Oral Surgery · single question
What is the minimum safe distance between a dental implant and the inferior alveolar nerve (IAN)?
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Correct answer: B. 2 mm
A minimum of 2 mm of bone must be maintained between the apex of a dental implant and the inferior alveolar nerve (IAN) canal to prevent nerve damage, paresthesia, or anesthesia. This safety margin accounts for measurement error, bone density variation, and drill deviation. Pre-surgical CBCT evaluation of the IAN canal position is essential. The IAN and mental foramen are the primary anatomical structures limiting implant placement in the posterior mandible.
- A. 1 mm is considered too small a safety margin.
- B. Correct. A ~2 mm safety zone above the IAN canal is the commonly recommended minimum.
- C. 3 mm is more than required as a minimum (though a comfortable buffer).
- D. 5 mm is unnecessarily large for a minimum.