Radiology chapter twenty three

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Radiology chapter twenty three
2010-10-14 09:08:12
chapter twenty three extraoral radiography

extra oral
Show Answers:

  1. Where are extra oral films primarily used?
    • orthodontics
    • oral surgery
  2. what are the extra oral films typically used for?
    • evaluate large areas of skull and jaw
    • evaluate growth and development
    • evaluate impacted teeth
    • detect diseases, lesions, conditions of the jaw
    • examine extent of large lesions
    • evaluate trauma
    • evaluate temporomandibular joint area
  3. What type of extraoral x rays is a stantard intraoral x ray machined used for?
    transcranial and lateral jaw projections
  4. includes a film holder and head positioner that allow the dental radiographer to position both the film and pt easily; a special extension arm and device used in conjunction with a panoramic x ray tube head
    cephalostat or craniostat
  5. What size of film are most often used in extraoral radiography?
    5 X 7 or 8 X 10
  6. What extraoral radiographs is an occlusal film used for?
    • lateral jaw
    • transcranial projection
  7. What are the disadvantages of using an occlusal or nonscreen film instead of a cassette or screen film?
    • it requires more radiation exposure
    • it does not cover as large of an area
  8. true or false. Extraoral film cassettes, excluding some panoramic cassettes, are rigid and are constructed of metal and plastic.
  9. Where must the front side, or tube side of the cassette always be facing during exposure?
    the patient
  10. a device used to reduce the amount of scatter radiation that reaches an extraoral film during exposure; can decrease film fog, and increase the contrast of the radiographic image
  11. What is a grid composed of?
    a series of thin lead strips embedded in a material, like plastic
  12. where is the grid placed?
    between the patients head and the film
  13. Why do you have to increase exposure time when using a grid?
    to compensate for lead strips found in the grid
  14. what is lateral jaw radiography used for? What is it's use valuble for?
    • to examine the posterior region of the mandible
    • valuble for children, pts with limited jaw opening due ot an injury, or pts who have difficulty stabilizing or tolerating intraoral film placement
  15. What type of x ray unit is used in lateral jaw radiography?
    standard x ray machine
  16. What is the purpose of the body of mandible projection?
    to evaluate impacted teeth, fractures, and lesions located on the body of the mandible
  17. film placement of body of mandible lateral projection? and head placement
    • flat against cheek over body of mandible, parallel to it
    • tipped 15 degrees towards side being imaged
  18. What is the purpose of the ramus of mandible lateral projection?
    • to evaluate impacted 3rd molars, large lesions, and fractures that extend into the ramus
    • demonstrates a view of the ramus from the angle of the mandible to the condyle
  19. What is the purpose of the lateral cephalometric projection?
    • evaluate facial growth and development, trauma, and disease and developmental abnormalities
    • demonstrates bones of the face and skull as well as soft tissue profile
  20. What is the purpose of the posteroanterior projection?
    demonstrates the frontal and ethmoid sinuses, the orbits, and the nasal cavity
  21. What is the purpose of the waters projection?
    • to evaluate the maxillary sinus area
    • demonstrates the frontal and ethmoid sinuses, orbits and nasal cavity
  22. What is the purpose of the submentovertex projection?
    • to identify position of the condyles, demonstrate the base of skull and evaluate fractures of the zygomatic arch.
    • demonstrates the sphenoid and ethmoid sinuses and lateral wall of the maxillary sinus
  23. What is the purpose of the reverse towne projection?
    identify fractures of the condylar neck and ramus area
  24. What is the TMJ radiography made up of?
    • glenoid fossa
    • articular eminence of the temporal bone
    • condyle of the mandible
    • articular disks
  25. What is the purpose of the transcranial projection, or lindblom technique?
    to evaluate the superior surface of the condyle and articular eminence
  26. What is the radiographic technology used to examine the temporomandibular joint?
    temporomandibular joint tomography