Anatomy of SCALP 2006-2007

ANATOMY OF Parotid Region By Dr. Fekry Shata Assistant prof ANATOMY OF Parotid Region By Dr. Fekry Shata Assistant prof. of anatomy & embryology Faculty 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

Parotid gland

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

Deep lobe Facial nerve Superficial lobe

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

Posteromedial surface 1- Surfaces Anteromedial surface Superficial surface 2- Borders Upper Pole (Base) 3- Poles Lower Pole (Apex) Posterior border Anterior border

EXTERNAL FEATURES Apex (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 facial nerve. external carotid artery. retromandibular vein.

Contents of parotid gland Retro-mandibular vein Facial nerve External carotid artery

The first plane is the venous plane retromandibular vein (posterior facial vein) and its tributaries: superficial temporal vein maxillary vein anterior division of retromandibular vein posterior division retromandibular vein

b- Posterior Facial Vein (Reteromandibular) Parotid Posterior Facial Vein (Reteromandibular)

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: temporal branch zygomatic branch buccal branches mandibular branch cervical branch

temporal branch (t) zygomatic branch (z) upper buccal branches (b) Lower buccal branches (b) mandibular branch (m) cervical branch (c) posterior auricular branch to posterior belly of digastric (db)

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: maxillary artery superficial temporal artery & its branch transverse facial artery

Superficial Temporal artery External carotid artery c- External carotid and superficial temporal arteries Superficial Temporal artery Post. Auricular artery occipital artery Maxillary artery Parotid External carotid artery

Deepest part of the parotid region is the parotid bed which includes: the neck of the condyle of the mandible (nc) Masseter muscle. The mastoid process . styloid process . stylopharyngeus muscle . stylohyoid muscle . posterior belly of the digastric muscle .

Neck of mandible Mastoid process external auditory meatus stylopharyngeus muscle styloid process masseter stylohyoid muscle sternomastoid

Relations

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. Retro-mandibular vein. [leaves gland] External carotid artery. [enters gland] Cervical branch of facial nerve. [leaves gland]

Retro-mandibular vein Cervical branch of facial nerve

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. Superficial temporal vein. [enters gland] Superficial temporal artery. [leaves gland] Temporal branch of facial nerve. [leaves gland] Auriculo-temporal nerve. [leaves gland]

Superficial temporal vessels Temporal branch of facial nerve Auriculo-temporal nerve

SUPERFICIAL SURFACE [LATERAL], [SUBCUTANEOUS] =Largest surface. =Related to the following structures:- from out inwards Skin. Superficial fascia. Deep fascia [parotid fascia] (deep lamina) Deep parotid L.N.

Skin Superficial fascia Deep fascia

The following structures emerge at this border:- BORDERS 1. ANTERIOR BORDER:- The following structures emerge at this border:- above downwards nerve . 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]

PAROTID DUCT

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.

Retro-mandibular vein VENOUS DRAINAGE Retro-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)