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1. GITAM DENTAL COLLEGE & HOSPITAL
DEPARTMENT OF
ORAL & MAXILLOFACIAL SURGERY
SEMINAR ON
Venous drainage of head & neck region & spread of infection through
venous drainage
Presented By:
Dr. Sambhav K Vora
I MDS

2. Contents
1. Introduction
2. Classification of veins
3. Veins of head & neck
4. Veins of scalp & face
5. Variations in the superficial cervical veins
6. Sinuses of the duramater
7. Emissary veins
8. Diploic veins
9. Spread of infection through the venous drainage
10.Cavernous sinus thrombosis.

3. Aim: To study the course & position of the veins of the head & neck & its
protection while performing surgeries related to that area.
The venous blood of head &neck is drained almost entirely by the internal
jugular vein, which joins the subclavian vein, behind the sternoclavicular
articulation to form the brachiocephalic vein. The two brachiocephalic vein
unites to form the superior vena cava. Along the neck .two superficial veins
are added to the deep internal jugular vein namely the external & anterior
jugular vein.
CLASSIFICATION OF VEINS;
 Veins of exterior of head &neck
 Cervical veins
 Diploic, meningeal, &dural venous sinuses

4. VEINS OF THE NECK
Veins of the neck are superficial and deep to the deep fascia. Superficial
veins are anterior jugular, external jugular and posterior jugular veins; they
drain a smaller part of tissue than deep veins. Deep veins drain all
subcutaneous structures mostly internal jugular veins and into the subclavian
vein. Superficial veins

5. Deep veins
VEINS OF HEAD &NECK
Vein Termination Tributaries Areas drained
Superficial
veins
1.facial
Common facial
vein
1.supratrochlear
2.supraorbital
3.nasal
4.superior labial
5.inferior labial
6.muscular
7.submental
8.tonsillar
9.
Submandibular.
Scalp, forehead
.upper eyelid
Scalp,forehead,uppe
r eyelid
External nose
Upper lip
Lower lip
Masseter &
buccinator muscle
Sub mental structure
Palatine
tonsil&tonsillar bed
Submandibular
gland
2.superficial Retromandibula 1.scalp Anterior & posterior

6. temporal r
2.glandular
3.auricular
4.articular
5.transverse
facial
region of scalp
Parotid gland
External ear
Temporomandibular
joint
Side of the face
&cheek.
3.pterygoid
plexus of veins
Maxillary veins
&small
contribution to
cavernous sinus
1.infraorbital
2.sphenopalatine
3.muscular
4.buccal
5.palatine
a. greater
palatine
b. lesser
palatine
6.inferior
alveolar
a. mental
7. deep facial
Lower eyelid,
external nose, upper
lip , maxillary teeth
Nasal cavity,
anterior end of hard
palate
Muscles of
mastication
Cheek & buccal
mandibular gingivae
Posterior two thirds
of the hard palate
Soft palate
Mandibular teeth
Lower lip, chin,
mandibular labial
gingivae
A direct
communication with
the facial
4.maxillary Retromandibula
r
Pterygoid plexus See above
Retromandibula
r
Anterior &
posterior
divisions
1.superficial
temporal
2.maxillary
See above
Common facial Internal jugular 1.facial
2,retromandibula
r
(anterior
division)
See above
External jugular Subclavian 1.retromandibula
r (posterior
See above

7. division)
2.posterior
auricular
3.transverse
cervical
4.suprascapular
5.anterior jugular
Scalp posterior to
ear, external ear
Neck
Neck &upper back
Structures of the
anterior triangle of
the neck.
INTERNAL JUGULAR VEIN:
The internal jugular vein receives blood from the brain, face, &neck. It
commences at the jugular foramen in the skull as the continuation of the
sigmoid sinus it descends through the neck in the carotid sheath &unites
with the subclavian vein behind the medial end of the clavicle to form the
brachiocephalic vein, immediately below the jugular foramen the vein is
widened to form the superior bulb of the internal jugular vein which is
contained in the jugular fossa on the inferior surface of the temporal bone.
Relations:
Anterolaterally –skin, fascia, sternocleidomastoid, &the parotid salivary
gland

