Prosthodontics & Occlusion · patient case question
Which complication is most likely to result from an underextended denture flange?
Patient case: A denture that will not stay put
demo: 71-year-old male
chief: His upper denture drops when he speaks and food collects under it. He also has a sore lump at the front.
history: He has worn the same maxillary complete denture for fourteen years and has never had it relined. Only the mandibular anterior teeth from 22 to 27 remain.
meds: None relevant.
findings: The maxillary anterior ridge is displaceable and mobile on palpation while the posterior ridge is firm. A folded, fibrous ridge of tissue lies in the labial sulcus adjacent to the denture flange. The mandibular anterior teeth show generalised wear.
Show answer and explanation
Correct answer: D. The denture dislodges when the lips are pursed
- A. A sunken profile results from underextension of the vertical dimension or inadequate flange contour and thickness, but the immediate mechanical consequence of an underextended border is loss of seal.
- B. Sulcus ulceration is the signature of an overextended flange, which is the opposite error.
- C. The opposite occurs. A flange that stops short of the sulcus leaves a space that food readily enters.
- D. Correct. An underextended flange fails to reach the functional sulcus depth, so the peripheral seal is incomplete. Border seal is what generates retention through atmospheric pressure and surface tension, and without it the denture unseats during lip and cheek movements such as puckering.
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