Disclosed is a method for preparing a dental appliance for a dental patient by using a computer with a program that includes a digital dental articulator apparatus. The method includes the steps of a. creating a digital model of the patient’s upper and lower teeth; b. digitally mounting the model in the digital dental articulator; c. calculating the guiding surfaces of the patient’s temporomandibular joints by using wear surfaces between the patient’s upper and lower teeth; and d. calculating wear surfaces of a dental appliance.