Intraoral Imaging Techniques Flashcards
Use this deck to study the paralleling, bisecting, bite-wing, occlusal and localization techniques and their exposure errors
Define the term: alveolar crest / crestal bone
- the most coronal portion of alveolar bone found between teeth
- composed of cortical bone (appears radiopaque)
Define the term: angle
in geometry, a figure formed by two lines diverging from a common point
Define the term: right angle
in geometry, an angle of 90 degrees formed by two lines perpendicular to each other
Define the term: angulation
the alignment of the central x-ray beam in the horizontal and vertical planes
Define the term: horizontal angulation
the positioning of the position-indicating device in a horizontal plane
Define the term: negative vertical angulation
the positioning of the position-indicating device below the occlusal plane that directs the central ray upward
Define the term: positive vertical angulation
the positioning of the position-indicating device above the occlusal plane that directs the central ray downward
Define the term: vertical angulation
the positioning of the position-indicating device in a vertical plane
Define the term: beam alignment device
- a device used to align the position-indicating device in relation to tooth and image receptor
- positions the intraoral image receptor in the mouth and retains the image receptor in position during exposure
- helps stabilize the image receptor in the mouth and reduces the chances of movement, thus reducing the patient’s exposure to x-radiation
Define the term: bisect
to divide into two equal parts
Define the term: bisecting technique
- an intraoral imaging technique used to expose periapical receptors
- the image receptor is placed along the lingual surface of the tooth, the central ray of the x-ray beam is directed perpendicular to the imaginary bisector formed by the image receptor and the long axis of the tooth
- receptor holder is used to stabilize the image receptor
Define the term: imaginary bisector
- an imaginary plane that divides in half the angle formed by the image receptor and the long axis of the tooth
- creates two equal angles and provides a common side for the two imaginary equal triangles
Define the term: horizontal bite-wing
the bite-wing receptor is placed in the mouth with the long portion of the receptor in a horizontal direction
Define the term: vertical bite-wing
the bite-wing receptor is placed in the mouth with the long portion of the receptor in a vertical direction
Define the term: bite-wing tab / bite loop / bite tab
a heavy paperboard tab or loop fitted around an intraoral image receptor during exposure
Define the term: bite-wing technique / interproximal technique
an intraoral imaging technique in which the interproximal surfaces of teeth are examined
Define the term: buccal object rule
- a method used to illustrate the orientation of structures portrayed in two images exposed at different angulations
- used to determine the buccal-lingual relationship of an object
Define the term: central ray (CR)
the central portion of the primary beam of x-radiation
Define the term: complementary metal oxide semiconductor-active pixel sensor (CMOS-APS)
- silicon-based detector used in digital imaging
- differs from the charge-coupled device in the way that pixels are read*
Define the term: full mouth series (FMX) / complete mouth series (CMS)
an intraoral series of dental images that show all of the tooth-bearing areas of the upper and lower jaws
Define the term: cone-cut
a clear, unexposed area on a dental image that occurs when the position-indicating device is misaligned and the x-ray beam is not centered over the image receptor
Define the term: contact areas
the areas where adjacent tooth surfaces touch each other
Define the term: open contacts
on a dental image, appears as a thin radiolucent line between adjacent tooth surfaces
Define the term: overlapped contacts
on a dental image, the area where the contact area of one tooth is superimposed over the contact areas of an adjacent tooth
Define the term: contrast
- how sharply dark and light areas are differentiated or separated on an image
- the difference in the degrees of blackness (densities) between adjacent areas on a dental image
Define the term: high contrast
a term describing an image with many very dark areas and very light areas and few shades of gray
Define the term: long-scale contrast
- a term describing an image with many densities, or many shades of gray
- results from the use of a higher kilovoltage range
Define the term: low contrast
a term describing an image with many shades of gray and few areas of black and white
Define the term: scale of contrast
the range of useful densities on a dental images
Define the term: short-scale contrast
- a term describing an image with predominately areas of black and white
- results from the used of a lower kilovoltage range
Define the term: subject contrast
the characteristics of the subject (patient) that influence contrast, including the size and thickness of the patient
Define the term: control devices
- the components of the control panel of the x-ray machine that regulate the x-ray beam
- includes the timer, kilovoltage and milliamperage selectors
Define the term: density
the overall darkness or blackness of an image
Define the term: dentulous
- with teeth
- areas that exhibit teeth
Define the term: diagnosis
identification of a disease by examination or analysis
Define the term: digital image
an image composed of pixels
Define the term: digital imaging
a system of filmless imaging used to capture an image using a sensor, breaking it into electronic pieces, and presenting and storing the image using a computer
