Harnessing Artificial Intelligence to Address Oral Health Disparities.

This Viewpoint explores the unique attributes of dentistry that could leverage artificial intelligence for many improvements including greater health equity.

Fairness of Machine Learning Algorithms for Predicting Foregone Preventive Dental Care for Adults.

Importance: Access to routine dental care prevents advanced dental disease and improves oral and overall health. Identifying individuals at risk of foregoing preventive dental care can direct prevention efforts toward high-risk populations. Objective: To predict foregone preventive dental care among adults overall and in sociodemographic subgroups and to assess the algorithmic fairness. Design, Setting, and Participants: This prognostic study was a secondary analyses of longitudinal data from the US Medical Expenditure Panel Survey (MEPS) from 2016 to 2019, each with 2 years of follow-up. Participants included adults aged 18 years and older. Data analysis was performed from December 2022 to June 2023. Exposure: A total of 50 predictors, including demographic and socioeconomic characteristics, health conditions, behaviors, and health services use, were assessed. Main Outcomes and Measures: The outcome of interest was foregoing preventive dental care, defined as either cleaning, general examination, or an appointment with the dental hygienist, in the past year. Results: Among 32 234 participants, the mean (SD) age was 48.5 (18.2) years and 17 386 participants (53.9%) were female; 1935 participants (6.0%) were Asian, 5138 participants (15.9%) were Black, 7681 participants (23.8%) were Hispanic, 16 503 participants (51.2%) were White, and 977 participants (3.0%) identified as other (eg, American Indian and Alaska Native) or multiple racial or ethnic groups. There were 21 083 (65.4%) individuals who missed preventive dental care in the past year. The algorithms demonstrated high performance, achieving an area under the receiver operating characteristic curve (AUC) of 0.84 (95% CI, 0.84-0.85) in the overall population. While the full sample model performed similarly when applied to White individuals and older adults (AUC, 0.88; 95% CI, 0.87-0.90), there was a loss of performance for other subgroups. Removing the subgroup-sensitive predictors (ie, race and ethnicity, age, and income) did not impact model performance. Models stratified by race and ethnicity performed similarly or worse than the full model for all groups, with the lowest performance for individuals who identified as other or multiple racial groups (AUC, 0.76; 95% CI, 0.70-0.81). Previous pattern of dental visits, health care utilization, dental benefits, and sociodemographic characteristics were the highest contributing predictors to the models' performance. Conclusions and Relevance: Findings of this prognostic study using cohort data suggest that tree-based ensemble machine learning models could accurately predict adults at risk of foregoing preventive dental care and demonstrated bias against underrepresented sociodemographic groups. These results highlight the importance of evaluating model fairness during development and testing to avoid exacerbating existing biases.

Did Dental Insurance Expansion Improve Dental Care Needs Among Korean Adults? Difference in Difference Analysis.

BACKGROUND: In 2012, the Korean government expanded dental insurance for the elderly to promote improved access to dental care. We examined the causal effect of this policy on dental care needs, focusing on low-income older adults. METHODS: We compared data before and after policy implementation using double difference (DD) and triple difference (DDD) analyses. We used the nationally representative data from the Korea National Health and Nutrition Examination Survey from 2010 and 2016-2018. Individuals aged ≥65 years were included in the treatment group, and individuals aged <65 years were included in the control group. RESULTS: Dental insurance expansion was associated with a paradoxical increase in perceived unmet dental needs among elderly individuals (8.8 percentage points increase, 95% CI: 4.7 to 13.0). However, there were improvements in dental prosthetics outcomes (denture wearing [4.0 percentage points, 95% CI: 0.2 to 7.9] and dental implants [5.0 percentage points, 95% CI: 2.1 to 7.9]; P < 0.01). Upon analyzing low-income elderly individuals using DDD analysis, we found that the insurance expansion led to a 21.6% smaller increase in unmet dental needs among low-income adults, compared to high-income adults (95% CI, -35.0 to -8.5; P < 0.01). CONCLUSION: Dental insurance expansion in South Korea resulted in improvements in access to dental prosthetic services overall. It also led to a smaller increase in unmet dental needs among low-income older adults, compared to high-income adults.

Early changes in health coverage and access to dental care associated with Medicaid expansion under the COVID-19 pandemic.

