# Which of the following areas are regarded as the ‘dangerous area’ of the face?
A. Chin and lower lips
B. Lower and upper lips
C. Upper lip and lower part of the nose
D. Upper part of nose and forehead
The correct answer is C. Upper lip and lower part of the nose.
The dangerous area of the face is drained by the facial vein. Deep connections of the facial vein with cavernous sinus includes:
i. A communication between the supraorbital and superior ophthalmic veins.
ii. Another with the pterygoid plexus through the deep facial vein which passes backwards over the buccinator. The pterygoid venous plexus in turn communicate with the cavernous sinus through an emissary vein. The veins of the dangerous area of face are valveless. Movements of the facial muscles and absence of valves in the facial vein might facilitate retrograde flow of blood. This allows retrograde infection, which is carried by facial, angular and nasofrontal veins and superior ophthalmic veins into cavernous sinus. This can lead to spread of septic emboli from the dangerous area of the face and can cause cavernous sinus thrombosis with serious complications.
Eagleton criteria for diagnosis of cavernous sinus thrombosis are:
- Known site of infection
- Paralysis of 3,4,6 nerves
- Proptosis of eye due to increased pressure in superior and inferior veins of the orbit.
