Loosening of a maxillary complete denture during yawning occurs if the prosthesis interferes with which anatomical structure?

The correct answer is related to the interference of a maxillary complete denture with the coronoid process during yawning. When a patient yawns, significant movement of the mandible occurs, including rotation and translation. The coronoid process is the anterior portion of the ramus of the mandible and can move upwards and forward during this motion.

If the denture is not adequately designed or positioned, it may impinge upon this anatomical structure, causing a loss of stability and retention of the denture. This can lead to a feeling of looseness as the mandible moves in ways that exert forces on the denture. Properly designed dentures should provide enough clearance in the path of this motion to ensure the denture remains seated and stable during yawning or other significant jaw movements.

In contrast, the hamular notch is an area of the maxilla that contributes to the fit and retention of the denture; interference here can affect stability, but it is less directly related to the action of yawning. The vibrating line is important for determining the posterior border of the maxillary denture, while the masseter muscle, an important muscle of mastication, contributes to occlusion and function but does not directly interfere with the stability of the