Oral health greatly affects well-being throughout the different stages of life from childhood to late adulthood. Loss of teeth due to poor oral health hinders mastication, leading to poor nutrition absorption, and affects pronunciation and aesthetics, leading to interpersonal difficulties. As social activities become limited, a sense of isolation and loneliness, stress, and depression grows while happiness decreases. This study aimed to examine the association of stress, depression, and suicidal ideation with oral health status and oral functions in a large nationwide sample of Korean adults aged 35 years or more. The sample comprised 15,716 adults, selected using a rolling survey sampling method and data were extracted from the Fifth Korea National Health and Nutrition Examination Survey (KNHANES) (2010–2012). Participants were interviewed about their self-evaluation of health including oral health status and mental health, such as stress, depression, and suicidal ideation. Data from 11,347 adults were finally selected after excluding participants with missing answers. The dependent variables were stress, depression, and suicidal ideation. The independent variables were gender, age, household income, education, smoking, drinking, oral health perception, chewing, and speaking. Complex samples logistic regression analyses were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). Participants met the criteria for stress (25.4%), depression (13.0%), and suicidal ideation (13.9%). Subjective oral health status was not significantly associated with stress, depression, and suicidal ideation. However, the presence of very uncomfortable chewing problems was significantly associated with stress (OR = 2.294, 95% CI = 1.41, 3.72), depression (OR = 3.232, 95% CI = 1.97, 5.31), and suicidal ideation (OR = 2.727, 95% CI = 1.58, 4.72). The presence of very uncomfortable speaking problems was significantly associated with stress (OR = 1.592, 95% CI = 1.13, 2.24) but not significantly associated with depression and suicidal ideation. Oral functional problems including chewing and speaking difficulties can be associated with mental health. It is necessary to develop oral health promotion programs for adults and help them maintain a good quality of life and mental health.

This study aimed to determine the association between the number of existing teeth (NET) and socioeconomic status (SES), oral health-related behaviours, and metabolic syndrome in Korean adults aged 55–79 years. The study included 3255 adults who underwent oral health examinations and answered questionnaires regarding SES, oral health-related behaviours, and metabolic diseases in the Sixth Korea National Health and Nutrition Examination Survey (2013–2015). The dependent variable was the binary status based on the median NET in each age group. The independent variables were based on SES, oral health-related behaviours, and the presence of metabolic syndrome. The study findings showed that the factors associated with the NET were sex, household income, education level, region of residence, daily toothbrushing frequency, dental visit within 1 year, smoking, and metabolic syndrome. NET was lower in males (adjusted OR: 0.74), in low household income group (adjusted OR: 0.77), in primary school graduates (adjusted OR: 0.53) and in rural residents (adjusted OR: 0.78). The interventions aimed at preserving existing teeth in elderly population should consider their SES, oral health-related behaviours, and metabolic syndrome and overhauling current oral healthcare system and redefining the roles of oral health professionals.

Several studies have demonstrated that nuclear magnetic resonance (NMR) metabolic profiles can differentiate patients with caries from healthy individuals; however, these studies only identified individual metabolites. The present study aimed to identify a salivary metabolite biomarker panel for the diagnosis of early childhood caries (ECC). Saliva samples from children with and without caries were analyzed using NMR spectroscopy. Multivariate and univariate analyses were performed to identify the discriminating metabolites. Selected metabolites were further evaluated and used to detect ECC. The saliva samples of children with ECC were characterized based on the increased levels of formate, glycerophosphocholine, and lactate and reduced levels of alanine, glycine, isoleucine, lysine, proline, and tyrosine. The levels of these metabolites were significantly different from those in the control in the ECC subgroup according to caries severity and correlated with the number of decayed and filled teeth or surfaces. Subsequently, an optimal salivary metabolite biomarker panel comprising formate, lactate, proline, and glycine was developed. This panel exhibited a better diagnostic performance for ECC than a single metabolite. These results demonstrate that salivary metabolic signatures can reflect oral conditions associated with dental caries, thereby emphasizing the importance of distinct salivary metabolic profiles as potential biomarkers of ECC.

The aim of this study was to analyse the prevalence and severity of dental caries among Korean children aged 8 and 12 years over a period of 12 years by determining the number of decayed, missing, and filled teeth (DMFT) and the Significant Caries index (SiC index). Stratified cluster-sampled data from the National Oral Health Survey conducted from 2000 to 2012 were analysed. In 2000, 2006, and 2012, a total of 2397, 2650, and 9601 children aged 8 and 12 years were examined, respectively. The children’s oral health status, including the number of DMFT and fissures sealed teeth, was examined and recorded. The SiC index was calculated according to the child’s residential district. Over the 12-year period, the percentages of caries-free children aged 8 and 12 years increased from 26.0 to 42.7 % and from 53.4 to 69.6 %, respectively. The percentages of children aged 8 and 12 years with sealed teeth in 2012 were 62.1 and 62.5 %, respectively, more than triple the rates in 2000. The mean DMFT values of children aged 8 and 12 years decreased from1.04 to 0.67 and from 2.86 to 1.84, respectively. The SiC index of children aged 8 and 12 years also decreased from 2.73 to 1.97 and from 6.13 to 4.51, respectively. The rate of reduction in DMFT among 8- and 12-year-old children in the second 6 years of the observation period was lower than that in the first 6 years. A remarkable decline in dental caries of 8- and 12-year-old Korean children was observed over the 12-year study period. The mean DMFT values and SiC index of children aged 8 and 12 years decreased. The reduction rate between 2000 and 2006 was higher than that between 2006 and 2012.

This study aimed to confirm the association between the community water fluoridation (CWF) programme and dental caries prevention on permanent teeth, comparing to a control area, neighbouring population without the programme, and verifying whether the programme can reduce the socio-economic inequality related to the oral health of children in Korea. Evaluation surveys were conducted among 6-, 8-, and 11-year-old children living in Okcheon (CWF) and neighbouring Yeongdong (non-CWF, control area) towns in South Korea. Data on monthly family income, caregiver educational level, and Family Affluence Scale scores were evaluated using questionnaires that were distributed to the parents. The effectiveness of CWF in caries reduction was calculated based on the differences in decayed, missing, and filled teeth and decayed, missing, and filled tooth surfaces indices between the two towns. The data were analysed using logistic regression and univariate analysis of variance. Both 8- and 11-year-old children living in the CWF area had lower dental caries prevalence than those living in the non-CWF community. Differences in dental caries prevalence based on educational level were found in the control area but not in the CWF area. Socio-economic factor-related inequality in oral health were observed in the non-CWF community. Additionally, 8- and 11-year-old children living in the CWF area displayed lower dental caries prevalence in the pit-and-fissure and smooth surfaces than those living in the non-CWF community. These results suggest that CWF programmes are effective in the prevention of caries on permanent teeth and can reduce oral health inequalities among children. The implementation of CWF programmes should be sustained to overcome oral health inequalities due to socio-economic factors and improve children’s overall oral health.