Final answer:
The jaw position with the maximal stable contact between upper and lower teeth is centric relation. The masseter muscle is primarily responsible for the chewing motion. The temporomandibular joint (TMJ) enables the necessary movements for these oral functions.
Step-by-step explanation:
The jaw position that produces maximal stable contact between the occluding surfaces of the maxillary and mandibular teeth is known as centric relation. This position is considered important for the stability of the occlusion (the contact between teeth). When in centric relation, the upper and lower jaws are positioned in a way that allows for optimal function and minimal stress on the temporomandibular joint (TMJ).
The action of the masseter, one of the muscles of mastication, is chewing (b). The masseter muscle elevates the mandible, closing the mouth, which is essential for the chewing process.
The TMJ is the joint responsible for the complex movements required for opening and closing the mouth, as well as facilitating chewing and speech. It is composed of the mandibular fossa of the temporal bone and the condyle of the mandible, with an interposed articular disc for smooth movement.