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 A nose is a protuberance in vertebrates that houses the nostrils, or nares, which receive and expel air for respiration alongside the mouth. Behind the nose are the olfactory mucosa and the sinuses. Behind the nasal cavity, air next passes th ...

, including the nose and

maxilla The maxilla (plural: ''maxillae'' ) in vertebrates is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. The t ...

. Due to the special nature of the

blood Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells. Blood in the c ...

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 A brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It is located in the head, usually close to the sensory organs for senses such as vision. It is the most complex organ in a v ...

, causing

cavernous sinus thrombosis The cavernous sinus within the human head is one of the dural venous sinuses creating a cavity called the lateral sellar compartment bordered by the temporal bone of the skull and the sphenoid bone, lateral to the sella turcica. Structure The cave ...

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 ...

brain abscess Brain abscess (or cerebral abscess) is an abscess caused by inflammation and collection of infected material, coming from local (ear infection, dental abscess, infection of paranasal sinuses, infection of the mastoid air cells of the temporal bone ...

. This is possible because of venous communication (via the

ophthalmic vein Ophthalmic veins are veins which drain the eye. More specifically, they can refer to: * Superior ophthalmic vein * Inferior ophthalmic vein The inferior ophthalmic vein is a vein of the orbit that - together with the superior ophthalmic vein ...

s) between the

facial vein The facial vein (or anterior facial vein) is a relatively large vein in the human face. It commences at the side of the root of the nose and is a direct continuation of the angular vein where it also receives a small nasal branch. It lies behind t ...

and the

cavernous sinus The cavernous sinus within the human head is one of the dural venous sinuses creating a cavity called the lateral sellar compartment bordered by the temporal bone of the skull and the sphenoid bone, lateral to the sella turcica. Structure The cave ...

. 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 Thrombosis (from Ancient Greek "clotting") is the formation of a blood clot inside a blood vessel, obstructing the flow of blood through the circulatory system. When a blood vessel (a vein or an artery) is injured, the body uses platelets (thro ...

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 A boil, also called a furuncle, is a deep folliculitis, which is an infection of the hair follicle. It is most commonly caused by infection by the bacterium ''Staphylococcus aureus'', resulting in a painful swollen area on the skin caused by an ...

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 An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting bacterial infections, and antibiotic medications are widely used in the treatment and prevention o ...

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 the ...

Infection of cavernous sinus

If the

is infected, it can cause the blood within the sinus to

clot A thrombus (plural thrombi), colloquially called a blood clot, is the final product of the blood coagulation step in hemostasis. There are two components to a thrombus: aggregated platelets and red blood cells that form a plug, and a mesh of c ...

resulting in a

. 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 The trochlear nerve (), ( lit. ''pulley-like'' nerve) also known as the fourth cranial nerve, cranial nerve IV, or CN IV, is a cranial nerve that innervates just one muscle: the superior oblique muscle of the eye, which operates through the pul ...

), CN VI (

abducens nerve The abducens nerve or abducent nerve, also known as the sixth cranial nerve, cranial nerve VI, or simply CN VI, is a cranial nerve in humans and various other animals that controls the movement of the lateral rectus muscle, one of the extraocula ...

), CN V (

trigeminal nerve In neuroanatomy, the trigeminal nerve ( lit. ''triplet'' nerve), also known as the fifth cranial nerve, cranial nerve V, or simply CN V, is a cranial nerve responsible for sensation in the face and motor functions such as biting and chewin ...

), specifically V1 (

ophthalmic nerve The ophthalmic nerve (V1) is a sensory nerve of the face. It is one of three divisions of the trigeminal nerve (CN V). It has three branches that provide sensory innervation to the eye, the skin of the upper face, and the skin of the anterior sca ...

) and V2 (

maxillary nerve In neuroanatomy, the maxillary nerve (V) is one of the three branches or divisions of the trigeminal nerve, the fifth (CN V) cranial nerve. It comprises the principal functions of sensation from the maxilla, nasal cavity, sinuses, the palate a ...

) 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 In neuroanatomy, the optic chiasm, or optic chiasma (; , ), is the part of the brain where the optic nerves cross. It is located at the bottom of the brain immediately inferior to the hypothalamus. The optic chiasm is found in all vertebrate ...

(resulting in vision problems) and/or the

pituitary gland In vertebrate anatomy, the pituitary gland, or hypophysis, is an endocrine gland, about the size of a chickpea and weighing, on average, in humans. It is a protrusion off the bottom of the hypothalamus at the base of the brain. The ...

. Failure of CN III will result in loss of function of the following muscles:

medial rectus The medial rectus muscle is a muscle in the orbit near the eye. It is one of the extraocular muscles. It originates from the common tendinous ring, and inserts into the anteromedial surface of the eye. It is supplied by the inferior division of ...

superior rectus The superior rectus muscle is a muscle in the orbit. It is one of the extraocular muscles. It is innervated by the superior division of the oculomotor nerve (III). In the primary position (looking straight ahead), its primary function is elevatio ...

inferior rectus Inferior may refer to: * Inferiority complex * An anatomical term of location * Inferior angle of the scapula, in the human skeleton * ''Inferior'' (book), by Angela Saini * ''The Inferior'', a 2007 novel by Peadar Ó Guilín See also *Junior ( ...

, and

inferior oblique The inferior oblique muscle or obliquus oculi inferior is a thin, narrow muscle placed near the anterior margin of the floor of the orbit. The inferior oblique is one of the extraocular muscles, and is attached to the maxillary bone (origin) and ...

as well as muscles that are responsible for opening the eyelid:

levator palpebrae superioris muscle The levator palpebrae superioris ( la, elevating muscle of upper eyelid) is the muscle in the orbit that elevates the upper eyelid. Structure The levator palpebrae superioris originates from inferior surface of the lesser wing of the sphenoid bon ...

and the

superior tarsal muscle The superior tarsal muscle is a smooth muscle adjoining the levator palpebrae superioris muscle that helps to raise the upper eyelid. Structure The superior tarsal muscle originates on the underside of levator palpebrae superioris and inserts ...

(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