Morphological classification of the masticatory muscles in dogs based on their innervation.

The masticatory muscles and their innervations in dogs are classified, from deep to superficial layers, as follows: 1) medial pterygoid muscle and medial pterygoid nerve, 2) lateral pterygoid muscle and lateral pterygoid nerve, 3) anterior deep part of temporal muscle and anterior deep temporal nerve, 4) posterior deep part of temporal muscle and posterior deep temporal nerve, 5) superficial part of temporal muscle and superficial temporal nerve, the only branch of the temporal nerve which passes out from the infratemporal fossa, 6) zygomaticomandibular part of masseter muscle, which is thought to belong to the masseter muscle, and masseter nerve, 7) deep layer of masseter muscle and masseter nerve, 8) superficial layer of masseter muscle and masseter nerve.