Extraversion and openness to experience moderate the relationship between orthodontic treatment need and oral health-related quality of life in adolescents: A cross-sectional study

Objective: To investigate the effects of personality traits to moderate the relationships between orthodontic treatment need and oral health-related quality of life (OHRQoL) in adolescents. Materials and Methods: A cross-sectional study was performed that included 230 subjects (125 girls and 105 boys) aged 11-14 years. Orthodontic treatment need was measured using the Index of Complexity, Outcome and Need (ICON). The Child Perceptions Questionnaire, the Basic Personality Traits Inventory (BPTI), and the Revised Life Orientation Test were used to assess the OHRQoL, basic personality dimensions, and dispositional optimism respectively. Potential moderation effects were evaluated with Spearman's correlations and multiple regression analyses. Results: There were weak correlations between orthodontic treatment need and quality of life with social and emotional well-being dimensions (r = 0.238, r = 0.296 and r = 0.209). A moderating effect of extraversion was observed in the relationship between orthodontic treatment need and OHRQoL, emotional well-being, and social well-being (SWB) (Delta R-2 = 0.03, Delta R-2 = 0.02, and Delta R-2 = 0.04, respectively). Openness to experience affected relationships between orthodontic treatment need and OHRQoL, and emotional well-being (EWB) (Delta R-2 = 0.03 and Delta R-2 = 0.04, respectively). In children with higher extraversion, the increase in ICON scores resulted in less increase in CPQ total, EWB, and SWB scores. In children with higher openness to experience, the increase influenced CPQ total and EWB scores similarly. Conclusions: The relationship between orthodontic treatment need and quality of life is moderated by personality traits. Early adolescents with higher extraversion and openness to experience are less affected by increased orthodontic treatment need.