8. Lower end is covered by the sternothyroid, sternohyoid, & omohyoid
muscles
Higher up is crossed by stylohyoid, posterior belly of the digastric &the
spinal accessory nerve
Posteriorly-transverse process of cervical vertebrae, levator
scapulae,scalenus medius,scalenus anterior ,cervical plexus,phrenic
nerve,thyrocervical trunk, vertebral vein,& the first part of subclavian artery
Medially –above lies the internal carotid artery& the ninth, eleventh,
&twelfth cranial nerves. Below lies the common carotid artery & the vagus

9. nerve.
Tributaries-
Into the superior bulb opens the inferior petrosal sinus,
Veins of the pharynx tongue. &sublingual area drain upper part of the
internal jugular vein,
Anastomosis between internal &external jugular vein is seen near the upper
corner of the carotid triangle.,

10. Facial vein along with anterior division of the Retromandibular vein joins
the internal jugular vein.
Veins of the larynx & thyroid glands are main tributaries at the lower part
of the neck,
Lingual veins-it drains the tongue & sublingual region. It has 3 division’s
namely dorsal veins, deep veins & sublingual vein. The largest of these
veins is the sublingual vein, which accompanies the hypoglossal nerve .vein
of the tongue may join single large trunk or may empty separately into the
internal jugular vein
Surface marking: it is along a line from the lobule of the ear to the sternal
end of the clavicle, between the two heads of the sternocleidomastoid, .In the
neck the internal jugular vein lies lateral to the common carotid artery, in
front of the scalenus anterior. .The jugular venous pulse is a guide to the
jugular venous pressure. With the patients reclining at 45 degrees the jugular
venous pulse should be visible just above the clavicle.
Ansa cervicalis lies in the front of the internal jugular vein & gives branches
to the infra hyoid muscles.
Catheterization: the right internal jugular vein can be cannulated for the
insertion of the central venous line, for measurements of central venous
pressure, or the rapid administration of the drugs when the peripheral
approach would be too slow. The vein is usually approached through the
centre of the triangle formed by the two heads of the sternocleidomastoid
&clavicle. The needle is directed caudally ,parallel to the sagittal plane at a
30 degree posterior angle with the coronal plane, entering the vein in about
4 -5 cm.
Complications-hematoma formation, common carotid artery puncture,
vagus nerve injury, & pneumothorax due to pleural perforation.
Pulsations of the IJV caused by contraction of the right ventricle of the heart
may be palpable superior to the medial end of the clavicle. The pulsations
usually are visible when the person’s head is 10 to 25° lower than the feet.
Because there are no valves in the brachiocephalic vein or superior vena
cava, a wave of contraction passes up these vessels to the IJV. The presence
of valves in the IJV and subclavian vein, near their respective junctions
prevents backflow during heart contractions

11. INTERNAL JUGULAR VEIN PUNCTURE
A needle and catheter may be inserted into the IJV for diagnostic or
therapeutic purposes. During this procedure, the clinician palpates the
common carotid artery and inserts the needle into the IJV just lateral to it at
a 30° angle, aiming at the apex of the triangle between the sternal and
clavicular heads of the SCM. The needle is then directed inferolaterally
toward the ipsilateral nipple.
EXTERNAL JUGULAR VEIN
It drains mainly scalp and face. .it is formed by the union of posterior
division of the retromandibular vein with the posterior auricular vein and
begins near the angle of the mandible just below or in the parotid gland.
From here it descends obliquely superficial to the sternocleidomastoid to the
root of the neck and then it crosses the deep fascia and ends in the
subclavian vein. Although valves are present in the external jugular vein but
it doesn’t prevent regurgitation. It is covered by the platysma, superficial
fascia and the skin.
Tributaries – it receives the posterior external jugular vein and transverse,
cervical , suprascapular and anterior jugular vein near it s end. It is also
joined by the branch from the internal jugular vein near the parotid gland.
PROMINENCE OF EXTERNAL JUGULAR VEIN

