This document provides an overview of the anatomical structures of the neck. It discusses the layers of the neck including skin, fascia and muscles. It describes the boundaries and contents of the neck triangles, including arteries, veins, nerves and glands. Key structures like the hyoid bone and thyroid cartilage are examined in detail. The document emphasizes applied anatomy concepts like the spread of neck infections.

1. SEMINAR ON
ANATOMICAL STRUCTURES
OF THE NECK
Dr. V. RAMKUMAR
CONSULTANT DENTAL&FACIOMAXILLARYSURGEON
REG NO:4118 TAMILNADU –INDIA(ASIA)

2. ANATOMICAL S TRUCTURES OF THE NECK
Introduction
The Neck is more or less cylindrical structure connecting the head to the trunk. The
anterior midline of the neck presents a bulge whose size reflects sexual dimorphism in
that it is considerably larger in male than in female, this prominence of neck is known as
‘Adams apple’.
Importance of Neck in Human Beings
The neck contains the most important vital structures like
Arteries – Common carotid artery and its branches
Veins – External and Internal Jugular vein
Gland – Thyroid
Nerves – Hypoglossal nerve
- Vagus nerve
- Ansa Cervicalis

3. - Brachial Plexus
- Cervical Sympathetic chain
Contents of the Vision
1. Layers of neck.
2. Triangles of Neck.
3. Contents of the Triangles and its surgical anatomy.
4. Lymphatic system of Head and Neck and surgical anatomy.
5. Anatomical spaces of Head and Neck
Boundaries of the Neck
Above : Lower border of the mandible,
Below : Clavicle
Anterior : Median Plane
Posterior : Anterior border of the trapezius

6. Skin : Langer lines are horizontal lines which run around the covering of the neck.
Deep to the dermis is a very thin facial layer consisting of an areolar type of connective
tissue known as hypodermis or superficial fascia
The superficial fascia envelopes the neck just as the overlying skin and contains
with in it a paper of thin sheet of skeletal muscle the platysma.
Superficial drainage of skin
It consist of external jugular vein formed by union of the posterior auricular vein and
retro mandibular veins, just posterior to the angle of the mandible some times with in the
body of the parotid gland. The external jugular vein drains into subclavian vein.
Sensory Innervation of the neck
The skin of the neck is supplied by sensory fibrous from branch of ventral primary
rami of C2,C3,C4 of cervical plexus.
It is also supplied by the C5,C6,C7,C8 and T1 of the brachial plexus.
Sensation of the back of the neck is supplied by dorsal primary rami of C2,C3 and
C4.

7. The Deep cervical fascia (fasciacoli)
The deep fascia of the necks is condensed to form the following layer
• Investing layer
• Pre tracheal layer
• Pre vertebral layer
• Carotid sheath
Investing layer of deep cervical fascia:
It lies deep to the platysma and surrounds the neck like acollar. It forms the roof of
the posterior triangle of the neck.
Attachements
Superiorly: a) External occipital Protuberance b) superior nuchal line c) Mastoid
process d) Base of the mandible e) Between the angle of mandible of the mastoid process
the fascia split to enclose the parotid gland.
Supra Clavicular Spaces
Boundaries
Posteriorly : ligamentum nuchae and spine of the vertebra C7

8. Other Features
The investing layer of deepcervical fascia splits to enclose
Muscles – Trapezius and Sternomastoid
Salivary glands – Parotid and submandibular
Spaces – Suprasternal and supraclavicular
The fascia form pulley to bind the tendons of the digastric and omohyoid muscles.
The suprasternal space contains
a) Sternal head of the right and Left sternomastoid muscles
b) Jugular venous arch
c) Lymphnode
d) Interclavicular ligament
The supra clavicular space is traversed by
External jugular vein
Supraclavicular nerves
Cutaneous vessels including lymphatics
Pre tracheal fascia
The importance of this fascia is that it encloses and suspends the thyroid gland.
Attachements

9. : Superiorly
• Hyoid bone in the median plane
• Oblique line of the thyroid cartilage
• Cricoid cartilage, more laterally
Inferiorly
Thyroid gland encloses the inferior thyroid vessels.
Other Features:
Posterior layer of thyroid capsule is thick on either side forms a suspensory
ligament of thyroid gland (Ligament of Berry). The ligaments are attached chiefly to
cricoid cartilage and may extend to thyroid cartilage they support the thyroid gland and
do not let it sink into the mediastinum.
Applied Anatomy
All swellings of the thyroid gland moves with deglutition because it is attached to
investing layer of pretracheal fascia.
Some of the malignancies of the thyroid gland are benign lesions adenoma,
malignant lesions, follicular, papillary, anaplastic carcinoma.

10. Prevertebral Fascia
It lies in front of the prevertebral muscles and forms the floor of the posterior
triangle of the neck.
Attachments and Relation
Superiorly : Base of the skull
Inferiorly : Extends to superior mediastinum where it is attached to anterior
longitudinal ligament and to the body of 3rd and 4th thoracic vertebra.
Anteriorly : Prevertebral facia separate from pharynx by the retro pharyngeal space
containing loose areolar tissue.
Others features
Cervical and Brachial plexus lie behind the prevertebral fascia the fascia is pierced
by the four cutaneous branches of the cervical plexus.
Axillary sheath it is the covering of prevertebral fascia the subclavian and
axillaryveins lie outside the sheath.
Relations: Brachial plexus, subclavian artery, muscles scalenus anterior and
scalenus medius.

12. The fascia forms a fixed base for the movement of the pharynx the oesphagus and
the carotid sheath during the movement of the neck and during swallowing.
Carotid Sheath
The sheath is not a fascia, it is condensation of fibroareolar tissue around the main
vessels of the neck.
Attachement
The carotid sheath is attached to the base of the skull at the margin of the carotid
canal and is continued down wards along the vessels to the aortic arch.
In front the lower part of the sheath is firmly attached to the deep surface of the
sternomastoid.
Relations
Ansacervicalis embedded in the anterior wall of the carotid sheath.
Cervical sympathetic chain lies behind the sheath
The sheath is overlapped by the anterior border of sternomastoid and is fused to all
the three layers of deep cervical fascia

14. Applied Anatomy
1. Parotid swelling are very painful due to he under lying nature of parotid
fascia.
2. Submandibular gland excision should bedone after the ligation and division
of facial artery ,otherwise bleeding occurs through the stylomandibular
ligament.
3. Thyroid gland and its swelling move with deglutition because the thyroid
gland is attached to larynx by suspensory ligament.
4. Neck infection - Behind prevertebral fascia tuberculosis is common in the
cervical vertebra (pots disease ) Pus produced as a result may extend in
various direction. The infections may pass down forming retropharyngeal
abscess which may form a bulging in the posterior wall of pharynx. The pus
may extend laterally through the axillary sheath, becomes continous in
posterior triangle , or in the lateral wall of axilla. It may extend downwards
into the superior mediastinum.
5. Neck infections – Infront of prevertibal fascia usually arise from
suppuration. In retro pharyngeal lymphnodes. The pus forms an acute
retropharyngeal abscess which bulges forward. The infection may extend
down through the superior media stinum to the posterior mediastinum.
6. Division of the external jugular vein in the supraclavicular space may cause
air embolism and consequence death, because the cut ends of the vein are
prevented from retraction and closure by the fascia.

15. TRIANGLES OF NECK
The neck of the face is divided into anterior and posterior triangle by sterno mastoid.
Anterior triangle
It is a part of side of neck infront of anterior margin of sternomastoid behind the
media line of the neck and below the lower margin of the mandible.
Bony Features: Hyoid bone is the keyland mark in the upper part of neck. The
thyroid and cricoid cartilages of larynx appear below it.
Hyoid Bone
This bone belongs to the floor of the mouth, but also suspends the thyroid and
cricoid cartilages belonging to the larynx. It is a ‘v’ shaped and is suspended from the
styloid process of the temporal bone by the stylohyoid lgaments. It has a body, the
greater cornu and lesser cornu.
The hyoid bone has
a) Body
b) Anteriorsurface
c) Posterior surface

16. a) Lower border
b) Upper border
c) Greater cornu
d) Lesser cornu
Body it lies at the level of C3 vertebra. It is quadrilateral inshape andhas the
following surface.
Anterior surface : vertical median ridge divides the body incompletely into two halves
the attachments on each half are.
- Geniohyoid into whole body.
- Medial fibres of Hyoglossus
- Mylohyoid – linear insertion below the geniohyoid.
- Sternohyoid and omohyoid are attached to lower boarder
Posterior surface
Smooth and related to thyrohyoid membrane, Retrohyoidbursa between the
membrane and body.
- Lower border- Omohyoid

