Trend Analysis of Average Frequency Using Toothbrushing per Day in South Korea: An Observational Study of the 2010 to 2018 KNHANES Data

The aim of this study was to examine the trend of average frequency of toothbrushing per day according to the sociodemographic characteristics using the 5th, 6th, and 7th Korean National Health and Nutrition Examination Survey (KNHANES) data for 9 years; from 2010 to 2018. It intends to understand the state of toothbrushing practices in South Korea, and to provide basic data for promoting toothbrushing practices. Data from the 5th, 6th, and 7th KNHANESs conducted by the Korean Disease Control and Prevention Agency each year was analyzed using IBM SPSS version 26.0 (IBM Co., Armonk, NY, USA). Tableau version 2020.1 was used for the graphs and geographic information system (GIS). The significance level of α was set at 0.05 for testing. In all analyses, the complex sampling analysis method with stratification variables, cluster variables, and weights was applied, and the complex sample linear regression analysis. The average frequency of toothbrushing per day was higher in women for all the years; these women belonged to the age group under 65 and the employed group. The average frequency of toothbrushing per day was lower in the married, elementary school graduate, part-time job, and low-income groups for all years. The demographic and social factors affecting the number of toothbrushing practices per day were gender, education level, income level, and work type. After analyzing the average frequency of toothbrushing per day in each of the cities and provinces, Gangwon-do and Jeonbuk showed the highest increase in the frequency of toothbrushing in 2018 compared to 2010, whereas Incheon showed the lowest increase. From the above results, the average frequency of toothbrushing per day was lower in males, those with a low education level, the unemployed, and those in the rural area for a period of 9 years. Therefore, in-depth oral health promotion projects and national benefit policies should be considered for effective toothbrushing education by identifying individuals who do not brush their teeth.