The associations between risk-taking behaviours, peer influence and traumatic dental injuries among Saudi adolescents

Background: Traumatic dental injuries (TDIs) are one of the most common body injuries and constitute an important public health problem. These injuries are considerably more common among adolescents, and can lead to pain, physical impairment, emotional distress and negative impact on the quality of life. Theories link most types of injuries to individual behaviours within a complex matrix involving both the physical and social environments. However, most of the aetiological studies on TDIs focus on proximal risk factors and overlook the underlying more distal determinants. This PhD thesis aimed to assess whether certain behavioural and psychosocial determinants were associated with the prevalence of TDIs among adolescents in Riyadh, Saudi Arabia, with a particular focus on the role of their risk-taking behaviours and peer influence. Methods: A stratified two-stage cluster sample of 902 students (461 boys and 441 girls) was randomly selected from adolescents attending 1st and 2nd years of public and private secondary schools in Riyadh, using a self-weighting design for both sexes and school types. Data were collected through clinical examination and questionnaire. TDIs were clinically diagnosed using a modified version of the WHO classification for epidemiological studies. The clinical examination also included assessment of overjet and lip coverage. The questionnaire was based on the WHO Health Behaviour in School-Aged Children questionnaire and the CDC Youth Risk Behaviour Surveillance System, assessing exposures risk-taking behaviours and peer influence, as well as demographics, socio-economic status and physical activity. The differences in prevalence of TDIs between the different groups of the covariates and exposures were calculated. Then, Poisson regressions with a robust error variance were used to estimate adjusted prevalence ratios (relative risks) of TDIs between the different exposures to provide sequential adjustment for confounding factors. The models were further checked for interactions between the main exposure and the peer influence variables. Results: 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, smoking was significantly associated with TDIs among girls (RR 2.50; 95% CI 1.42–4.41), and the same was the case among boys for fights (RR 1.46; 95% CI 1.19–1.79), for spending time with friends after school on more than three days a week (RR 1.25; 95% CI 1.07–1.46) and for having peers who carried weapons (RR 1.19; 95% CI 1.01–1.40), compared to their counterparts. TDIs were also significantly associated with both boys and girls who carried weapons (RR 1.36; 95% CI 1.12–1.66), had multiple risk-taking behaviours (RR 1.44; 95% CI 1.20–1.72) and had less than three close friends (RR 1.19; 95% CI 1.00–1.42) compared to their counterparts. The risk of TDIs was intensified among adolescents who carried weapons and had multiple risk-taking behaviours when they lacked peer support (RR 2.18; 95% CI 1.05–4.57 and RR 2.18; 95% CI 1.05–4.57, respectively) compared to their counterparts who had supportive peers (RR 1.28; 95% CI 1.01–1.62 and RR 1.36; 95% CI 1.11–1.68, respectively). Conclusions: Adolescents in Riyadh, particularly boys, had a very high prevalence of TDIs. Risk-taking behaviours (smoking, fights and carrying weapons) and negative peer influence (having peers who carried weapons) indicated an increased risk of TDIs among those adolescents independent of their age, socioeconomic status, physical activity and incisor overjet level. Negative peer influence (lack of peer support) intensified the association between risk-taking behaviours and TDIs.