yes, according to latest kaplan notes too, medial pterygoid ,masseter and temporalis muscles elevates the mandible,lateral pterygoid brings about depressive and protusive movements. medial and lateral pterygoids together work inprotrusion and side to side movements in grinding. lat but not the least tha suprahyoid muscles ant belly of digastric and mylohyoid also acts as muscles of mastication by depressing the mandible. hope it helps🙂