17. Sternohyoid
Levator glandulae thyroidae
Thyrohyoid
Upper Border :
- Hyo epiglotic ligament
- A few fibers of Genioglossus
Greater Cornu - Middle constrictor of pharynx
Hyoglossus – from lateral part of upper surface
- Stylohyoid – at the junction of greater cornu with the body.
- Fibrous loop of digastric muscles is attached lateral to stylohyoid.
Lesser Cornu : Small conical projection at junction of the body with greater cornu.
It attachement.
- Stylohyoid ligament at apex
- Chlondroglossus muscle at base
- Middle constrictor of pharynx posterolaterally.
Thyroid cartilage : Unpaired cartilage of larynx
It is at level of C 4 and C5 consists of two quadrilateral lamina joined anteriorly at
and angle to forma forward projection, the laryngeal prominence, adams apple.

18. Applied Anatomy
Hyoid bone will be fractured in hang over (suicide conditions). It is an important
evidence of forensic medicine.
Cricoid Cartilage
It lies at level of C6 vertebra. It gain attachment to the cricothyroid muscle which is
inserted into the posterior part of the lower border of the thyroidlamina and the anterior
surface of the inferior cornu of hyoid cartilage.
Subdivisions of anterior Triangle
1. Digastric Triangle
2. Carotid Triangle
3. Muscular Triangle
4. Submental Triangle Half of the triangle is shared by the anterior triangle of both
sides.
Digastric Triangle Ant: ant belly of digastric
Post : Posterior belly of Digastric

19. Roof : Skin, superficial fascia, platysma with in the superficial fascia are the facial
vein cervical branch of facial nerve – and branches of transverse cervical nerves (C2 , C3)
Floor Hyoglossus and middle constrictor posteriorly mylohyoid anteriorly overlapping
the hyoglossus. Floor is covered by the deep layer of superficial lamina of cervical fascia.
• Contents – lower part of submandibular salivary gland.
• Sub mandibular lymphnodes
Facial vein – pierces the deep fascia at lower border of the mandible across the
salivary gland.
Facial artery curves round the lower border of the mandible enters the face after
piercing the deep fascia.
Mylohyoid nerve : The nerve lies on the anterior surface of mylohyoid and supplies
mylohyoid muscle anterior belly of digastric.
Submental Vessels
They run forward on the inferior surface of submandibular salivary gland near the
mandible.

20. Hypoglossal nerve
The nerve is accompanied by the vein and run across the hyoglossus muscle
Lingual Artery
The artery is present on the deep side of the posterior belly of digastric

24. Applied anatomy
The sub mandibular group lymphnodes are affected in inflammation and in
malignancies.
The preservation of facial artery in surgical procedure
Preservation of marginal mandibular nerve in fracture of mandible.
Carotid Triangle
Boundaries
Superiorly : posterior belly of digastric
Inferiorly : Superiorly belly of omohyoid
Floor : Hyoglossus
• Thyrohyoid
• Middle and inferior constrictors
Roof - Skin
• Superficial fascia – containing platysma, cervical branch of facial nerve and
transverse cervical nerve.

25. • Investing layer of deep cervical fascia.
Contents
Carotid sheat which encloses. Common cartotid artery, vagus nerve internal jugular
vein, sympathetic trunk is embedded in the postero medial wall of the carotid sheath.
The Common carotid ascends from just behind the lower angle of the triangle. It is
divided in to external and internal carotid arteries at the level of upper border of thyroid
cartilage.
The externalcarotid ascends anteromedial to internal carotid and gives of following
branches.
1. Ascending pharyngeal
2. Superior Thyroid
3. Lingual
4. Facial
5. Occipital
6. Posterior Auricular
7. Maxillary artery
8. Superficial temporal artery

26. Vagus nerve
It descends in the carotid sheath posterolateral to the internal and common carotid
arteries, it has the following branches
1. Pharyngeal Branches : It runs inferomedially between both the carotid to join
the pharyngeal plexus on the middle constrictor of pharynx.
2. Superior laryngeal nerve : Runs on a deeper plane and lies deep to both
arteries, it divided into internal and external laryngeal nerves.
3. Accessory nerve : Runs down wards and backwards across the upper part of
the triangle superficial to internal jugular vein.
4. Hypoglossal nerve : Descends downwards between the internal jugular vein
and internal carotid artery and then runs forward crossing both the carotid
and forms a loop of the lingual artery and disappear under the digastric
tendon.
Pharyngeal plexus
It is formed by pharyngeal branches of vagus, glossopharyngeal nerve, branch from
superior cervical ganglion.
Applied Anatomy
1. Baro receptor: Carotid sinus a fusiform dilatation involving the bifurcation
of common carotid and beginning of internal carotid.

28. - The afferent limb of carotid reflex is mediated by the carotid branch of glosso
pharyngeal nerve – for controlling intracranial pressure.
- Efferent limb of inhibitory carotid reflex is mediated by vagus nerve.
Supra Ventricular Tachy cardia is susceptible to vagal effects and may be converted
into normal sinus rhythm by carotid massage.
Carotid body : Neuro vascular structure lying between bifurcation of common carotid
artery is very vascular. It is a chemo receptor sensitive to blood oxygenation and to lesser
extent partial pressure of Carbon-di-oxide .
Potato tumors or carotid body tumors or Chemodectoma : It is difficult to remove
because of their location, they are associated with slow pulse and attacks of fainting due
to pressure on carotid sinus.
Internal jugular vein is one of the vital structure in the neck to prevent damage
during surgical dissection of neck tumors.
Muscular Triangles
Boundaries : above : superior belly of omohyoid
Below: Anterior border of sternomastoid
Contents

29. Sternohyoid
Sterno thyroid
Thyro hyoid
They are known as the strap muscles of the neck.
The main importance of the triangle is that it overlies the thyroid gland
The omohyoid, steronohyoid, sternothyroid, thyrohyoid are known as infrahyoid
muscles.
They are innervated by C1, C2, C3 (Cervical nerve)
Actions : Muscles are involved swallowing and phonation as they fix the hyoid bone
to enable other muscles.
Sub mental triangle or suprahyoid region
Boundaries : Laterally – Anterior belly of digastric
Posteriorly : Body of hyoid bone.
Floor : Two mylohyoid muscles and median raphe between them
Covering layer : Skin, platysma, deepcervical fascia. Anterior jugular vein begins in
the superficial fascia deep to platysma.
Contents : Submental lymph nodes

30. Clinical Application : Infection of the median region of the floor of mouth, tip of the
tongue or the incisorteeth causes pain ful enlargement of the submental lymphnodes.
Median Region of the front of the Neck
It is divisible in to suprahyoid and infrahyoid regions. The submental triangle which
forms the region
Infrahyoid region is in the middle between the infrahyoid muscles of the two sides
the following structures are present above downwards.
• Median thyroid ligament – connects upper border of thyroid cartilage to upper
border of hyoid bone.
• Laryngeal prominence
• Cricothyroid ligament
• Cricothyroid muscle
• Isthmus of thyroid gland
Supro sternal space of burns – a fascial space formed by splitting of the investing
layer of deepcervical fascia just above the suprasternal notch contains some lymph nodes
jugular arch connecting lower end of anterior jugular vein. Sternal heads of orgin of
sternomastoid and interclavicular ligament.

31. Sterno mastoid muscle
The muscle pass obliquely upwards on the side of the neck. It is along bulky
muscle.
Origin : Arises by two head.
Sternal head : Arises by a rounded tendon upper part of manubrium sterni . It is
directed upwards and laterally.
Clavicular head : Superior border and anterior surface of medial one third of clavicle.
The two head of the muscles are separated by triangular interval in which the
internal jugular vein lies.
Insertion
Sternal head : Sterno mastoid part inserted into tip of the mastoid process.
Clavicular head: Cleido occipitalis part is formed by the posterior fibres of the
clavicular head and is inserted into the superior nuchal line with sterno occipitalis fibres.
Relations
Superficial
1. Skin, superficial fascia containing platysma.
2. Investing layer of deep cervical fascia
3. Greater auricular nerve

32. 1. External jugular vein
Deep relation
• Infrahyoid muscles
• Carotid sheath
• Subclavian artery
• Scalenus anterior muscle.
Crossing the muscle transversely from above downwards
• Inferior belly of omohyoid
• Transverse cervical artery
• Subclavian vein
Middle part
Common carotid artery
Internal jugular vein
Ansacervicalis
Upper part of brachial plexus.
Upper Part
• Mastoid process
• Cervical plexus

