1. A dental x-ray diagnostic apparatus for performing real-time digital radiography of a patient skull, comprising: a base frame to for supporting the apparatus; a sliding frame which is capable of sliding vertically along the base frame which is operated by an independent actuator under microcomputer control; a rotary frame coupled to the sliding frame by a cinematic unit, and supporting an x-ray source at one end, and an x-ray imager at the other end; said cinematic unit, allowing execution of orbital movements of said x-ray source and said x-ray imager around the patient skull, characterized in that the orbital movement is composed of one rotation movement and two linear movements in a plane, driven by independent actuators controlled by data momentarily supplied from a microcomputer.