(1) The aim of the study was to investigate the association between age, gender, and the component of psychosocial impact of dental aesthetics (PIDAQ) in Malaysian young people. (2) Cross-sectional data on the PIDAQ (comprised of dental self-confidence, social impact, psychological impact, and aesthetic concern variables) of Malaysian youth (n = 1425) recruited through multi-stage sampling were analyzed for mediation and moderated mediation analyses using the PROCESS macro on SPSS software. (3) Participants (mean age 16.0 ± 2.8) represented 54.8% of girls and 45.2% of boys. In the mediation model, psychological impact and aesthetic concern completely mediated the effects of social impact on dental self-confidence. In the moderated mediation model, social impact directly influenced dental self-confidence amongst participants at one standard deviation below the sample mean age and among boys. However, psychological impact completely mediated the influence of social impact on dental self-confidence amongst participants at the sample mean age and at one standard deviation above the sample mean ages, and among girls. Neither age nor gender moderated the effect of aesthetic concern on dental self-confidence. (4) Age and gender moderated the influence of social impact and psychological impact on dental self-confidence.