Am J Orthod Dentofacial Orthop. 2026 Aug 21:S0889-5406(26)00346-X. doi: 10.1016/j.ajodo.2026.06.016. Online ahead of print.
ABSTRACT
INTRODUCTION: Space opening with clear aligner therapy has been little researched. The aim of this retrospective observational study was to investigate the predictability of the Invisalign appliance (Align Technology, San José, Calif) in opening space for the permanent maxillary lateral incisor (PMLI).
METHODS: Data from Align Technology’s digital treatment planning software system, ClinCheck (Align Technology, San Jose, Calif), were evaluated to determine the initial, predicted, and achieved space opening for the PMLI in patients satisfying the selection criteria. Acquisition of the relevant measurement values was performed using the Geomagic (3D Systems, Rock Hill, SC) metrology system. A mixed-effects model was used to account for within-patient dependence among tooth spaces and the 2 one-sided tests for equivalence testing and Bland-Altman analysis were employed.
RESULTS: Space opening for 41 PMLIs in 25 patients with a mean age of 21.2 ± 13.0 years was evaluated. Approximately 65.2%-69.8% of predicted space opening was achieved, with the mean differences between predicted and achieved values ranging from 0.9 ± 1.0 mm to 1.4 ± 1.2 mm (P <0.05). For patients <18 years of age, the mean difference between predicted and achieved canine angulation changes was 9.4 ± 9.1°, with 95% limits of agreement from -8.4° to +27.2° (P = 0.015). Mean differences between predicted and achieved canine angulation changes in patients ≥18 years of age (5.3 ± 6.4°) and central incisor angulation changes in patients <18 years of age (-0.1 ± 8.0°) and ≥18 years of age (-4.8 ± 7.6°) were not statistically significant.
CONCLUSIONS: The findings can help clinicians better understand the planning of space opening for PMLIs before clear aligner therapy commences and provide baseline information for future research.
PMID:42627321 | DOI:10.1016/j.ajodo.2026.06.016
