The danger area of the face, some veins of the face, particularly in theupper lip and the nose area, are directly joined to the cavernous sinus.Excessive irritation or aggravation of infected tissues, whose venous drainage is connected to the cavernous sinus, may result in a spread of infection to the cavernoussinus and then to the brain. For this reason, particular caution should be used to avoidneedless aggravation of infected tissue in these areas.
The cavernous sinus lies within the cranial cavity, between layers of the meninges and is a major conduit of venous drainage from the brain.This venous drainage pattern is of particular importance since the veins of the face contain no valves as do veins in other parts of the body.