Buccal Shelf Stress Bearing — ORE Part 1 MCQ

Correct answer: C — The buccal shelf (the broad, flat area of bone lateral to the buccal alveolar ridge, bounded laterally by the external oblique ridge)

The buccal shelf is the primary stress-bearing area of the mandibular denture-bearing surface. Experimental strain-gauge studies demonstrate that the buccal shelf experiences significantly higher strain values than other mandibular denture-supporting regions, including the mental foramen area and distolingual structures. This broad, flat bony surface lateral to the buccal alveolar ridge provides optimal load distribution during mastication. Although the ridge crest, retromolar pad, lingual sulcus, and labial flange all contribute to denture stability or retention, none serve as the primary load-bearing structure. Understanding the buccal shelf's biomechanical role is essential for optimal denture design, border molding, and tissue conditioning to ensure proper support and minimize iatrogenic trauma to supporting tissues.

Reference: Evaluation of strain in mandibular denture-supporting area in three different occlusal schemes during jaw movements. PubMed Central. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5928470/