What is the secondary stress-bearing area in a mandibular completely edentulous patient?

Correct answer: D. Buccal shelf

• A. The retromolar pad is a primary landmark for posterior denture extension (posterior seal) but is NOT a primary stress-bearing area — the tissue there is soft and compressible.
• B. The buccal frenum is a soft tissue attachment that limits denture extension — not a stress-bearing area.
• C. The alveolar ridge is an important but secondary support area — it resorbs over time, making the buccal shelf more important.
• D. Correct. In a mandibular complete denture, the PRIMARY stress-bearing area is the BUCCAL SHELF (the horizontal bone between the mandibular buccal vestibule and the external oblique ridge). It is cortical bone covered by firmly attached mucosa — ideal for bearing occlusal loads. The retromolar pad and crest of the ridge serve as secondary/auxiliary support.