Our results suggested that MS might be associated with periodontitis and the association was confounded by age, gender, and smoking. MS with high glucose and hypertension showed the higher impact on this link.

A comparison of national surveys on oral health suggested that the population of South Korea has a better periodontal health status than that of Japan, despite their similar inherent backgrounds. Here, we investigated differences in oral bacterial assemblages between individuals from those two countries. To exclude potential effects of oral health condition on the microbiota, we selected 52 Korean and 88 Japanese orally healthy adults (aged 40–79 years) from the participants of two cohort studies, the Yangpyeong study in South Korea and the Hisayama study in Japan, and compared the salivary microbiomes. The microbiota of the Japanese individuals comprised a more diverse community, with greater proportions of 17 bacterial genera, including Veillonella, Prevotella, and Fusobacterium, compared to the microbiota of the Korean individuals. Conversely, Neisseria and Haemophilus species were present in much lower proportions in the microbiota of the Japanese individuals than the Korean individuals. Because higher proportions of Prevotella and Veillonella and lower proportions of Neisseria and Haemophilus in the salivary microbiome were implicated in periodontitis, the results of this study suggest that the greater proportion of dysbiotic oral microbiota in the Japanese individuals is associated with their higher susceptibility to periodontitis compared to the Korean individuals.

Periodontitis was independently associated with cognitive impairment after controlling for various confounders. Further longitudinal research is needed to determine whether periodontitis plays a role in cognitive decline in older adults.

The aims of this study were to investigate the prevalence of orofacial pain symptoms in the Korean elderly population, and to evaluate factors associated with orofacial pain and graded chronic pain. Of 4,342 Korean elders from the cohort of Korean National Interview Survey of Oral Health Status in 2000, telephone interviews were conducted on a stratified random sample of 1,032 people aged 55 years or older. Prevalence of five orofacial pain symptoms (jaw joint pain, face pain, toothache, oral sores, and burning mouth) in the past 6 months along with questions from the graded chronic pain scale were assessed by telephone using a structured questionnaire. The results suggested that the 6-month prevalence of joint pain (15.5%), face pain (9.3%), toothache (26.8%), oral sores (26.2%), and burning mouth (14.2%) in Korean elders were higher than in studies on Caucasian populations. Painful oral sores and burning mouth had higher prevalence for females than for males. Subjects with joint pain, burning mouth or toothache pain were more likely to report high levels of a pain-related disability compared with subjects not reporting those symptoms. There were no age group differences in pain intensity, but the older age group reported a higher number of disability days because of their pain. Chronic orofacial pain is a substantial health problem in the elderly population.