Which muscle is primarily used in biting and chewing?

The masseter muscle is primarily responsible for biting and chewing because it is the main muscle involved in the elevation of the mandible (lower jaw) during the process of mastication. It is a powerful muscle that originates from the zygomatic arch and inserts into the ramus of the mandible. Its primary function is to facilitate the closure of the jaw, enabling the grinding and crushing of food between the teeth.

In contrast, the buccinator muscle, while contributing to the manipulation of food in the mouth and the proper positioning of the cheeks during chewing, is not directly responsible for the movement of the jaw itself. Additionally, the trapezius and pectoralis major are not involved in mastication; the trapezius primarily moves the shoulder and neck, while the pectoralis major is involved in movements of the shoulder and arm. Thus, the masseter is clearly the muscle specifically dedicated to the mechanics of biting and chewing.