Abstract: A diagnosis device provided with a position data generation unit (224) and a linking unit (226). The position data generation unit (224) generates first position data and second position data using a relative position image showing the relative positions of an upper bow and a bite-fork, an upper-part image showing the positional relationship of the bite-fork and the maxillary dental arch of a patient, and an articulation image showing the positional relationship of the maxillary dental arch and the mandibular dental arch of the patient. The linking unit (226) generates a virtual articulator by positioning three-dimensional models of the patient's maxillary dental arch and mandibular dental arch generated by a model generation unit (223), using the first position data and the second position data.