Association of a visual oral health literacy instrument with perceived and clinical oral health status in Japanese adolescents

A visual oral health literacy instrument is a newly developed tool to assess health literacy level in dentistry. To use the visual oral health literacy instrument effectively, it is essential to understand how the instrument is associated with the subjects perceived and clinical oral health status. The purpose of this study was to examine which factor of subjects perceived and clinical oral health status affected the visual oral health literacy instrument. A self-administered questionnaire inquiring about concern about teeth and gums, self-rated oral health and oral observation, as well as a mouth drawing as a visual oral health literacy instrument were evaluated in 162 Grade 1 Japanese senior high school students. Students were instructed to freely draw a picture of their anterior teeth and gingiva while observing their mouth with a hand mirror. Mouth drawings were performed before (first) and after (second) an oral health education session. Drawing scores were calculated for both tooth and gingival aspects. In female subjects, those who observed their mouth every day had a significantly higher first tooth-recognition score than those who did not (p < 0.05). First and second gingival-recognition scores were significantly related with clinical gingival condition (p < 0.05). Subjects who observed their mouth daily and those who had occlusal or gingival problems significantly improved their second drawing scores (p < 0.05). The changes of oral health literacy had an association with their oral observation habit and actual oral health status. Therefore, it is necessary to provide self-related oral health education in order for students to correctly understand their own oral health status.