Association of periodontal disease treatment with mortality in patients with dementia: a population-based retrospective cohort study (2002-2018).

Dementia is one of the leading causes of death worldwide. In this study, we analyzed the association of periodontal treatment with the risk of death in patients with dementia. The analyzed data were obtained by linking the National Health Insurance Corporation claims data between 2002 and 2018 to the Statistics Korea death registry. In total, 1,131,406 patients with dementia aged ≥ 65 years had undergone dental treatment during the study period. Time-dependent Cox proportional hazards model was performed. The mortality rate was approximately 10% among the patients with dementia. The 17-years cumulative survival rates for patients who received periodontal treatment and their untreated counterparts were 83.5% and 71.5%, respectively. The crude hazard ratio of the periodontal group was approximately twice as high as that of the non-periodontal group (1.99; P < 0.001). Furthermore, in the regression model that was adjusted for socio-demographic variables and systematic chronic diseases, the risk of death in the non-periodontal group was approximately 1.83 times higher than that of the periodontal group (P < 0.00). These findings suggest that preventive periodontal treatment may decrease mortality risk in older people with dementia.

Disparity in access for people with disabilities to outpatient dental care services: a retrospective cohort study.

BACKGROUND: People with disabilities face difficulties in oral health management and gaining access to dental care. The availability of a regular source of dental care (RSDC) is an important factor that influences the access to health services and care management. The purpose of this study was to determine the effect of the availability of RSDC on the number of annual dental visits and dental expenses per visit among people with disabilities. METHODS: Data of 7,896,251 patients with dental problems in South Korea were analyzed using the 2002-2018 National Health Insurance claims data. A generalized estimating equation was applied to analyze the repeated-measurement data, and the interaction effect between RSDC and the disability severity was evaluated. RESULTS: The number of annual dental visits was higher among people with (2.62) than among those without (2.23) disabilities. Despite their increased dental needs, both annual dental visits and dental expenses per visit were low among older individuals (p < 0.001). The proportion and frequency of annual dental visits was lower among women than among men with disabilities. RSDC had differential effects on the severity of disability. Compared to people without disabilities, RSDC increased the number of annual dental visits (p = 0.067) and the dental expenses per visit (p < 0.05) among those with severe disabilities, but the effect on the number of annual dental visits was not significant among those with mild disabilities (p = 0.698). CONCLUSIONS: Our results suggest a need for a special dental care system for people with disabilities, to ensure an RSDC, particularly for women and for older people with disabilities.

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.

Travel Time for Dental Care Services Based on Patient Preference in South Korea.

This study analyzed patient preferences using travel time from residence to dental institution when selecting dental care services. We used data from the Korean Health Panel from 2008 to 2017 and analyzed each dental service episode. Since the distribution of travel time was skewed to the left, median travel time was analyzed. The association of travel time with services was analyzed via the population-averaged generalized estimating equation (GEE) with the Poisson family. The median of the average travel time per episode was longer for non-National Health Insurance (NHI)-covered services and shorter for NHI-covered services. The first quintile of low-income subjects traveled the longest for all services and utilized dental care the most. In the GEE analysis, travel time was approximately three times longer for implant treatment and gold inlay/resin fillings and >2 times longer for orthodontic care than for NHI-covered services. Patients residing in rural counties traveled for longer than residents of large cities. Income was statistically significant; however, the coefficient was close to zero. Travel time was related to the type of service and reflected patient preference. This was more prominent for expensive non-NHI-covered services than for NHI-covered services. The findings suggest patients' subjective preferences for dental clinic selection are expressed as rational deliberation considering each individual's situation.

Effects of tooth loss on functional impairment in elderly: A secondary data analysis of elderly cohort in the South Korea.

INTRODUCTION: This study aimed to assess the association of tooth loss with physical and cognitive impairments in the elderly aged over 65 years. METHODS: The Elderly Cohort database (2008-2013) of National Health Insurance Services in South Korea was used; 1485 individuals who underwent physical impairment evaluation and 1410 individuals who underwent cognitive impairment evaluation were analysed. The dependent variables were the standardized physical and cognitive function score. The generalized estimating equation method was used for repeated measures. The total number of teeth lost during the study period, sex, age, Charlson comorbidity index, income, medical aid, long-term care facility residence, living alone, and long-term care beneficiary was used as covariates. RESULTS: Differences between the baseline and endpoint standardized function scores of the participants with impaired physical function and impaired cognitive function were 13.6 and 20.1, respectively. The magnitude of functional impairment due to tooth loss was greater for cognitive function than for physical function. The number of teeth lost was associated with approximately 1.4- and 1.7-point decrease in physical and cognitive functions, respectively (both p < 0.001). CONCLUSIONS: These findings suggest that the oral health status is essential for maintaining physical and cognitive functions and that oral health services can be effective in delaying functional impairment among the elderly residing in coordinated long-term care facilities.