Define the term: object-receptor distance
- the distance from the object being imaged (tooth) to the image receptor influences image magnification
- less image magnification results when the tooth and the image receptor are as close as possible, and more magnification results when the tooth and receptor are far apart
Define the term: target-object distance
the distance from the source of x-rays (tungsten target in the anode) to the object being imaged (tooth)
Define the term: target-surface distance
the distance from the source of x-rays (tungsten target in the anode) to the surface of the patient’s skin
Define the term: distortion
- a geometric characteristic that refers to a variation in the true size and shape of the object being imaged
- influenced by object-receptor alignment and the vertical angulation of the x-ray beam
Define the term: edentulous
- without teeth
- an area where teeth are no longer present
Define the term: edentulous patient
a patient without teeth
Define the term: edentulous zone
an area where teeth are no longer present
Define the term: elongated image
an image of a tooth that appears long and distorted
Define the term: elongation
- a term used in imaging to describe an image of a tooth that appears longer than the actual tooth
- results from flat or insufficient vertical angulation
Define the term: exposure
a measure of ionization produced in air by x-radiation or gamma radiation
Define the term: exposure factors
factors that influence the density of an image (ex: milliamperage, kilovoltage, exposure time)
Define the term: exposure sequence
a defined order to place and expose intraoral receptors
Define the term: forshortened image
an image of a tooth that appears short and distorted
Define the term: forshortening
- a term describing the image of a tooth that appears shorter than the actual tooth
- results from steep or excessive vertical angulation
Define the term: hypotenuse
in geometry, the side of a right triangle opposite the right angle
Define the term: image
a picture or likeness of an object
Define the term: bite-wing image
intraoral image that is used to examine the interproximal surfaces of teeth
Define the term: dental image
a two-dimensional representation of a three-dimensional object produced by the passage of x-rays through teeth and supporting structures
Define the term: diagnostic image
a dental image that allows for the identifying and monitoring of diseases or injuries
Define the term: double image
- an exposure error that occurs when a PSP receptor is exposed twice in the patient’s mouth
- appears dark as the result of two superimposed images
Define the term: intraoral image
- an image the results when an image receptor is placed inside the mouth and exposed to x-rays
- used to examine teeth
Define the term: overexposed image
an exposure error that results in a dark image from excessive exposure time, kilovoltage, or milliamperage, or a combination of these factors
Define the term: periapical image
intraoral image that is used to examine the crowns and roots of teeth
Define the term: image receptor
a recording medium (ex: PSP plate, digital sensor)
Define the term: underexposed image
an exposure error that results in a light image due to inadequate exposure time, kilovoltage or milliamperage, or a combination of these factors
Define the term: dental imaging
the creation of digital representation of anatomic structures for the purpose of diagnosis
Define the term: Rinn XCP instrument
- a type of beam alignment device that is used with the paralleling technique
- includes plastic bite blocks, plastic aiming rings, and metal indicator arms
Define the term: interproximal
between two adjacent surfaces
Define the term: interproximal examination
an intraoral inspection used to examine the crowns of both maxillary and mandibular teeth on a single image
Define the term: intersecting
cutting across or through
Define the term: intraoral
inside the mouth
Define the term: intraoral imaging examination
a dental imaging inspection of teeth and intraoral adjacent structures
Define the term: inverse square law
- a rule that states that “the intensity of radiation is inversely proportional to the square of the distance from the source of radiation”
- as distance is increased, the radiation intensity at the object is decreased, and vice versa
Define the term: isometry
equality of measurement
Define the term: rule of isometry
a geometric principal that states that “two triangles are equal if they have two equal angles and share a common side”
Define the term: lead apron
a flexible lead shield used to protect the patient’s reproductive and blood-forming tissues from scatter radiation
Define the term: long axis of a tooth
an imaginary line that divides a tooth longitudinally into two equal halves
Define the term: magnification
- a geometric characteristic that refers to an image that appears larger than the actual size of the object it represents
- influenced by target-receptor distance and object-receptor distance
Define the term: mandible
the lower jaw
Define the term: maxilla
the upper jaw
Define the term: movement
motion of the image receptor or patient during image exposure that results in an image with decreased sharpness
Define the term: parallel
moving or lying in the same plane; always separated by the same distance and not intersecting
Define the term: paralleling technique / extension cone paralleling (XCP) technique / right-angle technique / long-cone technique
