Anatomy of SCALP 2006-2007

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ANATOMY OFParotid Region

By

Dr. Fekry ShataAssistant prof. of anatomy & embryologyFaculty of Dentstery – Majmaa university

• The parotid region is actually part of the neck but it extends into the facial region as well.

• It also must be studied before the infratemporal region can be examined.

• We will examine the parotid region from superficial to deep pointing out the gland itself and the structures running through it

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Parotid gland

Definition:- It is the largest salivary gland. Term [parotid]:- para = around; otic [otid] = ear Shape:- inverted pyramid Divisions:- It is divided into:-1. Superficial lobe.2. Deep lobe3. Isthmus :- connects two lobes.

Superficial lobe

Deep lobe

Facial nerve

Extent:-It is wedged in triangular hollow behind mandible.It extends into:-ANTERIORLY :-overlaps masseter.POSTERIORLY:-overlaps sternomastoid m.MEDIALLY :-to styloid process.LATERALLY :- covered by skin.SUPERIORLY :-external auditory meatus.INFERIORLY: between angle of mandible, sternomastoid.

Surfaces, Borders and Poles of

Parotid Gland

Superficial surface

Anteromedial surfacePosteromedial surface1- Surfaces

2- Borders

Anterior borderPosterior border

3- Poles

Upper Pole(Base)

Lower Pole(Apex)

EXTERNAL FEATURESApex (directed downwards). [lower pole]Base (directed upwards).[upper pole][superior s.]Surfaces :- are three Superficial (lateral)(subcutaneous). Antero-medial. Postero-medial. Borders :- are three Anterior. Posterior. Medial. Deep border. Parotid duct:-

Deep (medial) surfaces

Contents• It is a salivary gland that has a large

duct which crosses the masseter muscle to pierce the buccinator muscle opposite the upper 2nd molar tooth.

• Parotid gland is carefully removed; we can identify the structures located within it

1.facial nerve. 2.external carotid artery.3.retromandibular vein.

Contents of parotid gland

External carotid artery

Retro-mandibular vein

Facial nerve

The first plane is the venous plane

• retromandibular vein (posterior facial vein) and its tributaries:

1. superficial temporal vein 2. maxillary vein 3. anterior division of retromandibular vein 4. posterior division retromandibular vein

b- Posterior Facial Vein (Reteromandibular)

Posterior Facial Vein (Reteromandibular)

Parotid

The second plane is the nervous plane: • contain the facial (VII) nerve which leaves the skull

through the stylomastoid foramen and immediately enters the deep part of the parotid gland where it gives off its branches:

1. temporal branch2.zygomatic branch3.buccal branches4.mandibular branch5.cervical branch

posterior auricular

branch to posterior belly of digastric (db)

temporal branch (t)

zygomatic branch (z)

upper buccal branches (b)

Lower buccal branches (b)

mandibular branch (m)

cervical branch (c)

The third plane is the arterial plane: • Lies deep to the nervous plane which

includes terminal parts of the external carotid artery and its branches:

1.maxillary artery2.superficial temporal artery & its branch

transverse facial artery

c- External carotid and superficial temporal arteries

External carotid artery

Parotid

Superficial Temporal artery

occipital artery

Maxillary artery

Post. Auricular artery

Deepest part of the parotid region is the parotid bed which includes:

1.the neck of the condyle of the mandible (nc)2.Masseter muscle.3.The mastoid process .4.styloid process .5.stylopharyngeus muscle .6.stylohyoid muscle .7.posterior belly of the digastric muscle .

masseter

sternomastoid

styloid process

external auditory meatusNeck of mandibleMastoid

process

stylohyoid muscle

stylopharyngeus muscle

APEX (LOWER POLE)

=It is tapered.=Extends downwards between sternomastoid &

mandible.=Overlaps posterior belly of digastric muscle.=The following structures appear at the apex:- V.A.N.1. Retro-mandibular vein. [leaves gland]2. External carotid artery. [enters gland]3. Cervical branch of facial nerve. [leaves gland]

Cervical branch of facial nerve

Retro-mandibular vein

External carotid artery

BASE ((GLENOID LOBE))

=It is broad & concave.=Extends upwards and surrounds the E.A.M..=The following structures appear at the apex:- V.A. 2 N.1. Superficial temporal vein. [enters gland]2. Superficial temporal artery. [leaves gland]3. Temporal branch of facial nerve. [leaves gland]4. Auriculo-temporal nerve. [leaves gland]

Auriculo-temporalnerve

Superficial temporal vesselsTemporal branch of facial nerve

SUPERFICIAL SURFACE[LATERAL], [SUBCUTANEOUS]

=Largest surface.=Related to the following structures:- from out inwards1. Skin.2. Superficial fascia. 3. Deep fascia [parotid fascia] (deep lamina)4. Deep parotid L.N.

SkinSuperficial fascia

Deep fascia

1. ANTERIOR BORDER:-The following structures emerge at this border:-

above downwardsnerve . artery . nerve . & duct . nerve . nerve.

Zygomatic branch of facial nerve. Transverse facial artery. Upper buccal branch of facial nerve. Accessory parotid gland above the duct Parotid duct. Lower buccal branch of facial nerve. Mandibular branch of facial nerve.2. POSTERIOR BORDER:- Overlaps sternomastoid.3. MEDIAL BORDER:-

Related to lateral wall of pharynx [superior conistrictor]

BORDERS

1=Thick walled

2=Length: 5 cm.

3=Termination: pierce the buccinator muscle opposite the upper 2nd molar tooth

Neuro-vascular supply

NERVE SUPPLY(Innervation of Parotid gland)

1.Parasympathetic (secretomotor).2.Sympathetic (vasomotor).3.Sensory:- a. from capsule. b. from parenchyma.

Parasympathetic innervation (secretomotor).

ORIGIN:- Inferior Salivary Nucleus in medulla oblongata.CRANIAL NERVE:- glossopharyngeal nerve (9th n).PRE-GANGLIONIC FIBERS:-LESSER SUPERFICIAL PETROSAL n..=which descends through foramen oval.RELAY GANGLION: Otic ganglion.POST-GANGLIONIC FIBERS:- Auriculo-temporal n.(mandibular nerve)

2.Sensory.

=Great auricular nerve :- to the capsule.

=Auriculo-temporal nerve :- to parenchyma.

ARTERIAL SUPPLY

From external carotid artery & its branches.

VENOUS DRAINAGERetro-mandibular vein

+external jugular vein.

Lymph Drainage of Parotid Gland

1)-Superficial L.N. [Peri-auricular L.N.]2)-Deep L.N.

Clinical Notes Regarding Parotid Gland

1- Affection of Facial nerve within the Gland

2- Parotitis (Mumps)

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