An edentulous patient with a severely resorbed mandibular ridge reports pain along the crest under the denture. A lesion is visible toward the buccal. What is the most likely source of the pain?

Correct answer: D. The mental nerve exiting onto the crest of the resorbed ridge and being compressed by the denture base

• A. The lingual nerve runs on the lingual aspect of the mandible and is not the structure loaded by a denture on the crest.
• B. Physiological resorption is not painful in itself. Pain signals a specific mechanical or pathological cause that must be identified.
• C. The IAN within its bony canal is protected; it is the terminal mental branch emerging onto the crest that gets compressed.
• D. CORRECT. As the mandible resorbs, bone is lost from the crest downward, so the MENTAL FORAMEN — originally near the apices of the premolars — migrates relatively upward until it lies AT or NEAR the crest of the ridge. The denture base then loads the mental nerve directly, producing sharp, localised pain and sometimes paraesthesia of the lip. Management is relief of the denture base over the foramen, or surgical repositioning in severe cases.

Note: Source keyed 'denture not adapted,' which is the general management answer. The specific anatomical mechanism to know is mental foramen exposure on the resorbed crest.