- an intraoral imaging technique used to expose periapical receptors, where the receptor is placed parallel to the long axis of the tooth, the central ray is directed perpendicular to the receptor and the long axis of the tooth
- a beam alignment device must be used to keep the receptor parallel to the long axis to the tooth
Define the term: penumbra
the unsharpness or blurring of the edges of a structure viewed on a dental image
Define the term: periapical
around the apex of a tooth
Define the term: periapical examination
a type of intraoral imaging examination used to view the entire tooth (crown and root) and supporting bone
Define the term: perpendicular
intersecting at or forming right angles
Define the term: position-indicating device (PID) / cone
- an open-ended, lead-lined cylinder extending from the opening of the tubehead
*aims and shapes the x-ray beam
Define the term: radiolucent
the portion of an image that is dark or black, due to the structure readily permitting the passage of the x-ray beam and allowing more x-rays to reach the image receptor
Define the term: radiopaque
the portion of an image that is light or white, due to the structure resisting the passage of the x-ray beam and limiting the amount of x-rays that reach the receptor
Define the term: bite-wing receptor
an intraoral image receptor used to examine the crowns of both maxillary and mandibular teeth on one image
Define the term: intraoral receptor
an image receptor is placed inside the mouth during x-ray exposure to examine teeth and supporting structures
Define the term: periapical receptor
an intraoral image receptor used to examine the entire tooth (crown and root) and supporting bone
Define the term: image receptor holder
a device used to hold an intraoral image receptor in the mouth and stabilize the receptor’s position during the exposure
Define the term: image receptor placement
the specific area where the image receptor must be positioned before exposure
Define the term: contrast resolution
the number of gray-scale colors available to be chosen for each pixel in the image
Define the term: right-angle technique
a localization technique in which the orientation of structures can be seen in two images (one periapical and one occlusal)
Define the term: Rinn Snap-A-Ray Holder
an intraoral receptor holder used to stabilize an image receptor during exposure
Define the term: sensor
in digital imaging, an image receptor that is used to capture an intraoral or extraoral image
Define the term: sharpness
- refers to the capability of the image receptor to reproduce the distinct outlines of an object
- influenced by focal spot size and movement
Define the term: Stabe Biteblock
a disposable styrofoam device that can be used to hold an image receptor during exposure
Define the term: storage phosphor imaging
an indirect method of obtaining a digital image in which the image is recorded on phosphor-coated plates and then placed into an electronic processor, where a laser scans the plate and produces an image on a computer screen
Define the term: subject thickness
the thickness of soft tissue and bone in a patient
Define the term: anterior teeth
central incisors, lateral incisors, and canines/cuspids
Define the term: posterior teeth
first and second premolars/bicuspids, and first, second and third molars
Define the term: thyroid collar
a flexible lead shield used to protect the thyroid gland from scatter radiation during exposure
Define the term: tooth-bearing areas
regions of the maxilla and mandible in which the 32 teeth of the human dentition are normally located
Define the term: torus (plural: tori)
a bony growth in the oral cavity
Define the term: triangle
- in geometry, a figure formed by connecting three points not in a straight line by three straight-line segments
- has three angles
Define the term: equilateral triangle
in geometry, a triangle with three equal sides
Define the term: right triangle
in geometry, a triangle with one 90-degree angle
Define the term: congruent triangles
in geometry, triangles that are identical and correspond exactly when superimposed
Define the term: x-radiation
a high-energy radiation produced by the collision of a beam of electrons with a metal target in the x-ray tube
Define the term: x-ray beam angulation
one of the influencing factors for image distortion that refers to the direction of the x-ray beam
Define the term: anterior
towards the front
Define the term: posterior
towards the back
Define the term: maxillary teeth
teeth located in the maxilla or upper arch
Define the term: mandibular teeth
teeth located in the mandible or lower arch
Define the term: vertical
an up-and-down plane
Define the term: horizontal
a side-to-side plane
Define the term: adjacent / proximal
objects next to/touching each other
Define the term: apical
towards the apex of a tooth
Define the term: radiopacity / radiodensity
an area on a dental image appearing radiopaque (light/white) due to resisting the passage of the x-ray beam and limiting the amount of x-rays that reach the image receptor
Define the term: radiolucency
an area on a dental image appears radiolucent ((dark/black) due to readily allowing the passage of the x-ray beam so that more x-rays reach the image receptor
Define the term: apex
the area of a tooth that allows for blood vessels and nerves to enter the tooth and maintain the vitality of the tooth
Define the term: non-diagnostic image
an image that is not diagnostically accurate due to technique errors and must be retaken
Define the term: target-receptor distance
the distance from the source of radiation (tungsten target in the anode) to the image receptor
What are the two most common types of direct digital imaging receptors?
