Final answer:
The medial pterygoid muscle moves the jaw from side to side, while the lateral pterygoid muscle helps in moving the jaw forward and backward.
Step-by-step explanation:
The medial and lateral pterygoid muscles are located in the jaw and are involved in chewing and moving food within the mouth. The medial pterygoid muscle moves the mandible (lower jaw) from side to side, while the lateral pterygoid muscle helps in moving the mandible forward and backward. These muscles work together with the masseter and temporalis muscles to facilitate mastication.