33. • Posterior belley of digastric
Nerve supply
• Spinal accessory nerve.
• Ventral rami of C2 and C3
Blood supply
Sternomastoid from super thyroid artery
Two sternomastoid from occipital artery at the level of hyoid bone.
Action
Rotation of head to carry the face to opposite side
Raising the head while the person is lying flat on his back.
Lateral flexion and contra lateral rotation, it helps in looking to side and upwards.
Sternomastoid muscle involves in accessory respiration.
Applied Anatomy
Spasm of the muscle is one of the cause of flexion deformity of the neck known as
wry neck or torticolis. In this the case ear lies close to the tip of the shoulder. And the
chin is rotated to the opposite side.

34. Posterior Triangle
Boundaries
Anterior : Posterior border of sternomastoid
Posterior : Anterior border of trapezius
Inferiorly : Middle third of clavicle
Superiorly : Apex by meeting point of the trapezius and sternomastoid.
Subdivisions: The inferior belly of omohyoid crosses the lower part of the triangle
and divides it in to two parts.
i) Occipital Triangle
ii) Subclavian Triangle
Roof : Skin, Superficial fascia with platysma, investing layer of deep cervical fascia.
Platysma : Thin flat sheet of muscle embedded in the superficial fascia .
Origin : from skin, fascia below the clavicle over the upper part of deltoid and
pectoralis major.
Insertion : In to the outer surface of mandible just above the inferior margin and
into the lower facial muscles around the angle of the mouth.

35. Action : Wrinkles skin of the neck and helps to open the mouth.
Nerve supply : Cervical branch of facial nerve
Floor of the posterior Triangle
1. Splenius capitis
2. Levator scapulae
3. Scalenus medius
Contents of Posterior triangle:
Muscle : splenius capitis , levatorscapulae,posteriorscalene muscle
Veins : external Jugular , transverse cervical , suprascapular
Arteries : Occipital, subclavian, transverse cervical, Suprascapular,
Nerves : Spinal Accessoy nerve, trunks of brachial plexus,
Lymphnodes
Occipital
Retroauricular
Superficial cervical
Upper deep cervical

36. Clinical Application
1. Erbs point union of C5 and C6 of brachial plexus
2. Radial nerve paralysis (wrist drop)
3. Third part of subclavian artery is prone for aneurysm formation.
4. Cervical rib may elevate subclavian artery and the branch of T1 which
contributes the formation of lower trunk of brachial plexus. The pressure on post
ganglionic T1 sympathetic fibers causes vaso constriction, the small muscles of
the hand has numbness which later causes paralysis of the hand.

39. Lymphatic Driange of the Neck
They are Classified in to superficial and Deep
Superficial Nodes : The nodes are arranged in the form of a circle around the neck
called the pericervical collar.
Pericervical collar are horizontally disposed nodes and so are arranged in the form
of a circle at the junction of head and neck. They are divided into.
Submental nodes: These or four small nodes which lie just beneath the chin between
the anterior bellies of digastric on the inferior aspect of mylohyoid they drain the tip of the
tongue floor of the mouth, the lower incisor teeth, lower lip.
Submandibular Nodes: They lie beneath the deep fascia of the submandibular
salivary gland. These nodes drain an extensive area of lips, cheek, anterior part of scalp,
upper and lower teeth, gingiva, the side of the tongue, the anterior part of nasal cavity
and paranasal sinus.
Preauricular lymph Nodes: They lie in front of the tragus of the ear and are usually
superficial to the parotid gland. They drain in the skin of the anterior part of the scalp,
the temple, pinna and external acousticmeatus.

40. Mastoid nodes: they lie in the mastoid process behind the root of auricle, they drain
the back of pinna and external auditory meatus.
Occipital nodes : They lie at the apex of the posterior triangle of the neck. They
drain back of the scalp and back of upper part of neck.
Facial nodes: The nodes are present along the facial vein one of these nodes lies on
the buccinator muscle close to the facial artery and known as buccal node.
Infrahyoid nodes: They lie on the thyrohoid membrane they drain the larynx above
the level of vocal cord.
Pre tracheal nodes : They lie on the trachea close to inferior thyroid veins they
receive lymphatics from the anterior cervical nodes.
Deep Cervical Nodes : These nodes drain in the deeper tissue of the neck. They are
placed around the carotid sheath from the base of the skull to the root of the neck, deep
to sternomastoid.
Superior deep cervical nodes: These nodes lie above the level of omohyoid, they
drain, the parotid, submandibular nodes, the root of tongue, upper lateral part of
thyroidgland.