12. When venous pressure is within the normal range, the blood distending the
EJV is either not apparent or observable for only a short distance at the base
of the neck. However, when the pressure rises – as during heart failure for
example – the EJV becomes prominent throughout its course along the side
of the neck. Consequently, routine observation for distention of the EJV
during physical examinations may reveal diagnostic signs of heart failure,
obstruction of the superior vena cava (e.g. by tumour cells), enlarged
supraclavicular lymph nodes, or increased intrathoracic pressure
SUBCLAVIAN VEIN PUNCTURE
The right subclavian vein often is the point of entry to the venous system for
central line placement. This technique is used to administer parenteral fluids
(nutritional fluid not introduced via the digestive system) and medications
and to measure the central venous pressure. The pleura and/or the
subclavian artery are in danger of puncture during this procedure.
POSTERIOR EXTERNAL JUGULAR VEIN
It begins in the occipital scalp and drains into the skin and the superficial
muscles in the postero superior region of the neck. It joins the middle part of
the external jugular vein.
ANTERIOR JUGULAR VEIN
It arises near the hyoid bone and descends between the midline and the
anterior border of the sternocleidomastoid. Deep to the sternocleidomastoid
it joins the external jugular vein or may enter subclavian vein directly. There
are usually two anterior jugular veins which are united just above the
manubrium by large transverse jugular arch which receives the inferior
thyroid tributaries.
FACIAL VEIN:-it is the main vein of the face. It travels obliquely
downwards by the side of the nose &descends to the anterior border & then
passes over the surface of the masseter. It crosses body of the mandible
&runs in the neck to drain into the internal jugular vein. The common facial
vein originates below the angle of the mandible from the junction of the
facial &retromandibular vein, above its junction with the superior labial vein
it is termed as angular vein. The angular vein receives the frontal vein,
supraorbital vein, veins from the lower lid &from the bridge of the nose.
Supraorbital vein begins

13. near the zygomatic process of the frontal bone, passes medially piercing the
orbicularis oculi&unites with the supratrochlear vein .frontal &supra orbital
veins anastomoses through wide venous nets with the other veins of the
scalp. Superficial temporal, posterior auricular &occipital veins. The angular
vein is constantly in communication with the superior ophthalmic vein jus
above the medial palpebral ligament,& as superior ophthalmic vein opens
into the cavernous sinus a link between facial vein & intracranial sinuses of
the duramater is seen
Facial vein lacks valves & because of its connection with the cavernous
sinus it has the clinical significance in the spread of infection.
superficial temporal vein:
it begins from the wide spread plexus of veins on side of the scalp
&along zygomatic arch.frontal & parietal tributaries unite anterior to the
auricle, crosses temporal root of zygomatic arch to pass from the temporal
region & enter the substance of the parotid gland.it joins maxillary vein
posterior to the neck of the mandible to form the retromandibular vein.

14. Retromandibular vein:
It is formed by the union of the superficial temporal & maxillary vein in the
substance of the parotid gland behind the neck of the mandible.the vein
emerges at the lower pole of the gland to unite with the facial vein,it
continues downwards on the outer surface of the stylohyoid &digastric
muscles In some cases however the a deep branch of
retromandibular vein follows the external carotid artery in its deep course
&empties into the internal jugular vein.
Above the root of zygomatic arch ,a middle temporal vein opens into the
superficial temporal vein. This middle temporal vein drains into the venous
plexus situated underneath the temporal fascia
The two maxillary veins are the outlet of the large &dense pterygoid venous
plexus which surrouds the maxillary artery in the infra temporal fossa.
Pterygoid plexus of veins:
Veins of the deep structures of the face open here. It is situated between
the temporal &lateral pterygoid or between the lateral &medial pterygoid
muscles depending on the course of the maxillary artery..anteriorly it
reaches the tuberosity of the maxilla ,superiorly to the base of the skull.

15. Tributaries-veins of the masticatory muscles,sphenopalatine veins ,draining
posterior part of the nasal cavity &greater part of the palate , middle
meningeal veins draining the duramater , articular veins from rich plexus in
&around the capsule of the mandibular joint,auricular veins from the
external ear, transverse facial vein draining the posterior part of the cheek &
the parotid gland.
The dense venous plexus surrounding the maxillary artery serves to protect
the artery from the compressionwhen the masticatory muscles contract.
During their contraction the bulging muscles drive blood from the veins
&during relaxation the veins fill again.this type of mechanical protective
functions of veins is very rare & is seen in the venous plexus surrounding
the internal carotid artery in the carotid canal.
Variations in the superficial cervical veins
The most important and frequent variations are:-
1. the common facial vein does not exist. The retromandibualr vein
continues into the external jugular vein, the facial vein opens into the
internal jugular r vein.
2. the retromandibular vein opens into the internal jugular vein, the
facial vein continues intot the anterior jugular vein, and a common
facial vein again is absent.
3. the common facial vein loses its connection with the internal jugular
vein and empties instead into the external jugular vein.(choudhary et
al )
4. retromandibular vein continues into the external jugular vein, facial
vein continues into the anterior jugular vein.
5. In one of the cadavers the following variation was observed, the facial
vein was found running downward & backwards at the anterior border
of masseter,where the submental vein united with the facial vein to
form a common venous channel.the common venous channel united
with the retromandibular vein at the angle of the mandible to form the
common facial vein. Before this common facial vein joins the internal
jugular vein , a venous channel originating from the anterior jugular
vein comes & joins the common facial vein &which then joins the
internal jugular vein.( j anat.soc.india,52(1),64-65 (2003))
6. A case of facial vein uniting with the superficial temporal vein 5 mm
cranial to the undivided part of retromandibular vein has been
reported by Peuker et al (2001)

