Direct and Indirect Effects of Autism Spectrum Disorder Severity on Dental Health Status in Children and Adolescents: A Structural Equation Modeling Approach

<i>Background and Objectives</i>: Current evidence remains insufficient to determine whether the impact of autism spectrum disorder (ASD) on dental health is primarily mediated through oral hygiene and dietary habits or through direct effects of the disorder itself. This study examined the theoretical pathways through which ASD severity and toothbrushing-related and dietary-choice-related factors influence dental health in autistic children and adolescents. <i>Materials and Methods</i>: A cross-sectional study was conducted with 399 mothers reporting on their autistic children (aged 2-18 years, mean = 7.8). The exclusion criterion was being older than 18 years. Data included parent-reported data about ASD severity, dental health status, willingness to brush teeth, and dietary quality (assessed using the Diet Quality Inventory). Structural Equation Modeling (SEM) was used to analyze the direct and indirect effects of ASD severity on dental health, with probit regression coefficients estimated using the WLSMV method. <i>Results</i>: Parent-reported variables of ASD severity, diet quality, and toothbrushing willingness together explained 37% of the variance in dental health. The direct effect of ASD severity on dental health was 0.199 (<i>p</i> = 0.039). The indirect effect via toothbrushing was 0.137 (<i>p</i> = 0.006), and via diet quality, it was 0.070 (<i>p</i> = 0.020). The total indirect effect of ASD on dental health was 0.207 (<i>p</i> = 0.026), which was approximately as strong as the direct effect. The associations among the studied variables were statistically equivalent across sex and age groups. <i>Conclusions</i>: Parent-reported ASD severity shows significant association with dental health outcomes, both directly and indirectly, with toothbrushing behavior emerging as the primary mediator. Interventions that promote regular brushing (and, to a lesser extent, healthier eating) may help to reduce the dental health disparities associated with autism.