evidence regarding the effectiveness of EPDVs in improving children's oral health outcomes., Materials and Methods: A systematic literature search of the PubMed and Embase electronic databases was undertaken to identify peer-reviewed publications investigating the effectiveness of EPDVs on oral health outcomes, including clinical, behavioral, and cost end points up to October 30, 2013. Outcomes of the identified studies were abstracted and summarized independently by two investigators., Results: Four manuscripts met the inclusion criteria and were included in the review. All studies were conducted in the US and employed a retrospective cohort study design using public insurance-claims data, whereas one study matched claims files with kindergarten state dental surveillance data. That study found no benefit of EPDVs in future clinically determined dental caries levels in kindergarten. The other three studies found mixed support for an association of EPDVs with subsequent more preventive and fewer nonpreventive visits and lower nonpreventive service-related expenditures. Selection bias and a problem-driven dental care-seeking pattern were frequently articulated themes in the reviewed studies., Conclusion: The currently available evidence base supporting the effectiveness of EPDVs and the year 1 first dental visit recommendation is weak, and more research is warranted. The benefits of EPDVs before the age of 3 years are evident among children at high risk or with existing dental disease. However, EPDVs may be associated with reduced restorative dental care visits and related expenditures during the first years of life.

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.

The aim of this study was to investigate the association of extracurricular factors including socioeconomic status and career choice with perceived stress in dental school in a large cohort of Colombian dental students. Participants in the study were 5,700 students enrolled in seventeen Colombian dental schools. The study employed a Spanish adaptation of the Dental Environment Stressors (DES30-Sp) questionnaire and recorded an array of demographic, socioeconomic, career choice, and dental studies-related information. Data analyses relied on descriptive, bivariate, and multivariate methods based on multi-level mixed-effects linear regression and post hoc estimation of predictive margins. "Fear of failing a course or year" emerged as the highest ranked item. Male students consistently reported less perceived stress than females, and stress scores were higher among seniors. Independent of gender, age, and study year, having dentistry as one's first career choice, relying on financial support, and belonging to higher socioeconomic strata were associated with lower stress levels. Academic environment interventions aimed to improve students' educational well-being will need to account for the individual heterogeneity among them. These data from a robust cohort of predoctoral dental students underscore the importance of considering students' educational experiences in a broader social and economic context.

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.

Background: Links between the demanding nature of studies in the health sciences, students' personality traits and psychological distress have been well-established. While considerable amount of work has been done in medicine, evidence from the dental education arena is sparse and data from Latin America are lacking. The authors conducted a large-scale investigation of psychological distress among dental students in Colombia and sought to determine its curriculum and student-level correlates., Methods: The Spanish version of the Derogatis' Symptoms Checklist Revised (SCL-90-R) was administered to all students officially registered and attending classes or clinics in 17 dental schools in 4 geographic districts of Colombia between January and April 2012. Additional information was collected on participants' socio-demographic information and first career choice, as well as school's characteristics such as class size. The Global Severity Index (GSI) score, a measure of overall psychological distress, served as the primary analytical endpoint. Analyses relied on multilevel mixed-effects linear and log-binomial regression, accounting for study design and sample characteristics., Results: A total of 5700 dental students completed the survey, a response rate of 67%. Pronounced gradients were noted in the association between socio-economic status and psychological distress, with students in higher strata reporting fewer problems. After adjustment for all important covariates, there was an evident pattern of increasing psychological distress corresponding to the transition from the didactic, to the preclinical and clinical phases of training, with few differences between male and female students. Independent of other factors, reliance on own funds for education and having dentistry as the first career choice were associated with lower psychological distress., Conclusions: Levels of psychological distress correlated with students' socio-economic and study-level characteristics. Above and beyond the influence of person-level factors, variations in levels of distress paralleled specific transitional stages of the 5-year dental curriculum, providing opportunities for targeted interventions.

