Isabel Knaup1, Jenny Rosa Bartz2, Ulrike Schulze-Späte3, Rogério Bastos Craveiro2, Christian Kirschneck4, Michael Wolf2. 1. Department of Orthodontics, RWTH Aachen University Hospital, Aachen, Germany. iknaup@ukaachen.de. 2. Department of Orthodontics, RWTH Aachen University Hospital, Aachen, Germany. 3. Section of Geriodontics, Department of Conservative Dentistry and Periodontology, Jena University Hospital, Jena, Germany. 4. Department of Orthodontics, Regensburg University Hospital, Regensburg, Germany.
Abstract
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.
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.
Authors: Simon J Littlewood; Declan T Millett; Bridget Doubleday; David R Bearn; Helen V Worthington Journal: Cochrane Database Syst Rev Date: 2016-01-29