Extra-oral films oral and maxillofacial radiology

3. Extra-oral films
They are films used outside the oral cavity

4. How to use ????

5. • 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.

6. Screen films: Non-screen films
The 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.

7. Films for skull views Films for panoramic views
5×7 inches (13×18 cm)
8×10 inches (20×26 cm).. the most
commonly used
6.5×8.5 inches
10×12 inches
5×12 inches (13×30 cm)
6×12 inches (15×30 cm) the most
commonly used

8. A. Skull views B. Panoramic views

9. o Evaluation of growth and development.
o Examination of multiple impacted teeth.
o Examination of TMJ, Maxillary Sinus, and
trauma.
o Detect pathology in the jaws.
o Detect the complete extent of a large
lesion.
o Used as alternative to intra-oral films in
case of severe gagging ,trismus and
A.Skull views

10. 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

11. It 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.

12. Actions

13. Contents of a Cassette
Cassette front: made of plastic,
aluminum or carbon fibers to
allows more rays to passand 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.

14. Types
Rigid Cassettes Curved Cassettes

15. 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.

16. 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: