OBJECTIVES: The aim of this study was to clarify the applied initial forces and moments by different aligners of various materials and manufacturing methods. METHODS: The finite-element-method was used to analyze the forces and moments generated by the aligners on a maloccluded tooth. Plaster models of dental arches with a mesiorotated tooth 11 were fabricated, digitized and virtually analyzed. Four types of aligners with various layer thicknesses were selected: two splints with novel shape memory properties: a printable aligner made of the resin Tera Harz TC-85 DAC (Graphy Inc., South Korea) and a self-manufactured aligner consisting of the components polypropylene carbonate and thermoplastic polyurethane. The other two aligners were conventional, thermoformable aligners: CA RESULTS: The force and moment analyses showed that the thermoformable CA CONCLUSIONS: To avoid periodontal overloading, aligners with lower force and moment delivery should be chosen for this type of tooth movement.