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39 Cards in this Set
- Front
- Back
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What are typically seen in Normal Radiographic Anatomy Interpretation?
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- Complexity of anatomic structures
- Superimposition of structures - Changing projection orientation - Errors & ghosts |
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What characterizes Zone 1?
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The Dentition
-Smile-like upward curve -Interocclusal space -Crowns & roots visualized |
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What characterizes Zone 2?
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Nose & Sinus
-Inferior turbinates & meati within the nasal cavity -hard palate image within the sinuses, above the apices -no air space shadow over the apices |
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What characterizes Zone 3?
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Mandibular Body
-Cortex smooth and continuous -No ghost Image superimposition (hyoid bone) |
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What characterizes Zone 4?
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TMJ
-Centered, not cut-off & equal in size bilaterally |
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What characterizes Zone 5?
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Ramus-Spine
-Same width bilaterally -Spine may not be seen. If observed, equal distance between spine & ramus -Spine should not be superimposed over the ramus |
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What characterizes Zone 6?
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Hyoid
-Double image, equal in size bilaterally and no ghost Image formation over the body of the mandible |
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What is the indicator that a patient is too far forward?
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Canine light not on mesial of max. canine
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What results from teeth being to far forward over the notch on the bite stick?
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Anterior teeth narrower and blurred and results in less magnification horizontally
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What is the appearance of anterior teeth that are too far forward?
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- Teeth appear long & skinny - reduced mesiodistal dimensions anteriorly-thin teeth
- Real image of spine superimposed over the rami |
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When do Bicuspids overlap bilaterally?
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When the teeth are positioned too far forward.
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What occurs when a patient is positioned too far back on the bite stick?
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Anterior teeth will be wider and blurred due to greater magnification.
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What can be viewed on the dental radiograph when the is excessive horizontal magnification?
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Wide blurred teeth, spread, condyles off lateral edges of film
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What are the errors that occur from Rotation of sagittal plane: head rotated to right?
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- Left side is closer to receptor
- Right is further from the receptor - Relative magnification of right side is noted - Teeth also appear overlapped on right (Overlapped contacts) |
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What are the errors that occur from Patient tilted in the machine-
Midsagittal plane is not correct? |
- Mandible appears tilted
- Unequal distance between chin & mandible - One condyle is higher than other |
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What happens when the head is tilted down? (Frankfort horizontal plane is not aligned with the light)
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Mandibular incisors are shortened
V-shaped mandible |
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What can be seen radiographically when a patients head is tilted down?
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- Excessive curving of occlusal plane
- Narrowing of intercondylar distance - Head of condyle may be cut off |
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What errors can be seen if the patients head is tilted upward?
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Squared off mandible
Palate superimposed over the roots of maxillary teeth Lengthening of intercondylar distance |
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What errors are seen when the patient does not rest their chin on the headrest?
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The epiglottis and hyoid bone
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What errors are seen when the
patient is slumped? |
Ghost image of cervical spine superimposed on anterior region on film
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What is visualized when the tongue is not on the palate?
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Palatoglossal air space
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What is seen on the radiograph when the lips are open?
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Relative radiolucency on coronal portion of upper & lower teeth
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When should a Bite block not be used?
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Edentulous jaws
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What occurs when a bite guide is not used?
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Incisal & occlusal surfaces of upper & lower teeth overlapped
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What occurs when there is movement during exposure?
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Wavy outline of cortex of inferior border of the mandible
Blurring of image above the wavy cortical outline |
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What must you always remove before exposure?
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Napkin Chains
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What does a dark line down the center of the radiograph indicate?
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Cassette resistance
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What happens if there is light exposure before processing?
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Looks like over exposure on one side of the film
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What occurs due to excessive dry conditions?
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Static Electricity Marks
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What occurs from a defective or damaged screen?
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White line indicating no reaction on film
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What do dust particles prevent and how do they appear?
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Prevent light emission and
will appear as scattered white dots on the processed film |
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Lack of screen support, from either faulty locking of the cassette or deterioration of the screen backing,
can produce _____ . This film fault is referred to as _____. |
blurring of the image, poor screen contact
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What causes light films to occur?
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- Exhausted developer
- Developer too dilute - Developer contamination by fixer - Developer too cold - Incorrect kV/mA setting (underexposure) - Cassette positioned back to front |
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What causes dark films to occur?
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- Developer too concentrated
- Film developed for too long a period of time - Developer is too hot or Incorrect - kV/mA setting (overexposure) |
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What causes fogged film?
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- Improper storage of film
- Outdated film - Crack in safelight filter of automatic processor, - Incorrect wattage of bulb or incorrect filter in safe light - Incorrect distance between safe light and film - Chemical fog |
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How often do you clean screens and what do you clean it with?
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Clean screens weekly using a anti-static screen cleaner and use a cloth that doesn't deposit fibers on the screens
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Don't soak the screens as they are _____ and will subsequently _____.
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hydrophilic, crack
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Screens also become _____ with age so replace them. These changes are often accompanied by a lack of screen support following _____ of the attached _____.
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less efficient, deterioration, foam backing
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Cassettes should also be replaced if their _____ fail or become _____.
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locking clips, detached
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