MDA (Maxillary Distilizing Appliance)

The MDA is a T-Rex variation with additional wires extended out of welded sheathes on the screw underside. These wires prevent the pre-activated springs from distalizing the molars until after the arch has been widened. When the clinician wishes to release the springs, they can clip these wires and smooth off the sharp ends to allow the springs to begin distalizing the molars.