Abstract: A device and method for seating orthodontic aligners over the dentition of a user includes a light-based device having a bite plate or mouthpiece, with light-emitting elements, for contacting the aligners. Instructions are provided for using of the light-based aligner seating device by placing the mouthpiece over the aligners, applying light radiation during a predetermined number of sessions throughout a predetermined treatment period, wherein the seating and the fit between the aligners and teeth are better than without use of the light-based device.