10/22: Panoramic Imaging Principles Flashcards
what is the biggest indication for pano indication?
overal evaluation of dentition
what are advantages of Pano over FMX?
less radiation dose
quicker
easier
better for trimus patients
what are the disadvantages of Pano over FMX?
lower resolution
overlap of premolars
unequal magnification so measurements are not reliable
how does the pano rotation work?
start on right, behind head, end on left
the sensor is never where?
back of the patient
the tube is never where?
in front of patient
this is a 3-dimensional curved zone where structures are reasonably well-defined
focal trough
(T/F) there is 1 center of rotation
false
objects closer to the receptor will be
narrowed
objects closer to the source will be
wider
buccal objects will appear
lower
lingual objects will appear
higher
what is the beam angulation?
-4 degrees
why is the angulation -4?
avoid projection of occipital bone
are structures closer to the source projected higher or lower?
higher
are structures further to the source projected higher or lower?
lower
how are the colors found?
yellow = lingual (closer to source)
blue = middle
green = buccal (closer to source)
how is horizontal magnification determined?
position of object within the focal trough
the giant tooth blurry tooth is positioned how?
lingual because it is wider
do you have more degrees of magnification in the anterior or posterior?
anterior
2 identical objects in both anterior and posterior, will they have the same horizontal magnification?
no it will vary
where are real images located?
between CoR and receptor
this is every anatomical structure positioned between CoR and receptor
real imaegs
these are located between the CoR and the source
ghost images
what objects cast a ghost image?
inferior border of mandible, angle, ramus, jelewry, apron, cervical spine, palate
what are the 4 characteristics of ghost images?
appear on opposite side
appear higher
appear more blurry
vertical dimension is highly magnified
what is images do you see here?
ghost of palate
ghost of inferior border of mandible
no because sensor does not go in front
ghost image of lead apron
ghost of cervical spine
these are objects that lie posterior to CoR and are intercepted 2 times
double real images
what is the positioning order for the Pano?
remove jelewry
put on lead apron
bite on biteblock groove
sit upright
align central laser line
align frankfurt horizontal plane
close side guides
have patient swallow, close lips, tongue on roof of palate
take image
if the patient is slumped, what happens?
cervical spine too opaque
the frankfurt horizontal plane runs through
tragus to infraorbital forament
where is the horizontal and vertical magnification equal?
central plane of the image layer
what causes a double real image of the cervical spine?
too far forward
ghost image of lead apron is caused by
apron behind patients neck
