Radiation Safety
What does ALARA stand for?
As Low As Reasonably Achievable
What causes overlapping in bitewings?
Incorrect horizontal angulation
What part aims the x-ray beam?
PID or position indicating device
What solution develops the film?
Developer
Who discovered x-rays?
Wilhelm Roentgen
What part of the body does the thyroid collar protect during x-rays?
the thyroid gland
What’s it called when the image has a clear curved white area?
Cone cut
What does the control panel on an x-ray unit allow you to adjust?
the exposure time, kilovoltage (kVp), and milliamperage (mA)
In what order should films be mounted?
Anatomical position: maxillary on top, mandibular on bottom
What’s a cephalometric radiograph used for?
Orthodontics and skull measurements
What two protective items are worn by patients during x-rays?
Lead apron and thyroid collar
What causes a blurry x-ray image?
patient movement during exposure
What controls how long x-rays are emitted?
Exposure time
What does it mean if a radiograph comes out completely black?
the film was exposed to light before processing
What does a panoramic radiograph show?
the entire mouth, including both jaws, teeth, and surrounding structures
Why should dental professionals stand at least 6 feet away or behind a barrier during exposure?
to protect themselves from scatter radiation
A radiograph appears too light. What could be the cause?
is underexposure or underdevelopment
What is the purpose of the collimator in an x-ray machine?
to limit the size and shape of the x-ray beam, reducing patient exposure
What helps ensure x-rays are mounted correctly and match the patient’s anatomy?
the identification dot (used to determine left from right)
What extraoral radiograph is commonly used in orthodontics to evaluate growth and development?
a cephalometric radiograph
What is a dosimeter badge used for?
To measure radiation exposure for dental workers
If the film is placed backwards, what does the image look like?
It has a herringbone or tire-track pattern
What’s the difference between a panoramic and a periapical x-ray?
Panoramic is extraoral and shows the full mouth; periapical is intraoral and shows individual teeth.
What causes completely clear film?
Film that wasn’t exposed
What year were x-rays discovered?
1895