Dental<unk> y equipment consists of a horizontal rotating arm which holds an X-ray source and a moving film mechanism (carrying a film) arranged at opposed extremities. The patient's skull sits between the X-ray generator and the film. The X-ray source is rectangular collimated beam. Also the height of that beam covers the mandibles and the maxilla regions. The arm moves and its movement may be described as a rotation around an instant center which shifts on a dedicated trajectory. The manufacturers propose different solutions for moving the arm, trying to maintain constant distance between the teeth to the film and generator. Also those moving solutions try to project the teeth arch as orthogonally as possible. It is impossible to select an ideal movement as the anatomy varies very much from person to person. Finally a compromise is selected by each manufacturer and results in magnification factors which vary strongly along the film (15%-30%). The patient positioning is very critical in regard to both sharpness and distortions. Films There are two kinds of film moving mechanisms, one using a sliding flat cassette which holds the film, and another using a rotating cylinder around which the film is wound. There are two standard sizes for dental<unk>  films: 30 cm × 12 cm (12″ × 5″) and 30 cm x 15 cm (12″ × 6″). The smaller size film receives 8% less X-ray dosage on it compared to the bigger size. Digital Dental X-rays' radiology is moving from film technology (involving a chemical developing process) to digital X-ray technology, which is based on electronic sensors and computers. One of the principal advantages compared to film based systems is the much greater exposure latitude. This means many fewer repeated scans, which reduces costs and also reduces patient exposure to radiation. Lost X-rays can also be reprinted if the digital file is saved. Other significant advantages include instantly viewable images, the ability to enhance images, the ability to email images to practitioners and clients (without needing to digitize them first), easy and reliable document handling, reduced X-ray exposure, that no darkroom is required, and that no chemicals are used. One particular type of digital system uses a photostimulable phosphor plate (aka PSP - Phosphor Plate) in place of the film. After X-ray exposure the plate (sheet) is placed in a special scanner where the latent formed image is retrieved point by point and digitized, using a laser light scanning. The digitized images are stored and displayed on the computer screen. This method is in between old film based technology and the current direct digital imaging technology. It is similar to the film process because it involves the same image support handling and differs because the chemical development process is replaced by the scanning process. This is not much faster than film processing and the resolution and sensitivity performances are contested. However it has the clear advantage of being able to fit with any existing equipment without any modification because it replaces just the existing film. Also sometimes the term "digital X-rays" is used to designate the scanned film documents which further are handled by computers. The other types of digital imaging technologies use electronic sensors. A majority of them first convert the X-rays in light (using a GdO2S or CsI layer) which is further captured using a CCD or a CMOS image sensor. Few of them use a hybrid analog-to-digital arrangement which first converts the X-ray into electricity (using a CdTe layer) and then this electricity is rendered as an image by a reading section based on CMOS technology. In current state-of-the-art digital systems, the image quality is vastly superior to conventional film-based systems. The latest advancements have also seen the addition on Cone Beam 3D Technology to standard digital<unk>  devices.
Panoramic radiograph
Autoradiograph
Xeroradiography
Focal plane tomography
Projectional radiography
Digital radiography
Photofluorography
Tractography