Chronic periodontitis (CP) is a common oral disease that confers substantial systemic inflammatory and microbial burden and is a major cause of tooth loss. Here, we present the results of a genome-wide association study of CP that was carried out in a cohort of 4504 European Americans (EA) participating in the Atherosclerosis Risk in Communities (ARIC) Study (mean age-62 years, moderate CP-43% and severe CP-17%). We detected no genome-wide significant association signals for CP; however, we found suggestive evidence of association (P < 5 × 10(-6)) for six loci, including NIN, NPY, WNT5A for severe CP and NCR2, EMR1, 10p15 for moderate CP. Three of these loci had concordant effect size and direction in an independent sample of 656 adult EA participants of the Health, Aging, and Body Composition (Health ABC) Study. Meta-analysis pooled estimates were severe CP (n = 958 versus health: n = 1909)-NPY, rs2521634 [G]: odds ratio [OR = 1.49 (95% confidence interval (CI = 1.28-1.73, P = 3.5 × 10(-7)))]; moderate CP (n = 2293)-NCR2, rs7762544 [G]: OR = 1.40 (95% CI = 1.24-1.59, P = 7.5 × 10(-8)), EMR1, rs3826782 [A]: OR = 2.01 (95% CI = 1.52-2.65, P = 8.2 × 10(-7)). Canonical pathway analysis indicated significant enrichment of nervous system signaling, cellular immune response and cytokine signaling pathways. A significant interaction of NUAK1 (rs11112872, interaction P = 2.9 × 10(-9)) with smoking in ARIC was not replicated in Health ABC, although estimates of heritable variance in severe CP explained by all single nucleotide polymorphisms increased from 18 to 52% with the inclusion of a genome-wide interaction term with smoking. These genome-wide association results provide information on multiple candidate regions and pathways for interrogation in future genetic studies of CP.

Background: Our previous research (Pediatrics 2010:126) found a strong association between caregiver oral health literacy (OHL) and children's oral health status; however, we found a weak association with oral health behaviors (OHBs). We hypothesize that this may be due to social desirability bias (SDB). Our objectives were to compare caregivers' responses to traditional OHB items and newer SDB-modulating items, and to examine the association of caregiver literacy with OHBs., Methods: We performed a cross-sectional study of 102 caregiver-child dyads, collecting data for OHBs using both traditional and new SDB-modulating items. We measured OHL using REALD-30, a validated word recognition test. We relied upon percent agreement and Cohen's kappa (k) to quantify the concordance in caregivers' responses and multivariate log-binomial regression to estimate the impact of OHL on OHBs., Results: Caregivers' mean REALD-30 score was 20.7 (SD = 6.0), range 1-30. We found an association between OHL and 4 of 8 OHBs examined. A subset of behavior questions compared traditional versus SDB-modulating items: history of bottle-feeding: agreement = 95%, k = 0.83 (95% CL:0.68,0.99); daily tooth brushing: agreement = 78%, k = 0.25 (95% CL:0.04,0.46); fluoridated toothpaste use: agreement = 88%, k = 0.67 (95% CL:0.49,0.85). After controlling for caregivers' race, marital status and study site, higher literacy scores remained associated with a decreased prevalence of parental report of "decided not brush the child's teeth because it would be frustrating"., Conclusions: Agreement between responses was high for 2 of 3 behavior items. Item 3 (tooth brushing frequency) revealed discordance, likely due to SDB. Use of the SDB-modulating items appears to yield a better estimate of OHB.

Introduction: The prevalence of high levels of stress as well as its multilevel consequences is well documented amongst students in the health sciences, and particularly in dentistry. However, investigations of perceived stress amongst Spanish-speaking student groups are sparse. This study aimed to (i) describe the translation, adaptation and psychometric properties of a Spanish version of the Dental Environment Stressors questionnaire and (ii) to examine the perceived sources of stress and their associations with the students' study year and gender in two dental schools in Latin America., Materials and Methods: All students officially registered in the dental schools of the University of San Sebastian (USS) in Chile and the Catholic University of Cordoba (CUC) in Argentina were invited to participate in the study. The DES30 questionnaire was adapted in Spanish using translation/back-translation, an expert bilingual committee, and consensus building. Cronbach's alpha was used to measure the instrument's internal consistency, and iterated principal factor analysis with promax rotation was employed to explore its underlying factor structure. Descriptive, bivariate and multivariate methods were used to examine the patterns of association between individual stressors, factor scores and students' characteristics., Results: Three hundred and four students comprised the study's analytical sample, with two-thirds of those being female. The DES30-Sp demonstrated good internal consistency (Cronbach's α = 0.89). A four-factor solution emerged and included 'academic workload', 'clinical training', 'time constraints' and 'self-efficacy beliefs' factors. 'Fear of failing a course or a year', 'examinations and grades' and 'lack of time for relaxation' were amongst the top individual-item stressors reported by students in both schools. Amongst this group of undergraduate dental students, those in Argentina, in higher study year, and females reported higher perceived stress., Conclusions: Increased workload, time constraints and some aspects of clinical training were the top stressors of approximately 300 Chilean and Argentinean dental undergraduates. Some variations between schools, males and females and study years were noted. The Spanish version of the DES30 questionnaire performed well, but future studies should evaluate the instrument's properties in larger and more diverse dental student populations., (© 2012 John Wiley & Sons A/S.)

