The plexus features venous valves. The contractions of the lateral pterygoid muscle promote venous drainage.[2]
Tributaries
The plexus drains all veins that correspond to the branches of the maxillary artery (however, much of the blood delivered by the maxillary artery is returned by other routes), as well as two additional veins.[2]
This plexus communicates freely with the anterior facial vein; it also communicates with the cavernous sinus, by branches through the foramen Vesalii, foramen ovale, and foramen lacerum. Due to its communication with the cavernous sinus, infection of the superficial face may spread to the cavernous sinus, causing cavernous sinus thrombosis. Complications may include edema of the eyelids, conjunctivae of the eyes, and subsequent paralysis of cranial nerves which course through the cavernous sinus.[citation needed]