b. Types of Film.
(1) Intraoral film. Periapical, bite-wing, and occlusal are three types of
intraoral film used to reveal different dental structures.
(a) Periapical film is used primarily for radiographic examination of
teeth and adjacent tissues to include the periapical region. The standard periapical film
(type 2) used in the Army is 1 1/4 by 1 5/8 inches, which is large enough to include a
view of about three teeth. A small size periapical film (type O) is also a standard item of
issue for use in radiography of children's teeth and measures 7/8 by 1 3/8 inches.
(b) Bite-wing film is used to obtain a radiograph of the coronal two-
thirds of opposing maxillary and mandibular teeth and their adjacent tissues on a single
film. The film packets are provided with tabs that extend from the center of the film.
When a radiograph is being made, the patient is instructed to bite down on the tab. The
tab holds the film firmly in position with the lower half lying lingual to the mandibular
teeth and the upper half held lingual to the maxillary teeth. Type 3 is the standard type
of bite-wing film used in the Army. It measures 1 1/16 by 2 1/8 inches. When the type 3
bite-wing film is unavailable or if the dental officer requests it, the type 2 periapical film
may be used to take bite-wing x-rays. However, these films would require the use of
paper adapters. Type O periapical film may be used as a bite-wing film for children.
These, also, would require the use of paper adapters.
(c) Occlusal film is a highly sensitive double-emulsion film supplied in
packets similar to periapical film but in a size convenient for obtaining a view of the
entire upper or lower arch or portions thereof. It measures 2 1/4 by 3 inches. Some
packets contain two films. The first film is developed at normal time to give a detailed
image of hard structures. The second film is developed in one half the normal time to
reveal soft tissue images.
(2) Extraoral film. Extraoral film is used for radiographs of the jaws, facial
bones, the temporomandibular joints, and other relatively large areas. This film has no
embossed dot to identify right and left.
(a) Intensifying screens are used with extraoral film to intensify the
effects of the exposing rays and lessen the exposure time.
(b) A cassette is constructed of rigid metal, plastic, or cardboard. It
often contains intensifying screens that magnify the x-ray beam, thus reducing exposure
time. The film must be transferred to the cassette from its paper covering in the
protection of the dark room.
(3) Panoramic film. Panoramic film, a type of extraoral film, is used in
panoramic radiography. This film shows the entire dentition and surrounding bone