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Dental Technican, Volume 2 - Dentist training manual for military dentists | Next
PARALLEL PLACEMENT TECHNIQUE |
2. Position the patient as shown in figure 1-23 for
maxillary radiographs or figure 1-24 for mandibular
radiographs. Remember that the patient's midsagittal
plane must be perpendicular to the floor.
3. Position the film packet in the patient's mouth.
Have the patient hold the film packet in place with a pair
of hemostats or other holding device.
4. Set the vertical angulation of the tube head
accord ing to the chart in figure 1-26.
5. Center the tube head cylinder on the area to be
radiographed. To simplify this process, the numbered
anatomical landmarks are provided in figure 1-30. Take
radiographs of the area by centering the tube head
cylinder on these landmarks:
Mandibular cuspid area: Landmark 6, directly
below landmark 2 1/4 inches above the lower
border of the mandible.
Mandibular incisor area: Landmark 5, the tip
of the chin.
Maxillary molar area: Landmark 4, below the
outer angle of the eye and below the
zygomatic bone.
Maxillary bicuspid area: Landmark 3, below
the pupil of the eye.
Maxillary cuspid area: Landmark 2, beside
the ala of the nose.
Maxillary incisor area: Landmark 1, the tip of
the nose.
Figure 1-30.—Cylinder positioning landmarks for periapical
radiographs.
Mandibular bicuspid area: Landmark 7,
directly below landmark 3 1/4 inches above
the lower border of the mandible.
Mandibular molar area: Landmark 8, directly
below landmark 4 1/4 inches above the lower
border of the mandible.
6. When you have the tube head cylinder centered
on the horizontal landmark, double check to make sure
that you have the correct horizontal angulation. The
central X-ray beam should be projected straight through
embrasures of the teeth to be radiographed.
7. Make the exposure.
8. Remove the film packet from the patient's
mouth and place it in a clean paper cup. Place the
disposable container in a lead container or behind a
protective screen before making the next exposure.
INTERPROXIMAL (BITEWING)
EXAMINATION
The interproximal examination reveals the
presence of interproximal caries, certain pulp
conditions, overhanging restorations, improperly
fitting crowns, recurrent caries beneath restorations,
and resorption of the alveolar bone.
A typical interproximal radiograph (fig. 1-31)
records in a single exposure the coronal and cervical
portions of both maxillary and mandibular teeth, along
with the alveolar bone of the region.
Bitewing X-ray film packets are used for the
interpromixal examination. The bitewing film packet
(fig. 1-32) has a paper tab, or wing, that the patient
bites on to hold the packet in place during the exposure
(thus the name bitewing).
Interpromixal radiographs can be made using
either the paralleling technique or the bisecting angle
technique.
Figure 1-31.—Typical interproximal (bitewing) radiograph.
1-22
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