41. They consistof jugulo digastric node, it is the chief node of draining the palatine
tonsil.
Waldeyer internal ring : It is a lymphoid tissue of the entrance of pharynx it is
formed.
Superiorly : pharyngeal tonsil
Inferiorly : Lingual tonsil
Laterally : palatine and tubal tonsil

44. Inferior deep cervical nodes: These nodes lie below the level of the thyroid cartilage
and the bifurcation of the common carotid artery, they drain the superior deep cervical
nodes, lower lateral part of thyroid gland, lower part of larynx.
Jugulo omohyoid belong to this group and it lies above the inferior belly of
omohyoid. “It is an important lymphatic drainage of tongue.
Paratracheal nodes: These lie between the trachea and oesophagus close to
recurrent laryngeal nerve . They are extension of inferior deep cervical nodes.
They receive lymphatic drainage from thyroidgland, cervical part of oesophagus,
trachea and neighbouring vessels.
Applied anatomy
Pain ful enlargement of submandibular nodes are common in infection.
Malignancy : The lymphnodes are hard in consistency and may be fixed to the
under line structures.
Occipital nodes: Enlarge in German measles.
Enlargement of jugular digastric node in pharyngeal or tonsilar involvement.

46. Lymphnodes of the Neck
They are classified according to the following levels
Level 1 : Lymphnodes of the submandibular triangle which includes those in the
submental region, those adjacent to sub mandibular gland above the digastric muscle,
prevascular lymphnodes adjacent to the facial artery and vein.
Level 2, 3 and 4: Represent deep jugular lymphnodes along the internal jugular vein
extending from the base of the skull to the supra clavicular region, They are divided into
three levels.
Upper third – Level 2
e.g Jugulodigastric and juguloomohyoid
Middle third upto the tendon of omohyoid muscle is level 3
Those in the deep jugular chain cauded from the omohyoid tendon up to clavicle are
level 4.
Level 5. Lymphnodes in the posterior triangle of the neck and contain in those in
the floor of posterior triangle of the neck (e.g. Sternomastoid and supraclavicular
lymphnodes.)

48. Levelling of Lymphnodes is prognosis for primary carcinoma of the oral cavity. The
prognosis is significantly worse with increasing level of involvement of lymph nodes by
metastatic cancer. The sequential fashion.
Level 1 and 2 followed by 3 and 4 then level 5
It would be rare to find involvement of Level 5 for primary oral carcinoma in the
absence of metastatic disease at levels 1 through 4.
Lymph nodes dissection
Modified radical neck dissection Type 1
Level 1 to level 5
Structure preserved
Spinal accessory nerve
Structure excised : sternomastoid muscle, internal jugular vein, submandibular
gland.
Modified radical neck dissection Type 2
Lymph nodes excised : Level 1 to Level 5
Structure preserved : sternomastoid and spinal accessory nerve
Structure excised : Internal Jugular vein

49. Modified radical neck dissection Type 3
Lymph nodes dissected - Level 1 to level 5
Structures excised - Submandibular gland
Structures preserved – Sternomastoid muscle
Internal jugular vein and spinal accessory nerve
ANATOMICAL S PACES
Sublingual space : The Space lies above mylohyoid muscle
Roof – Mucous Membrane of floor of mouth
Floor – Mylohyoid
Laterally – Inner surface of body of mandible above the mylohyoid line.
Medially – Geniohyoid, Genioglossus
Contnts : Sublingual gland, sub mandibularduct, deep part of sub mandibular
gland, hypoglossal nerve, lingual nerve, terminal branches of lingual artery.

