Assessment of Iranian orthodontic specialists’ knowledge and perceptions regarding the efficacy of clear aligner therapy in various orthodontic tooth movements (2024)

Clear aligner therapy (CAT) is increasingly used in orthodontics, but the predictability of specific tooth movements remains variable. This study assessed Iranian orthodontic specialists’ perceptions of the relative efficacy of CAT for common malocclusions and tooth movements. A cross-sectional survey was completed by 96 Iranian orthodontic specialists with prior clinical experience in CAT. An adapted structured questionnaire recorded demographic and CAT-exposure variables and used a five-point comparative scale to rate CAT versus fixed appliances for movement-specific efficacy. Friedman mean ranks summarized relative ratings across tooth movements. Exploratory analyses included Pearson correlation between clinician age and an overall perceived-efficacy score, a one-sample t-test against the neutral midpoint, and one-way ANOVA across annual CAT case-volume groups (two-sided α = 0.05). CAT was most frequently preferred for Class I spacing (72.9%) and Class I crowding (70.0%). Posterior extrusion (91.6% worse/much worse), occlusal settling (88.5%), and posterior derotation (85.4%) received the least favorable ratings, whereas lateral-incisor intrusion had the highest Friedman mean rank (11.68). The overall perceived-efficacy score was below the neutral midpoint (2.36 ± 0.51; t(95) = -12.0, p < 0.001). Age showed a moderate negative unadjusted correlation with the overall score ( r = -0.568, p < 0.001), while mean scores did not differ significantly by annual CAT case volume (F(3, 92) = 0.52, p = 0.667). Orthodontic specialists with prior CAT experience generally perceived CAT as more suitable for selected Class I cases and less predictable for posterior extrusion, occlusal settling, and posterior derotation than fixed appliances. Younger age was associated with more favorable perceived efficacy in unadjusted analysis; however, this finding should not be interpreted as an independent age effect. These results reflect clinicians’ perceptions rather than objective treatment effectiveness.