A digital subtraction technique for dental radiography.

The relative accessibility and stability of the teeth facilitate generation of geometrically identical radiographs over a period of time. When such radiographs are digitized with the aid of a TV camera coupled to an analog to digital converter and a computer, it is possible to conveniently produce subtraction images of high diagnostic value. A digital subtraction technique for longitudinal dental radiography is described; this technique should be applicable to diagnostic situations characterized by a need to detect small changes occurring over a period of time in areas where substantial amounts of structured noise limit their detectability.