DRC Risk Assessment & Mitigation 2 — Questions and Answers
Question 1: A pregnant patient in her first trimester requires dental radiographs for acute pain. What is the most appropriate action?
- Refuse all radiographs until after delivery
- Take only periapical films with leaded apron and thyroid collar (Correct answer)
- Proceed normally as radiation risk is overstated
- Delay treatment and refer to physician for approval
Correct answer: Take only periapical films with leaded apron and thyroid collar
When radiographs are clinically necessary, they can be taken during pregnancy with proper shielding (leaded apron and thyroid collar) to minimize fetal exposure.
Question 2: Which factor most significantly increases a patient's radiosensitivity to dental X-rays?
- Advanced age over 65
- Being a child under 10 years (Correct answer)
- Having a pacemaker
- Male biological sex
Correct answer: Being a child under 10 years
Children are more radiosensitive than adults because their cells are rapidly dividing and their tissues are still developing.
Question 3: A patient reports having had multiple medical CT scans in the past year. How should this affect your radiographic risk assessment?
- It is irrelevant; dental X-rays are a separate concern
- It should prompt consideration of cumulative dose when deciding imaging necessity (Correct answer)
- It means the patient has already exceeded safe limits and no X-rays should be taken
- It lowers their risk because they have demonstrated radiation tolerance
Correct answer: It should prompt consideration of cumulative dose when deciding imaging necessity
Cumulative radiation exposure from all sources should be considered during risk assessment, though dental doses are far lower than CT doses.
Question 4: Which selection criterion best justifies taking a full-mouth series (FMX) for a new adult patient?
- The patient requests it for their records
- Evidence of generalized bone loss on clinical exam and no radiographs in 3+ years (Correct answer)
- The patient has dental insurance that covers it annually
- Standard protocol requires FMX for every new patient regardless of risk
Correct answer: Evidence of generalized bone loss on clinical exam and no radiographs in 3+ years
Clinical evidence of pathology combined with an extended interval since last radiographs justifies a comprehensive full-mouth series.
Question 5: What does the term 'stochastic effect' mean in the context of radiation risk?
- An effect with a definite threshold dose below which it cannot occur
- A probabilistic effect where the likelihood increases with dose but severity does not (Correct answer)
- An immediate tissue reaction such as skin reddening
- A genetic mutation that is always passed to offspring
Correct answer: A probabilistic effect where the likelihood increases with dose but severity does not
Stochastic effects, such as cancer induction, are probabilistic — higher doses increase the chance of occurrence, but the severity of the disease is independent of dose.
Question 6: A patient with a history of thyroid cancer requests that no thyroid collar be used because 'it bothers them.' The appropriate response is to:
- Accommodate the request since patient autonomy is paramount
- Explain the importance of thyroid shielding and insist on its use (Correct answer)
- Use the apron only and omit the thyroid collar as a compromise
- Document the refusal and proceed without any shielding
Correct answer: Explain the importance of thyroid shielding and insist on its use
The thyroid is especially radiosensitive and patients with a history of thyroid cancer have elevated risk; the clinician should educate and strongly recommend thyroid collar use.
Question 7: According to the ALARA principle, which of the following is the LEAST acceptable risk-reduction strategy?
- Using digital sensors instead of film
- Applying selection criteria before prescribing radiographs
- Limiting exposure time with proper technique
- Taking additional exposures to ensure a perfect diagnostic image is obtained (Correct answer)
Correct answer: Taking additional exposures to ensure a perfect diagnostic image is obtained
Taking unnecessary additional exposures violates ALARA because it increases dose without a clinically justified benefit.
DRC Risk Assessment & Mitigation 2
A pregnant patient in her first trimester requires dental radiographs for acute pain.
What is the most appropriate action?