Prosthodontics & Occlusion · single question
A patient wearing a maxillary complete denture complains of poor retention. How do you identify issues with the peripheral (border) seal?
Show answer and explanation
Correct answer: A. Thickened buccal flange impinging on the coronoid process
A) Thickened buccal flange — CORRECT.
If the buccal flange of the maxillary denture is too thick or overextended, it will be displaced by the coronoid process during mandibular movements (opening, lateral excursions), breaking the peripheral seal and causing denture dislodgment. This is a classic prosthodontic problem — the coronoid process sweeps medially and anteriorly upon opening, impinging on an overbuilt buccal flange.
B) Thin/insufficient extension: Would reduce retention but wouldn't be identified as the "peripheral seal issue" related to coronoid impingement.
C) Post-dam issue: Affects posterior seal — not the peripheral/buccal border seal.
D) Excessive VDO: Affects stability and phonetics — not directly the peripheral seal.
If the buccal flange of the maxillary denture is too thick or overextended, it will be displaced by the coronoid process during mandibular movements (opening, lateral excursions), breaking the peripheral seal and causing denture dislodgment. This is a classic prosthodontic problem — the coronoid process sweeps medially and anteriorly upon opening, impinging on an overbuilt buccal flange.
B) Thin/insufficient extension: Would reduce retention but wouldn't be identified as the "peripheral seal issue" related to coronoid impingement.
C) Post-dam issue: Affects posterior seal — not the peripheral/buccal border seal.
D) Excessive VDO: Affects stability and phonetics — not directly the peripheral seal.
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