The extent to which the COVID-19 pandemic has affected early changes in health coverage and access to dental care services in states that expanded Medicaid versus those that did not is currently not well known. Using data from the National Health Interview Survey, we found that, during the first year of the COVID-19 pandemic, states that had previously expanded their Medicaid programs under the Affordable Care Act had lower uninsurance rates for White low-income adults (-8.8 percentage points; 95% CI: -16.6, -1.0) and lower dental uninsurance rates for all low-income adults (-5.4 percentage points; 95% CI: -10.4, -0.5). Our findings also suggest that the combination of Medicaid expansion with coverage of adult dental benefits in Medicaid was associated with improved dental coverage and access to dental care during the pandemic. With the expiration of the public health emergency declaration, states are considering strategies to prevent disruptions in Medicaid coverage. Our study adds to the evidence of the importance of Medicaid expansion in stabilizing health coverage during a public health crisis.

Comparison of Dental Care Visits Before and After Adoption of a Policy to Expand the Dental Workforce in Minnesota.

Importance: Currently, 13 states and tribal nations have expanded their dental workforce by adopting use of dental therapists. To date, there has been no evaluation of the influence of this policy on dental care use. Objective: To assess changes in dental care use in Minnesota after the implementation of the policy to authorize dental therapists in 2009. Design Setting and Participants: In this cross-sectional study of 2 613 716 adults aged 18 years and older, a synthetic control method was used to compare changes in dental care use after the authorization of the policy in Minnesota relative to a synthetic control of nonadopting states. Data from the Behavioral Risk Factor Surveillance System from 2006 to 2018 were analyzed. Data analysis was conducted from June 1, 2021, to December 18, 2021. Exposure: Authorization of dental therapy. Main Outcomes and Measures: Self-reported indicator for whether a respondent had visited a dentist or a dental clinic in the past 12 months. Results: Among 2 613 716 adults aged 18 years or older, the mean (SD) age at baseline was 46.0 (17.7) years, 396 501 were women (weighted percentage, 51.3%), 503 197 were White (weighted percentage, 67.9%), 54 568 were Black (weighted percentage, 10.1%), 39 282 were Hispanic (weighted percentage, 14.5%), and 34 739 were other race (weighted percentage, 6.7%). The proportion of adults visiting a dentist before the authorization of dental therapists in Minnesota was 76.2% (95% CI, 75.0%-77.4%) in the full sample, 61.5% (95% CI, 58.4%-64.6%) for low-income adults, and 58.4% (95% CI, 53.0%-63.5%) among Medicaid-eligible adults. Authorizing dental therapists in Minnesota was associated with an increase of 7.3 percentage points (95% CI, 5.0-9.5 percentage points) in dental care use among low-income adults, a relative increase of 12.5% (95% CI, 8.6%-16.4%), and an increase of 6.2 percentage points (95% CI, 2.4-10.0 percentage points) among Medicaid-eligible adults, a relative increase of 10.5% (95% CI, 3.9%-17.0%). In addition, the policy was associated with an increase in dental visits among White adults (low-income sample, 10.8 percentage points [95% CI, 8.5-13.0 percentage points]; Medicaid sample, 13.5 percentage points [95% CI, 9.1-17.9 percentage points]), with no corresponding increases among other racial and ethnic groups in the low-income and Medicaid population. Conclusions and Relevance: In this cross-sectional study, expanding the dental workforce through authorization of dental therapists appeared to be associated with an increase in dental visits. In Minnesota, the policy was associated with improved access to dental care among low-income adults overall. However, racial and ethnic disparities in dental use persist.

Chilling Effects on Immigrants' Health Insurance Coverage After the 2016 Presidential Election.

BACKGROUND: Depressed enrollment in public benefits among immigrants and their families may occur due to concerns about deportation and obstacles to permanent residency status related to immigration policies. METHODS: Using data from the American Community Survey (ACS) from 2014 to 2019, we conducted an interrupted time series analysis to estimate Medicaid enrollment, private insurance enrollment, and uninsured rates among low-income non-citizen adults and their children, compared to U.S. citizens before and after the Trump administration entered office in January 2017. RESULTS: Compared to U.S. citizen adults, Medicaid enrollment among non-citizen adults decreased and the uninsured rate increased (1.5 percentage points per year, p < 0.05) from 2017 to 2019. Decreases in coverage starting in 2017 were larger among both children with at least one non-citizen parent and non-citizen children. DISCUSSION: These findings suggest that the Trump administration immigration policy climate is associated with decreased health insurance enrollment among this population.

