Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
148 Cards in this Set
- Front
- Back
|
Filament Circuit |
regulates flow of electrical current to the filament and is controlled by mA settings. |
|
|
Increased density will cause the film to appear |
darker |
|
|
What increased exposure factors will make the film darker |
mA, kVp, et |
|
|
Decreased density will make the film appear |
lighter |
|
|
Contrast |
differences in light & darkness of images on the film |
|
|
Low contrast |
shades of gray -good to detect perio disease |
|
|
high contrast |
distinct diff btw light and darkness -good for detection of caries |
|
|
What influences contrast |
film contrast, subject contrast, kVP |
|
|
what exposing factor effects contrast |
kVP |
|
|
Higher kVp |
the more easily xrays pass through objects in their path, resulting in low contrast and many shades of gray |
|
|
Low kVp |
high contrast with more areas of distinct b&w |
|
|
stepwedge |
monitoring device for film quality & quality contrast tests for film density & contrast |
|
|
What does kVp control? |
the QUALITY or wavelength & speed of the xray beam |
|
|
Dental radiographs require the use of how much kV (kilovolt) |
65-100 kv |
|
|
when kvp is increased by 15 what happens to the Exposure time? |
ET cut in half |
|
|
When kVp is decreased by 15 what happens to the Exposure Time? |
ET is doubled. |
|
|
Increase kVp |
increase density, low contrast, good for detecting perio, darker image |
|
|
decrease kVp |
decreased density, high contrast, good for detecting caries, lighter image |
|
|
Milliamperage measures what? |
Quantity of xrays |
|
|
10mA x 1.5 =15 mA x 15 = 15x x= |
1.0 seconds |
|
|
When distance is doubled, the beam is __ as intense |
1/4 |
|
|
When the distance is halved, the beam is --- as intense |
4 times |
|
|
kVp measures |
speed of electrons/ quality |
|
|
mA measures |
number of electrons/ quantity |
|
|
exposure time measures |
number of electrons produced |
|
|
How many anterior periapicals do you take for a full mouth series and what color are they |
6, blue |
|
|
How many xrays do we take in a full mouth series in the clinic?
|
18 |
|
|
How many posterior periapical do you take in a full mouth.
|
8 |
|
|
The red xcp takes how many radiographs in a full mouth series |
4 |
|
|
what view does a red XCP take
|
posterior bitewings |
|
|
Is a film place in the red xcp vertically or horizontally
|
Vertically/horizontally |
|
|
The yellow XCP takes how many radiographs in the full mouth series
|
8 |
|
|
What view does the yellow XCP take
|
posterior periapicals |
|
|
Is a film placed in the yellow XCP vertically or horizontally
|
horizontally |
|
|
The blue XCP takes how many radiographs and a full mouth series
|
6 |
|
|
Which view does the blue XCP take
|
Anterior periapicals |
|
|
Is a film place in the blue XCP vertically or horizontally
|
vertically |
|
|
Which teeth are viewed in the lower right corner on the Mount |
Left mandibular molars |
|
|
Which teeth are viewed in the lower center on the Mount |
Mandibular incisors
|
|
|
What teeth are viewed in the upper right corner of the mouth |
Left maxillary molars |
|
|
Where is the dot placed on anterior view radiographs |
Occlussal/incisor surface |
|
|
Where's the dot place on the bitewing radiograph
|
anywhere |
|
|
Which teeth are viewed in the upper center of the mouth |
maxillary incisors |
|
|
How many bitewings are viewed on a full mouth series
|
four |
|
|
What is the main principle of the paralleling technique |
The film and receptor is placed parallel to the long axis of tooth; while the central beam is perpendicular to the receptor |
|
|
What are example of receptor exposure errors |
Unexposed film and film exposed to light |
|
|
What does unexposed film appear as and what is the cause? |
Film appears clear due to the receptor not exposed. To avoid this make sure the machine is on. |
|
|
How does film exposed to light appear and what is it caused by? |
Film appears black. Avoid by opening film packet only under a safe light under darkroom conditions. |
|
|
How does overexposed film appear and what is it caused by? |
Film appears dark and is caused by increase in settings. Check the kVp, et, mA settings |
|
|
How does underexposed film appear and what is it caused by? |
Film appears too light due to decrease in settings. Check the mA, kVp, or et settings. |
|
|
What is the correct placement for periapical exposure? |
receptor covers entire tooth including apex, and extends 1/8 in incisally. |
|
