On tongue protrusion, which muscle displaces the mandibular denture? (Mylohyoid is NOT an option)

Correct answer: A. Genioglossus

• A. The genioglossus is the primary muscle that protrudes the tongue. When a patient protrudes their tongue, the genioglossus contracts and its attachment to the mental spine pulls the lingual flange of the mandibular denture anteriorly/superiorly, displacing it. With mylohyoid excluded, genioglossus is correct for tongue protrusion displacement.
• B. The digastric opens the mandible — it is not involved in tongue protrusion or denture displacement.
• C. The hyoglossus retracts and depresses the tongue — it does not cause denture displacement on protrusion.
• D. The masseter is a muscle of mastication (closes the jaw) — it does not displace the denture on tongue protrusion.