The morphology and innervation of the lateral pterygoid muscle of the dog.

The number of heads possessed by the lateral pterygoid muscle was investigated in the dog. Only a single head was observed which it is suggested may correspond to the lower head in other mammals. It inserted both onto the condyle and into the articular disc. The nerve which innervated this muscle arose directly from the mandibular nerve, separate from the medial pterygoid nerve. Because of this, it should be termed the lateral pterygoid nerve and not the pterygoid nerve.