1. A method for preoperative evaluation comprising the steps of: 1. preparing maxillary and mandibular dental models, said models each having a base portion of a given configuration; 2. mounting a articulator base on a dental articulator, said articulator base having at least one positional keying means; 3. placing said models on the articulator in a first position that presents the patient's malocclusion and then temporarily securing the models in said first position; 4. casting a first template means having (1) a complementary replica of the base portion of one of said dental models when the model is in such first position and (ii) at least one positional keying means that mates with said at least one positional keying means of said articulator base; 5. unsecuring said dental models from said first position; 6. placing said dental models on the articulator in a second position that presents the patient's proposed corrective position and then temporarily securing the models in said second position; 7. casting a second template means having (1) a complementary replica of the base portion of said one of said dental models when the model is in said second position and (ii) at least one positional keying means that mates with said at least one positional keying means on said articulator base; 8. unsecuring said dental models from said second position; 9. placing the base of one of said dental models in the complementary replica thereof in one of said template means and engaging the positional keying means thereof with the positional keying means of articulator base; 10. establishing a coordinate reference system with respect to the dental model in said one of said template means; 11. substituting the other of said template means for said one of said template means and thereafter; 12. determining the deviation of said dental model with respect to said established coordinate reference system; and, 13. determining from said coordinate reference system and from the deviation therefrom the rotational and translational movements required to move said one of said models from the first position to the second position.