Lecture 3 - Radiology Flashcards
Black X thru tooth?
Blue X thru tooth?
Congenitally missing
Previously extracted
Existing
Composite?
Amalgam?
Gold?
Porcelain/Ceramic crown?
Outline surfaces in blue
Fill in surfaces in blue
Cross hatch surface in blue
Outline tooth in blue
Red color means what?
Needs to be done
Look at slide 5 and understand what is happening.
Do it
What are 3 ways to maximize sharpness and resolution (image clarity)?
Use as small an effective focal spot as practical (Built into tube head)
Increase distance from focal spot to object with long open ended cylinder (aiming cylinder)
Minimize distance from object to image receptor (Film next to tooth)
How is image size distortion minimized? 2 ways.
Increase focal spot to image receptor distance (aiming cone)
Decrease object to image receptor distance (film placement)
How can image shape distortion be minimized? 2 ways.
Position image receptor (film) parallel to long axis of object (tooth)
Orient central ray (cone) perpendicular to the object and image receptor
*This can manifest as foreshortening or elongation of the film image
What is foreshortening?
Central beam is perpendicular to the image receptor (film), BUT the object (tooth) is not
What is elongation?
Central beam is perpendicular to the object (tooth), BUT not the image receptor (film)
What is ideal?
Central ray should be perpendicular to the long axes of both the tooth and the image receptor
What is the bisecting-angle technique?
Central beam should be directed at a right angle to the imaginary plane bisecting the angle formed by the image receptor (film) and the central axis of the object (tooth).
*Image is of correct length, but with distortions in tooth and height of alveolar crest
What is the SLOB rule?
Same Lingual - Opposite Buccal
*Used for determining if an object found on a radiograph is located buccal, lingual, or in the same plane as the teeth
- Take normal radiograph, move x-ray head so its angled from the mesial and take it again
- If object moves mesial, or the same direction as you moved the tube head, then it is LINGUAL to the teeth
- If object moves opposite, distal, then it is located buccal to the teeth
T/F - On a bitewing, you should see alveolar crestal bone.
TRUE
Define radiolucent.
Any substance (part of the patient) that permits the transmission of xrays (less dense - appears dark on the radiograph)
Define radiopaque.
Any substance (part of the patient) that blocks the transmission of xrays (more dense - more light)
T/F - Enamel is radiopaque.
TRUE
What is the lamina dura?
Tooth sockets are bound by a thick layer of dense bone - contiguous with cortical bone at the alveolar crest
Wider in teeth with heavy occlusion
Maxillary molar PA
ALL molars, including 3rds
Distal 2nd premolar
Contacts open, proximal surfaces of molars
3-5 mm past apices, minimum
Maxillary Premolar PA
Both premolars
Distal of canine
Medial of 1st molar
Contacts open, proximal surfaces of premolars
3-5 mm past apices, minimum
Maxillary Canine PA
Canine and lateral incisor
Mesial of 1st premolar
Contact open b/t canine and lateral
3-5 mm past apices, minimum
Maxillary Central Incisor PA
Central incisors - both
Mesials of lateral incisors
Contacts open b/t proximals of centrals
3-5 mm past apices, minimum
Molar BWX Molars
All upper/lower
Distal of 2nd premolar
Molar contacts open
Crestal bone clearly visible
Premolar BWX
Premolars - All upper/lower
Mesial of 1st molar
Distal of canines
Contacts open, proximal surfaces of premolars
Crestal bone clearly visible
Mandibular Molar PA
All molars including 3rds
Distal 2nd premolar
Contacts open, proximal surfaces of molars
3-5 mm past apices, minimum
Mandibular Premolar PA
Both premolars
Distal of canine
Mesial of 1st molar
Contacts open, proximal surface of premolars
3-5 mm past apices, minimum
Mandibular Canine PA
Canine and lateral incisor
Mesial of 1st premolar
Contact open b/t canine and lateral
3-5 mm past apices, minimum
Mandibular Central Incisor PA
Central incisors - both
Mesials of lateral incisors
Contacts open b/t proximals of centrals
3-5 mm past apices, minimum
The alveolar crest is what?
Gingival margin of the alveolar process that extends b/t the teeth
RADIOPAQUE
*Normal when it is not more than 1.5mm apical to the CEJ
**May recede with age
PDL - what is it?
CT that surrounds the root and connects it w/ the bone
Seen b/t the root and lamina dura extending from the alveolar crest around the root to the opposite alveolar crest
RADIOLUCENT
What is cancellous/trabecular bone?
Lies b/t cortical plates
RADIOPAQUE plates and rods surrounding RADIOLUCENT marrow pockets
What restorative materials are RADIOLUCENT?
Silicate cements - rare
Some composite resins
Porcelain
What restorative materials are radiopaque?
Amalgam Gold Pins/posts CaOH2 Gutta percha Silver points Some composites Stainless steel crowns Ortho appliances Implants
When can the nose be seen on a radiograph?
Max Ant PAs
Slightly radiopaque
Sometimes RADIOLUCENT nares are visible
Where can you see the mental foramen on a radiograph?
Just apical to the 2nd premolar
