Which muscle might affect the borders of a mandibular complete denture?

The orbicularis oris muscle plays a significant role in affecting the borders of a mandibular complete denture due to its location and function. This muscle encircles the mouth and is responsible for actions such as pursing the lips, which can influence how the denture fits, seals, and maintains retention in the oral cavity. When a complete denture is made, it is essential to consider the activity of the orbicularis oris, as its contraction can create dynamic forces that may dislodge the denture.

In contrast, while the mentalis, lateral pterygoid, and levator anguli oris muscles are also in proximity to the mandible, they do not have the same comprehensive effect on the borders of the mandibular denture. The mentalis muscle impacts the chin and may affect aesthetics but does not directly influence the denture's retention along its borders. The lateral pterygoid muscle primarily involves the movement of the jaw and does not significantly interact with the denture edges. The levator anguli oris assists with facial expressions but is not directly involved in the retention or sealing of the denture. Therefore, the orbicularis oris is the muscle most closely associated with the borders of a