DANB Radiation Health and Safety (RHS)

On a bitewing radiograph, the proximal contacts of adjacent teeth overlap. Which error in technique is the MOST likely cause?

• AIncorrect horizontal angulation of the central ray
• BExcessive vertical angulation of the PID
• CUnderexposure of the receptor
• DReversed placement of the receptor in the mouth

A periapical image shows teeth that appear longer than the actual teeth (elongation). What adjustment corrects this?

• AIncrease the vertical angulation of the PID
• BDecrease the vertical angulation of the PID
• CIncrease the milliamperage
• DMove the receptor closer to the tooth

A periapical image shows teeth that appear shorter than the actual teeth (foreshortening). What is the cause?

• AExcessive vertical angulation of the PID
• BInsufficient vertical angulation of the PID
• CIncorrect horizontal angulation
• DToo long an exposure time

A clear, unexposed curved area appears at the edge of an intraoral image. This 'cone cut' is corrected by:

• ARe-centering the PID so the beam fully covers the receptor
• BIncreasing the exposure time
• CUsing a larger receptor
• DDecreasing the vertical angulation

Which intraoral technique places the receptor parallel to the long axis of the tooth and directs the central ray perpendicular to both, producing the most dimensionally accurate image?

• AParalleling technique
• BBisecting-angle technique
• COcclusal technique
• DLocalization (SLOB) technique

The SLOB rule (Same Lingual, Opposite Buccal) is used to:

• ADetermine the buccal or lingual position of an object using two images taken at different…
• BSet the correct exposure time for a patient's size
• CDecide between a panoramic and a full-mouth series
• DConfirm the receptor is not placed backward

Which radiographic series is the standard choice to detect interproximal (between-the-teeth) caries in posterior teeth?

• ABitewing radiographs
• BPeriapical radiographs
• CPanoramic radiograph
• DCephalometric radiograph

According to FDA/ADA selection criteria, radiographs should be prescribed:

• ABased on the individual patient's clinical needs after an examination
• BOn a fixed routine schedule for every patient regardless of findings
• COnly when the patient specifically requests them
• DAt every recall visit to maintain a complete record

The embossed (raised) dot on an intraoral receptor should be positioned:

• AToward the occlusal or incisal surface and facing the X-ray source
• BToward the apex of the tooth
• CFacing away from the X-ray source against the tongue
• DIn any orientation because it does not affect the image

An intraoral image is light and shows a faint herringbone or 'tire-track' pattern. The MOST likely cause is:

• AThe receptor was placed backward, with the back facing the beam
• BThe exposure time was too long
• CThe kVp was set too high
• DThe patient moved during exposure

An intraoral image is too dark (high density). Assuming the same machine, which change would produce a lighter, more diagnostic image on the retake?

• ADecrease the exposure time
• BIncrease the milliamperage
• CIncrease the kVp
• DIncrease the exposure time

Which exposure factor primarily controls the radiographic CONTRAST of a dental image?

• AKilovoltage peak (kVp)
• BMilliamperage (mA)
• CExposure time
• DSource-to-image distance

Radiographic DENSITY (overall darkness) of a dental image is most directly controlled by changing:

• AMilliamperage and exposure time (mAs)
• BHorizontal angulation
• CReceptor size
• DThe type of beam-alignment ring

When imaging a patient with a strong gag reflex during a maxillary posterior periapical, the BEST first strategy is to:

• APlace the receptor decisively and minimize time in the posterior, using distraction or a…
• BIncrease the exposure time so fewer images are needed
• CAlways switch to a panoramic and skip intraoral views
• DHave the patient hold the receptor with a finger to speed placement

A full-mouth radiographic series (FMX) of intraoral films typically consists of:

• APeriapical and bitewing radiographs covering all tooth-bearing areas
• BA single panoramic image
• COnly four bitewing radiographs
• DTwo occlusal radiographs

On a panoramic image, the patient's anterior teeth appear blurred and widened, and the spine is superimposed in the midline. The MOST likely positioning error is:

• AThe patient was positioned too far back, behind the focal trough
• BMetal earrings were left in place
• CThe exposure time was too short
• DThe patient's chin was tipped too low

On a panoramic image the occlusal plane curves upward at the ends like a 'smile.' This indicates the patient's chin was:

• APositioned too high (tipped up)
• BPositioned too low (tipped down)
• CRotated to the left
• DToo far forward in the focal trough