Dental Outcomes After Medicaid Insurance Coverage Expansion Under the Affordable Care Act.

Importance: Dental coverage for adults is a state option in Medicaid, and despite significant gains in coverage after the Medicaid expansion under the Affordable Care Act (ACA), dental outcomes among adults in expansion states remain unexplored. Objective: To explore the association of state coverage of dental benefits through Medicaid expansion with clinical dental outcomes. Design, Setting, and Participants: This cross-sectional study analyzed data from the National Health and Nutrition Examination Survey from 2009 to 2018. Included participants were low-income adults aged 19 to 64 years with income up to 138% of the federal poverty level. The study used a difference-in-differences analysis to compare changes from before to after ACA expansion in expansion states vs in control states. Changes were examined in the full sample and separately in states that did and did not provide Medicaid adult dental benefits. We defined a state as providing Medicaid adult dental benefits if it covered services beyond emergency dental benefits in 2014. Data were analyzed from November 2020 to March 2021. Exposures: Medicaid expansion under the ACA. Main Outcomes and Measures: Rates of health coverage, having a dental visit, affordability of dental care in the past year, poor oral health, and teeth flossing were obtained from self-reported data. Mean number of missing teeth and prevalence of untreated decayed teeth, filled teeth, and functional dentition were obtained from clinical examination data. Results: Among 7637 low-income adults, the mean (SD) age was 37.8 (13.4) years and 4153 (weighted percentage, 54.5 %) were women. At baseline, 1732 low-income adults in nonexpansion states compared with 2520 low-income adults in expansion states were more likely, as shown by weighted percentage, to be Black (473 individuals [21.0%] vs 508 individuals [15.1%]) and US born (1281 individuals [76.7%] vs 1613 individuals [69.6%]). In the full sample, Medicaid expansion, compared with nonexpansion, was associated with an increased rate of seeing a dentist in the prior year (12.4 percentage points; 95% CI 4.6 to 20.2 percentage points; P = .003). In expansion states that provided dental benefits, compared with nonexpansion states that provided dental benefits, the expansion was associated with increases in rates of Medicaid coverage (8.2 percentage points; 95%CI 0.5 to 15.8 percentage points; P = .04) and having seen a dentist in the previous year (11.4 percentage points, 95% CI, 3.7 to 19.1 percentage points; P = .006) and decreases in the uninsured rate (-12.6 percentage points, 95% CI -18.9 to -6.4 percentage points; P < .001) and prevalence of untreated decayed teeth (-16.8 percentage points; 95% CI, -25.5 to -8.0 percentage points; P = .001). In states without Medicaid dental benefits, the expansion was associated with an increase in the mean number of missing teeth (1.3 teeth; 95% CI 0.1 to 2.5 percentage points; P = .04) and a decrease in the prevalence of functional dentition (-8.7 percentage points; 95% CI, -14.1 to -3.3 percentage points; P = .003) compared with nonexpansion states. Conclusions and Relevance: This study found that the combination of Medicaid expansion and coverage of Medicaid dental benefits was associated with improved oral health among low-income adults.

Predictors of tooth loss: A machine learning approach.

INTRODUCTION: Little is understood about the socioeconomic predictors of tooth loss, a condition that can negatively impact individual's quality of life. The goal of this study is to develop a machine-learning algorithm to predict complete and incremental tooth loss among adults and to compare the predictive performance of these models. METHODS: We used data from the National Health and Nutrition Examination Survey from 2011 to 2014. We developed multiple machine-learning algorithms and assessed their predictive performances by examining the area under the receiver operating characteristic curve (AUC), accuracy, sensitivity, specificity, and positive and negative predictive values. RESULTS: The extreme gradient boosting trees presented the highest performance in the prediction of edentulism (AUC = 88.7%; 95%CI: 87.1, 90.2), the absence of a functional dentition (AUC = 88.3% 95%CI: 87.3,89.3) and for predicting missing any tooth (AUC = 83.2%; 95%CI, 82.0, 84.4). Although, as expected, age and routine dental care emerged as strong predictors of tooth loss, the machine learning approach identified additional predictors, including socioeconomic conditions. Indeed, the performance of models incorporating socioeconomic characteristics was better at predicting tooth loss than those relying on clinical dental indicators alone. CONCLUSIONS: Future application of machine-learning algorithm, with longitudinal cohorts, for identification of individuals at risk for tooth loss could assist clinicians to prioritize interventions directed toward the prevention of tooth loss.

