Several studies have reported the harmful effects of lead poisoning. However, the relationship between lead exposure and oral health of children has not been well defined. The aim of this study was to investigate the relationship between blood lead level (BLL) and oral health status of children. A total of 351 children (aged 7–15 years) were recruited from the pilot data of the Korean Environmental Health Survey in Children and Adolescents, which was designed to examine environmental exposure and children’s health status in South Korea. Blood samples were taken to determine BLLs and oral examinations were performed to assess oral health parameters, including community periodontal index (CPI), gingival index (GI), and plaque index (PI). Information regarding socioeconomic status, oral hygiene behavior, and dietary habits was collected from parents and guardians. The participants were divided equally into four quartiles, with quartile I comprised of children with the lowest BLLs. There were significant differences for PI (p < 0.05) among the quartile groups. Using logistic regression models, we found a significant relationship between BLL and oral health parameters. The crude odds ratios for CPI, GI, and PI in the third quartile were 5.24 (95% CI: 1.48-18.56), 4.35 (95% CI: 1.36-13.9), and 4.17 (95% CI: 1.50-11.54), respectively, while the age and gender-adjusted odds ratios were 7.66 (95% CI: 1.84-31.91), 6.80 (95% CI: 1.80-25.68), and 3.41 (95% CI: 1.12-10.40), respectively. After adjustments for age, gender, parent education level, and frequency of tooth brushing, the adjusted odds ratios were 7.21 (95% CI: 1.72-30.19), 6.13 (95% CI: 1.62-23.19), and 3.37 (95% CI: 1.10-10.34), respectively. A high BLL might be associated with oral health problems in children, including plaque deposition and gingival diseases.

Chewing ability is also related to activities of daily living (ADLs) and nutritional status; however, these associations have not been firmly established. We examined chewing ability as a predictor variable and explored its relationship with cognitive functioning as mediated by ADLs and nutritional status data were collected by face-to-face interviews. Patients were receiving home healthcare service in Mun-gyeong city, Gyung-buk, Korea. Participants comprised 295 patients aged 81.35 ± 6.70 years. Structural equation modeling (SEM) was performed using AMOS 18.0 (SPSS Inc., Chicago, IL, USA). The model fit was based on absolute fit index and incremental fit index. Data were collected to assess cognitive functioning (using the Korean version of the Mini-Mental Status Examination for dementia screening (MMSE-DS)), ADL, a mini-nutritional assessment (MNA) questionnaire, and a chewing ability test. Participants with better chewing ability had significantly better cognitive functioning, ADLs, and nutritional status (p < 0.001). Chewing ability directly affected cognitive functioning and indirectly affected how ADLs and MNA affected MMSE-DS. Chewing ability is an important factor influencing the cognitive functioning of elderly adults in Korea, both directly and indirectly through mediating variables such as nutritional status and ADLs. Efforts to help older adults maintain their chewing ability are necessary for preventing cognitive impairment.