Mock - Parotid Gland

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Parotid Gland

Describe surface anatomy boundaries of parotid

Superior: Zygomatic arch
Anterior: Anterior border of masseter
Posterior: Line down from Mastoid process
Inferior: Angle of mandible

Surface marker of parotid duct

The middle 1/3 of a line drawn between intertragic notch to the corner of the mouth.

Where does duct open

In vestibule of mouth against 2nd upper molar teeth.

Differential diagnosis of parotid swelling?

Infection (parotitis, mumps)
Obstructed duct (calculus or external compression)
Neoplasm (pleomorphic adenoma, Warthin's tumour)
Deep parotid lymph nodes

Most common benign parotid swelling?

Pleomorphic adenoma

Most common malignant parotid swelling?

Mucoepidermoid carcinoma

Where does facial nerve exit the skull

Exit through the stylomastoid foramen.

Demonstrate terminal branches of facial nerve

Branches in the face: "The Zebra Bothered My Cat"
Temporal branch
Zygomatic branch
Buccal branch
Marginal mandibular branch
Cervical branch

What are the other branches of facial nerve rather than terminal branches?

Within facial canal:
Nerve to stapedius
Chorda tympani
Greater petrosal nerve (preganglionic to lacrimal)
After leaving skull (motor):
Nerve to stylohyoid
Nerve to posterior belly of digastric
Posterior auricular nerve (occipital belly of occipitofrontalis muscle)

Which muscle is supplied by the facial nerve after leaving the facial canal, other than muscles of facial expression?

Stylohyoid muscle

Where to palpate facial artery?

As it crosses the inferior border of the mandible.
Adjacent to the anterior border of the masseter.

In case of injury or ligation of facial artery, what will happen and why?

No ischemia, as there is rich anastomosis with the contralateral vessels.

(Note: This refers to the highly vascular nature of the face and the extensive communication between the left and right facial arteries, as well as branches from the ophthalmic and maxillary arteries.)