Effectiveness of Acceptance and Commitment Therapy on Self-Efficacy and Treatment Adherence in Patients Undergoing Fixed Orthodontic Treatment

Abstract

This study aimed to determine the effectiveness of Acceptance and Commitment Therapy (ACT) in improving self-efficacy and treatment adherence among patients undergoing fixed orthodontic treatment. This randomized controlled study employed a pretest–posttest design with a two-month follow-up. The study population consisted of patients aged 18–25 years undergoing fixed orthodontic treatment at Isfahan Dental School and its affiliated clinics in 2026. Forty eligible patients were purposively recruited and randomly allocated to an ACT group and a control group, with 20 participants in each group. Data were collected using the Sherer General Self-Efficacy Scale and the Tervonen Orthodontic Treatment Adherence Measure. In addition to standard orthodontic education, the experimental group received eight weekly 90-minute ACT sessions, whereas the control group received standard orthodontic education only. Outcomes were assessed at baseline, immediately after the intervention, and at the two-month follow-up. Data were analyzed using repeated-measures analysis of variance and Bonferroni post hoc comparisons in SPSS version 26. Repeated-measures ANOVA demonstrated a significant Time × Group interaction for self-efficacy (F=141.98, p<.001, partial η²=.789), together with a significant between-group effect (F=12.90, p=.001, partial η²=.253). A significant Time × Group interaction was also observed for treatment adherence (F=132.11, p<.001, partial η²=.777), and the between-group effect was significant (F=29.37, p<.001, partial η²=.436). Bonferroni comparisons revealed significant between-group differences in self-efficacy at posttest and follow-up (both p<.001), whereas the baseline difference was nonsignificant (p=.811). Likewise, significant between-group differences in treatment adherence were found at both posttest and follow-up (both p<.001), demonstrating that the intervention effects were maintained over the two-month follow-up period. ACT appears to be an effective psychological adjunct to standard fixed orthodontic care for enhancing patients’ self-efficacy and treatment adherence, with beneficial effects persisting for at least two months following treatment completion.