Objectives: Fluoride varnish (FV) is efficacious in caries prevention although its effects among different tooth surfaces are poorly understood. This study sought to determine the extent to which caries-preventive effects of a community intervention that included FV application among preschool-aged children varied according to primary tooth anatomy and baseline tooth pathology., Methods: Secondary analysis was undertaken of data from a community-randomized controlled trial among 543 3- to 5-year-old Aboriginal children in 30 Northern Territory Australian communities. Children in intervention communities received community health promotion and FV application once every 6 months. Net caries (d(3)mfs) risk and 95% confidence limits (CL) were estimated for the control and intervention arms, and stratified according to tooth anatomy/location and baseline pathology (sound, enamel opacity, hypoplastic defect or precavitated carious lesion). The intervention's efficacy was quantified using generalized estimating equation modeling accounting for study design and clustering. The assumption of efficacy homogeneity was tested using a Wald χ(2) test with a p < 0.2 criterion and post hoc pairwise comparisons., Results: The intervention resulted in a 25% reduction (relative risk, RR = 0.75; 95% CL = 0.71, 0.80) in the 2-year surface-level caries risk. There was substantial heterogeneity in FV efficacy by baseline surface pathology: RRs were 0.73 for sound, 0.77 for opaque, 0.90 for precavitated, and 0.92 for hypoplastic surfaces. Among sound surfaces, maxillary anterior facials received significantly more benefit (RR = 0.62) compared to pits and fissures (RR = 0.78)., Conclusion: The intervention had greatest efficacy on surfaces that were sound at baseline. Among those sound surfaces, maxillary anterior facials received most caries-preventive benefit., (Copyright © 2012 S. Karger AG, Basel.)

Introduction: Despite recent advances in the management of HIV infection and increased access to treatment, prevention, care and support, the HIV/AIDS epidemic continues to be a major global health problem, with sub-Saharan Africa suffering by far the greatest humanitarian, demographic and socio-economic burden of the epidemic. Information on HIV/AIDS clinical care and established cohorts' characteristics in the Central Africa region are sparse., Methods: A survey of clinical care resources, management practices and patient characteristics was undertaken among 12 adult HIV care sites in four countries of the International Epidemiologic Databases to Evaluate AIDS Central Africa (IeDEA-CA) Phase 1 regional network in October 2009. These facilities served predominantly urban populations and offered primary care in the Democratic Republic of Congo (DRC; six sites), secondary care in Rwanda (two sites) and tertiary care in Cameroon (three sites) and Burundi (one site)., Results: Despite some variation in facility characteristics, sites reported high levels of monitoring resources, including electronic databases, as well as linkages to prevention of mother-to-child HIV transmission programs. At the time of the survey, there were 21,599 HIV-positive adults (median age=37 years) enrolled in the clinical cohort. Though two-thirds were women, few adults (6.5%) entered HIV care through prevention of mother-to-child transmission services, whereas 55% of the cohort entered care through voluntary counselling and testing. Two-thirds of patients at sites in Cameroon and DRC were in WHO Stage III and IV at baseline, whereas nearly all patients in the Rwanda facilities with clinical stage information available were in Stage I and II. WHO criteria were used for antiretroviral therapy initiation. The most common treatment regimen was stavudine/lamivudine/nevirapine (64%), followed by zidovudine/lamivudine/nevirapine (19%)., Conclusions: Our findings demonstrate the feasibility of establishing large clinical cohorts of HIV-positive individuals in a relatively short amount of time in spite of challenges experienced by clinics in resource-limited settings such as those in this region. Country differences in the cohort's site and patient characteristics were noted. This information sets the stage for the development of research initiatives and additional programs to enhance adult HIV care and treatment in Central Africa.

Background: Caregivers' perceptions of their young children's oral health status (OHS) are a strong determinant of whether the children visit a dentist. Our aims were to quantify the correlation between caregivers' assessments and their children's clinically determined restorative treatment needs, while investigating factors related to this association., Methods: One hundred eight caregivers assessed their children's OHS by answering a question on the self-reported National Health and Nutrition Examination Survey III instrument. Children underwent clinical oral examinations at one of two study sites of the Carolina Oral Health Literacy Project: a dental school-based clinic and a community-based health clinic. Examiners recorded the children's clinical treatment needs by using a modification of the caries severity index. The authors quantified concordance between the two measures with use of the Spearman rank correlation (ρ) and Kendall τ rank correlation, whereas they assessed differences in sociodemographic factors and oral health literacy (OHL) levels by using a homogeneity χ(2) test (P < .2 criterion)., Results: The concordance between caregivers' assessments and clinically determined OHS was lower for younger children (< 2 years, ρ = 0.29 versus = 2 years, ρ = 0.63 [homogeneity P = .03]), a pattern that was evident in the community clinic but not in the university clinic. Caregivers' age, education and OHL did not influence the accuracy of self-reports., Conclusions: For children younger than 2 years, caregivers' assessments correlated poorly with clinical needs, which routinely were underestimated. Practice Implications. These findings underscore the importance of preventive dental visits at a young age and the early establishment of a dental home.