Dental Expenditure by Household Income in Korea over the Period 2008-2017: A Review of the National Dental Insurance Reform.

Since 2009, the National Health Insurance in Korea (NHI) has been implementing a series of policies to expand the scope of dental benefits. This study reviewed the changes in co-payments and dental use patterns before (2008 to 2012) and after (2013 to 2017) the NHI's dental health insurance reform. The study used Korea Health Panel data of 7681 households (16,493 household members) from a 10-year period (2008-2017). Dental expenditures and equivalent income using square root of household size were analyzed. Dental services were categorized into 13 types and a concentration index and 95% confidence interval using the delta method was calculated to identify income-related inequalities by a dental service. Dental expenditures and the number of dental services used increased significantly, while the proportion of out-of-pocket spending by the elderly decreased. The expenditure ratio for implant services to total dental expenditures increased substantially in all age groups, but the ratio of expenditures for dentures and fixed bridges decreased relatively. The concentration index of implant services was basically in favor of the rich, but there was no longer a significant bias favoring the better-off after the reforms. The dental health insurance reform in Korea appears to contribute not only to lowering the ratio of out-of-pocket to total dental expenses per episode in the elderly but also to improving the inequality of dental expenses.

The association between oral health literacy and oral health behaviors in North Korean defectors: a cross-sectional study.

BACKGROUND: The present study aimed to investigate the association between oral health literacy and oral health behaviors among North Korean defectors. METHODS: This study involved the collection of self-reported questionnaires from 123 North Korean defectors visited a dental clinic that offered complimentary services, to receive dental treatment in a metropolitan area of South Korea from December 2017 to April 2018. Oral health literacy was measured with the Test of Korean Functional Health Literacy in Dentistry (TOKFHLiD), which consists of 30 items concerning verbal oral health literacy and 42 items concerning functional oral health literacy (28 items for reading comprehension and 14 items for numeracy). In addition, the questionnaire contains 15 and 14 items related to demographic characteristics and oral health behaviors (interest, lifestyle, diet, prevention), respectively, for a total of 101 items. RESULTS: The mean oral health literacy score was 44 (out of a maximum possible score of 72). Oral health literacy and oral health behaviors were positively correlated (r = 0.526, P < 0.001), and oral health literacy also had a significant effect on oral health behaviors (Beta = 0.26, 95% CI: 0.04-0.33). However, although functional oral health literacy had a significant effect on oral health behaviors (Beta = 0.20, 95% CI: 0.01-0.43), verbal oral health literacy did not (Beta = 0.13, 95% CI: - 0.06-037). CONCLUSIONS: Educational interventions are needed to improve oral health literacy, and thus oral health behaviors, as a part of the health promotion measures undertaken to facilitate the stable adjustment of North Korean defectors in South Korean society.

The association between Antonovsky's sense of coherence and job stress among dental hygienists in Korea.

OBJECTIVE: High stress levels experienced by medical professionals are a well-established phenomenon in current literature. However, there are few studies focusing on stress experienced in the field of oral health or on the sense of coherence (SOC) that helps to actively respond to job stress. The purpose of this study was to analyse if there is an association between SOC and job stress among dental hygienists in Korea. METHODS: A cross-sectional study was conducted on a convenience sample of 441 dental hygienists in the Seoul Gyeonggi province, Korea. The independent variable was SOC which had three dimensions: comprehensibility, manageability and meaningfulness. The dependent variable was job stress, which was evaluated using the Korean Occupational Stress Scale Short Form. Confounding factors were age, marital status, educational background, type of hospital, and work experience. The chi-square test and t test measures were used for bivariate analysis. Multiple logistic regression analysis was performed to confirm the association between SOC and job stress. The collected data were statistically analysed using SPSS version 22.0. RESULTS: The SOC score showed a significant difference in relation to the job stress score. The SOC score was high when the job stress was low (P < .001). Overall SOC scores showed an inverse correlation with job stress. CONCLUSION: This study reports that a higher SOC is associated with lower job stress in Korean dental hygienists. Since a higher SOC in dental hygienists indicated that they could cope with job stress more positively, it is important to increase their SOC.

Spatial barriers and the bypassing of nearby dental clinics for dental services: a secondary data analysis in Korea.

