A complete denture patient reports gagging. Which is the MOST likely cause?

Correct answer: C. Overextension of the denture borders, particularly the posterior palatal region

• A. Teeth set too far lingually crowd the tongue space and interfere with speech and stability, but posterior border overextension is the dominant cause of gagging.
• B. The TISSUE surface of a denture is not polished — it must reproduce the impression detail. Polishing applies to the external surface, and does not cause gagging.
• C. CORRECT. The commonest denture-related cause of gagging is a border that is OVEREXTENDED into mobile tissue — most often a posterior border extending beyond the vibrating line onto the movable soft palate, or overextended flanges contacting mobile sulcus tissue. An excessively THICK posterior border, or a posterior palatal seal cut too deep or placed too far posteriorly, does the same thing. Correction is mechanical: identify the overextension with a pressure-indicating paste or disclosing medium and reduce it.
• D. An inadequate vertical dimension causes angular cheilitis, a collapsed lower facial third and reduced masticatory efficiency. An EXCESSIVE vertical dimension causes clicking teeth, muscle fatigue and soreness — but neither is the primary gagging mechanism.

Note: Work through gagging systematically: first check EXTENSION and border thickness, then the posterior palatal seal, then the occlusion and vertical dimension, and only then consider a psychogenic component. Adjunctive measures — a training plate, behavioural desensitisation, topical anesthetic — are for the residual cases, not the first response.