School Achievement and Oral Health Behaviour Among Adolescents in Finland: A National Survey.

Purpose We examined oral health behaviour and its association with school achievement among Finnish adolescents. Materials and methods This study is part of the Finnish national School Health Promotion study (SHP). The study population comprised a representative sample of Finnish 15-year-olds (N = 45,877). A questionnaire inquired about the respondents' school achievements and health habits (toothbrushing, smoking), background factors (age, gender, school type, family structure), and their parents' background factors (education, smoking). Chi-square tests and logistic regression models were used in the statistical analyses. Results Better school achievements were associated with better oral health behaviour: 73.1% of students with the highest mean grades (9-10) brushed their teeth twice daily, compared to 33.8% of those with the lowest mean grade (6.9 or less). The lowest mean grade was associated with brushing less than twice daily, especially among boys (odds ratios (OR) = 4.1; 95% CI 3.6-4.7) when compared to those with the highest mean grade, but also among girls (OR = 2.3; 95% CI 2.1-2.7). Smoking among boys was associated with poor oral hygiene (OR = 1.3; 95% CI 1.2-1.4). Conclusion School success is strongly associated with oral health behaviour among adolescents. Preventive treatment should be targeted especially at boys with poor school achievement and smoking behaviour.