16. VEINS OF THE SCALP & FACE:
The superficial part of scalp is drained by supra orbital &supra trochlear
veins.
Supratrochlear vein- it starts from the venous network connected to the
frontal tributaries of the superficial temporal vein, it descends near the
midline to the bridge of the nose.where it unites with the supraorbital vein to
form the facial vein near the medial canthus of the eye.
Supraorbital vein begins near the zygomatic process of the frontal
bone,passes medially piercing the orbicularis oculi&unites with the
supratrochlear vein .frontal &supra orbital veins anastomose through wide
venous nets with the other veins of the scalp.superficial temporal,posterior
auricular &occipital veins.
SINUSES OF THE DURAMATER
The blood of the brain and the eye is collected by system of specialized vein
in the duramater called sinuses. These sinuses are non collapsible and are
formed by the dense rigid and inelastic tissue of the duramater. They drain
eventually into the internal jugular vein but there are numerous
communications between the sinuses and the extracranial vein.
SUPERIOR SAGITTAL SINUS
This sinus commences in the region of crista gali of the ethmoid bone and
curves posteriorly in the midline over the frontal, parietal and occipital
bones. On its way it receives numerous veins from the convexity of the
brain.
Arachnoid granulations are small cauliflower like extension that protrude
into the lateral aspects of the superior saggital sinus .csf leaks back across
the arachnoid membrane through these archnoid granulations to enter the
venous blood of the superior sagittal sinus.
INFERIOR SAGITTAL SINUS
A narrow sinus, enclosed in the lower free border of a sickle shape median
fold of the dura, the falx cerebri which separates the two hemispheres of the
cerebrum.
STRAIGHT SINUS
A roughly horizontal fold of the dura between the cerebrum and
cerebellum,meets the inferior saggital sinus joins with a deep vein of brain

17. &continues backwards &downwards as the straight sinus.it unites with the
superior saggital sinus at the inner occipital eminence.
OCCIPITAL SINUS:
This small vein begins on either side of the great occipital foramen
&ascends in the midline.it ends at the inner occipital eminence.
TRANSVERSE SINUS;
The point where the superior saggital sinus ,straight sinus ,&occipital sinus
unite is called the confluence of the sinuses.from here the blood is drained
by the paired transverse sinus.,sometimes the straight &superior saggital
sinus do not join but continue each into one transverse sinus,even if they join
also a greater amount of blood usually enters into the right transverse sinus
than the left, as a consequence the right internal jugular vein is often much
larger than the left.
The transverse sinus runs almost horizontally across the occipital bone
&then over the temporal bone to the point where the superior crest of the
temporal pyramid commences.from this point the transverse sinus continues
in an s shaped curve as the sigmoid sinus,descending towards the cranial
base ,the sigmoid sinus continues through the jugular foramen into the
internal jugular vein.
CAVERNOUS SINUS: it is a large venous space situated in the middle
cranial fossa on either side of the sphenoid bone. The floor of the sinus is
formed by the endosteal duramater .the lateral wall, roof, &medial wall is
formed by meningeal duramater. Anteriorly the sinus extends up to the
medial end of the superior orbital fissure &posteriorly up to the apex of
petrous temporal bone.
Relations –
Structure outside the sinus-

18. a.superiorly : optic tract,optic chiasma,olfactory tract,internal carotid
artery,
b.inferiorly:foramen lacerum & the junction of the body &greater wing of
sphenoid bone
c.medially:hypophysis cerebri &sphenoidal air sinus
d.laterally:temporal lobe with uncus
e.anteriorly:superior orbital fissure & the apex of the orbit
f.posteriorly:apex of the petrous temporal & the crus cerebri of the mid
brain
structure in the lateral wall of the sinus-
a.occulomotor nerve- in the anterior part of the sinus,it divides into the
superior &inferior divisions which leave the sinus by passing through the
superior orbital fissure
b. trochlear nerve-it enters the orbit through superior orbital fissure
c.opthalmic nerve-in the anterior part of the sinus it divides into the
lacrimal,frontal,& nasociliary nerves
d.maxillary nerve-it leaves the sinus by passing through the foramen
rotandum
e.trigeminal ganglion
structures passing through the centre of the sinus:
a. internal carotid artery with the venous & sympathetic plexus around it.

