Related Experiment Video
Updated: Mar 23, 2026
Author Spotlight: 3D Movement Assessment of Maxillary Posterior Teeth in Clear Aligner Treatment
Published on: February 23, 2024
Three-dimensional accuracy of in-office aligner therapy: a retrospective comparison between planned and achieved
Clara Ribeiro de Souza1, Bruna Caroline Tomé Barreto1, Luísa Schubach da Costa Barreto2
1Department of Pediatric Dentistry and Orthodontics, Universidade Federal do Rio de Janeiro (UFRJ), Av. Prof. Rodolpho Paulo Rocco, 325, Ilha do Fundão, Rio de Janeiro, RJ 21.941-913, Brazil.
Objectives:
To evaluate the three-dimensional clinical predictability of an in-office aligner workflow by comparing digitally planned virtual setups (T1) with post-treatment dental models (T2) using a reproducible open-source protocol.
Methods:
Sixty-eight digital dental models (maxillary and mandibular arches) from adult patients treated with in-office aligners were retrospectively analyzed. T1 and T2 STL models were superimposed using a landmark-based three-dimensional protocol, and linear and angular discrepancies were quantified using freely available Slicer CMF software (version 4.11). Statistical analyses were conducted at a 5% significance level, including intraexaminer reliability assessment after a 15-day interval and Wilcoxon signed-rank test for paired comparisons. Clinically relevant thresholds were defined as linear displacements >0.5 mm and angular deviations >2° RESULTS: Planned and achieved tooth positions showed high three-dimensional agreement. No statistically significant differences were detected for any linear or angular variables (p > 0.05), and all observed deviations remained below predefined clinical relevance thresholds. Incisal edge positions, intercanine widths, and intermolar widths exhibited minimal discrepancies between T1 and T2.
Conclusions:
Virtual setups for in-office aligner therapy demonstrated high three-dimensional accuracy, with no clinically meaningful differences between planned and achieved tooth positions. These findings support the clinical predictability of digitally planned, in-office aligners.
Clinical Relevance:
In-office aligner systems provide clinicians with full control over digital planning and fabrication. Their demonstrated predictability supports reliable treatment, reduces the need for refinements, and improves clinical efficiency. Moreover, three-dimensional superimposition may serve as an objective, open-access tool for auditing treatment outcomes and refining digital planning strategies in daily clinical practice.