Medicaid healthy behavior incentives and use of dental services.

OBJECTIVE: To examine changes in access to dental care in states using Section 1115 waivers to implement healthy behavior incentive (HBI) programs in their Medicaid expansion under the ACA, compared to traditional expansion states and nonexpansion states. DATA SOURCES: Behavioral Risk Factor Surveillance System from 2008 to 2018. STUDY DESIGN: We used difference-in-differences analysis to compare changes in three Medicaid expansion states with HBI (Iowa, Indiana, Michigan) to traditional expansion (Minnesota, North Dakota, Ohio) and nonexpansion states (Nebraska, South Dakota, Wyoming) in the same mid-Western region of the country. The sample included 32 556 low-income adults. DATA COLLECTION/EXTRACTION METHODS: NA. PRINCIPAL FINDINGS: We found no significant changes in dental visits associated with HBI or traditional expansion relative to nonexpansion states. HBI expansion was associated with an increase of 2.2 percentage points in reporting a dental visit in the past year for adults in urban areas (P < 0.05) while the traditional expansion was associated with a reduction of 8.5 percentage points (P < 0.01) in utilization in rural areas relative to nonexpansion states. However, after adjustment for preexisting trends, the coefficients were no longer significant, suggesting that these differences are likely due to preexisting trends. CONCLUSIONS: We did not find evidence of increased utilization of routine dental care associated with HBI programs.

Changes In Coverage And Access To Dental Care Five Years After ACA Medicaid Expansion.

With the implementation of the Affordable Care Act (ACA), millions of low-income adults gained health coverage. We examined how the ACA's expansion of Medicaid eligibility affected dental coverage and the use of oral health services among low-income adults, using data from the National Health Interview Survey from the period 2010-18. We found that the ACA increased rates of dental coverage by 18.9 percentage points in states that provide dental benefits through Medicaid. In terms of utilization, expansion states that provide dental benefits saw the greatest increase in people having a dental visit in the past year (7.2 percentage points). However, there was no significant change in the overall share of people who had a dental visit in the past year, although the expansion was associated with a significant increase in this metric among White adults. The expansion was also associated with a 1.4-percentage-point increase in complete teeth loss, which may be a marker of both poor oral health and the potential gaining of access to dental services (with subsequent tooth extractions). Our findings suggest that in addition to expanded coverage, policies need to tackle other barriers to accessing dental care to improve population oral health.

Prescribing patterns in a US dental school from 2010 to 2017.

OBJECTIVE: Dental education has an essential role in helping combat the opioid and antibiotic resistance crises. This study evaluates the prescribing practices of clinical instructors, advanced graduate residents, and predoctoral students in an academic dental setting. METHODS: A retrospective chart review was conducted of electronic dental records from the years 2010 to 2017. The proportions of prescriptions for each drug group was calculated by prescribers' training level and specialty. Descriptive statistics were calculated for the daily opioid Morphine Milligram Equivalent (MME) dose prescribed across years and provider characteristics. RESULTS: Over the 8 years, 65,160 prescriptions were written for 10,374 patients by 625 prescribers. The most commonly prescribed drugs were for fluoride-based medications (30%) and antibiotics (24%). Periodontists had the greatest absolute number of opioid analgesics prescriptions (n = 2712); oral maxillofacial surgeons (OMFS) prescribed more opioids than other classes of drug (49%) as a proportion of within-specialty prescriptions. Antibiotics were the most common drugs prescribed by endodontists (46%) and second most common drugs prescribed by periodontists (25%), OMFS (28%), and prosthodontists (21%). From 2010 to 2017, the proportion of prescriptions for antibiotics remained unchanged, while that of fluoride-based drugs increased from 2010 to 2014 and plateaued thereafter. The proportion of prescriptions for opioid analgesics decreased from 18% to 7%. The median daily MME dose across year and provider characteristics stayed constant (<50 MME). CONCLUSION: These results demonstrate encouraging prescription trends for opioid and fluoride-based drugs. Due to the high prevalence of antibiotic prescriptions in academic dental settings, stewardship approaches should be emphasized.

