RESUMO
BACKGROUND: Dental malocclusion is a highly prevalent health condition in adolescence. Patients seek treatment primarily for aesthetic reasons. Therapy benefits are regarded, in the first place, to be psychosocial in nature. Therefore, it is mandatory to consider the perspective of the patient in treatment planning and control using a dental-aesthetics-related quality of life measure. The objective of this study was to investigate whether the Psychosocial Impact of Dental Aesthetics Questionnaire (PIDAQ) developed in adult samples including the subscales Dental Self-Confidence, Social Impact, Psychological Impact and Aesthetic Concern is also applicable in adolescents aged 11 years and above. The psychometric properties were examined across three age-groups (11-12, 13-14, 15-17 year olds) with respect to factorial invariance, internal consistency, temporal stability, discriminant validity and gender- or age-associated scale mean differences and item response bias. METHOD: Participants were 1,112 adolescents recruited from 4 institutions: orthodontic and dental practices, schools, and youth clubs. They answered the 23 partially reformulated items of the PIDAQ. Subjective and dentist evaluations of dental occlusion were assessed using the Perception of Occlusion Scale and the Aesthetic Component of the Index of Orthodontic Treatment Need. Both indices were aggregated to one Malocclusion Index (MI-S and MI-D). RESULTS: The fit indices using confirmatory factor analyses suggested that the factor structure and factor loadings underlying the PIDAQ items were invariant across ages (comparative fit index = 0.91, root-mean-square error of approximation = 0.04). Internal consistency and temporal stability were adequate within the age-groupings (Alpha = 0.71-0.88; intra-class correlations = 0.82-0.96). Adolescents with severe compared to slight malocclusion according to both self-evaluation and dentist evaluation were found to differ in all PIDAQ subscales at a level of p < 0.001 for all ages. PIDAQ scale scores were not related to age and gender. On the item level, no evidence for gender or age bias has been found. CONCLUSION: The PIDAQ demonstrates to have good psychometric properties in adolescents, independent of their age. The instrument can be applied in making clinical decisions and in the assessment of psychosocial outcomes of orthodontic therapy.