DENTAL RADIOLOGY Flashcards
Before ordering or prescribing x-rays, what must happen
dentist must examine their patients and determine what radiographs are needed
how often should radiographs be taken
depends on patient need
no radiograph should be retaken until
a thorough investigation reveals the exact cause of the error and the appropriate corrective action is identified
how do xrays work
the line current is alternating (60cycles/second) so the polarity of the x-ray tube alternates and the x-ray beam is generated as a series of pulses
dont PANIC
positive is anode negative is cathode
how are radiographs washed?
in running water to ensure removal of thiosulfate ions and silver thiosulfate complexes that stain the film if left
what does slob stand for
same lingual opposite buccal
foreshortening results from
vertical angulation too great
OVERangulation of the x-ray beam
too much vertical angulation
elongation results when
vertical angulation is too small
UNDERANGULATION of the x ray beam
what does ALARA stand for
as low as reasonably achievable
what is the most common tumor
odontoma
X-ray tube made of what? and why?
leaded glass because Xray cant pass through lead
why is tube head surrounded by oil?
oil conducts heat, will help to dissipate the heat
filament is in _____ and made of_____
filament is in cathode and made of tungsten
why is tungsten used
metal that has the highest melting point
more x rays =
more density , darker
radiographic density is
the overall degree of darkening of exposed film
energy is
mA (milliamperage)
increase in mA
darker film
decrease in mA
lighter film
anode is made of ___beacause
tungsten because it can withstand high temperatures
anode aka
tungsten target
kvp measures
speed of electrons
increasing kvp(speed) will increase
penetrating power of the xrays
increase kvp
darker film
decrease kvp
lighter film
more exposure time = more xrays hitting
more Xrays hitting the receptor
increase exposure time
darker film
decrease exposure time
lighter film
increase :
KVP
mA
exposure time
darker film
decrease :
KVP
mA
exposure time
lighter film
what gives better quality xrays : short or long wavelengths
short wavelengths
aluminum filter does what
filters out the long wavelengths
problem with rectangular collimator
cone cut
inverse square law
increasing distance of pid will decrease intensity
on panoramic machines you cant control
exposure time
quality of beam refers to
how good the image is
quality of beam is affected by
kVp
filtration
quantity of beam is affected by
mA
increasing distance between focal spot and film
decrease density
decreasing distance between focal spot and film
increase density
the most popular digital detector
charge-coupled device (CCD)
the faster the film the less
the less exposure it needs
silver halide salts are in
the emulsion
the coronoid process can be seen in what radiograph
maxillary molar PA
x/y formation is found on what radiograph
max PA of canine
inverted Y is radiopaque
PDL is radiolucent or radiopaque?
radiolucent
pulp horn is radiolucent or radiopaque?
radiolucent
lamina dura is radiolucent or radiopaque?
radiopaque
zygomatic is what shape
U or J shaped
medial palatal suture looks like
a fracture line, radiolucent line located between maxillary central incisors
incisive foramen, is radiolucent or radiopaque?
hole in the bone, radiolucent , between max central incisors
incisive foramen aka
nasopalatine foramen
nasal septum
radiopaque, right above the roots of max central incisors
nasal fossa aka ____ is is radiolucent or radiopaque?
nostrils, radiolucent , separated by nasal septum
buccainator crest
External oblique ridge
found on posterior mandibular PA, radiopaque structure
mylohyoid ridge
below the external oblique ridge, radiopaque
submandibular gland fossa
below the mylohyoid, diffused (not well-defined) radiolucent area
what runs into the mandibular canal
IA nerve
mandibular canal
tube like structure
mental foramen
radiolucent, circular, around apices of first and second premolar . (mandibular)
mental ridge
lower ant PA
linear radiopacity
genial tubercle is radiolucent or radiopaque?
radiopaque
lingual foramen is radiolucent or radiopaque?
radiolucent, in the middle of the genial tubercle
SLOB is for locating
foreign objects in the oral cavity
the imaginary bisector is perpendicular to the
bisecting angle
in the paralleling technique, the receptor is moved farther away from the tooth because
the receptor can get parallel with the long axis of the tooth
why is the parallel technique the preferred technique
less distortion
to increase the positive angulation
PID pointing down
to increase negative angulation
PID pointing up
less than 90 degrees
foreshortening
more than 90 degrees
elongation
overlap is a ____ alignment error
horizontal alignment error
to fix the overlap you move the tube head
move the tube head more mesially
underexposed makes ______ image
light image
overexposed makes ______ image
darker image
reverse smile line (frown) on pan
chin is too high
too much smiling on pan
patients chin is too low
in pan if the patient is too close the image will be
image will be too far
in pan if the patient is too far away the image will be
image will be too close
roentgen measures how much
radiation is produced
before taking x rays on the pregnant patient you have to
talk to the OBGYN get consultation first
safest trimester for dental work
2
4-6 months preggo
most often area for ameloblastoma
mandible most often in molar-ascending ramus area 80-85%
ameloblastoma is usually benign but is very aggressive
periapical cemento-osseous dysplasia is radiolucent but in a few years can turn
radiopaque
periapical cemento-osseous dysplasia affects who the most
middle-aged black females
florid cemento-osseous dysplasia
involves no teeth
focal cemento-osseous dysplasia affects who the most
middle-aged white female
all teeth involved with cemento-osseous dysplasia are vital or nonvital
vital
pagets disease appearance
cotton wool
most common cyst
periapical cyst
dentigerous cyst aka
follicular cyst
highest recurrence rate cyst
odontogenic keratocystic
dentigerous cyst tx
remove tooth then curettage
what is the most common non-odontogenic cyst of the oral cavity
nasopalatine duct cyst
a dense, vertical radiopacity separating two paired oval radiolucencies were observed in the maxillary anterior region
nasal septum
large paired oval radiolucencies separated by a dense, vertical radiopacity observed in the maxillary anterior region
max anterior nasal cavity
a thin radiolucent line resembling a fracture observed between the maxillary anterior region
median palatal suture
a round or pear shaped radiolucency observed between the maxillary central incisors
incisive foramen
a broad U-shaped radiopacity was observed superimposed over the maxillary posterior teeth roots
zygomatic process of maxilla
a radiopaque downward projection of the bone that appears pointed or hook-like observed in the far posterior region of the maxilla
hamulus
a large triangular-shaped radiopacity was observed superimposed over the maxillary tuberosity region
coronoid process
a large radiolucency outline by a thin radiopaque border that is observed in almost all the periapical radiographs of the maxilla, from the canine posteriorly
maxillary sinus
a very small round radiolucency observed in the midline apical (below) the mandibular incisors
lingual foramen
a horizontal radiopaque line extending from the premolar region to the symphysis
mental ridge
a round radiolucency that resembles an abscess observed near the apex of the second premolar
mental foramen
a horizontal radiopaque line was observed in the mandibular posterior region superimposed across the molar roots
oblique ridge
another horizontal radiopaque line observed in the mandibular posterior region but inferior to the oblique ridge. the line observed is inferior to the molar roots
mylohyoid ridge
a large irregularly shaped radiolucency observed below the mylohyloid ridge
submandibular fossa
penumbra
area of unsharpness/lack of sharp detail
Which combination of film speed and collimation for dental imaging will result in the lowest dose to the patient?
F-speed film with rectangular collimation