Abstract: The invention relates to a dental instrument for optimal positioning of an X-ray film support in the X-raying of teeth, especially front teeth, or adjacent tissues. The instrument comprises a bridge having at its one end which is located in the patient's oral cavity inside the subject to be X-rayed a holder keeping the film positioned perpendicularly to the longitudinal axis of the bridge and means receiving an alignment rod which is parallel to the longitudinal axis of the bridge and which projects outside the oral cavity whereby the optical axis of the X-ray camera can be positioned relatively the rod and hence relatively the film. The instrument is improved by means of a transverse support arm connected to the bridge and adapted to be held pressed between the teeth in the upper and lower jaws permitting rotation of the film holder around the geometric longitudinal axis of the support arm.

Abstract: A bite block integral with an X-ray film support and extending generally at right angles to the X-ray film support to one side thereof, is formed of upper and lower flat plate portions, one which is integral with the film support, with the other being spaced from said one flat plate portion, normally parallel thereto and connected thereto by means permitting pivoting of the upper plate portion relative to the second about an axis perpendicular to the plane of bite, when positioned in the mouth of the patient between upper and lower tooth rows. An integral bridge may form the pivot axis for the upper and lower plate portions, a rotatable sleeve may effect such pivot connection with the sleeve being shiftable laterally between the upper and lower plate portions. Rectangular block wings may be detachably mounted to respective sides of the bite block plate portions via flanges which are inserted within the gap between the plates to respective sides of the pivot axis between the plates for the bite block.