Extra-Oral Films

Amira GamalAmira Mahmoud

Engy ThabetEngy AhmedAndrew Ezat

Extra-oral filmsThey are films used outside the oral cavity

How to use ????

Supply• Boxes of extra-oral films may contain different quantities either 25, 50 or 100 films.

• Each film lies between two pieces of protective paper to separate films from each other.

• The entire group of films is wrapped in lead foil for protection.

• Boxes of extra-oral films are labeled with the type of film , film size , the total number of films enclosed and expiration date.

Types Screen films: Non-screen

filmsThe majority of extra-oral films

they are placed between two special intensifying screens, and all are kept in a cassette.

They are more sensitive to fluorescent light

They don't require intensifying screens for exposure.

They are exposed directly to X-rays.

Sizes

Films for skull views

Films for panoramic views 5×7 inches (13×18 cm) 8×10 inches (20×26 cm).. the most commonly used6.5×8.5 inches 10×12 inches

5×12 inches (13×30 cm)6×12 inches (15×30 cm) the most commonly used

Indications A. Skull views B. Panoramic views

oEvaluation of growth and development.oExamination of multiple impacted

teeth.oExamination of TMJ, Maxillary

Sinus, and trauma.oDetect pathology in the jaws.oDetect the complete extent of a

large lesion.oUsed as alternative to intra-oral

films in case of severe gagging ,trismus and children.

A.Skull views

B.Panoramic viewso In case of impacted teeth , implants and dentures o Fractures o Orthodontics treatment o Shows cysts , tumors and any pathology of the jaws . o Shows sinuses and floor of the nose.oEvaluation of carotid arteries calcifications.

Hemimandibulectomy

Intensifying ScreenIt is a device that converts X-rays to visible light.It intensifies the effect of the X-ray photons by producing a larger number of light photons.

serves as a mechanical support for the phosphor layer.intercepts light headed in other direction and redirects it to the film. absorbs the X-ray photon and convert it to visible light that is recorded by the film.makes the screen resistant to abrasion and damage caused by handling.

Actions

Cassettes Contents of a CassetteCassette front: made of plastic, aluminum or carbon fibers to allows more rays to pass and thus reducing patient exposure.Two intensifying screens. The screen film.Felt padding: to assure intimate and even contact between film & screens.Cassette back: made of lead.

Types Rigid Cassettes Curved Cassettes

Screen film Emulsion of extra-oral screen films which are made of silver halide is designed to be more sensitive to light rather than x-ray photons.

No embossed dot found on the surface facing the X-ray as in intraoral films. Because, they are used in cassettes that have letter R or L made of lead on exposure side of the cassettes.  

STANDARD SILVER HALIDE emulsion is sensitive to → Blue light.MODIFIED SILVER HALIDE emulsion with U.V sensitizers is sensitive to → Ultraviolet light ORTHOCHROMATIC emulsion is sensitive to → Green light this is faster two times and has better clarity of most diagnostic tasks, so they are the most commonly used extra-oral films in panoramic and cephalometric radiography.PANCHROMATIC emulsion is sensitive to → Red light.

Different emulsions are sensitive to different colors:

Any Questions ?

Thank you