The prevalence and severity of periodontal disease in Mainland China: Data from the Fourth National Oral Health Survey (2015–2016)

To evaluate periodontal conditions in adults in mainland China based on data from the 4th National Oral Health Survey.Data of adult subjects (35- to 44-year-old group [N = 4409], 55- to 64-year-old group [N = 4622], and 65- to 74-year-old group [N = 4428]) were analysed. Demographic, socio-economic, personal habit, dental history, and health attitude data were obtained using a questionnaire. Periodontal condition was assessed using the standardized case definitions of the 2018 classification scheme. A multivariate analysis was performed to investigate the relationship between periodontitis severity and age, smoking status, gender, and region using generalized additive models after adjusting for confounders.The frequency of subjects with periodontitis was 52.8%, 69.3%, and 64.6% in the three age groups, respectively. The frequency of subjects with severe periodontitis (stage III or IV) was 10.6%, 37.3%, and 43.5% in the three age groups, respectively. The severity of periodontal disease was positively associated with age. Current and former smokers exhibited significantly greater disease severity than non-smokers after adjustment for confounders. No significant difference of severity was found between males and females.Within the limitations of the study, the prevalence of periodontitis is very high among adults in mainland China. Periodontal status is associated with age and smoking status.