Which muscle elevates the hyoid and assists in opening the mouth?

• A. Geniohyoid
• B. Stylohyoid
• C. Sternohyoid
• D. Mylohyoid

Answer: (A)

Geniohyoid acts to lift the hyoid bone and pull it forward. That upward and anterior movement of the hyoid helps position the floor of the mouth and the tongue in a way that facilitates opening the jaw, making it easier for the mandible to depress. This dual action—elevating the hyoid and assisting jaw depression when the hyoid is stabilized—fits the scenario described in the question.

Stylohyoid mainly elevates and retracts the hyoid, not particularly aiding in opening the mouth. Sternohyoid depresses the hyoid rather than elevating it. Mylohyoid does elevate the hyoid and the floor of the mouth, but its primary role is supporting the floor of the mouth and tongue, not specifically the combination of hyoid elevation with aiding mouth opening.