RESUMO
The aim of this research was to evaluate the efficiency and effectiveness of an orthodontic treatment with clear-aligner systems, specifically with Invisalign®. In addition to a review of the literature, 4 orthodontists and 9 patients treated with fixed orthodontic therapy and Invisalign® were interviewed. The literature showed that it is difficult to correct an extrusion, rotation or overjet with clear aligners. Often 'refinement' (additional intervention during treatment) is necessary to achieve the best possible end result. The patients interviewed experienced few limitations in their daily lives caused by the clear aligners and hardly any pain. Treatment duration was comparable to that with fixed appliances; it depended on the experience of the orthodontist, the complexity of the case and cooperation of the patient. The cost of an Invisalign® treatment is higher than that of fixed-appliance therapy. Additionally, making a plan for clear-aligner treatment often takes more time for the orthodontist than planning treatment for fixed-appliance therapy.