Association of income inequality with orthodontic treatment use

Association between dental visit behavior and mortality: a nationwide longitudinal cohort study from NHANES

OBJECTIVES

The benefits of professional dental treatment for oral diseases have been widely investigated. However, it is unclear whether professional dental treatment provides additional benefits for improving general health.

MATERIALS AND METHODS

Data were obtained from the US National Health and Nutrition Examination Survey (NHANES) 1999 to 2004 and 2011 to 2018 cycles. A total of 36,174 participants were included and followed-up for mortality until December 31, 2019. Dental visit behavior was defined as the time interval of last dental visit (TIDV, < 0.5 year, 0.5-1 year, 1-2 years, 2-5 years, and > 5 years) and the main reasons of the last dental visit (treatment, examination, and other reasons). The Cox proportional risk model was used to estimate the hazard ratio (HR) and 95% confidence interval (CI).

RESULTS

Compared with participants with time interval of less than 0.5 year, the multivariate-adjusted HRs and 95%CI for participants with time interval of more than 5 years were 1.45 (1.31, 1.61) for all-cause mortality (P trend < 0.0001), 1.49 (1.23, 1.80) for cardiovascular diseases mortality (P trend = 0.0009) and 1.53 (1.29, 1.81) for cancer mortality (P trend = 0.013). Compared with dental visit for examination, participants who had their dental visit for treatment had higher risk for mortality. For participants with dental visit for examination, TIDV of less than 1 year showed lower risk for mortality, whereas TIDV of less than 0.5 year is recommend for population with dental visit for treatment.

CONCLUSIONS

Poor dental visit behavior is associated with an increased risk of mortality. Further well-designed studies are needed to confirm the association between professional dental visit and mortality.

CLINICAL RELEVANCE

This study highlights the potential benefits of regular dental visits in maintaining general health.

The effects of orthodontic treatment on personal dental expenditures in South Korea: a follow-up study using Korean health panel survey

BACKGROUND

This study aimed to investigate the effects of orthodontic treatment on cumulative out-of-pocket (OOP) expenditures for up to 8 years and the factors contributing to changes in individual OOP dental expenses.

METHODS

The data of adults aged ≥19 years, 218 with experience of orthodontic treatment (OT group) and 654 without experience of orthodontic treatment (non-OT group) were extracted from the Korea Health Panel Survey between 2009 and 2017 using the propensity score matching method. The total personal OOP expenditure for dental care incurred after orthodontic treatment in the OT group and that incurred in the matched non-OT group were calculated. Since dependent variables, cumulative dental expenditures, were continuous with excess zeros, Tweedie compound Poisson linear models were used to explore the influence of orthodontic treatment experience and demographic and socioeconomic factors, including private insurance, on per capita OOP dental expenditures.

RESULTS

The OT group had socioeconomic characteristics distinct from those of general dental patients. The Box-Cox transformed per capita OOP expenditures for dental care in the OT group were lower than those in the non-OT group (P < 0.05). When all covariates were held constant, the non-OT group spent 1.4-times more on OOP dental expenditures, but this was not statistically significant (P > 0.1). The data from those with higher incomes revealed the opposite trend (P < 0.05), while the other covariates were not statistically significant.

CONCLUSIONS

Orthodontic treatment had no positive or negative effect on future oral care use. This finding is similar to the inconsistent results of previous clinical studies on oral health and orthodontic treatment.

Unemployment and expenditure on health and education as mediators of the association between toothbrushing and global income inequalities

Objective

The study assessed the association of country-level income inequalities with the percentage of schoolchildren toothbrushing-at-least-twice-daily; and the mediating effect of country-level unemployment rate and governmental expenditure on health and education (EH&E).

Methods

This was an ecological study. The dependent variable was country-level toothbrushing-at-least-twice-daily among 11-15-year-old schoolchildren. Data for the period 2009 to 2019 were extracted from two global surveys about schoolchildren’s health and from manuscripts identified through a systematic search of three databases. The independent variable was country-level income inequalities measured by the Gini coefficient (GC) extracted from the Sustainable Development Report 2021. The mediators were the unemployment rate and EH&E. We stratified the sample by the level of GC and assessed the correlation between the dependent and independent variables in each stratum. Linear regression was used to assess the relations between the dependent and independent variables, and mediation path analysis was used to quantify the direct, indirect, and total effects.

