Cassette
A light-tight device used in extraoral radiography to hold the film and intensifying screens.
Collimator
A diaphragm, usually made of lead, used to restrict the size and shape of the x-ray beam.
Exposure factors
Factors that influence the density of a radio-graph
Film, screen
An extraoral film that requires the use of a screen for exposure; this film is sensitive to the light emitted from intensifying screens
Focal trough
A three-dimensional curved zone in which structures are clearly demonstrated on a panoramic image.
Frankfort plane
The imaginary plane that intersects the orbital rim of the eye and the opening of the ear.
Ghost image
An artifact on a dental radiograph produced when a radiodense object is penetrated twice by the x-ray beam; appears radiopaque
Head positioner
One of the component parts of a panoramic unit consisting of a chin rest, notched bite-block, forehead rest, and lateral head supports.
Midsagittal plane
An imaginary line or plane passing through the center of the body that divides it into right and left halves.
Panoramic
A wide view
Panoramic imaging
And extraoral technique used to examine the upper and lower jaws on a single projection.
Receptor, panoramic
Receptor used in panoramic examination, shows a wide view of the maxilla and the mandible.
Rotation center
In a panoramic radiography, the axis or pivotal point on which the receptor and x-ray tubehead rotate around the patient
Screen, intensifying
A device used in extraoral radiography that converts x-ray energy into visible light; the light , in turn, exposes the screens film.
Tomography
Radiography technique that allows the imaging of one layer or section of the body while blurring images from structures.
Tubehead
The tightly sealed heavy metal housing that contains the dental x-ray tube.