The muscles are: 1  The masseter (composed of the superficial and deep head). 2  The temporalis (the sphenomandibularis is considered a part of the temporalis by some sources, and a distinct muscle by others). 3  The medial pterygoid.4  The lateral pterygoid.here are four classical muscles of mastication. During mastication, three muscles of mastication (musculi masticatorii) are responsible for adduction of the jaw, and one (the lateral pterygoid) helps to abduct it.