|
What error would improper placement or dropped film corner appear as, and what causes it? |
If teeth on the film appear to be dipping downward. This is caused because the edge of the receptor has slipped and is not parallel to incisal or occlusal surfaces, most often seen in bisecting the angle with PT. holding film |
|
|
What error would cause teeth to appear with overlapping contacts due to the central ray not going through interproximal contacts |
What would incorrect horizontal angulation cause |
|
|
What error would cause the radiographic image to not be the same size as tooth? The disproportionate amount of occlusal surface on BW. |
What would incorrect vertical angulation cause? |
|
|
What causes foreshortened images? |
Vertical angulation is too steep |
|
|
What causes elongated images? |
Insufficient vertical angulation |
|
|
What does cone cut look like and what causes it? |
Film has clear (white) unexposed area; the PID is not lined up correctly and beam did not expose entire film. |
|
|
Premolar bitewings should show? How would the you correct it otherwise? |
premolars and distal edge of canine; line up the front edge of film in the middle of the canine |
|
|
What should molar bitewings show? |
film should show max and mand molars; place the front edge of the film over the midline of 2nd premolar. For vertical BW = distal of 2nd premolar and posterior molars. |
|
|
Film bending is caused by |
When images appear stretched and distorted caused by the bending of film in palate and excessive pressure from finger. |
|
|
If a film appears with radiolucent lines What is the likely error? |
Film creasing, the film was bent causing film emulsion to crack. |
|
|
What does phalangioma mean? |
Finger appears on the film |
|
|
Light images with herringbone pattern (from embossed pattern on lead foil) is called _____ and is placed in the mouth backwards, lead in film decreases amt of beam that exposes film. |
Reversed film
|
|
|
Describe the ANT receptor placement of a maxillary canine?
|
entire crown and root, mesial contact must be present, distal contact may be obscured by 1st premolar |
|
|
Describe the ANT receptor placement of maxillary incisors |
one film for both centrals and laterals |
|
|
Describe the ANT receptor placement of mandibular canine? |
entire crown and root, and both mesial and distal contacts |
|
|
Describe the ANT receptor placement of mandibular incisors |
all four mandibular incisors, all contacts, and apex of tooth. |
|
|
What are somatic effects? |
Effects seen in the radiated person that will not pass down generations and effect all cells but reproductive ones |
|
|
What are genetic effects? |
Effects not sen in the person radiated and passed on to future generations because it effects the reproductive cells. |
|
|
Radiosensitive |
Cells that are sensitive to radiation |
|
|
Radioresistant |
Cells that are resistant to radiation |
|
|
Radiosensitive organs |
lymphoid, bone marrow, reproductive cells, immature cells, |
|
|
Radioresistant tissues |
mature bone, muscle, nerve |
|
|
The amount of energy absorbed by tissue when x-rays are produced is also known as |
Rad=Traditional unit (radiation absorbed dose) and Gray - SI equivalent |
|
|
What is used to compare biologic effects of different kinds of radiation on different kinds of tissues |
REM (Roetgen equivalent man) Sievert (SI equivalent) |
|
|
Traditional or standard doses: |
Roetgen -exposure Rad-dose REm-dose equivalent |
|
|
International or metric exposures |
coulumbs, gray, and seivert |
|
|
What is the process of removing low energy xrays that do not contribute to the formation of an xray image and increase exposure of the body to x-radiation |
filtration |
|
|
What resricts the size of beam |
collimation |
|
|
What filtration does not alone meet the standards regulated by state and federal law, so additional filtration is required. |
Inherent filtration |
|
|
What does added filtration do |
by adding aluminum disks you can filter out longer wavelengths or the lower energy xrays. |
|
|
What does adding aluminim disk do |
it results in a higher energy and more penetrating useful beam through added filtration |
|
|
What is the amount of inherent and added filtration |
total filtration |
|
|
*Dental x-ray machines above 70kVp require a minimum total filtration of _____ |
2.5mm |
|
|
Dental xray machines below 70 kVp must have a minimum of ___ total filtration |
1.5mm |
|
|
Rectangular collimation produces a beam slightly larger then |
