Projection Geometry Flashcards
When chafing teeth what color do you use when the tooth is congenitally missing?
Black
What you should you do first before ordering radiographs?
Give the patient an exam * missing teeth * existing restorations
What color do you use to chart existing procedures?
Blue
What is different when you chart a gold crown?
It is cross hatched
Closer the object to the image receptor the ______ fuzzy the image is around the edges.
Less
When the focal spot is _____ away from the object the less fuzzy the image is.
Farther
When you decrease the angle at which the image is being taken you elongate the image. T or F
False- when you increase the angle the image elongates
List three ways to maximize sharpness and resolution of the image
Use a small effective focal spot Increase the distance from the focal spot to the object Decrease the distance from the object to the image receptor
List two ways you can minimize image size distortion
Increase focal spot to image receptor distance
Decrease object to image receptor distance
Don’t increase distance too much - the image may not get enough exposure and will end up being white
The film should be parallel with the tooth. T or F
True
This will minimize shape distortion.
The central ray should be parallel to film and tooth. T or F
False - should be perpendicular
What is foreshortening?
The image receptor and tooth are not parallel, the beam or photons is Perpendicualr to the image receptor but NOT the tooth
What is elongation?
The tooth and film are not parallel, the beam of photons is perpendicular to the tooth but NOT to the image receptor
What is the preferred method of capturing an image?
Parallelling the tooth and film. Beam should be perpendicualr go both
What is the bisecting line angle?
The line produced that bisects the angle formed by the image receptor and the central axis of here tooth.
If the preferred method is can not be achieved an individual should use the bisecting line technique. T or F
True
How do you use the bisecting line technique?
Line the central beam up perpendicular to the bisecting line.. Will still get some distortion or the tooth height and alveolar bone
How do you locate an object on the film?
SLOB same lingual opposite buccal
What is SLOB?
Same lingual Opposite buccal Doesn’t shift - in the same plane as the teeth
If you shift the tube head medically and take and image and the object moves mesially in the image than it is _____ to the teeth.
Lingual
If you shift the tube head to mesially and the object in the image move distally than the object is ________ to the teeth.
Buccally
What is the cotton roll technique?
Helps get a parallel technique
What is a periapical film?
A film that gets the root tips
What is a bitewing?
Looking at the crown, inter proximal contacts and the alveolar bone health
Full mouth series
18 films 6 anterior PAs 8 posterior PAs 4 bitewings
1 sensor vs #2 sensor
1 is narrower - will need to take more images to get a full moths series
Why don’t we take anterior bitewings?
You can see the inter proximal contacts in the PAs
Bicuspid PAs
Should see the distal canine and cuspid on the first molar
Molar PAs
Should see the distal of there cuspid
Bicuspid bitewings
Should see the inter proximal contacts of the laterals
What is radiolucent
Any substance that permits the transmission of X-rays Black or darker colored
What is radiopaque
Any substance that blocks the transmission of X-rays White or light colored
Radiolucent and radiopaque refer to the image on the film. T or F
False - refers to the object the photons are passing through
What is more opaque? Enamel or dentin Dentin or cementum Cortical bone or calculus bone Dentin and bone
Enamel Dentin Cortical bone About the same
What makes up the largest portion of the tooth?
Dentin
Is the pulp Radiolucent or radiopaque ?
Radiolucent
What lies between the Latin dura and the tooth
PDL
What type of bone is the alveolar crests.
Cortical bone
Restorative material appearance varies depending on thickness and ______ _______
Atomic number Different atomic numbers (metals) make up different implants - that is why they all look different
What anatomy is visible in an anterior maxillary PA?
Nasal Fossa Nose soft tissue
What anatomy is visible in a posterior maxillary PA?
Maxillary Sinus - commonly Maxillary tuberosity - distally Hammulus - distally
What anatomy is visible in an anterior mandibular PA?
Mental ridge (chin) Lingual Foramen Genial Tubercle ** opacity: tubercle ** radiolucent: foramen
What anatomy is visible in a posterior mandibular PA?
Mental foramen Mandibular canal (inferior alveolar nerve resides) Mylohyoid Ridge Submandibular Gland Fossa External oblique ridge
What objects on an image are lighter on the film?
Radioopaque objects
What objects on an image are darker on the film?
Radiotranslucent objects
What is this foramen?
Mental Foramen
What is this phenomenon called?
Forshortening
What is this phenomenon called?
Enlongation
What is the radiopaque structure surrounding the tooth?
Lamina dura - continuous with the cortical bone (alveolar bone)
Is the periodontla ligament radiopaque or radiolucent?
Shape distortion can manifest itself as what? (2)
Elongating
Foreshortening
