Mediation and moderation effect of the big five personality traits on the relationship between self-perceived malocclusion and psychosocial impact of dental esthetics

Objective:  To explore the mediation and moderation effects of personality traits on the relationship between self-perceived malocclusion and the psychosocial impact of dental esthetics. Materials and Methods:  The sample included 252 subjects (62% female) aged 12–39 years. Self-perceived malocclusion was estimated using the 10-point scale Aesthetic Component of the Index of Orthodontic Treatment Need. The Psychosocial Impact of Dental Aesthetics Questionnaire was used to assess the psychological impact and the Big Five Inventory for personality traits. Moderation and mediation effects were evaluated with Pearson correlations and stepwise regression analysis, respectively. Results:  Self-perceived malocclusion ranged from 1 to 8 and was the most significant predictor of psychosocial impact of dental esthetics, whose unique contribution accounted for 11%–36.4% of variability, while age and sex accounted for 1.2%–2.5%. Personality traits had no mediating effect on this relationship. The moderating effect of agreeableness was present in the relationship between self-perceived degree of malocclusion and Social Impact (SI), Psychological Impact (PI), and Aesthetic Concern (AC) (ΔR2  =  0.035, 0.020, and 0.013, respectively; P < .001), while conscientiousness affected the relationship between perception of malocclusion and SI and PI (ΔR2  =  0.018 and 0.016, respectively; P < .05). In people with lower agreeableness and conscientiousness, increasing the severity of self-perceived malocclusion leads to less increase in SI and PI. In people with lower agreeableness, the increase influences AC in a similar manner. Extraversion, neuroticism, and openness do not have a moderating effect. Conclusions:  The relationship between self-perceived malocclusion and the psychosocial impact of dental esthetics appears to be moderated and not mediated by personality traits. Adolescents and young adults with lower agreeableness and conscientiousness seem to be less affected by the increased severity of self-perceived malocclusion, as demonstrated in reporting some psychosocial impacts.