Masticatory muscles
Musculi masticatorii
- Synonym: Muscles of mastication
 
Definition
The four masticatory muscles (muscles of mastication) are responsible for adduction and lateral motion of the jaw.
They are :
- The masseter
 - The temporalis (the sphenomandibularis is considered a part of the temporalis by some sources, and a distinct muscle by others)
 - The medial pterygoid
 - The lateral pterygoid
 
Each of these primary muscles of mastication is paired, with each side of the mandible possessing one of the four.
References
This definition incorporates text from a public domain edition of Gray's Anatomy (20th U.S. edition of Gray's Anatomy of the Human Body, published in 1918 – from http://www.bartleby.com/107/).