3. Dental radiograph
I – Extra oral
II- Intraoral : Periapical
Bite wing
Occlusal
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4. Occlusal radiography is defined as those
intraoral radiographic techniques taken using
a dental X-ray set where the film packet (5.7 x
7.6 cm) or a small intraoral cassette is placed
in the occlusal plane.
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6. Lower 90° occlusal
This projection shows a plan view of the tooth bearing
portion of the mandible and the floor of the mouth. A
minor variation of the technique is also used to show
unilateral lesions.
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10. Main clinical indications
Detection of the presence and position of
radiopaque calculi in the submandibular salivary
ducts
• Assessment of the bucco-lingual position of
unerupted mandibular teeth
• Evaluation of the bucco-lingual expansion of the
body of the mandible by cysts, tumours or
osteodystrophies
• Assessment of displacement fractures of the
anterior body of the mandible in the horizontal
plane.
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11. Technique and positioning
1. The film packet, with the white (pebbly) surface facing
downwards, is placed centrally into the mouth, on to
the occlusal surfaces of the lower teeth, with its long
axis crossways. The patient is asked to bite together
gently.
2. The patient then leans forwards and then tips the head
backwards as far as is comfortable, where it is
supported.
3. The X-ray tubehead, with circular collimator fitted, is
placed below the patient's chin, in the midline, centring
on an imaginary line joining the first molars, at an
angle of 90° to the film .
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12. Variation of technique. To show a particular
part of the mandible, the film packet is placed in
the mouth with its long axis anteroposteriorly over
the area of interest. The X-ray tubehead, still
aimed at 90° to the film, is centred below the
bodyof the mandible in that area.
Note: The lower 90° occlusal is mounted as if the
examiner were looking into the patient's mouth.
The radiograph is therefore mounted with the
embossed dot pointing away from the examiner.
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18. Lower 45° occlusal
This projection is taken to show the lower
anterior teeth and the anterior part of the
mandible. The resultant radiograph resembles
a large bisected angle technique periapical of
this region.
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19. Main clinical indications
• Periapical assessment of the lower incisor
teeth, especially useful in adults and children
unable to tolerate periapical films
• Evaluation of the size and extent of lesions
such as cysts or tumours affecting the anterior
part of the mandible
• Assessment of displacement fractures of the
anterior mandible in the vertical plane.
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21. Technique and positioning
1. The patient is seated with the head supported
and with the occlusal plane horizontal and parallel
to the floor.
2. The film packet, with the white (pebbly)surface
facing downwards, is placed centrally into the
mouth, on to the occlusal surfaces of the lower
teeth, with its long axis anteroposteriorly, and
thepatient is asked to bite gently together.
3. The X-ray tubehead is positioned in the midline,
centring through the chin point, at an angle of
45° to the film
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25. Lower oblique occlusal
• This projection is designed to allow the image
of the submandibular salivary gland, on the
side of interest, to be projected on to the film.
However,because the X-ray beam is oblique,
all the anatomical tissues shown are distorted.
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26. Main clinical indications
• Detection of radiopaque calculi in a
submandibular salivary gland
• Assessment of the bucco-lingual position of
unerupted lower wisdom teeth
• Evaluation of the extent and expansion of
cysts, tumours or osteodystrophies in the
posterior part of the body and angle of the
mandible.
ikassem@dr.com
27. Technique and positioning
1. The film packet, with the white (pebbly) surface facing downwards,
is inserted into the mouth, on to the occlusal surfaces of the lower
teeth, over to the side under investigation, with its
long axis anteroposteriorly. The patient is asked to bite together gently.
2. The patient's head is supported, then rotated away from the side
under investigation and the chin is raised. This rotated positioning
allows the subsequent positioning of the X-ray tube head.
3. The X-ray tubehead with circular collimator is aimed upwards and
forwards towards the film, from below and behind the angle of the
mandible and parallel to the lingual surface of the mandible
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