Therapeutic accuracy of the completely customized lingual appliance WIN

Abstract

ObjectiveThe aim of this retrospective cohort study was to assess the accuracy of the completely customized lingual appliance WIN (DW Lingual Systems, Bad Essen, Germany) employing a three-dimensional (3D) comparison between the setup and the final result.Materials and methodsThe setup and final models of 20 consecutively debonded patients (40 jaws; 7 males, 13 females; mean age 15.76 ± 4.45 years) with various malocclusions of a private practice specialized in orthodontics were digitalized using a 3D scanner. The 3D models of the setup and the final model of each jaw were then digitally matched using the best fit algorithm and segmented into single teeth. After placing individual coordinate systems, the homologous teeth of the setup and the final model were matched to be able to calculate the exact deviations of all rotational and translational components. The t test for unpaired samples, Kruskal–Wallis tests, U tests, and ANOVA with Duncan post hoc test were applied statistically.ResultsRegarding the incisors, the angle discrepancies between the setup and the final result appeared to be less than 3° (torque 2.96°; tip 2.04°; rotation 2.00°). The translations showed mean values less than 0.3 mm (mesiodistal 0.16 mm; buccolingual 0.15 mm; vertical 0.29 mm). Slightly higher values could be measured in the lateral segments regarding rotations (torque 5.18°; tip 3.10°; rotation 3.70°) as well as regarding translations (mesiodistal 0.26 mm; buccolingual 0.64 mm; vertical 0.36 mm).ConclusionsUsing the completely customized lingual appliance WIN, it is possible to achieve the final result predicted by the setup with a high accuracy.

Quality in orthodontics: The role of customized appliances

“…• Reduction of the incidence of decalcification with its inherent savings in terms of enamel and financial burden (see discussion below), 20 • Individualized treatment plans that can be predictably transferred to the patients' mouth, 21 F I G U R E 4 Small changes in angulation as seen in the lower right first molar can have a significant adverse effect on occlusion in all three planes of space-especially in the vertical dimension. In crowded situations the angulation discrepancy may not be perceptible until late in treatment.…”

“… Reduction of the incidence of decalcification with its inherent savings in terms of enamel and financial burden (see discussion below), 20 Individualized treatment plans that can be predictably transferred to the patients' mouth, 21 Better torque control because of precise slot and arch wires dimensions, 22 Biomechanical advantages in terms of vertical control thanks to ribbon‐arch wires, 23 and Avoidance of secondary effects due to conventional non‐customized orthodontic treatment …”

Korrektur einer mandibulären Asymmetrie mit frontal offenem Biss mittels Frontzahnextraktion und Lingualtechnik

“…Von erwachsenen Patienten wird häufig eine möglichst ästhetisch unauffällige Korrektur von Zahnfehlstellungen gewünscht. Es konnte bereits gezeigt werden, dass geplante Zahnbewegungen mit einer vollständig individuellen lingualen Apparatur mit hoher Genauigkeit umzusetzen sind [8,9] -dies deckt sich mit dieser Kasuistik. Im Zuge des Herstellungsprozesses der Apparatur ist die Erstellung eines physischen therapeutischen Setups eine Conditio sine qua non.…”

Controlling incisor torque with completely customized lingual appliances

“…In order to address these issues of controlling the moment/ force ratio adequately, the bracket slots of the CCLAs used in this study were made by high-speed milling with manufacturing tolerances of only up to ±2 μm (<0.5%) [38]. As a consequence, the magnitude of torque expression with these appliances compared to conventional labial or lingual brackets can be easily controlled by the orthodontic specialist [37,[39][40][41][42][43][44][45]. In order to account for torque play, the undersized maxillary rectangular 0.016 00 × 0.024 00 stainless steel archwires of the CCLA used here during space closure were provided with an incorporated canine-to-canine extra torque bend of 13°, and, in the case of one patient, 21°.…”