Results

Data were available for 127 countries. The mean (SD) percentage of children who brushed-at-least-twice-daily was 67.3 (16.1), the mean (SD) GC = 41.4 (8.2), unemployment rate = 7.5 (4.7) and EH&E = 8.4 (3.3). The percentage of children brushing at-least-twice-daily had weak and non-significant correlation with GC that was positive in countries with the least inequality and negative for countries with higher levels of inequality. A greater percentage of schoolchildren brushing-at-least-twice-daily was significantly associated with higher GC (B = 0.76, 95%CI: 0.33, 1.18), greater EH&E (B = 1.67, 95%CI: 0.69, 2.64) and lower unemployment rate (B=-1.03, 95%CI: -1.71, -0.35). GC had a significant direct positive effect (B = 0.76, 95%CI: 0.33, 1.18), a significant indirect negative effect through unemployment and EH&E (B=-0.47, 95%CI: -0.79, -0.24) and a non-significant total positive effect (B = 0.29, 95%CI: -0.09, 0.67) on the percentage of schoolchildren brushing-at-least-twice-daily.

Conclusion

Unemployment and EH&E mediated the association between income inequality and toothbrushing. Country-level factors may indirectly impact toothbrushing.

Associations among Orthodontic History, Psychological Status, and Temporomandibular-Related Quality of Life: A Cross-Sectional Study

OBJECTIVES

This cross-sectional study aimed to evaluate the associations among orthodontic history, psychological status, and temporomandibular-related quality of life.

METHODS

A questionnaire was developed and distributed to students in a local college, containing questions about demographic information, the Patient Health Questionnaire-4 (PHQ-4), the Fonseca anamnestic index, and the Oral Health Impact Profile for Temporomandibular Disorders (OHIP-TMD). The respondents were divided into with orthodontic history (OS) group and without OS group. Binary logistic regression and multiple linear regression were performed for statistical analysis.

RESULTS

A total of 531 valid questionnaires were collected, covering 161 participants with OS and 370 participants without OS. No statistically significant differences were observed in the scores of PHQ-4 between the two groups. There was statistical difference in the prevalence of TMD (with OS group, 54.66%; without OS group, 40.81%) and the mean value ( ± standard deviations) of the scores of OHIP-TMD (with OS group, 9.64 ± 12.36; without OS group, 6.64 ± 10.79) (p < 0.05). After adjusting confounding factors, participants with OS have worse temporomandibular-related quality of life and a higher risk of having TMD than the participants without OS.

CONCLUSIONS

Orthodontic history was related with the higher prevalence of TMD and worse temporomandibular-related quality of life, but not related with psychological distress, and the cause-and-effect relationship needs further exploration.

Inequalities in utilization and provision of dental services: a scoping review

BACKGROUND

There are many determinants that can affect inequality in oral and dental health. This study is aimed to explore the main determinants of inequality in both utilization and provision of dental services in Organization for Economic Co-operation and Development (OECD) countries.

METHODS

Four databases including PubMed, ISI WOS, Scopus, and ProQuest were searched up to 8 Aug 2020, applying the relevant keywords. Thematic analysis was used for synthesizing and extracting data. Trend analysis was applied to determine the trends of the inequality determinants.

RESULTS

Thematic analysis led to 6 main themes, 13 sub-themes, and 53 sub-sub-themes. The main themes represent the main inequality determinants for both utilization and provision of dental services. The streamgraph illustrated that fewer studies have been conducted on social and cultural determinants, and for almost all determinants the trend of published articles has been increasing since 2007, with the exception of health policies.

CONCLUSIONS

Inequality in the utilization and provision of dental services is addressed by various factors including individual, social, cultural and economic determinants, health policies, and availability of services. The first four determinants are related to utilization and the last two are related to the provision of services. All these aspects must be considered to reduce inequality in dental services.