- charge-coupled device (CCD)
- complementary metal oxide semiconductor-active pixel sensor (CMOS-APS)
What are the two methods of obtaining a digital image?
- direct digital imaging
- indirect digital imaging
What type of image receptor is common when using indirect digital imaging?
photo-stimulable phosphor imaging (PSP) plate
True or false: The PSP plate used in indirect digital imaging is a one-time-use product.
False
What can be used to help stabilize the image receptor during exposure?
beam alignment device
List the three types of intraoral imaging examinations.
- periapical examination
- interproximal examination
- occlusal examination
List the two imaging techniques used to capture a periapical image.
- paralleling technique
- bisecting technique
What imaging technique is used for occlusal examinations?
occlusal technique
In order to prevent the gag reflex at the beginning of your exposure sequence, what area of the mouth should you begin?
anterior region
Which image receptor placement area is most likely to elicit the gag reflex?
maxillary molars
Why do edentulous patients still require dental imaging?
- to detect the presence of root tips, impacted teeth, and lesions
- to identify objects imbedded in bone
- to establish the position of anatomic landmarks relative to the crest of the alveolar ridge
- to observe the quality and quantity of the remaining bone
List the landmark requirements for a diagnostic image of a maxillary canine.
- the entire crown and root, including the apex and surrounding structures
- the interproximal alveolar bone and mesial contact of the canine
*the lingual cusp of the first premolar cannot obscure the distal contact of the canine
List the landmark requirements for a diagnostic image of maxillary incisors.
- the entire crowns and roots of all four maxillary incisors, including the apices and surrounding structures
- the interproximal alveolar bone between the central incisors and the central and lateral incisors
List the landmark requirements for a diagnostic image of a mandibular canine.
- the entire crown and root, including the apex and surrounding structures
- the interproximal alveolar bone and mesial and distal contacts of the canine
List the landmark requirements for a diagnostic image of mandibular incisors.
- the entire crowns and roots of all four mandibular incisors, including the apices and surrounding structures
- the contacts between the central incisors and the central and lateral incisors
List the landmark requirements for a diagnostic image of maxillary premolars.
- the entire crowns and roots of the first and second premolar and first molar, including the apices, alveolar crests, contact areas, and surrounding structures
- the distal contact of the maxillary canine
List the landmark requirements for a diagnostic image of maxillary molars.
- the entire crowns and roots of the first, second, and third molars, including the apices, alveolar crests, contact areas, tuberosity region, and surrounding structures
- the distal contact of the maxillary second premolar
List the landmark requirements for a diagnostic image of mandibular premolars.
- the entire crowns and roots of the first and second premolars and the first molar, including the apices, alveolar crests, contact areas, and surrounding structures
- the distal contact of the mandibular canine
List the landmark requirements for a diagnostic image of mandibular molars.
- the entire crowns and roots of the first, second, and third molars, including the apices, alveolar crests, contact areas, and surrounding structures
- the distal contact of the mandibular second premolar
When imaging anterior teeth, is the intraoral image receptor placed vertically or horizontally?
vertically
When imaging posterior teeth, is the intraoral image receptor placed vertically or horizontally?
horizontally
What types of images can be exposed using the paralleling technique?
periapical and bite-wing images
How is the image receptor placed when using the paralleling technique?
the image receptor is placed parallel to the long axis of the tooth being imaged
How is the central ray of the x-ray beam positioned when using the paralleling technique?
the central ray of the x-ray beam is directed perpendicular to the long axis of the tooth being imaged
True or false: A beam alignment device is required for the paralleling technique.
