Aligner technology has developed greatly over the last 15 years. Patients like clear aligner because of their esthetic aspects and convenience, while the treatment efficiency of clear aligners remains unsolved. There are still some limitations in treating severe malocclusion, i.e., root-movement control, intermaxillary width discrepancy correction, anterior extrusion and rotation control. Recent generation of clear aligner has been modified to place several attachments where difficult tooth movements are required.
Availability of tooth movement with clear aligners has been presented using a reported data from two of the larger aligner manufacturing companies, Align technology and ClearCorrect. However, parameters that influence the biomechanics of tooth movement by clear aligners include the properties of the material, the thickness of the material, and sequential series. Many clear aligners may be made in a series using one aligner material. Some other systems, different aligner materials may be used in a sequential series.
Aim of this presentation was to review the characteristics of tooth movement with available clear aligner material stiffness or thickness, accuracy of computer aided virtual planning and thermoforming process, and different sequential series.

Keyword: Clear aligner material stiffness, material thickness, computer aided virtual planning, thermoforming process, sequential series