19. b. Abducent nerve-inferolateral to the internal carotid artery.
Tributaries or incoming channels:
From the orbit-
a.superior ophthalmic vein
b. branch of inferior ophthalmic veinor sometimes the vein itself.
c.the central vein of retina may drain into the superior ophthalmic vein or
into the cavernous sinus.
From the brain-
a.superficial middle cerebral vein
b. inferior cerebral veins
from the meninges-
a. Sphenoparietal sinus
b. Frontal trunk of middle meningeal vein which may drain into the
pterygoid plexus through the foramen ovale or into the sphenoparietal
or cavernous sinus.

20. Draining channelsor communications-
a. Transverse sinus through the superior petrosal sinus
b. Internal jugular vein through the inferior petrosal sinus &through a
plexus around the internal carotid artery.
c. Pterygoid plexus of veins through the emissary veins passing through the
foramen ovale,foramen lacerum& the emissary sphenoidal foramen
d. Facial vein through the superior ophthalmic vein
e. Right &left cavernous sinuses communicate with each other through the
anterior &posterior intercavernous sinuses &through the basilar plexus
of veins.
superior petrosal sinus (sinus petrosus superior) small and narrow,
connects the cavernous with the transverse sinus. It runs lateralward and
backward, from the posterior end of the cavernous sinus, over the trigeminal
nerve, and lies in the attached margin of the tentorium cerebelli and in the
superior petrosal sulcus of the temporal bone; it joins the transverse sinus
where the latter curves downward on the inner surface of the mastoid part of
the temporal. It receives some cerebellar and inferior cerebral veins, and
veins from the tympanic cavity.
Inferior petrosal sinus (sinus petrosus inferior) is situated in the inferior
petrosal sulcus formed by the junction of the petrous part of the temporal
with the basilar part of the occipital. It begins in the postero-inferior part of
the cavernous sinus, and, passing through the anterior part of the jugular
foramen, ends in the superior bulb of the internal jugular vein. The inferior
petrosal sinus receives the internal auditory veins and also veins from the
medulla oblongata, Pons, and under surface of the cerebellum.
Relations: of the parts to one another in the jugular foramen is as follows:
the inferior petrosal sinus lies medially and anteriorly with the meningeal
branch of the ascending pharyngeal artery, and is directed obliquely
downward and backward; the transverse sinus is situated at the lateral and
back part of the foramen with a meningeal branch of the occipital artery, and
between the two sinuses are the glossopharyngeal, vagus, and accessory
nerves. These three sets of structures are divided from each other by two
processes of fibrous tissue. The junction of the inferior petrosal sinus with
the internal jugular vein takes place on the lateral aspect of the nerves.

21. SIGMOID SINUS: it continues medially from the transverse sinus & ends at
the mouth of the jugular foramen. Thus all venous blood ultimately collected
by the sigmoid sinus drains through the jugular foramina to the internal
jugular vein below.
BASILAR SINUS: it lies below the Dura of the clivus, scattered in a
plexiform fashion. It receives blood from the cavernous sinus inferior
petrosal sinus &then drains to the vertebral plexus of veins through the
foramen magnum.
Emissary Veins (emissaria).—the emissary veins pass through apertures in
the cranial wall and establish communication between the sinuses inside the
skull and the veins external to it. Some are always present, others only
occasionally so. The principal emissary veins are the following:
(1) A mastoid emissary vein, usually present, runs through the mastoid
foramen and unites the transverse sinus with the posterior auricular or with
the occipital vein.
(2) A parietal emissary vein passes through the parietal foramen and
connects the superior sagittal sinus with the veins of the scalp.
(3) A net-work of minute veins (rete canalis hypoglossi) traverses the
hypoglossal canal and joins the transverse sinus with the vertebral vein and
deep veins of the neck.
(4) An inconstant condyloid emissary vein passes through the condyloid
canal and connects the transverse sinus with the deep veins of the neck.
(5) A net-work of veins (rete foraminis ovalis) unites the cavernous sinus
with the pterygoid plexus through the foramen ovale.
(6) Two or three small veins run through the foramen lace rum and connect
the cavernous sinus with the pterygoid plexus.
(7) The emissary vein of the foramen of Vesalius connects the same parts.
(8) An internal carotid plexus of veins traverses the carotid canal and unites
the cavernous sinus with the internal jugular vein.
(9) A vein is transmitted through the foramen cecum and connects the
superior sagittal
sinus with the veins of the nasal cavity.
DIPLOIC VEINS:

