Lecture 1 (chapters 16-19) Flashcards
How many images are taken in a regular FMX (full mouth series)?
18
How many images are taken in a perio FMX (full mouth series)?
20
What is visible in a FMX?
All teeth, apices of roots, supporting structures
Beam angulation
The optimum angle at which the radiation is directed towards the film.
Excessive vertical angulation results with an image…
foreshortened
Insufficient vertical angulation results with an image…
elongated
What results when the PID is positioned too far distally, causing the anterior portion of the receptor to receive no exposure?
cone cut image
What results when the CR (central ray) is NOT directed through the contacts [of the teeth]?
overlapped image
Proper receptor position (Paralleling Technique)
Positioned parallel to the long axis of the tooth. The receptor and beam alignment device must be placed away from the teeth and toward the middle of the oral cavity.
Proper vertical angulation (Paralleling Technique)
The CR (central ray) of the x-ray beam must be directed perpendicular to the receptor and long axis of the tooth.
Proper horizontal angulation (Paralleling Technique)
The CR of the x-ray beam must be directed through the contact areas between the teeth.
Advantages to Bisecting Angle Technique
Receptor held with less pressure, receptor is close to the teeth, and increased comfort
Disadvantages to Bisecting Angle Technique
Difficult to determine bisector, increasing elongation & foreshortening; superimposed zygomatic arch over the maxillary molar apices, increased Magnification
Radiographic machines should operate between…
50 kV-100 kV (preferably 60-80 kV)
All new and existing X-ray installations must have a protection survey performed by a qualified expert and shall be continued once every _________
4 years
All radiographic exams shall be performed only on direct prescription of the dentist or physician and only after ______(3)
clinical history, examination, and expectation of a health benefit
Quality Assurance Program
The monitoring and documentation of procedures and corrective actions of: X-ray machines ,Image receptor systems, Processors, Darkroom
Never stand closer than _____ to the x-ray unit during an exposure without protection.
6 feet
Never stand in the direct line of the primary beam. It is best to _______. If you cannot, stand at least a ___ angle to the beam as it exits the patient.
stand behind a fixed barrier; 45 degree
Rectangular collimation shall be used routinely for _____ radiographs and when feasible for _________
radiography.
periapical; interproximal
The 3 types of intraoral radiographs
periapical, bitewing, occlusal
This type of radiograph shows an image of tooth and supporting structures. It’s used to interpret normalcy or pathology in root area and surrounding tissues.
Periapical (PA)
This type of radiograph shows tooth crowns (Max. & Mand. In one film) and Interproximal region (crest of alveolar bone)
Bitewing (BWX)
______ radiographs are more anatomically and dimension-ally accurate than _____ radiographs.
Bitewing; periapical
This type of radiograph is used to reveal interproximal or recurrent decay/caries, overhangs, calculus, crestal bone level, internal pulpal pathology, occlusal relationships, developing teeth
Bitewing
This type of radiograph records image on entire arch in one film.
Occlusal
This type of radiograph is used to add dimension to locate objects. Ex: Unerupted teeth, impactions, foreign bodies, fractures, pathology.
Occlusal
Receptor size for children with primary teeth
Size 0 (BCTC only has size 1 and 2)
Receptor size for mixed dentition and adult anteriors
Size 1
Receptor size for posterior periapicals and bitewings; older children and adults.
Size 2
Receptor size 3
Not recommended
Receptor size 4
Occlusal films
A bitewing survey usually contains ___ to ____ films for adults, and ____ films for children.
4-6; 2
Type of radiographic survey that includes:
Posteriors (from distal of canine back)
Max. and Mand. Crowns (No crown overlaps)
Crestal alveolar bone
TYPES: Horizontal and Vertical
Bitewing
an extremely effective method for reducing the radiation dose from intraoral radiography; it simply shapes and sizes the x-ray beam to the shape and size of the imaging receptor.
rectangular collimation