50. Floor – mylohyoid muscle
Roof – skin, platysma, deep cervical fascia,
Laterally – Anterior belly of digastric
Contents : Anterior Jugular vein, submental lymph nodes.
Submandibular Space or Digastric Space
It lies postero lateral to submental space
Floor – Mylohyoid and Hyoglossus
Roof – skin and platysma
Posteroinferiorly – Stylohyoid, post belly of digastric
Anterio inferiorly – Anterior belly of digastric.
Space – closed by investing layer of deep cervical fascia
Superior layer – inferior border of the mandible
Deep layer – mylohyoid line

51. Contents
Submandibular gland
Facial artery
Nerve to mylohyoid
Mylohyoid vessels
Applied anatomy
Ludwigs angina is the common complication of sub mandibular, sublingual and sub
mental space infection. It is a life threatening condition which requires immediate
surgical treatment.
Masticator space infection
The space includes along the border of the mandible, ramus of the mandible,
muscles of mastication.
The fascia splits into outer sheath covers the external surface of the mandible,
masseter and temporalis muscles, the inner sheath covers the inner border and is
attached at the mylohyoid ridge.

52. Communications
Posterior it communicate with the parotid space laterally and para pharyngeal space
medially superiorly it continuos with the temporal pouches.
Applied anatomy
Trismus is the common complication of masticator space infection . The infection
can spread from 1st , 2nd and 3rd molar teeth.
Buccal Space Infection:
This Space exist between buccinator and masseter muscle. It contains buccal pad of
fat which extends upwards and inwards between the muscles of mastication.
Applied anatomy
Periapical abscess is a common complication of this space. Which is related to
infection from maxillary first and second molar
Infection of Temporal pouches
They are classified into superficial and Deep.
Temporal pouches are the spaces in relation to temporalis muscle.

53. Deep pouch – It lies between the skull and temporalis muscles.
Inferiorly the two pouches communicate with the infra temporal space at the level of
zygomatic arch.
Applied anatomy
Infection are secondary to masticator, infratemporal and pterygopalatine space.
Infratemporal Space
It lies inferior to the temporal pouches below the horizontal line drawn at the level of
zygmoatic arch. Laterally it is bound by zygomatic arch and ramus of the mandible.
Medially : Lateral surface of lateral pterygoid and lateral wall of pharynx.
Posteriorly : parotid gland
Anteriorly : Posterior surface of maxilla
Superiorly : Infra temporal crest of great wing of sphenoid.
Contents
1. Lateral pterygoid muscle
2. Inter maxillary artery

54. 1. Mandibular nerve
2. Buccal nerve
3. Lingual Nerve
4. Chordatympani nerve
5. Pterygoid plexus
6. Pharyngeal plexus
Applied Anatomy
Infections from maxillary first, second and Third molars can cause infection of this
space.
Parotid Space
It is formed by splitting of investing layer of deep cervical fascia. It contains the
parotid gland as well as lymph nodes. The fascia on the external surface of the gland is
thick. The fascia on the internal side is thin and in complete .

55. Communications
Superiorly it communicate with lateral pharyngeal space. It forms a strong band
medially called the stylomandibular ligament that separates parotid space from
submandibular space.
Applied anatomy
Mumps and infectious viral disease can cause bilateral enlargement of parotid gland.
Benign and malignant tumors of the parotid gland may affect this space. Example -
Plemorphic adenoma, adenoid cystic carcinoma may affect the space.
Lateral Pharyngeal Space:
It is cone shape space the base of cone lying at base of skull and the apex at carotid
sheath at the level of hyoid bone. This space lies lateral to pharynx, and medial to
submandibular, pterygomandibular and parotid space.
Laterally – Medial pterygoid and parotid gland
Medially – Superior constrictor of pharynges
Post : Prevertebral muscles

56. Anteriorly – Pterygomandibular raphe
Superiorly – Petrous part of temporal bone with foramen lacerum with jugular
foramen
Inferiorly – the Stylohyoid and capsular attachment of parotid gland.
Styloid process divides the space in to two compartments
Anterior compartment – Deepcervical and facial
Posterior Compartment – Carotid sheath
- Internal carotid artery
- Internal Jugular vein
- Vagus nerve
Applied anatomy
Infection of the lateral pharyngeal space may cause erosion of the internal carotid
artery and may cause fatal to life.

57. REFERENCE BOOKS
1. Grays Anatomy
2. Last Anatomy
3. Chaurasia
4. Colour Atlas of Anatomy
5. Infection by Topazian
SPECAL ACKNOWLEDGEMENT TO
My Department Professor, Reader, Lecturer.
My Beloved Parents and My Batch Mates
I am extremely thankful to
1. Dr. Suresh Kannan
2. Dr. Saravanan
3. Dr. Srivatsa
My Senior colleague for their guidance

58. Thank
you