Changes in emergency department dental visits after Medicaid expansion.

OBJECTIVES: To estimate the effect of Medicaid expansion under the Affordable Care Act (ACA) on the frequency and payment source for Emergency Department (ED) visits for dental care. STUDY DESIGN: Retrospective, quasi-experimental study. DATA SOURCES/STUDY SETTING: We used the State Emergency Department Database to compare changes in ED visit rates and payment source for dental conditions among patients from 33 states. These states represent four distinct policy environments, based on whether they expanded Medicaid and whether their Medicaid programs provide dental benefits. We first assessed the number of ED dental visits before (2012) and after (2014) the ACA. Then, we used differences-in-differences regression to estimate changes in insurance for dental visits by nonelderly adults. PRINCIPAL FINDINGS: Our sample contained 375 944 dental ED visits. In states that expanded Medicaid and offered dental coverage, dental ED visits decreased by 14.1 percent (from 19 443 to 16 709, for a net difference of 2734). By contrast, in the remaining three state groups, dental ED visits rose. Meanwhile, the expansion significantly increased Medicaid coverage and decreased the rate of self-pay for ED dental visits. CONCLUSIONS: Medicaid expansion, combined with adult dental coverage in Medicaid, was associated with a reduction in ED utilization for dental visits.

Comparison of the Color Appearance of Peri-implant Soft Tissue with Natural Gingiva Using Anodized Pink-Neck Implants and Pink Abutments: A Prospective Clinical Trial.

PURPOSE: The aim of this study was to assess the visual effects of pink-neck implants and pink abutments with respect to the color of natural gingiva. The distribution pattern and magnitude of CIELAB color difference coordinates were studied. MATERIALS AND METHODS: Forty subjects with a tooth in the maxillary esthetic zone deemed hopeless were recruited. Patients were randomized to either a conventional gray implant or a pink-neck implant. The hopeless tooth was removed and patients received an immediate implant along with an immediate customized provisional prosthesis. The provisional was maintained for 3 months to allow for complete healing of the implants. Two identical CAD/CAM titanium abutments only differing in color (gray and pink) were fabricated along with an all-ceramic zirconia crown. The gray abutment was delivered first with a zirconia crown, and it was replaced with the pink abutment 3 weeks later. Three weeks after insertion of each abutment with the zirconia crown, a spectrophotometer was used to collect the color of the peri-implant mucosa and natural gingiva, so the difference between the two sites could be calculated (ΔL* [difference in lightness], Δa* [difference in green-red axis], Δb* [difference in blue-yellow axis]). The natural gingiva measured was the gingiva of a contralateral or adjacent unrestored tooth. The effect of implant color and abutment on the color difference between peri-implant mucosa and natural gingiva was investigated with a linear regression model using a generalized estimating equation (GEE) approach. RESULTS: Raw data demonstrated statistically insignificant smaller ΔL*, Δa*, Δb* between peri-implant soft tissue and natural gingiva when the implant was pink versus gray. Further, there were statistically insignificant smaller ΔL* and Δb* between peri-implant soft tissue and natural gingiva when the abutment was pink versus gray. Δa* between peri-implant soft tissue and natural gingiva was significantly smaller when using a pink abutment regardless of the implant type (P < .05). CONCLUSION: Using an anodized pink abutment and/or a pink-neck implant minimizes the color difference observed between the peri-implant mucosa and the natural gingiva in the redness spectrum. These advances in technology assist in helping the peri-implant mucosa appear more natural by minimizing the color variance.

Socioeconomic status, oral health and dental disease in Australia, Canada, New Zealand and the United States.

