Pterygoid venous plexus

Anatomy and course

The pterygoid plexus is a network of numerous veins that surround the pterygoid segment of the maxillary artery. It is found in the infratemporal fossa, lying partly between temporal and lateral pterygoid muscles, and partly between the lateral and medial pterygoid muscles. The tributaries of the into the pterygoid plexus correspond to the branches of the maxillary artery and include the sphenopalatine, deep temporal, pterygoid, masseteric, buccal, alveolar, greater palatine, inferior ophthalmic and middle meningeal veins.

The pterygoid plexus anastomoses anteriorly with the facial vein via the deep facial vein, and superiorly with the cavernous sinus via emissary veins that pass through the sphenoidal emissary foramen (of Vesalius), foramen ovale and foramen lacerum. These connections have clinical significance due to the potential spread of infection from the pterygoid plexus into the cranial cavity via the cavernous sinus.

The pterygoid plexus drains many deep structures of the head, including the palate, nasal cavity, paranasal sinuses, nasopharynx, auditory tube and deep parts of the scalp in the temporal region. It is continued by a short maxillary vein, which lies deep to the neck of the mandible. The maxillary vein conveys the blood from the pterygoid plexus and goes on to enter the substance of the parotid gland, where it joins the superficial temporal vein to form the retromandibular vein.