A vein that consists of a short trunk which accompanies the first part of the internal maxillary artery. It is formed by a confluence of the veins of the pterygoid plexus, and passes backward between the sphenomandibular ligament and the neck of the mandible, and unites with the superficial temporal vein to form the retromandibular vein. [WP,unvetted]. [ http://en.wikipedia.org/wiki/Maxillary_vein ]