Method: A stratified two-stage cluster sample of 902 students (461 boys and 441 girls) was randomly selected from adolescents attending 1st and 2ndyears of both public and private secondary schools in Riyadh using a self-weighting design for both sexes and school types. Only participants who consented, as did their parents/guardians, were recruited. Data were collected through a clinical examination and a questionnaire. Clinical examinations were conducted by 2 qualified and calibrated dentists. TDIs were diagnosed using a modified version of the WHO classification for epidemiological studies. In addition, clinical covariates such as overjet and lip coverage were measured. The questionnaire was based on the WHO Health Behaviour in School-Aged Children questionnaire and the CDC Youth Risk Behaviour Surveillance System, and was used to assess exposures (risk-taking behaviours and peer influence) and covariates (demographics, socio-economic status and physical activity).
Result: Overall, 42.6% of adolescents had TDIs to their anterior teeth (Boys: 59.4%; Girls: 24.9%). After adjusting for age, sex, father’s education, nationality, physical activity and overjet >3mm, there was a significantly higher risk of TDIs in girls who smoked (RR 2.38; 95% CI 1.35-4.20), boys who were involved in a fight (RR 1.26; 95% CI 1.08-1.49), boys whose peers carried weapons (RR 1.25; 95% CI 1.06-1.47), boys who spent time with their friends after school on more than three days a week (RR 1.24; 95% CI 1.06-1.45), and both boys and girls who carried weapons (RR 1.20; 95% CI 1.02-1.42) and who had multiple risk-taking behaviours (RR1.44; 95% CI 1.20,1.73).
Conclusion: TDIs were highly prevalent among adolescents in Saudi Arabia. Risk-taking behaviours and negative peer influences were associated with increased risk of TDIs.