Villa Rotograph EVO, Руководство по обслуживанию

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SERVICE MANUAL
Troubleshooting
Rotograph EVO (Rev. 1) 8-62
8.5.1. Proper positioning of the patient
The proper positioning of the patient during the panoramic examination
is very important in order to get a good quality radiography. This is due
to the fact that the shape of the focussed area, e.g. of the layer clearly
shown on the film, tends to follow the dental arch and has a non-
constant deepness.
The objects outside this focussed area will therefore appear blurred on
the resulting radiography.
1. The patient should not wear clothes that may interfere with the X-ray
beam, also leave more space between the patient’s shoulders and the
rotating arm of the machine. Care must be taken in order to avoid
interference between the X-ray beam and the protective apron worn
by the patient.
2. Metal objects (neck chain, ear-ring) must be avoided; these objects
not only create radio-opaque images in their own position but also
false images projected in other parts of the radiography, so
disturbing the correct view of the anatomy.
3. The patient’s head must be lightly tilted downward in order to have
the Frankfurt plane horizontal. In this way, the hard palatal ceiling
will be projected slightly over the superior apex of the anterior teeth.
If the patient has a low palatal ceiling, slightly increase the tilting
downward.
4. Align the middle sagittal plane with centre of the chin support,
normally indicated by the relevant light beam.
5. Check that the vertical light beam falls on the canine and lies
between the third and fourth teeth. This will insure that the apex of
the anterior teeth are positioned within the focussed area and
therefore will be properly reproduced on the radiography. Normally,
the panoramic equipment has a narrower focussed layer in the front
area, and therefore a proper positioning of the anterior teeth is of the
utmost importance.
Figure 8-2