Dangerous area of the face: the lower part of the nose, upper lip and adjoining part of the cheek, whose venous drainage communicates directly with the cavernous sinus.
Infection here can spread in retrograde direction into the cranial venous system, instead of following the normal downward drainage route.
Facial Vein: Formation and Course
Formed at the medial angle of the eye by union of the supratrochlear and supraorbital veins; runs downwards and backwards behind the facial artery to the anteroinferior angle of masseter.
Pierces the deep fascia, crosses superficial to the submandibular gland, and joins the anterior division of the retromandibular vein below the angle of the mandible.
This forms the common facial vein, which drains into the internal jugular vein.
Tributaries of the facial vein correspond to the branches of the facial artery.