FAS technology has been developed to overcome the limitations of other aligner systems. One of these limitations is the efficiency of force applied to the teeth that lies in the deformation of the aligner margins. In order to solve this problem, the FAS system, in addition to the changes in the position of the teeth, takes into account the changes that will occur at the gingival level and the relationship between the aligner and the attached gingiva. The aligners adapt to the cervical margin and reproduce the gingival contour ideally, thanks to our unique software. This feature provides strength to the aligner in this critical area, resulting in more effective corrections, treatment time and accuracy of the final result.