An orthodontic appliance for realigning one or more teeth in the intra oral cavity of a subject, includes a base having formed therein one or more guiding cells arranged to fit over a preselected tooth sought to be realigned from an initial position to a final position, each said guiding cell including a guiding structure defining a predetermined trajectory specific to the preselected tooth, along which the tooth is sought to be moved from the initial position thereof to the final position thereof; and apparatus, arranged within each guiding cell, for urging a predetermined tooth along its trajectory.