DPTs Flashcards
(20 cards)
What are the difficulties in imaging the dental arches?
Curved object
Super-impostition of other structures
Individual occlusion and jaw shapes
How are all angles of the jaw picture on a DPT?
3 points of rotation
How long does it take a DPT to be taken?
20secs
What is the first vertical line seen on a DPT above the teeth?
Posterior wall of maxillary sinus
What is the difference between CBCT generated vs conventional DPT
CBCT much clearer because it is a 3d imagine device that can choose a very thin sample to picture
Why are CBCT’s not used generally?
Very high radiation dose
Why are full mouth periapicals not used?
Much higher radiation than DPT
List 6 situations in which a DPT may be used?
Orthodontic assessment Bony lesions Pre-GA Periodontal disease Trauma Pre-implantion 3rd molar view Cannot tolerate intra-oral views
Where does the Frankfort plane run from?
Upper border of external auditory meatus to lower border of orbit
What is the correct position of X-ray in terms of Frankfort plane?
Frankfort plane should be parallel to line of X-ray
In what position should teeth be for DPT?
Slightly seperated
What is the position problem if the image shows too much spine and the anterior teeth are thin and elongated?
Patient too close to the imagine machine
What is the problem with positioning if the image shows magnified teeth and no spine?
Patient too far away from imaging machine
In what position will a DPT lose the smile line?
Chin too far up and too far away
What positioning problem will cause magnification of one side of the DPT?
Rotation
What is a common ghost image seen on a DPT?
Opposite side of the mandible
List the characteristics of chest images?
Located on opposite side than actual object Same shape as actual object Larger than image of actual object Projected on higher film Less distinct
Why might a DPT of an edentulous jaw be helpful?
Good assessment of any retained roots and visualisation of ID canal (pressure on denture)
What do multiple radiolucencies at roots suggest (when teeth are healthy)
Malignancy
What should you do if a child has prematurely erupting teeth?
Red flag - malignancy
