Different from traditional intraoral X-ray photography, dental panoramic X-ray is an extraoral photography, which means that the imaging machine and film are outside the oral cavity. According to the Radiological Society of North America (RSNA), a dental panoramic X-ray machine projects light through your mouth onto a film or detector that rotates to face the X-ray tube.
The basic design of the dental panoramic X-ray machine is that the picture tube is mounted on a horizontal rod that can point to one side of the patient's cheek, and the opposite horizontal rod points to the other side containing the X-ray film or detector. Generally speaking, the head is positioned by the lower handle, forehead and sides, and a pair of swallowing stops is used to keep the mouth open. Then, the rod of the X-ray machine will rotate in a semicircle around the patient's head, starting from one side of the lower handle and ending on the other side.