22. The diploic veins occupy channels in the diploë of the cranial bones. They
are large and exhibit at irregular intervals pouch-like dilatations; their walls
are thin, and formed of endothelium resting upon a layer of elastic tissue.
1
So long as the cranial bones are separable from one another, these veins are
confined to the particular bones; but when the sutures are obliterated, they
unite with each other, and increase in size. They communicate with the
meningeal veins and the sinuses of the dura mater, and with the veins of the
pericranium. They consist of (1) the frontal, which opens into the
supraorbital vein and the superior sagittal sinus; (2) the anterior temporal,
which is confined chiefly to the frontal bone, and opens into the
sphenoparietal sinus and into one of the deep temporal veins, through an
aperture in the great wing of the sphenoid; (3) the posterior temporal,
which is situated in the parietal bone, and ends in the sigmoid sinus, through
an aperture at the mastoid angle of the parietal bone or through the mastoid
foramen; & also communicates with the occipital vein and (4) the occipital,
the largest of the four, which is confined to the occipital bone, and opens
either externally into the occipital vein, or internally into the transverse sinus
or into the confluence of the sinuses (torcular Herophili).
2
Veins of the diploe
SPREAD OF INFECTION THROUGH
VENOUS DRAINAGE
CONNECTIONS BETWEEN EXTRACRANIAL VEINS &
INTRACRANIAL VEINS:

23. There are 4 ways by which extracranial veins communicate with the
intracranial veins.
1. Emissary veins
2. Diploic veins
3. Venous plexus surrounding internal carotid artery & cranial nerves
4. Through superior ophthalmic vein or facial vein and retromandibular
vein.
As already mentioned there are various 1.emissary veins found in the head
& neck region, but the most important of our concern is the connection
between pterygoid plexus & cavernous sinus through foramina ovale ,
foramina lacerum , & sphenoidal foramina.
Pterygoid plexus of veins is drained by posterior superior alveolar vein
which drains the posterior part of the maxilla,so infection from this region
can directly enter into cavernous sinus through the pterygoid plexus
Facial vein through the deep facial vein communicates with the pterygoid
plexus.
2. Diploic veins:
Four diploic veins are present
Frontal diploic vein- connects to superior sagittal sinus & to the frontal vein
Anterior temporal vein- connects to sphenoparietal sinus & deep temporal
vein
Posterior temporal vein – connects to sigmoid sinus &to the occipital vein
Occipital diploic vein- connects to transverse sinus & to the occipital veins
3. venous plexus :
The veins that connect the sinuses & the extracranial veins along the internal
carotid artery & many of the cranial nerves are loosely connected with the
surrounding tissue & therefore collapsible. This acts as compressible
cushioning allowing for the changes in the volume of the artery during its
pulsation.
The internal carotid plexus of veins connects the cavernous sinus with the
pterygoid plexus of veins . another important plexus of vein accompanies the
hypoglossal nerve through the hypoglossal canal.
5. Of all the communications , those established by the ophthalmic veins
are of greatest clinical importance

