A method for treating a patient's teeth includes determining an initial configuration of the patient's teeth, determining a final configuration of the patient's teeth, designing a movement path for at least one of the patient's teeth from the initial configuration to the final configuration, dividing the movement path into a plurality of successive treatment steps, each having a target configuration for the patient's teeth, and producing two or more dental aligners of substantially identical shape for at least one of the treatment steps in accordance with the target configuration.