BACKGROUND: Socioeconomic inequalities are associated with oral health status, either subjectively (self-rated oral health) or objectively (clinically-diagnosed dental diseases). The aim of this study is to compare the magnitude of socioeconomic inequality in oral health and dental disease among adults in Australia, Canada, New Zealand and the United States (US). METHODS: Nationally-representative survey examination data were used to calculate adjusted absolute differences (AD) in prevalence of untreated decay and fair/poor self-rated oral health (SROH) in income and education. We pooled age- and gender-adjusted inequality estimates using random effects meta-analysis. RESULTS: New Zealand demonstrated the highest adjusted estimate for untreated decay; the US showed the highest adjusted prevalence of fair/poor SROH. The meta-analysis showed little heterogeneity across countries for the prevalence of decayed teeth; the pooled ADs were 19.7 (95% CI = 16.7-22.7) and 12.0 (95% CI = 8.4-15.7) between highest and lowest education and income groups, respectively. There was heterogeneity in the mean number of decayed teeth and in fair/poor SROH. New Zealand had the widest inequality in decay (education AD = 0.8; 95% CI = 0.4-1.2; income AD = 1.0; 95% CI = 0.5-1.5) and the US the widest inequality in fair/poor SROH (education AD = 40.4; 95% CI = 35.2-45.5; income AD = 20.5; 95% CI = 13.0-27.9). CONCLUSIONS: The differences in estimates, and variation in the magnitude of inequality, suggest the need for further examining socio-cultural and contextual determinants of oral health and dental disease in both the included and other countries.

Does providing dental services reduce overall health care costs?: A systematic review of the literature.

BACKGROUND: The authors conducted a systematic review of the literature to assess the impact of dental treatment on overall health care costs for patients with chronic health conditions and patients who were pregnant. TYPES OF STUDIES REVIEWED: The authors searched multiple databases including MEDLINE, Embase, Web of Science, and Dentistry & Oral Sciences Source from the earliest date available through May 2017. Two reviewers conducted the initial screening of all retrieved titles and abstracts, read the full text of the eligible studies, and conducted data extraction and quality assessment of included studies. RESULTS: The authors found only 3 published studies that examined the effect of periodontal treatment on health care costs using medical and dental claims data from different insurance databases. Findings from the qualitative synthesis of those studies were inconclusive as 1 of the 3 studies showed a cost increase, whereas 2 studies showed a decrease. CONCLUSIONS AND PRACTICAL IMPLICATIONS: The small number of studies and their mixed outcomes demonstrate the need for high-quality studies to evaluate the effect of periodontal intervention on overall health care costs.

A prospective clinical trial to assess the optical efficacy of pink neck implants and pink abutments on soft tissue esthetics.

OBJECTIVE: The purpose of this prospective, randomized, controlled, multicenter clinical study was to analyze the optical effects of an anodized pink colored implant shoulder/abutment system in the peri-implant mucosa of immediately placed dental implants. MATERIALS AND METHOD: Forty subjects with a restoratively hopeless tooth in the maxillary esthetic zone, were recruited and randomized to receive either a pink-neck implant, or a conventional gray implant. All patients received an immediate implant and immediate provisional and two identical CAD/CAM titanium abutments with different surface colors: pink and gray, and one zirconia all-ceramic crown. The color of the peri-implant mucosa was measured using a dental spectrophotometer and analyzed using CIELAB color system. RESULTS: The overall color difference between the peri-implant mucosa with a pink abutment and a gray abutment was ΔE = 4.22. Patients with gray implants presented a color change of ΔE = 3.86-4.17 with this abutment change, while patients with pink implants had a color change of ΔE = 3.84-4.69. The peri-implant mucosa with a pink abutment was significantly more red when compared with a gray abutment (P ≤ .01). CONCLUSIONS: When a pink abutment was used, there is a significant color change of the peri-implant mucosa that is above the detectable color threshold. CLINICAL SIGNIFICANCE: Esthetic outcomes are important for the success of implant treatment of maxillary anterior implants. The phenomenon of the gray color of a dental implant and abutment shining through the peri-implant mucosa has been documented in the literature. The objective of this study was to assess the optical effect of an anodized pink-neck implant and a pink abutment on the color of peri-implant mucosa. This study demonstrates that using pink-neck implant and a pink abutment would contribute positively to the overall esthetic outcome for an anterior implant.

Social inequalities in tooth loss: A multinational comparison.

