Chapter 19: Paralleling Technique Flashcards
Principles, Equipment and Guidelines of the Paralleling Technique
Define this term: anterior
towards the front
Define this term: periapical examination
a type of intraoral imaging examination used to view the entire tooth (crown and root) and supporting bone
Define this 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
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
Define this term: periapical image
intraoral image that is used to examine the crowns and roots of teeth
Define this term: image receptor
a recording medium (ex: PSP plate, digital sensor)
Define this 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 this term: Rinn Snap-A-Ray Holder
an intraoral receptor holder used to stabilize an image receptor during exposure
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
Define this term: maxillary teeth
teeth located in the maxilla or upper arch
Define this term: Stabe Biteblock
a disposable styrofoam device that can be used to hold an image receptor during exposure
Define this term: horizontal angulation
the positioning of the position-indicating device in a horizontal plane
Define this term: parallel
moving or lying in the same plane; always separated by the same distance and not intersecting
Define this term: intraoral imaging examination
a dental imaging inspection of teeth and intraoral adjacent structures
Define this term: mandible
the lower jaw
Define this term: intraoral
inside the mouth
Define this term: horizontal
a side-to-side plane
Define this term: posterior
towards the back
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
Define this term: angulation
the alignment of the central x-ray beam in the horizontal and vertical planes
Define this term: bite-wing receptor
an intraoral image receptor used to examine the crowns of both maxillary and mandibular teeth on one image
Define this term: target-receptor distance
the distance from the source of radiation (tungsten target in the anode) to the image receptor
Define this term: image receptor placement
the specific area where the image receptor must be positioned before exposure
Define this term: apical
towards the apex of a tooth
Define this 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
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 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
What is the primary advantage of using the paralleling technique?
images without dimensional distortions
True or false: A beam alignment device is required for the paralleling technique.
True
Define this term: central ray (CR)
the central portion of the primary beam of x-radiation
Define this term: vertical
an up-and-down plane
Define this term: periapical
around the apex of a tooth
Define this term: intersecting
cutting across or through
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 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
Define this term: right angle
in geometry, an angle of 90 degrees formed by two lines perpendicular to each other
Define this 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
What is the primary disadvantage of the paralleling technique?
image receptor placement
Define this 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 this term: bite-wing image
intraoral image that is used to examine the interproximal surfaces of teeth
What types of images can be exposed using the paralleling technique?
periapical and bite-wing images
Define this 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 this term: contact areas
the areas where adjacent tooth surfaces touch each other
Define this term: interproximal
between two adjacent surfaces
Define this 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 this term: vertical angulation
the positioning of the position-indicating device in a vertical plane
Define this term: long axis of a tooth
an imaginary line that divides a tooth longitudinally into two equal halves
Define this term: maxilla
the upper jaw
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
Define this 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 this term: open contacts
on a dental image, appears as a thin radiolucent line between adjacent tooth surfaces
Define this term:mandibular teeth
teeth located in the mandible or lower arch
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)
Define this term: anterior teeth
central incisors, lateral incisors, and canines/cuspids
Define this term: intraoral receptor
an image receptor is placed inside the mouth during x-ray exposure to examine teeth and supporting structures
Define this 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 this term: exposure sequence
a defined order to place and expose intraoral receptors
Define this term: x-ray beam angulation
one of the influencing factors for image distortion that refers to the direction of the x-ray beam
Define this term: posterior teeth
first and second premolars/bicuspids, and first, second and third molars
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
Define this term: perpendicular
intersecting at or forming right angles
