Denture Retention Loss — NDEB AFK MCQ

Correct answer: A — Deficiency in the posterior palatal seal (inadequate post-dam)

A maxillary denture that drops during chewing (loss of retention during function) most commonly indicates an inadequate posterior palatal seal (post-dam). Without an effective seal at the vibrating line, air enters beneath the posterior border during the opening movement of the chewing cycle, breaking the suction that contributes to retention. Correction involves relining the posterior border area or adding post-dam material to re-establish the seal. Other causes include insufficient border extension or poor ridge form.

Reference: Zarb – Prosthodontic Treatment for Edentulous Patients, 13th ed., 2013