Midterm Review Questions
A bitewing radiograph is useful in diagnosing all of the following EXCEPT:
impacted tooth
Where is the most appropriate place to store dental film?
in a dry, cool closet
What theory BEST describes the free radical formation that is so injurious to living tissue?
indirect theory
Disposal of an extracted tooth is considered to be:
infectious waste
Which of the following is considered secondary radiation?
radiation that reflects off the patient's face
A white area with a right-angle shaped border on a film is caused by
rectangular PID
Which of the following situations increases pnumbra?
reduced focal spot
When identifying anatomical structures and dental materials on a radiograph, which of the following is TRUE about dentin and enamel?
the dentin is not as radiopaque as enamel
The bitewing view visualizes crowns, contacts, and height of alveolar bone. The bitewing is not included in a full-mouth series.
the first statement is true, second is false
What type of chemical is used in developing agent to convert the silver halide crystals to black?
hydroquinone
if partially formed third molars are noted on a panoramic radiograph, how old is the patient?
11 to 15 years of age
A FMS generally includes:
14 PAs and 4-6 BW
If the x-ray machine is operating at 70 kVp, what thickness of filtration is necessary?
2.5mm
Exposure of a radiograph for 3/5 of a second is equal to how many impulses?
36
What is the maximum permissible dose (MPD) of radiation for a dental assistant?
5 rem/year
What is the proper distance for the operator to stand away from the x-ray beam to minimize exposure?
6 feet
During manual processing, how long should the film remain in the developer solution if the temperature of the solution is 65 degrees F?
6 minutes
If films were exposed at 6 mA for 4 seconds, films exposed for 3 seconds would have an mA of
8
Which one of these film-processing ingredients converts energized crystals into metallic silver?
hydroquinone
When x-rays interact with an outer shell electron of an atom, causing ionization and scattering in a different direction, it is called
Compton scatter
A new patient has recently moved to the area and arrives for her first appointment in the dental practice. She is 6 months pregnant. She is complaining of a toothache. She does not bring dental records with her. Which of the following would be the most appropriate for obtaining dental x-rays?
Only x-ray the area that she is complaining about using the lead apron and thyroid collar for protection
For intraoral x-rays, what film speed is the fastest and reduces the amount of patient exposure to radiation?
F-speed
What is the name of the device used to monitor employees for radiation exposure?
Dosimeter
Which of the following is NOT a disadvantage to digital radiography?
Lost images
What unit of radiation represents the amount of radiation energy absorbed by the tissue?
gray
How does the use of photostimuable storage (PSP) plates affect digital radiogrpahy?
PSP plates do not offer immediate access to the digital image
What is the best possible scenario for a pregnant dental hygienist in terms of employment?
She should make her decision as early as possible in the pregnancy regarding whether the risks to her unborn child are acceptable in her current position
Which one of these extraoral techniques is used specifically to evaluate the maxillary sinuses?
Waters
Which one of the following cell types is MOST sensitive to radiation?
immature cells
The use of outdated dental film may cause the x-ray to have:
a foggy or gray appearance
Which of the following would not be a reason for the dental x-ray image to come out black? a. processing time is too short b. temperature is too warm c. film has been exposed to white light d. damaged safelight
a. processing time is too short
Which of the following is FALSE regarding handwashing?
alcohol-based hand gel can be used in place of soap and water on hands that are visibly dirty
What part of the x-ray machine functions to remove the most dangerous x-rays from reaching both the patient and the operator?
aluminum filter
What product in the dental office contains mercury?
amalgam
Compton scatter occurs when...
an electron is ejected and x-ray photon scatters in a different direction
According to the American Academy of Oral and Maxillofacial Radiology, how often should x-ray machines be tested?
annually
The best radiograph to obtain for diagnosis of TMJ is:
arthrography
A young patient is having difficulty holding still for x-rays. What is the most appropriate step for the dental professional to take?
ask the patient to have the child sit on his or her lap with both covered by the lead apron
Which of the following are NOT maxillary landmarks? a. hard palate, nasal septum, nasal conche b. alveolar crest, genial tubercle, coronoid process c. infraorbital foramen, orbit, mastoid process d. external auditory meatus, malar, glenoid process
b. alveolar crest, genial tubercle, coronoid process
Which of the following is LEAST likely to cause fogged film? a. improper safelighting b. developer spots c. outdated film d. light leakage
b. developer spots
Which of the following do NOT include anatomical landmarks of the mandible? a. lingual foramen, coronoid process, ramus b. incisive foramen, mental foramen, genial tubercle c. medial sigmoid notch, symphysis, external oblique notch d. trabecular patterns, alveolar crest, internal oblique ridge
b. incisive foramen, mental foramen, genial tubercle
Genial tubercles are an exit for incisive vessel branches, Genial tubercles appear as radiolucent circle inside opaque lingual foramen tubercles.
both statements are false
Optimum developing takes approximately 10 minutes at 50 degrees F. Developing reduces exposed silver halide crystals into black metallic silver through one ingredient in solution.
both statements are false
Film duplication is the process of copying or reproducing a second film or set of films. With film duplication, there is no need to re-expose the patient to radiation.
both statements are true
Overdeveloped film that is too dark may occur because developing solution is at too high a temperature.
both the statement and reason are correct and related
What part of the circuit provides the energy to propel the electrons and produce x-rays?
high-voltage circuit
Overlap on a left molar bitewing radiograph is caused by improper
horizontal angulation
Contaminated areas in the radiography area must be disinfected using:
hospital-grade disinfectant solution
Chronic radiation exposure to the lens of the eye may result in:
cataracts
What type of radiograph is used by an orthodontist to assist with treatment planning?