True
What is the correct vertical angulation used for the paralleling technique?
The central ray of the x-ray beam must be directed perpendicular to the image receptor and long axis of the tooth
What is the correct horizontal angulation used for the paralleling technique?
The central ray of the x-ray beam must be directed through the contact areas between the teeth
Why does a shallow palate create a difficulty when using the paralleling technique?
the shallow palate tilts the bite-block, which results in a lack of parallelism between the image receptor and the long axis of the tooth
What are the two modifications that can be made for a patient with a shallow palate when using the paralleling technique?
- cotton roll placement on each side of the bite block
- increase the vertical angulation by 5-15 degrees
How is the paralleling technique modified for a patient with maxillary tori?
the image receptor must be placed on the far side of the tori (not on the tori)
How is the paralleling technique modified for a patient with mandibular tori?
the image receptor must be placed between the tori and the tongue (not on the tori)
What is the primary advantage of using the paralleling technique?
images without dimensional distortions
Why is the paralleling technique easy to learn?
the use of a beam alignment device eliminates the need for the dental radiographer to determine vertical and horizontal angulation
What is the primary disadvantage of the paralleling technique?
image receptor placement
Why is image receptor placement often difficult when using the paralleling technique?
for patients with a small mouth or shallow palate, the receptor placement can be difficult to access, and can also cause discomfort to the patient
What geometric principle is the bisecting technique based on?
rule of isometry
Where is the image receptor placed when using the bisecting technique?
along the lingual surface of the tooth
Once the image receptor is placed, how must the central ray be positioned against the imaginary bisector when using the bisecting technique?
the central ray must be perpendicular to the imaginary bisector
What images can be taken using the bisecting technique?
periapical images
What is the correct horizontal angulation in the bisecting technique?
the central ray is directed perpendicular to the dental arch and through the contact areas of the teeth
How will the contact areas appear as a result of correct horizontal angulation in the bisecting technique?
opened contacts
How will the contact areas appear as a result of incorrect horizontal angulation in the bisecting technique?
overlapped contacts
What is the correct vertical angulation in the bisecting technique?
- vertical angulation is determined by the imaginary bisector
- the central ray is directed perpendicular to the imaginary bisector
What is the result of correct vertical angulation when using the bisecting technique?
the image is the same length as the tooth
What is the result of incorrect vertical angulation when using the bisecting technique?
the image is not the same length as the tooth, and appears distorted or elongated
What is the primary advantage of using the bisecting technique?
eliminating the use of a beam alignment device
What is the primary disadvantage of using the bisecting technique?
dimensional distortion
When using the bite-wing technique, how is the image receptor placed intraorally?
parallel to the crowns of both the maxillary and mandibular teeth
When using the bite-wing technique, how is the central ray of the x-ray beam directed towards the image receptor?
the image receptor is directed through the contacts of the teeth, using a vertical angulation of +10 degrees
When using the bite-wing technique, what is the correct horizontal angulation of the central ray of the x-ray beam?
the central ray is directed perpendicular to the curvature of the arch and through the contact areas of the teeth
When using the bite-wing technique, what does incorrect horizontal angulation cause on the image?
overlapped contacts
When using the bite-wing technique, what is the correct vertical angulation of the central ray of the x-ray beam?
+10 degrees
Why is positive vertical angulation needed for the bite-wing technique?
the +10 degrees compensates for the slight bend of the upper portion of the image receptor and the slight tilt of the maxillary teeth
Are vertical angulations above the occlusal plane considered positive or negative?
positive
Are vertical angulations below the occlusal plane considered positive or negative?
negative
When using the bite-wing technique, how is zero angulation achieved?
when the position-indicating device and the central ray of the x-ray beam are parallel to the floor
Why is a horizontal bite-wing commonly contraindicated for patients with periodontal disease?
the horizontal bite-wing may not extend far enough to show the amount of bone loss
What modification may be made for a patient with extracted teeth when using the bite-wing technique?
the dentist may determine that the patient needs only one bite-wing image per side, if all present teeth can be captured in one image
When using the bite-wing technique what error can occur with an edentulous area if you do not place cotton rolls around the image receptor?
the bite-wing tab or the beam alignment device is not supported, and can result in a tipped occlusal plane on the image
How does the image appear with an unexposed image receptor error?
blank
What is the cause of an unexposed image receptor error?
