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Updated: Nov 28, 2025
Author Spotlight: 3D Movement Assessment of Maxillary Posterior Teeth in Clear Aligner Treatment
Published on: February 23, 2024
Side effects of twistflex retainers-3D evaluation of tooth movement after retainer debonding
Isabel Knaup1, Jenny Rosa Bartz2, Ulrike Schulze-Späte3
1Department of Orthodontics, RWTH Aachen University Hospital, Aachen, Germany. iknaup@ukaachen.de.
Purpose:
Evaluation of tooth movement after retainer debonding in retainer-associated misalignment cases.
Methods:
This pilot study is based on a retrospective data analysis. Adult patients (age 25.5 ± 4.9 years) wearing fixed twistflex retainers and having visible retainer-associated misalignment were included and examined for tooth movement after retainer debonding. Orthodontic study models were taken at retainer debonding (t0) and 14 (±1) weeks later (t1). They were digitally superimposed using 2D/3D dental imaging software and tooth movement was analyzed in all three dimensions.
Results:
A total of 23 teeth (12 upper teeth: 10 incisors, 2 canines; 11 lower teeth: 7 incisors, 4 canines) were analyzed. Mean overall tipping was 1.11 ± 0.82° in the mesial/distal direction (angulation, x‑axis), 2.02 ± 1.9° in the buccal/lingual direction (inclination, y‑axis) and 1.28 ± 0.99° around the tooth axis (z-axis). Mean overall bodily movement was 0.30 ± 0.31 mm in the mesial/distal direction (angulation, x‑axis), 0.10 ± 0.13 mm in the buccal/lingual direction (inclination, y‑axis), and mean in- or extrusion 0.22 ± 0.24 mm (z-axis). Mean tipping and bodily movement were more pronounced in the upper jaw.
Conclusion:
The present data shows that tooth movement after debonding of twistflex retainers can be expected in misalignment cases.
