10 X-ray apparatus for dental purposes; X-ray generators, X-ray detectors, Rotation arms supporting an X-ray generator and an X-ray detector, Rotation arm supporting pillars, Base generator and an X-ray detector, Rotation arm supporting pillars, Base plates for fixing the rotation arm supporting pillars, X-ray irradiation controllers, Control panels, Cephalostats, Patient's chin positioners, Spacing mouthpieces to be disposed between patient's upper and lower incisors, all for use with X-ray apparatus for dental purposes