Long-standing complete denture with ridge pain

Correct answer: B. The mental nerve

• A. The maxillary division supplies the upper jaw and has nothing to do with a mandibular denture.
• B. CORRECT. As the mandible resorbs, the alveolar crest recedes until the mental foramen comes to lie at or near the crest of the residual ridge. The mental nerve then sits directly beneath the denture base and is compressed with every occlusal load, producing sharp localised pain in the premolar region and paraesthesia of the lower lip and chin. The remedy is generous relief of the denture base over the foramen.
• C. The lingual nerve runs along the lingual aspect of the mandible near the third molar region and supplies the tongue and lingual mucosa; it is not compressed by a denture base over the ridge crest.
• D. The buccal nerve supplies buccal mucosa and skin of the cheek, and it is not positioned to be compressed by the denture-bearing surface.

Note: Mandibular resorption follows a DOWNWARD AND OUTWARD path, so the ridge becomes BROADER as it resorbs. The maxilla resorbs UPWARD AND INWARD and becomes NARROWER. This is why the intra-arch relationship progressively shifts toward a pseudo-Class III appearance in long-term denture wearers.

Correct answer: A. The mandible

• A. CORRECT. The mandible resorbs downward and outward because the buccal cortical plate is thinner in the posterior region and the crest is lingual to the base of the body. The residual ridge therefore migrates buccally and the arch becomes wider.
• B. Both jaws change substantially in width with long-term edentulism.
• C. The two jaws resorb in opposite directions, which is precisely why the relationship changes over time.
• D. The maxilla resorbs upward and INWARD, because its buccal plate is thin and resorbs preferentially, so the maxillary arch becomes narrower and shorter.

Correct answer: A. 6 mm

• A. CORRECT. A maxillary major connector is kept at least 6 mm from the gingival margins of the remaining teeth. This clearance keeps the connector off the marginal gingiva, prevents plaque accumulation at a site the patient cannot clean, and avoids the gingival inflammation and recession that follow connector impingement.
• B. 8 mm is the minimum VERTICAL SPACE required to place a mandibular lingual bar, not the gingival clearance for a maxillary connector.
• C. 4 mm is insufficient clearance for a maxillary major connector.
• D. 2 mm is the mandibular figure — actually the mandibular lingual bar requires at least 3 mm of relief from the gingival margin, and at least 8 mm of vertical space in the lingual sulcus.

Note: Carry the three numbers separately: maxillary major connector 6 mm from gingival margins · mandibular lingual bar 3 mm of relief · 8 mm of vertical sulcus space needed to accommodate a lingual bar at all (otherwise use a lingual plate).