OBJECTIVE: This study aimed to calculate the distance patients travel to dental clinics, the rate of bypassing nearby dental clinics and the distance covered when bypassing nearby dental clinics, and explored factors associated with patients' spatial access to dental clinics. DESIGN: A secondary data analysis. SETTING: Korea Health Panel. PARTICIPANTS: We included users of dental care services from 2008 to 2011. A total of 2375 patients and 15 978 dental visits were analysed. PRIMARY OUTCOME MEASURES: Korea Health Panel data (2008-2011) were used to geocode patients' and healthcare facilities' addresses. The distance travelled was calculated using road network information. To analyse the panel data, we adopted a generalised estimating equation: geographical measures on the choice of dental care facility were examined based on sex, age, educational level, equivalent income, treatment details and regional classification. RESULTS: The median distance travelled to a dental clinic was 1.8 km, which is farther for rural (8.4 km) than for urban (1.5 km) patients. The bypass rate was 58.9%. Patients bypassing nearby dental clinics travelled 9.6 times farther for dental care (p<0.001). Unlike bypass distance, travel distance was not associated with equivalent income. People with higher education and those with implants/orthodontic treatment were more likely to bypass nearby dental clinics and travelled 1.27 times and 1.17 times farther (p<0.01), respectively. CONCLUSIONS: Given the spatial barrier to available dental resources, factors associated with spatial access were mostly the same between travel and bypass distance except for equivalent income. The findings of this study suggest that spatial distance acts as a utilisation barrier and demands additional opportunity cost. At the same time, patients' preferences for services also increase their willingness to bypass nearby dental clinics and travel greater distances.

The association between visual impairment and dental care utilization in the Korean elderly.

INTRODUCTION: Individuals with visual impairment cannot recognize early-stage oral diseases, thus fail to receive prompt treatment. AIMS: To evaluate the association between visual impairment and dental care utilization in patients aged ≥65 years. DESIGN: Retrospective analysis. MATERIALS AND METHODS: We analyzed annual pooled data collected by the Korean Health Panel between 2011 and 2014; a total of 1472 patients and 13,285 dental visits were analyzed. Visual impairment was categorized as follows: normal vision, moderate vision impairment, and severe vision impairment. Dental treatments were categorized as conservative, prosthodontic, implant, periodontal, surgical, preventive, or others. All data were statistically analyzed using a negative binomial regression. MAIN OUTCOME MEASURE: Frequency of dental care utilization. RESULTS: Approximately 50% of the subjects had visual impairment. The frequency of dental care utilization for patients with severe vision impairment was 41% less than patients with normal vision. The dental care utilization for implant treatment was two times higher and periodontal treatment was 1.7 times lower than the conservative treatments among patients who reported moderate and severe vision impairment, respectively. CONCLUSIONS: Visual impairment has a negative association with dental care utilization among older adults. It is imperative to implement systematic interventions to prevent visual impairment from becoming a barrier to dental care in this population.

Implant survival and patient satisfaction in completely edentulous patients with immediate placement of implants: a retrospective study.

BACKGROUND: This study evaluated full-arch rehabilitation of patients with immediately placed implants in terms of the cumulative implant survival rate, risk factors for implant failure, and patient satisfaction. METHODS: Time-to-event data of 52 completely edentulous jaws (370 implants) were collected using retrospective clinical chart review for the time period from 2008 to 2014. A conventional two stage approach for surgery was adopted to immediately placed implants in the maxilla, and immediate placement and immediate loading protocols for the mandible were followed. The study calculated the 7-year cumulative survival rates (CSR), and a Bayesian hierarchical Cox proportional hazard model was used to measure the effect of covariates. Patient satisfaction on chewing ability, esthetic appearance, and overall satisfaction was also measured with a face-to-face interview survey. RESULTS: Of the total 370 implants, 194 were immediate placement. Two delayed loading maxillary implants failed within the first year, and another one failed in the second year of loading. Two failures were recorded in the first year and one in seven years for the immediate loading mandibular implants. The 1-, 5-, and 7-year CSR of the 370 implants were 0.989 (0.979, 1.000), 0.986 (0.975, 0.998), and 0.978 (0.957, 0.999), respectively. Only the length of the implant affected implant failure (p < 0.05); other patient characteristics, systemic diseases, implant diameter, immediate loading, and immediate placement, did not have an effect on implant failure rates. Patients reported a high degree of satisfaction regardless of their age group or length of the observation period. CONCLUSIONS: Immediately placed implant had CSR as high as delayed placed implants, and 7-year CSRs of immediate loading were not significantly different from delayed loading. The procedure also had a high degree of chewing ability, esthetic appearance, and overall satisfaction. The study results suggested that the clinical procedures applied in this study to completely edentulous patients were acceptable rehabilitation procedures.