Dental radiographic apparatus for photographing entire jaws

摘要

A radiographic apparatus for photographing the entire jaws designed to make a tomogram of a curved plane approximate to a dental arch by the locus of center of rotation of the X-ray beam projected from an X-ray source onto an X-ray film holder describing an approximately V-shaped envelope which forms an apex on an approximate medial line and recedes from the apex toward the left and right of the approximate medial line by moving a rotary arm around a patient, the arm having the X-ray source at one end and the X-ray film holder at the other end thereof, wherein the apparatus comprises a means for changing straight-line distance on the approximate medial line between the apex and receding point of limit of the envelope and a means for indicating the distance of shift thus changed or a means for automatically moving the indication means a distance equal to the distance of shift.