RESUMO
(1) This study aimed to do a longitudinal validation of the psychosocial impact of dental aesthetics questionnaire (PIDAQ) and determine its minimal important difference (MID) following orthodontic treatment; (2) 42 adolescents (11 to 18 years old) were recruited for treatment with fixed appliances and the participants answered the Malaysian PIDAQ prior to treatment (T0), mid-treatment (T1), and post-treatment (T2), plus a global health transition scale at T1 and T2. Data analyses included repeated measures ANOVA and paired sample t-tests. Test-retest was administered 2 to 6 weeks from T0; (3) The final sample comprised 37 subjects (response rate = 88.1%). The 95% limits of agreement were -10.3 to 8.5 points. In the anchor-based approach, those who experienced the smallest changes by reporting their dental aesthetics as "a little improved" had an insignificant PIDAQ score change of -5.3 at T1. At T2, the PIDAQ scores of those in this category were reduced significantly (mean change = -26.2; effect size (ES) = 1.0; p = 0.34). In the distribution-based approach, standardized PIDAQ scores were significantly reduced, with medium (0.7) to large (1.5) ES at T1 and T2, respectively; (4) The PIDAQ can detect orthodontic-related changes in patients' psychosocial well-being. The post-treatment MID is 26 scale points with large ES.
RESUMO
(1) This study aimed to generate a simplified form of the Malaysian psychosocial impact of dental aesthetics questionnaire (PIDAQ[M]) and validate its use in the sociodental approach for estimating orthodontic treatment need. (2) Two eight-item forms were derived: an impact simplified PIDAQ[M] (ISP8), comprising the most impactful items as rated by 35 participants, and a regression simplified PIDAQ[M] (RSP8), derived from regression analysis of 590 participants' data from the PIDAQ[M] validation study. Their psychometric performances were assessed for internal consistency, validity (criterion and construct), reproducibility (reliability and agreement), and responsiveness to change. The sociodental estimates were based on 204 orthodontic patients' data who were assessed for normative need, impact-related need, and propensity-related need. McNemar analysis compared the sociodental estimates when both simplified PIDAQ[M] forms and the original PIDAQ[M] were used to measure impact-related need. (3) Both simplified PIDAQ[M] forms were valid, reproducible, and responsive. The sociodental estimates when using the ISP8 (38.2%) were similar to when the PIDAQ[M] (35.8%) was used (p > 0.05) but overestimated by 3.4% (p < 0.05) when the RSP8 (39.2%) was used as the assessment tool. (4) The simplified PIDAQ[M] can replace the original PIDAQ[M] in the sociodental approach to estimate the orthodontic treatment needs of the Malaysian population.