- the image receptor was not exposed to x-radiation
- this could be due to the x-ray machine not being turned on, an equipment malfunction, or failure to align the position-indicating device over the receptor
How do you prevent the error of an unexposed image receptor from occurring?
- ensure the x-ray machine is turned on
- ensure the position-indicating device is positioned over the image receptor
- listen for the audible exposure signal
How does the image appear from an overexposed image receptor error?
dark or high in density
What is the cause of an overexposed image receptor error?
- the image receptor was exposed to too much x-radiation, due to incorrect exposure settings
How does the image appear from an underexposed image receptor error?
light or low in density
What is the cause of an underexposed image receptor error?
the image receptor was not exposed to enough x-radiation, due to incorrect exposure settings
What imaging techniques can cause an error of missing apical structures?
paralleling and bisecting
What is the cause of the error in missing apical structures?
the image receptor was not positioned in the patient’s mouth to cover the apical regions
How do you correct the error of missing apical structures?
- ensure that the patient is firmly biting on the bite block of the receptor holder
- ensure that no more than 1/8 of an inch of the receptor edge extends beyond the incisal/occlusal surfaces
What imaging techniques can cause an error with a dropped receptor corner?
paralleling or bisecting
How does an image appear with an error of a dropped receptor corner?
the occlusal plane appears tipped or tilted
What is the cause of error with a dropped receptor corner?
- the edge of the receptor was not placed parallel to the incisal/occlusal surfaces of the teeth
- this can be caused by the patient not correctly biting on the bite block
How do you prevent an error of a dropped receptor corner?
- ensure the patient is firmly biting on the bite block
- ensure that the edge of the receptor is placed parallel to the incisal/occlusal surfaces of the teeth
What type of angulation causes overlapped contacts?
incorrect horizontal angulation
What type of angulation causes forshortened images?
incorrect vertical angulation
What type of angulation causes elongated images?
incorrect vertical angulation
How do you correct overlapped contacts when exposing a periapical image?
direct the central ray of the x-ray beam through the proximal contacts of the teeth
How does a forshortened image appear?
the teeth appear short with blunted roots
What is the cause of a forshortened image error?
the vertical angulation was too steep
How does an elongated image appear?
the teeth appear long and distorted
What is the cause of an elongated image error?
the vertical angulation was too flat
How does an image appear that has a cone-cut error?
a clear, unexposed area is seen on the image
What is the cause of a cone-cut error when using a beam alignment device?
the position-indicated device was not properly aligned with the beam alignment device and the x-ray beam did not exposure the entire receptor
How do you correct a cone-cut error when using a beam alignment device?
ensure that the position-indicating device and the aiming ring are flush and properly aligned
What is the cause of a cone-cut error when not using a beam alignment device?
the position-indicating device was not positioned properly at the center of the receptor, and the central ray of the x-ray beam did not expose the entire receptor
How do you correct a cone-cut error when not using a beam alignment device?
ensure the x-ray beam is centered over the receptor and the entire receptor is covered by the diameter of the position-indicating device
What type of image receptor can result in a bent image?
PSP plates
How does an image appear if the PSP plate has been bent?
the image appears stretched and distorted
What is the cause of a bent image receptor?
- improper handling of the PSP plate
- the receptor could have been bent because of the curvature of the patient’s hard palate
How do you correct the error of a bent image receptor?
- check receptor placement prior to exposure
- if the receptor is bent because of the patient’s hard palate, cotton rolls can be used with the paralleling technique, or you can switch to the bisecting technique
- use a beam alignment device
- use caution with handling PSP plates
What type of image receptor can result in a creased image?
PSP plates
How does an image appear if the image receptor has been creased?
the creased area appears as a white line
What is the cause of a creased image receptor?
improper handling
How do you prevent an image receptor from becoming creased?
