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Persistent IAN Numbness Prognosis — ORE Part 1 MCQ

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HardOral SurgeryPersistent IAN Numbness PrognosisORE Part 1

A 50-year-old patient has persistent unilateral numbness of the lower lip 6 months after an inferior alveolar nerve block for routine dental treatment. CT and MRI show no structural cause. Which statement best describes the prognosis and next step?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: EPersistent deficit may be permanent; arrange specialist assessment

Explanation lettering: C = shown as A · E = shown as C · A = shown as E

A is best. Persistent lower-lip numbness at 6 months after IANB represents a persistent iatrogenic IAN injury with an unfavourable prognosis; dental literature conventionally regards sensory deficit persisting beyond 6 months as permanent. Normal CT and MRI exclude some structural pathology but do not rule out peripheral nerve injury. Specialist assessment is appropriate to document neurosensory function, provide prognosis and consider management options. B and C give unjustified reassurance: recovery may occur, but it is neither guaranteed by 12 months nor likely within days after six months of numbness. D is incorrect because normal imaging does not exclude neuropathy. E is also wrong because surgical intervention is not invariably indicated and cannot reliably restore normal sensation.

Reference: Cochrane Review: Interventions for iatrogenic inferior alveolar and lingual nerve injury, 2014. https://www.england.nhs.uk/long-read/oral-surgery-clinical-standard/