size 2 standard film |
|
|
A rectangular collimator will result in ____ radiation |
55% less |
|
|
Explain an 8in PID vs 16in PID |
8 in PID results in more radiatoin a 16 in PID results in less radation |
|
|
How far away should a dental radiographer stand? |
6 feet away |
|
|
What is the maximum dose for occupational person |
5.0 rem per year |
|
|
What is the maximum dose for a pregnant woman? |
.1 rem per year same as noncoccupants |
|
|
When xray photons interact with water ____ occurs resulting in |
ionization; free radical formation |
|
|
this effect is a direct function of the disember and can cause cancer and genetic mutations |
stochastic effects |
|
|
This effect has a threshold; when biological damage increases in security so does the absorbed rose. ex: hair loss, redness or erythema |
nonstochastic effects |
|
|
Nausea, vomitting, diarrhea, hair loss, and hemorhage are signs of |
acute radiation syndrome
|
|
|
what determines radiosensitivity or resistance? |
mitotic activity, cell differentiation, cell metabolism |
|
|
what is the potential risk of dental radiography inducing a fatal cancer in an idividual |
3 in1 mill |
|
|
Dental xrays account for only ---- total annual exposure |
0.1% |
|
|
- a continuation of the anterior border of the Ramus that extends downwards and forward on the lateral surface of the mandible - appears as a radiopaque horizontal line of varied width superimposed across the molar roots |
oblique ridge |
|
|
__________are made up of four small, bony crests on the lingual surface of the mandible that serve for muscle attachments - visible as a round radiopaque doughnuts at that midline below the apices of the central incisors
|
genial tubercles |
|
|
Location – near midline of ant hard palate between central incisors with exit point for nasopalatine nerven. Appearance – small round radiolucent area between roots of maxillary teeth |
incisive foramen |
|
|
two openings located in bone of the floor of nasal cavity. These openings join to form incisive canal. the nasopalatine exits thru incisive foramen |
superior foramina of incisive canal |
|
|
Joint between the two palantine processesof the maxilla, that extends between two CI to the post hard palate. appears as thin radioLUCENT line between two CI, bound by cortical bone that is radiopaque |
medial palatal suture |
|
|
smooth depressed area in the maxillary bone between the canine and lateral incisiors located inferior and medial to theinfraorbital foramen. Radiograph: Radiolucent area between lateral and canine incisors |
Lateral or canine fossa |
|
|
Pear or triangular-shaped area of bone above max central incisors. The inferior portion is formed by the floor of nasal cavity if formed by the palatine processes of the max. The lateral walls are formed by the ethmoid bone and maxillae. Radiograph – large triangular area of radiolucency above max incisors |
nasal cavity |
|
|
vertical bony partition that runs thru the area of the nasal cavity. Radiograph – vertical radiopaque area running thru nasal cavity |
Nasal Septum |
|
|
Water thin-like plates of bone that extend from lateral walls of nasal cavity. Seen in lower lateral portions of nasal cavity. Radiograph – radiographic projections in the nasal cavity above the apices of the teeth |
Inferior nasal conchae |
|
|
sharp bony projection of max located on the ant and inferior portion of nasal cavity. Radiograph – on periapical appears a V-shaped radiopaque area at the intersection of the nasal cavity and the nasal septum |
anterior nasal spine |
|
|
paired cavities surrounded by bone located above premolar and molar teeth. Several variations on radiographs. Radiograph – radiolucent area above apices of max premolars and molars, floor is composed of dense cortical bone and appears as radiopaque lines, often following the apices of teeth |
maxillary sinusues |
|
|
bony walls that separate max sinuses into compartments. Radiograph – radiopaque lines within maxsinus varies with individuals |
septa within maxillary sinus |
|
|
tiny tube-like canals thru bone that contain blood vessels and nerves that supply max teeth and interdental areas. Radiograph – narrow radiolucent band bounded by two thin radiopaque lines -walls of cortical bone |
nutrient canals in max. sinus |
|
|
appears as a radiopaque upside down Y formed by the lateral wall of nasal fossa and ant border of max sinus -above the max canine |
inverted y |
|
|
rounded prominence of bone that extends posterior to third molar area. Radiograph – radiopaque bulge distal to third molar region |