- use caution when handling
- if needed, gently soften the corners if the PSP plate prior to placement intraorally
What image receptor can result in a debris accumulation error?
digital sensors
How does an image appear that has debris accumulation?
debris on the surface of the sensor may cause permanent radiopaque artifacts or radiolucent scratch marks on the sensor
What is the cause of an accumulation of debris on a digital sensor?
improper handling or cleaning can cause dirt or dust particles to accumulate on the surface of the sensor
How do you prevent an accumulation of debris on a digital sensor?
- gentle handling
- correct infection prevention and cleaning procedures
What image technique can cause a phalangioma error?
the bisecting technique with the finger-holding method
How does an image appear with a phalangioma error?
the patient’s finger is seen on the image
What is the cause of a phalangioma error?
when using the finger-holding method, the patient’s finger was incorrectly positioned in front of the image receptor instead of behind it during exposure
How do you prevent a phalangioma error?
never allow a patient to hold an image receptor during exposure
True or false: A double image cannot be produced with a digital receptor.
True
What image receptor can result in a double image error?
PSP plates
How does an image appear when a double image error occurs?
a double image will present and appears dark with superimposed structures
What is the cause of a double image error?
the same receptor was exposed twice in a patient’s mouth
Why is a double image error a serious error on the part of the dental radiographer?
it requires two retakes, one for each of the two areas previously exposed, which doubles the exposure to x-radiation
How do you prevent a double image error?
always separate the exposed and unexposed PSP plates during the exposure sequence
How does an image appear when an error of movement occurs?
a blurred image
What is the cause of a movement error?
either the x-ray tubehead, the image receptor, or the patient moved during exposure
How do you prevent an movement error from occurring?
- stabilize both the x-ray tubehead and the patient’s head prior to exposure
- instruct the patient to remain still during exposure
- never press the exposure button if you know the x-ray tubehead is drifting or the patient is moving
How does the image appear if the receptor was placed backward during exposure?
a blank or white image is seen with no anatomic structures recorded
How does an image appear if the wired cable of the digital sensor is captured in the image?
the wired cable appears as a radiopaque outline
What is the cause of the wired cable appearing on an image?
the wired cable of the digital sensor was was placed in front of the image receptor during exposure
How do you prevent a wired cable of the digital sensor from being imaged?
ensure that the wired cable is not in front of the image receptor prior to exposure
When using the occlusal technique, how is the image receptor positioned?
the image receptor is placed with the tube side facing the arch that is being exposed, with the receptor between the occlusal surfaces of the maxillary and mandibular teeth
When using the occlusal technique, how is the image receptor stabilized during exposure?
by the patient gently biting on the surface of the image receptor
List the three types of maxillary occlusal projections.
- maxillary topographic occlusal projection
- maxillary lateral occlusal projection
- maxillary pediatric occlusal projection
How is the patient’s head and midsaggital plane positioned for maxillary occlusal exposures?
with the maxillary arch parallel to the floor and the midsagittal plane plane perpendicular to the floor
What is the correct vertical angulation for a maxillary topographic occlusal projection?
+ 65 degrees
What is the correct vertical angulation for a maxillary lateral occlusal projection?
+60 degrees
What is the correct vertical angulation for a maxillary pediatric occlusal projection?
+60 degrees
What is the correct vertical angulation for a mandibular topographic occlusal projection?
-55 degrees
What is the correct vertical angulation for a mandibular cross-sectional occlusal projection?
90 degrees
What is the correct vertical angulation for a mandibular pediatric occlusal projection?
-55 degrees
List the three types of mandibular occlusal projections.
- mandibular topographic occlusal projection
- mandibular cross-sectional occlusal projection
- mandibular pediatric occlusal projection
List the two types of localization techniques.
- buccal object rule
- right angle technique
What angulation is used when trying to localize vertically aligned objects?
horizontal angulation
What angulation is used when trying to localize horizontally aligned objects?
vertical angulation
What is the “SLOB” rule?
Same = Lingual / Opposite = Buccal
When using the buccal object rule, if the object being localized has moved in the same direction as the shift of the position-indicating device, how is that object positioned?
lingually
When using the buccal object rule, if the object being localized has moved in the opposite direction as the shift of the position-indicating device, how is that object positioned?
buccaly
Which localization technique is commonly used to locate objects in the mandible?
the right angle technique
