Abstract: Effective centers of rotation of the X-ray beams when projecting the anterior regions are caused to be disposed considerably more interiorly of the dental arch, i.e., farther from the incisors and closer to the X-ray source, to thus provide longer projection radii of the beams at the anterior region. Lengthening of the projection radii is achieved through unique velocity profiles of patient chair movement along an x-axis and film travel within the camera. The longer effective projection radii of beams at the anterior region provide for a substantially wider or thicker layer thereat with a concomitant modest narrowing of the layer at the canine regions.

Abstract: A device for performing X-ray examinations of the teeth comprises a film holder which is detachably connectable to an arm which in turn is detachably connectable with an aligning disc. An opening in the aligning disc is provided to position the X-ray machine when the device is assembled in alignment with the X-ray film. The arm, the aligning disc and the film holder are so designed that exposure can take place with lying as well as standing film, that the upper as well as the lower gum can be exposed, and that the arm may be connected to the left as well as to the right. The invention also includes an extension part by means of which the biting surface may be increased.