It is an area on the face that is sensitive to infections but the name Dangerous is given to it because of the nature of blood vessel supply and spread of infections if there is an infection occurring in this area. Speaking of the danger, the infection that occurs in this region can spread to the brain and cause cavernous sinus thrombosis, meningitis or brain abscess.
Location of Dangerous Area of the Face
Also called as the danger triangle, the area spreads from the corners of the mouth to the bridge of the nose. This area includes the nose and the maxilla. The tip of the triangle is on the medial angle of the eye and the lower base of the triangle includes the nose and the upper lip.
What is the link between Dangerous triangle and infection spread?
The venous valves are present in the ophthalmic and facial veins. This existence of the communication between the facial vein and cavernous sinus and the direction of the blood flow is what leads to the spread of the infections.
It is also said that the presence of loose areolar tissue having the emissary veins allows the infection spread into the cavernous sinus, and thus cavernous sinus thrombosis occurs.
Infection of cavernous sinus – What happens?
If the infection happens inside the cavernous sinus, this can lead to clot formation within the sinus, and this would lead to cavernous sinus thrombosis. The thrombosis affects the structures surrounding the sinus or passing through it. Following are the nerves that get constricted inside the cavernous sinus.
Cranial nerve III (oculomotor nerve)
Cranial nerve IV (trochlear nerve)
Cranial nerve VI (abducens nerve)
Cranial nerve V (trigeminal nerve)
V1 (ophthalmic nerve) and V2 (maxilla and or a parasympathetic innervation (from CN III)
The inflammation of the cavernous sinus will lead to compression of the optic chiasm, resulting in problems of vision.
Cranial nerve III failure can lead to problems in the functioning of the following muscles – medial rectus, superior rectus, inferior rectus, and inferior oblique as well as muscles that are responsible for opening the eyelid: levator palpebrae superioris muscle and the superior tarsal muscle (Muller’s muscle).