cephalometric
Which one of the following is used to restrict the size of the x-ray beam?
collimation
The lead diaphragm in the tubehead is referred to as the...
collimator
Developing solution splashed on the film before processing will result in...
dark spots
Which of the following can be disposed of in the regular trash or down the drain?
developer
What is the processing order that films undergo in an automatic film processor?
developer, fixer, water, dry
Which one of the following reduces operator exposure to radiation?
distance
A dental assistant experiences occupational exposure. A patient's blood has splashed into the employee's eyes. Which of the following is an appropriate step to take?
document the incident, including the source individual, the employee, route of exposure, and how it happened
Which of the following would likely NOT be necessary in the case of an accidental radiation exposure? a. report the exposure to the Radiation Protection Office b. Turn the power to the system off immediately c. Advise exposed individuals to obtain medical care if needed d. evacuate the building
evacuate the building
On a mandibular molar film the MOST superior radiopaque anatomical landmark is the...
external oblique ridge
Which of the following diseases has a "ground glass" appearance on radiogrpahs?
fibrous dysplasia
For manual duplication of x-ray films, which of the following conditions is incorrect?
film duplication can be done in the regular office setting without any special conditions
Root fracture occurs MOST frequently in the anterior portion of the mouth. Root fracture appears as a radiopaque horizontal line on the root.
first statement is true, second is false
Which of the following energies in the electromagnetic spectrum is considered ionizing radiation?
gamma rays
Which statement best describes the effects of long-term low-dose radiation exposure?
it can cause changes at the cellular level in the human body that would not be observed for many years
What is the function of the collimator?
it forms the shape and size of the x-ray beam upon leaving the tubehead
Which of the following is used to control the degree of penetration of the x-ray beam?
kilovoltage peak selector
what factor is MOST important in a consideration of the biological effects of radiation used in dentistry?
limited area exposure
Magnification occurs when there is a
long object-film distance
The lingual foramen should be evident on the...
mandibular anterior film
When mounting dental film, the preferred order is:
maxillary anterior PA, mandibular anterior PA, bitewing, maxillary posterior PA, mandibular posterior PA
Which radiopaque maxillary anatomical landmark is MOST likely to be seen on a maxillary incisor periapical radiograph?
median palatine suture
What is the term used to describe the number of electrons that are produced?
milliamperage selector
A patient is moving and asks for the most recent x-rays for the new dentist. Which of the following is NOT the preferred procedure for fulfilling this request?
obtain the original x-rays from the patient's record and give them to the patient to take to the new dentist
If the source to film distance is changes from 8 to 24 inches, the intensity of the beam becomes
one-ninth as intense
What is the correct way for the dental hygienist to wear the dosimeter?
only when they are at the dental office
Which radiographic technique has LESS distortion and magnification and creates a MORE accurate image on film?
paralleling
A patient of record complains of temperature sensitivity in the maxillary right second molar region of the mouth. A full-mouth series of radiographs was taken 2 years previously. Which radiographs should be prescribed?
periapical
The type of radiograph that would show the whole tooth including the crown, roots, and jawline is called:
periapical x-ray
Which is the FIRST step in the radiograph mounting process?
placing films dot side up
A reversed smile line observed on a panoramic image is likely due to:
position of the patient's chin is too high
All of the following reduce patient exposure to radiation, EXCEPT one. What is the exception? a. filtration b. collimation c. positioning d. lead apron
positioning
The "coin test" is a method of assessing
proper safe-lighting
A dental x-ray that has the appearance of black lines that look like a tree branch is caused by:
static electricity
Which radiolucent mandibular anatomical landmark is MOST likely to be seen on a mandibular molar periapical radiograph?
submandibular fossa
Which of the following is a true statement regarding the use of lead aprons and thyroid collars?
the apron should cover from the neck to just above the patient's knees
Contrast is the difference between lighter and darker shades (grays) on the radiograph. Decreased kVp (90 or higher) results in many shades of gray on the film.
the first statement is true, the second is false
What will happen to an x-ray film that is left in the processing solution too long?
the image will be either partially or completely missing
What is the inverted Y junction in a radiograph?
the point where the nasal fossa and maxillary sinus meet
Fogged films with white streaks may occur because there is improper safelighting in the darkrooms.
the statement is not correct, but the reason is
Which of the following situations created the error of a radiolucent shadow that obscures the apices of the maxillary dentition on a panoramic film?
tongue was not touching the palate
Lateral cephalometric projection evaluates
trauma and facial growth and development
What is the source of electrons used for x-ray production?
tungsten filament
Where does generation of x-rays in the x-ray tube actually occur?
tungsten target
Root caries of a tooth is
typically located at the middle third of the root
Which of the following is not an effective way that the "as low as reasonably achievable" (ALARA) principle can be achieved in the dental office for the protection of the patient? a. use of lead aprons and thyroid collars b. use of d film c. minimize the exposure time d. use of digital radiographs
use of d film
A cone-shaped radiopaque image in a panoramic x-ray is likely caused by:
use of thyroid collar during imaging
When placed backward, a film exposed in the mouth will exhibit
waffle pattern
During what stage of pregnancy is the fetus most sensitive to the effects of radiation exposure?
weeks 2-15
In what part of the x-ray machine are the x-rays produced?
x-ray tube
Characteristics of x-rays include all of the following EXCEPT: a. x-rays aren't visible or apparent to any of the senses b. x-rays travel at the half speed of light c. x-rays travel in a straight ling but can be easily deflected d. shorter x-rays are more useful in dental radiographs
x-rays travel at the half speed of light
