A 22-year-old who hasn't seen a dentist since age 18 says 'I think I have a cavity.' Which is the best open-ended question to ask?

Correct answer: C. What made you think you have a cavity?

• A. 'Is the tooth bothering you?' is a closed yes/no question.
• B. 'Which tooth?' is a closed question requiring a specific factual response.
• C. 'What made you think you have a cavity?' is truly open-ended — it invites the patient to elaborate on symptoms, reasoning, and concerns, essential for comprehensive history-taking.
• D. 'When did it happen?' is a closed question requiring a date/time.