OBJECTIVES: To conduct cross-national comparison of education-based inequalities in tooth loss across Australia, Canada, Chile, New Zealand and the United States. METHODS: We used nationally representative data from Australia's National Survey of Adult Oral Health; Canadian Health Measures Survey; Chile's First National Health Survey Ministry of Health; US National Health and Nutrition Examination Survey; and the New Zealand Oral Health Survey. We examined the prevalence of edentulism, the proportion of individuals having <21 teeth and the mean number of teeth present. We used education as a measure of socioeconomic position and measured absolute and relative inequalities. We used random-effects meta-analysis to summarize inequality estimates. RESULTS: The USA showed the widest absolute and relative inequality in edentulism prevalence, whereas Chile demonstrated the largest absolute and relative social inequality gradient for the mean number of teeth present. Australia had the narrowest absolute and relative inequality gap for proportion of individuals having <21 teeth. Pooled estimates showed substantial heterogeneity for both absolute and relative inequality measures. CONCLUSIONS: There is a considerable variation in the magnitude of inequalities in tooth loss across the countries included in this analysis.

A systematic review of stress in dental students.

The aim of this study was to systematically review the available literature on the levels, causes, and impact of stress among dental students. The investigators searched eight electronic databases: Medline, Medline in process, Psychinfo, ERIC, Embase, Cochrane Library, Web of Science, and SCOPUS. Two independent reviewers conducted the selection, data extraction, and quality appraisal for included studies. The investigators then coded both quantitative and qualitative studies using similar codes and pooled results from studies that used the Dental Environment Stress questionnaire to demonstrate dental students' stress levels. The search initially identified 4,720 studies, of which 124 studies were included in the final qualitative synthesis and twenty-one were included in the meta-analysis. Evidence from this research showed that dental students experience considerable amounts of stress during their training. This stress is mainly due to the demanding nature of the training. In addition, studies suggest adverse effects of elevated stress on students' health and well-being. Most of the available literature is based on cross-sectional studies; thus, future longitudinal studies are needed to follow students throughout their curriculum. In addition, further research needs to explore and test stress management interventions.

Sources of stress in Canadian dental students: a prospective mixed methods study.

The objectives of this study were to describe sources of stress in predoctoral dental students and first-year residents at one dental school and to understand how these sources evolved during the four-year curriculum and in the first year after graduation. The study used a mixed methods design. Quantitative data were collected from subjects in each of the five cohorts of students and residents, every month for a period of one year (other than the summer holiday period; N varied each month from 77 to 127). Sources of stress were measured using the Dental Environment Stress questionnaire (DES). The investigators administered the DES twice, once at the end of each academic semester, and used DES categories that emerged from factor analysis to assess monthly sources of stress. Qualitative data collected through individual interviews (N=6) were aimed at understanding the main sources of stress in each year of the curriculum. Results from both quantitative and qualitative phases demonstrated that the main stressors for all dental students throughout the year were examinations and grades as well as workload. Students in the clinical years were also concerned about patient treatment. The residents and final-year students reported future plans as an additional stressor. Over the year, there was a significant increase for workload stress in the fourth year (p<0.05); in the third year there was a significant increase in patient treatment stress (p<0.05) with a significant decrease for personal factors (p<0.05). The study demonstrated that sources of stress in these students and first-year residents varied according to their stage in the program and the period of the year.

Coping and psychological distress among head and neck cancer patients.

INTRODUCTION: Few studies have described the relationship between the psychological distress associated with head and neck cancer and how patients cope with their disease. PURPOSE: The purpose of this study is to investigate how head and neck cancer patients 6-12 months after their diagnosis cope with their disease and how their coping skills are related to their anxiety and depression levels. METHODS: We conducted a cross-sectional study among 157 head and neck cancer patients. We evaluated coping strategies using the Ways of Coping Checklist and anxiety and depression using The Hospital Anxiety and Depression Scale. RESULTS: Bivariate analyses revealed that there was an association between patients' levels of anxiety and depression and the type of coping strategies used. Patients with higher levels of anxiety and depression used more "blamed self", "wishful thinking", and "avoidance" coping strategies. These associations were further confirmed by multivariate linear regression analyses that controlled for age, gender, time since end of treatment, tumor stage, and occupation. CONCLUSION: These findings suggest that coping strategies in head and neck cancer patients vary according to their level of psychological distress. However, the cross-sectional nature of the data does not permit directional inferences for this association.