Background: The authors conducted an observational cohort study to determine the levels of and examine the associations of oral health literacy (OHL) and oral health knowledge in low-income patients who were pregnant for the first time., Methods: An analytic sample of 119 low-income patients who were pregnant for the first time completed a structured 30-minute, in-person interview conducted by two trained interviewers in seven counties in North Carolina. The authors measured OHL by means of a dental word recognition test and assessed oral health knowledge by administering a six-item knowledge survey., Results: The authors found that OHL scores were distributed normally (mean [standard deviation], 16.4 [5.0]). The percentage of correct responses for each oral health knowledge item ranged from 45 to 98 percent. The results of bivariate analyses showed that there was a positive correlation between OHL and oral health knowledge (P < .01). Higher OHL levels were associated with correct responses to two of the knowledge items (P < .01)., Conclusions: OHL was low in the study sample. There was a significant association between OHL and oral health knowledge., Clinical Implications: Low OHL levels and, thereby, low levels of oral health knowledge, might affect health outcomes for both the mother and child. Tailoring messages to appropriate OHL levels might improve knowledge.

Objectives: To investigate the association of caregivers' oral health literacy (OHL) with their children's oral health related-quality of life (C-OHRQoL) and explore literacy as a modifier in the association between children's oral health status (COHS) and C-OHRQoL., Methods: This study relied upon data from structured interviews with 203 caregivers of children aged 3-5 from the Carolina Oral Health Literacy (COHL) Project. Data were collected for OHL using REALD-30, caregiver-reported COHS using the NHANES-item and C-OHRQoL using the Early Childhood Oral Health Impact Scale (ECOHIS). This study also measured oral health behaviors (OHBs) and socio-demographic characteristics and calculated overall/stratified summary estimates for OHL and C-OHRQoL. Spearman's rho and 95% confidence intervals (CI) were computed as measures of correlation of OHL and COHS with C-OHRQoL. To determine whether OHL modified the association between COHS and C-OHRQoL, this study compared literacy-specific summary and regression estimates., Results: Reported COHS was: excellent-50%, very good-28%, good-14%, fair-6%, poor-2%. The aggregate C-OHRQoL mean score was 2.0 (95% CI: 1.4, 2.6), and the mean OHL score 15.9 (95% CI: 15.2, 16.7). There was an inverse relationship between COHS and C-OHRQoL: ρ = -0.32 (95% CI: -0.45, -0.18). There was no important association between OHL and C-OHRQoL; however, deleterious OHBs were associated with worse C-OHRQoL. Literacy-specific linear and Poisson regression estimates of the association between COHS and C-OHRQoL departed from homogeneity (Wald χ(2) p < 0.2)., Conclusion: In this community-based sample of caregiver/child dyads, a strong correlation was found between OHS and C-OHRQoL. The association's magnitude and gradient were less pronounced among caregivers with low literacy.

Purpose: To study the third molar occlusal caries incidence and identify related patient-level sociodemographic, dental behavior, and clinical risk factors., Patients and Methods: A prospective cohort study was used to study caries risk (crude increment and incidence rate) on retained and erupted to the occlusal plane third molars among a moderate-size (n = 215) group of healthy (American Society of Anesthesiologists class I and II) young adults (median age, 26 years) followed up for a mean of 4.6 years. Clinical data were gathered by calibrated examiners using visual-tactile and radiographic diagnostic methods on all molar teeth. The covariates included age at enrollment, gender, race, income, education, frequency of dental visits, oral hygiene behaviors, and smoking. Summary statistics and visual methods were used for data description. The analyses relied on bivariate and multivariate methods using generalized estimating equations, extensions of Poisson modeling., Results: Of the 215 patients, 33% developed occlusal caries on 1 or more retained third molars. The incidence rate was 0.11 (95% confidence interval 0.09 to 0.13) third molar "increments"/person-year. Those with any molar caries at baseline were 80% more likely to have a new third molar caries lesion at the end of follow-up compared with those with caries-free molars (prevalence ratio, 1.80; 95% confidence interval, 1.08 to 3.00). The third molar caries rate was halved for every approximately 9 years of the subjects' baseline age. Favorable oral hygiene behaviors and better socioeconomic status were associated with decreased caries risk. However, independent of other covariates, smoking increased the third molar caries risk twofold., Conclusions: Younger patients from lower socioeconomic strata, smokers, and those with poor oral hygiene behavior are at an increased risk of occlusal caries development on their retained third molars., (Copyright © 2012 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)