Socioeconomic status and remaining teeth in Japan: results from the Toyama dementia survey

Abstract

Background The prevalence of periodontal disease is increasing among elderly individuals in Japan. Reports on the risk factors for tooth loss have included socioeconomic status (SES); however, few studies have addressed the association between remaining teeth and SES by examining whether education and occupation have a synergistic effect on tooth loss. Accordingly, the present study evaluated the association of remaining teeth with the socioeconomic factors of educational and occupational histories in Japanese elderly individuals. Methods This retrospective case-control study used data from the Toyama Dementia Survey, Japan. Toyama Prefecture residents aged ≥65 years were randomly selected for the study (sampling rate, 0.5%), and 1303 residents agreed to participate (response rate, 84.8%). Structured interviews with participants and family members (or proxies, if necessary) were conducted. Participants’ lifestyle factors (e.g., smoking and alcohol consumption), medical history, and SES (educational and occupational history) as well as the presence or absence of remaining teeth were assessed. The association between SES and remaining teeth was examined using a logistic regression analysis. Results Overall, 275 cases with no remaining teeth and 898 controls with remaining teeth were identified. The odds ratio (OR) for complete tooth loss was higher among less educated participants (≤6 years) than among highly educated participants [age- and sex-adjusted OR, 3.29; 95% confidence interval (CI), 1.90–5.71]; furthermore, it was higher among participants with a blue-collar occupational history than among those with a white-collar occupational history (age- and sex-adjusted OR, 2.16; 95% CI, 1.52–3.06). After adjusting for employment history or educational attainment, the ORs for tooth loss were 2.79–3.07 among less educated participants and 1.89–1.93 among participants with a blue-collar occupational history. A current or former smoking habit and medical history of diabetes and osteoporosis increased the risk of tooth loss. The interaction term of a low level of education and a history of blue-collar occupation with tooth loss was not significant. Conclusions In Japan, a low SES is a risk factor for tooth loss. A low level of education is a more important predictor of tooth loss than a blue-collar occupation.

Individual- and City-Level Socioeconomic Factors and Tooth Loss among Elderly People: A Cross-Level Multilevel Analysis

“…Our findings on the link between social inequalities and tooth loss are consistent with previous population-based single-level studies conducted in the Uruguay, Korea and Japan despite the methodological differences in the sample size, sample age group, sampling procedures, definition of outcome (e.g., severe tooth loss, number of remaining teeth) and measures of socioeconomic status (e.g., occupational history, income) [6][7][8]. Overall, these studies showed a high prevalence of tooth loss in the studied samples.…”

“…Secondary analysis of nationwide oral health surveys in different countries reported the influence of poor individual socioeconomic characteristics, such as family income, occupational history and educational level, on tooth loss among elders and adults [5][6][7][8]. These findings are in accordance with a recent systematic that concluded that lower levels of education and poor income were meaningful factors associated with edentulism among elderly people [9].…”

“…Overall, these studies showed a high prevalence of tooth loss in the studied samples. Furthermore, lower individual socioeconomic status was a meaningful factor of tooth loss among older adults and elderly people after adjusting for possible confounders [6][7][8]. Only one multilevel study reported significant associations of contextual social disadvantage and individual socioeconomic position with complete denture need [15].…”

Bidirectional Association between Tooth Loss and Hypertension: A Systematic Review and Meta-analysis

“…In our study, a total of 294 studies were considered for further review, including the results of key words search (n=290) and additional records identi ed from relevant reviews and reference lists of other studies (n=4). Through the careful reading of full texts, seven cohort studies [12][13][14][15][16][17][18] and nine cross-sectional studies [19][20][21][22][23][24][25][26][27] were thought eligible for meta-analysis ( Figure 1).…”

“…Six included studies [12][13][14][15][16]19] reported the association between tooth loss and incident hypertension, among which one study [15] reported incidence of diabetes among participants with edentulism. The other nine studies reported the association between hypertension and incidence of tooth loss, among which four studies [24][25][26][27] were concerned on the incidence of edentulism. The main information of eligible studies was given in Table 1.…”