24. There are two types of propagation of a facial thrombophlebities to the
cavernous sinus .one path leads from the facial vein into the superior
ophthalmic vein or sometimes rarely into the inferior ophthalmic vein
which in turn passes through the superior orbital fissure. Second path
leads from the retromandibular vein into the pterygoid venous plexus
,from here through the inferior orbital fissure into the terminal part of the
inferior ophthalmic vein , & then immediately through the superior
orbital fissure into yhe cavernous sinus.
In the first path, there will be warning signals like involvement of orbital
or retro bulbar cellulitis in the second pathway , there will be no warning
signal directly meningeal symptoms may occur.
Facial & retromandibular veins communicate by deep as well as by
superficial anastomoses. The anterior region of the upper jaw drains into
the infraorbital veins , which anastomoses freely with the tributaries of
the facial vein at the infraorbital foramen , where as infra orbital vein
itself enters into the pterygoid plexus draned by retromandibular vein.
The posterior part of the upper jaws drains mainly into the posterior
superioralveolar veins which are also tributaries of the pterygoid plexus
of veins
Venous blood of the lower jaw is primarily drained into the inferior
alveolar vein . a branch of the maxillary vein which drains into the
retromandibular vein & there is also wide anastomoses between the
inferior alveolar vein & tributaries of the facial vein through the mental
foramen.
Facial & retromandibular veins are also in direct communication by the
veins of the cheek which drains forward to the facial vein & backward to
the retromandibular vein.
Spread of infection through the facial vein:
The facial vein makes clinically important connections with the cavernous
sinus through the superior ophthalmic vein, the pterygoid plexus ,a network
of small veins within the infratemporal fossa through the inferior ophthalmic
&deep facial veins. Because of these connections, an infection of the face
may spread to the cavernous sinus &pterygoid venous plexus.
Blood from the medial angle of the eye, nose, &lips usually drains inferiorly
through the facial vein, especially when a person is erect, & as facial vein

25. has no valves blood may pass through it in the opposite direction
consequently, venous blood from the face may enter the cavernous sinus.
In individuals with thrombophlebitis of the facial vein, pieces of infected
clot may extend into the intracranial venous system & produces
thrombophlebitis of the cavernous sinus.
Infection of the facial vein spreading to dural venous sinuses may result
from the lacerations of the nose or be initiated by pimples on the side of the
nose &upper lip, consequently the triangular area from the upper lip to the
bridge of the nose is considered the danger area of the face.
CAVERNOUS SINUS THROMBOSIS:
It is a serious complication of infections of the upper &lower face & neck
region .it is more likely to be involved in the potentially fatal spread of
infection.each cavernous sinus communicates with each other, with
pterygoid plexus of veins,& superior ophthalmic vein which anastomoses
with the facial vein.these major veins drain teeth through the posterior
superior &inferiorvein & lips through the superior & inferior labial
veins.none of the veins that communicate with the cavernous sinus have
valves to prevent the retrograde blood flow back into the cavernous sinus

26. ,therefore dental infection that drain through this major veins initiate the
inflammatory respone resulting in blood stasis ,thrombus formation,&
increasing extra vascular fluid pressure. Increased pressure can change the
direction of blood flow,enabling the transport of this thrombus into the
venous sinuses causing cavernous sinus thrombosis.
Needle track contamination can also result in spread of infection through
pterygoid plexus of veins while administrating posterior superior alveolar
block incorrectly.non odontogenic infections originating from the danger
triangle of face i.e orbit , nasal region & para nasal sinus.
Signs & sympthoms of cavernous sinus thrombosis:
 Fever,
 Pappiloedema
 Proptosis
 opthalmoplegia
 Drowsiness,
 Rapid pulse,
 Loss of function of abducent nerve,
 Diplopia,
 Edema of eyelids, conjunctiva,
 Exopthalmos, depending on the infection
 Damage to other cranial nerves, like occulomotor &trochlear as well
as ophthalmic &maxillary division
 Meningitis.

27. Most common sites of primary infection-
1. Facial infection: medial third of face around the eyes & nose
Ophthalmic vein.
2 .sphenoid & ethmoid sinus infection- emissary veins & superior
ophthalmic vein.
3. Dental infection – pterygoid plexus of veins.
4. Otitis media & complication- mastoiditis
REFERENCES-
1. Clinical Anatomy for medical students- Richard S. Snell,
sixth edition.
2. Clinically Oriented Anatomy- Keith L. Moore, Arthur F.Dalley, fifth
edition.
3. Gray’s Anatomy- Henry Gray, thirty ninth edition.
4. Last’s Anatomy regional & applied- Chummy S. Sinnatamby,
eleventh edition.
5. The Anatomical Basis Of Dentistry- Bernard Liebgott, second edition
page no 394-395
6. Unusual Venous Drainage Pattern of Face: A Case Report. Mehra,S.
Kaul J.M. and Das S. J Anat. Soc. India 52(1) 64-65 (2003)