Which mandibular depressor elevates the oral cavity and tongue?

• A. Anterior Digastric
• B. Mylohyoid
• C. Geniohyoid
• D. Stylohyoid

Answer: (A)

When opening the mouth, several small jaw depressors work with the hyoid to coordinate the position of the floor of the mouth and the tongue. The anterior belly of the digastric is key here because it attaches to the mandible and to the intermediate tendon that connects with the hyoid. When this muscle contracts, it pulls the mandible downward to open the mouth, but it also pulls the hyoid upward. Elevating the hyoid lifts the floor of the mouth and raises the tongue, effectively elevating the oral cavity and the tongue as part of the swallowing and speaking movements.

The other muscles listed also help with mandibular depression or hyoid elevation, but they don’t raise the oral cavity and tongue as their primary effect when the jaw is opened. The anterior digastric uniquely links mandibular depression with elevation of the floor of the mouth and tongue via its action on the hyoid, making it the best answer.