The danger triangle of the face consists of the area from the corners of the

mouth In animal anatomy, the mouth, also known as the oral cavity, or in Latin cavum oris, is the opening through which many animals take in food and issue vocal sounds. It is also the cavity lying at the upper end of the alimentary canal, bounded on ...

to the bridge of the nose, including the nose and maxilla. Due to the special nature of the blood supply to the

human nose The human nose is the most protruding part of the face. It bears the nostrils and is the first organ of the respiratory system. It is also the principal organ in the olfactory system. The shape of the nose is determined by the nasal bones ...

and surrounding area, it is possible, albeit extremely unlikely, for retrograde infection from the nasal area to spread to the brain, causing cavernous sinus thrombosis,

meningitis Meningitis is acute or chronic inflammation of the protective membranes covering the brain and spinal cord, collectively called the meninges. The most common symptoms are fever, headache, and neck stiffness. Other symptoms include confusion or ...

or brain abscess. This is possible because of venous communication (via the ophthalmic veins) between the facial vein and the cavernous sinus. The cavernous sinus lies within the

cranial cavity The cranial cavity, also known as intracranial space, is the space within the skull that accommodates the brain. The skull minus the mandible is called the ''cranium''. The cavity is formed by eight cranial bones known as the neurocranium that in ...

, between layers of the

meninges In anatomy, the meninges (, ''singular:'' meninx ( or ), ) are the three membranes that envelop the brain and spinal cord. In mammals, the meninges are the dura mater, the arachnoid mater, and the pia mater. Cerebrospinal fluid is located in th ...

and is a major conduit of venous drainage from the brain. Despite this relatively plausible anatomical argument, only severe facial infections (e.g., nasal abscess) can lead to a deeper central nervous system infectious complication. It was discovered that venous valves are present in the ophthalmic and facial veins. Thus, it is not the absence of venous valves but rather the existence of communications between the facial vein and cavernous sinus and the direction of blood flow that is important in the spread of infection from the face. Most people, but not all, have valves in these particular veins of the face. The relationship between this area and a risk of cavernous sinus thrombosis was described as early as 1852. In 1937, a study found that 61% of the cases of cavernous sinus thrombosis were the result of furuncles on the upper part of the face. While the disorder has become extremely uncommon with the development of antibiotics, it still carries a very small chance to develop a high risk of death and needs to be treated aggressively with antibiotics and

blood thinners Anticoagulants, commonly known as blood thinners, are chemical substances that prevent or reduce coagulation of blood, prolonging the clotting time. Some of them occur naturally in blood-eating animals such as leeches and mosquitoes, where t ...

Infection of cavernous sinus

If the cavernous sinus is infected, it can cause the blood within the sinus to clot resulting in a cavernous sinus thrombosis. This affects the structures that are going through it or surround it. Inside the cavernous sinus, constriction of the following cranial nerves (CN) can be found: CN III (

oculomotor nerve The oculomotor nerve, also known as the third cranial nerve, cranial nerve III, or simply CN III, is a cranial nerve that enters the orbit through the superior orbital fissure and innervates extraocular muscles that enable most movements of ...

), CN IV ( trochlear nerve), CN VI ( abducens nerve), CN V ( trigeminal nerve), specifically V1 ( ophthalmic nerve) and V2 ( maxillary nerve) branches. Failure of each of the nerves listed above will manifest in loss of function of the specific muscle, gland or a parasympathetic innervations (from CN III). In addition, it is possible that inflammation of the cavernous sinus will result in compression of the optic chiasm (resulting in vision problems) and/or the pituitary gland. Failure of CN III will result in loss of function 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 (Müller's muscle). CN III damage also results in loss of parasympathetic innervation of the eye (loss of pupillary constriction and lens accommodation).

References

External links

* *{{cite web , url=http://www.drpaulose.com/ear/ent-pediatric-children/nasal-abscess-in-danger-area-of-face, title= Nasal Abscess in Danger Area of Face , access-date=2011-04-08 Human head and neck Face