Disclosed is a system for preparing a dental appliance for a dental patient by using a computer with a program that includes a digital dental articulator apparatus. The system creates a digital model of the patient&rsquo；s upper and lower teeth. Then the system uses a computer for digitally mounting the model in the digital dental articulator. The guiding surfaces of the patient&rsquo；s temporomandibular joints by using wear surfaces between the patient&rsquo；s upper and lower teeth is calculated using Eric&rsquo；s rim. A dental appliance is prepared by using the calculated guiding surface.
