Journal of Aligner Orthodontics, 02/2023

Objectives: Numerous therapy systems are based on the de-termination of a virtual treatment objective to manufacture individual fixed appliances or sequential aligners. The present study aimed to undertake a comprehensive scientific litera-ture search and subsequently establish guidelines that de-scribe the biological limits and the individual position of teeth and arches to create a virtual treatment objective for the time period between 1930 and September 2022. Methods: A systematic literature search was performed using the MEDLINE (via PubMed) and Google Scholar databases. Further relevant articles were collected by manual searching. The results were evaluated using the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines. Results: Following the selection process, 18 articles were identified that showed a relative amount of heterogeneity. The results of the literature search revealed more detailed information about the optimal tooth position and arch rela-tion. The WALA ridge allows individual determination of the shape and size of the dental arch, and the optimal anterior tooth position and position of the maxillary molars are de-fined in more detail according to the vertical and horizontal planes. Based on the parameters discussed as well as some additional ones, it is possible to create a virtual setup with respect to biological limits. Conclusion: Despite the limited scientific evidence, the stud-ies selected reveal references to biological limit values and offer guidance regarding optimal tooth position and arch re-lation. Nevertheless, further investigations are highly recom-mended to allow comprehensive and evidence-based state-ments to be made. Schlagwörter: biological limits, orthodontics, setup, tooth position, virtual treatment objective

To overcome the limitations of the conventional vacuum thermo forming manufacturing process, the method of direct 3D printing of aligners has been developed. This presents more advantages than simply avoiding a two-step process, whereby the model needs to be printed first before the aligners are thermoformed. The shape memory function of-fers new and improved biomechanical options. This article presents the new direct 3D printed aligner material from Graphy (Seoul, South Korea) and a patient example demon-strating the course of treatment with the new material. Schlagwörter: 3D printing, aligner orthodontics, direct aligner printing, Graphy, in-office aligners, interdisciplinary treatment, shape memory, tooth movement

Objectives: To present seven orthodontic cases treated using the Invisalign First system (Align Technology, San Jose, CA, USA), showing the discrepancy between the maxillary width expansion achieved in the canine and first molar regions using Invisalign First and the expansion simulated in the ClinCheck planning software in the same areas, and suggest-ing potential improvements to the ClinCheck plan when per-forming expansion with Invisalign First. Materials and methods: Seven patients treated with Invis-align First were evaluated retrospectively. The patients’ ClinCheck models, which simulated the situation of the final aligners, and their scan-based models representing the same final aligners were compared. The intercanine and intermolar width discrepancies for both models were summarised in tables. Results: Six out of the seven patient cases indicated that the effectiveness of Invisalign First for achieving the planned transverse expansion width when treating patients seems to be greater in the canine region than in the first molars, creat-ing the appearance of a broad smile due to small buccal corridors. Conclusion: These results suggest that future ClinCheck simu-lations should be adapted by avoiding overcorrection during expansion in the intercanine area to compensate for the in-creased expansion achieved in this region compared to that obtained in the first molar region. Schlagwörter: ClinCheck, Invisalign First, predictability, transverse expansion

This article describes the complex case of an adult patient with skeletal Class II malocclusion and a hyperdivergent facial pattern, dental crowding and protrusion, and her extraction treatment with Invisalign clear aligners (Align Technology, San Jose, CA, USA). To achieve an optimal result, it was necessary to carry out accurate treatment planning using the ClinCheck software (Align Technology), following the principles of face-driven orthodontics. The patient, motivated by the invis-ible nature of the chosen appliance, displayed optimal compli-ance, which was essential to achieve all the planned treatment objectives. After 20 months of orthodontic treatment, the pa-tient was highly satisfied with the result, which reflected what had been planned in the beginning. It can therefore be said that Invisalign clear aligners, in addition to improving aesthetic outcomes, are a reliable and efficient appliance that is also suitable for complex orthodontic treatments. Schlagwörter: Class II, clear aligners, dental protrusion, extraction