Objective: To determine the mechanical properties of commercially available thermodynamic wires and to classify these wires mathematically into different groups. Materials and Methods: The samples examined were 48 nickel-titanium (NiTi) alloy orthodontic wires commercially available from five manufacturers. These samples included 0.016-inch, 0.016- × 0.022-inch, 0.017- × 0.025-inch, and 0.018- × 0.025-inch wires. The superelastic properties of the NiTi wires were evaluated by conducting the three-point bending test under uniform testing conditions. The group classification was made under mathematically restricted parameters, and the final classification was according to their clinical plateau length. Results: The orthodontic wires tested are classified as follows: (1) true superelastic wires, which presented a clinical plateau length of ≥0.5 mm; (2) borderline superelastic with a clinical plateau length of 0.05 mm; and (3) nonsuperelastic, with a clinical plateau length of ≤0.05 mm. The results showed that the range of products displays big variations in quantitative and qualitative behavior. A fraction of the tested wires showed weak superelasticity, and others showed no superelasticity. Some of the products showed permanent deformation after the three-point bending test. Conclusion: A significant fraction of the tested wires showed no or only weak superelasticity. The practitioner should be informed for the load-deflection characteristics of the NiTi orthodontic wires to choose the proper products for the given treatment needs.

Objective: To evaluate the effect of material thickness and width of the gingival edge on the forces and moments delivered by aligners prepared from Duran foil (PET-G) to a maxillary incisor during tipping and intrusion. Materials and Methods: Aligners prepared from PET-G of three material thicknesses (0.5, 0.625, and 0.75 mm) and three widths of gingival edges (0–1, 3–4, and 6–7 mm) were investigated during incisor palatal tipping and intrusion of 0.5 mm each. Forces and moments were measured with a six-component measuring device. The influence of aligner thickness and aligner extend on the force and moment development were tested for statistical significance ( P < .05). Results: The F _x and F _z forces produced during palatal tipping and intrusion by the 0.75-mm aligner material was significantly higher than those produced by the 0.5-mm-thick material ( P = .005 and P = .047, respectively). There was no statistical difference between aligner thickness of 0.5 and 0.625 mm and between 0.625 and 0.75 mm. The same behavior was observed for the palatal moment (M _y ). The F _x and F _z forces produced during palatal tipping and intrusion by the aligner with an extension of 0–1 mm edge was significantly lower than that of the aligner with a larger extension (3–4 mm edge: P = .003; 6–7 mm: P = .001). However, there was no statistical difference between aligners with a 3–4-mm and a 6-mm edge. The same behavior was observed for the palatal moment (M _y ). Conclusions: The forces and moments exerted by the PET-G aligner on teeth vary, depending on the material thickness, width of the aligner edge, and direction of tooth movement.

Summary: Objective: This study aimed to assess oral health-related quality of life (OHRQoL) in relation to associated covariates in orthodontic patients of different age groups (children, adolescents, and adults) in a cross-sectional study. Methods: A total of 898 subjects (50.6% females, 49.4% males; mean age 16.89 years) undergoing orthodontic treatment anonymously completed the German version of the Oral Health Impact Profile (OHIP-G14) to assess OHRQoL in addition to completing 23 other items. Descriptive, exploratory statistical analysis and multiple linear regression modelling were performed. Results: The mean score of the OHIP-G14 was 8.3 for the 6- to 11-year olds, 8.9 for the 12- to 17-year olds, and 12.6 for adults. Physical pain (Subscale 2) was the highest factor in all groups. Additionally, a relevant factor was Subscale 3 (psychological discomfort). A linear regression model showed that, in the adolescent group, aesthetics in combination with pain had a significant negative influence on OHRQoL, whereas, in the adult group, function in combination with pain showed the same significant negative influence. Second, except for the children, fixed appliances had a significant negative effect on OHRQoL compared to removable appliances. Conclusions: Our study showed that the majority of the 6- to 11-year olds and 12- to 17-year olds reported a good OHRQoL. Nevertheless, adolescents and adults who reported aesthetic/pain and function/pain problems, respectively, as reasons for orthodontic treatment showed a significant occurrence for reduced OHRQoL. Fixed appliances, in comparison with removable appliances, also resulted in a significant reduction in OHRQoL for both groups.

Purpose: To investigate the bracket transfer accuracy of the indirect bonding technique (IDB). Methods: Systematic search of the literature was conducted in PubMed MEDLINE, Web of Science, Embase, and Scopus through November 2021. Selection Criteria: In vivo and ex vivo studies investigating bracket transfer accuracy by comparing the planned and achieved bracket positions using the IDB technique were considered. Information concerning patients, samples, and applied methodology was collected. Measured mean transfer errors (MTE) for angular and linear directions were extracted. Risk of bias (RoB) in the studies was assessed using a tailored RoB tool. Meta-analysis of ex vivo studies was performed for overall linear and angular bracket transfer accuracy and for subgroup analyses by type of tray, tooth groups, jaw-related, side-related, and by assessment method. Results: A total of 16 studies met the eligibility criteria for this systematic review. The overall linear mean transfer errors (MTE) in mesiodistal, vertical and buccolingual direction were 0.08 mm (95% CI 0.05; 0.10), 0.09 mm (0.06; 0.11), 0.14 mm (0.10; 0.17), respectively. The overall angular mean transfer errors (MTE) regarding angulation, rotation, torque were 1.13° (0.75; 1.52), 0.93° (0.49; 1.37), and 1.11° (0.68; 1.53), respectively. Silicone trays showed the highest accuracy, followed by vacuum-formed trays and 3D printed trays. Subgroup analyses between tooth groups, right and left sides, and upper and lower jaw showed minor differences. Conclusions and implications: The overall accuracy of the indirect bonding technique can be considered clinically acceptable. Future studies should address the validation of the accuracy assessment methods used.