What are the advantages of panoramic radiographs?
large anatomic area covered, relatively low dose of radiation, easy to operate, improved patient cooperation
one panoramic radiograph has the dose equivalent to _____ PA's
4
What are some disadvantages of panoramic radiographs?
decreased sharpness/accuracy, high cost, may not see objects outside focal trough
What are panoramic radiographs used for?
to evaluate trauma, pathology, lesions, to locate foreign objects, mixed dentition analysis, evaluate developmental anomalies
Tomography
technique that allows for imaging of one section of the body while blurring images from structures in other planes
Which direction is the tube head angled for a pan?
upward (negative)
double center
split image
triple center
continuous image
moving center
continuous image
What is the equipment involved in taking a pan?
cassette holder, arm, tubehead
What kind of film is used when taking a pan?
screen film", intensifying screen, double sided emulsion, rare earth
What is the ideal film used when taking a pan and why?
rare earth (green) becuase it reduces the amount of radiation used by half
What are the types cassettes used with a pan?
rigid, flexible, straight, curved
ghost image
opaqque shadow of an object (jewlery, anatomy) located on the opposite side of the patient
ghost image
opposite side, same shape, larger, projected higher on film, less distinct
What are some examples of ghost images?
earrings, R/L markers, necklace chain, vertebral column, hyoid bone
what are some of the soft tissues that are visible on a pan?
soft tissue of the nose, lips, nasiolabial fold, soft palate, dorsum of tongue, epiglottis, tonsil, ear/earlobe
What are the instructions given to the patient before positioning for a pan?
remove all jewlery-- anything removable between neck and top of ears
T/F: a thyroid collar is used in addition to a lead apron when taking a pan.
false-- no thyroid collar becuase it interferes with image
What is the ideal positioning for a pan?
incisors in notch, frankfort plane parallel to floor, midsagital plane centered, spinal column straight
What directions are given to the patient after he/she is positioned?
swallow and put tongue to top of mouth; maintain this position for 20 seconds
Air space artifact
appears if patient does not swallow and put tongue to roof of mouth