maxillary tuberosity |
|
|
small hooklike projection appears radiopaque posterior to max. tuberosisty |
hamulus |
|
|
Radiograph – appears as J or U shaped radiopacity (dense cortical bone) superior to max first molar area |
zygomatic process of maxilla |
|
|
Radiograph – radiopaque band extending posteriorly from zygomatic process above molar area |
zygoma |
|
|
Radiograph – ring shaped radiopacity below apices of mand incisors |
genial tububercles |
|
|
Radiograph – small radiolucent dot located inferior to apices of mandular incisors surrounded by genial tubercles |
lingual foramen |
|
|
vertical radiolucent lines that are tubelike passages that carry blood vessels and nerves to mand. teeth |
nutrient canals |
|
|
Radiograph – thick radioapaque band often superimposed over ant teeth; extend from premolar to midline sloping slightly upward |
mental ridge |
|
|
depressed area of bone located on external surface of ant man, above mental ridge in incisal area. Radiograph – radiolucent area above mental ridge varies with individual depending on density of bone |
mental fossa |
|
|
opening or hole in bone on external surface of mandible which contains blood vessels & nerves. Radiograph – small oval radiolucent area in apical area of mand premolar |
mental foramen |
|
|
Radiograph – dense radiopaque band extending downward and forward from molar area and often superimposed over roots of mandibular teeth |
mylohyoid ridge |
|
|
tubelike passageway from posterior mand to mand foramen to mental foramen, that houses the inferior alveolar nerve. Radiograph – radiolucent band outlined by cortical walls of radiopaque bone, superimposed over apices of mand teeth |
mandibular canal |
|
|
depressed area of bone located on internal surface of mandible - inferior to mylohyoid ridge . The submandibular gland is found here. |
submandibular fossa |
|
|
Radiograph– triangular radiopacity superimposed over, or inferior, to the maxillary tuberosity area. Seen on periapical max molar film |
coronoid process |
|
|
Radiographic – dense radiopaque line that surrounds root of tooth |
lamina dura |
|
|
Radiograph – appears radiopaque located1.5-2.0 mm below junc of crown and roots surfaces |
alveolar crest |
|
|
Radiograph – appears as thin radiolucent line around root of tooth |
periodontal ligament space |
|
|
alveolar bone in the anterior region appears |
dense radioapaque line, sharp,and pointed |
|
|
in the posterior region the alveolar bone appears |
flat and smooth, less dense and radioapaque |
|
|
When using the paralleling technique where should the receptor be? |
The receptor should be parallel to the long axis of the tooth and toward the center of the mouth. |
|
|
What PID should be used to increase distance from the target film? |
16 in PID |
|
|
What size film will be used in a FMS |
size 2 |
|
|
Film should be placed with _____ facing teeth |
the white side |
|
|
How would you modify taking an xray if the patient has a maxillary torus? |
Place film on far side of torus |
|
|
How would you modify taking an xray if the patient has a mandibular torus? |
Place the film between tongue and tori |
|
|
How dangerous/safe is ionizing radation? |
All -- is harmful and produces biological changes in the tissues |
|
|
Two mechanisms of radiation injury are.. |
ionization and free radical formation |
|
|
What results when xrays strike the patients tissues and results in a positive atom and dislodged negative electron? |
ionization |
|
|
What is a free radical? |
An atom that exists with a single,unpaired electron in its outermost shell |
|
|
How reactive and stable are free radicals? |
Highly reactive and unstable
|
|
|
what three things can free radicals do |
1) combine with molecules and not produce effects 2. combine with others and cause changes in cell 3. May combine with other molecules and produce a toxin |
|
|
Damage to living tissue caused by exposure to ionizing radiation may result from |
Direct or in direct theorys |
|
|
Direct theory |
absorption of an xray photon within a cell causing damage to critical areas such as dna |
|
|
indirect theory |
absorpition of an xray photon by water within a cell accompanied by free radical formation and formation of toxins causing biological damage |
|
|
Time that elapses between exposure to ionizing radiation and the appearance of observable clinical signs |
latent period |
|
|
the more radiation and faster the dose; the ____ the latent period |
shorter |
