Parotid Fossa

Question 1

Parotid Fossa:

Answer 1

Wedge shaped space with apex medial and base lateral

Question 2

Anterior and posterior boundaries of the Parotid Fossa are composed of:

Answer 2

Fascia

Question 3

Posterior Boundary of Parotid Fossa:

Answer 3

Sternocleidomastoid
Posterior Digastric
Stylohyoid muscle
Styloid process

Question 4

Superior Limit of parotid fossa:

Answer 4

Capsule of TMJ

Floor of external acoustic meatus

Question 5

Inferior boundary of Parotid fossa:

Answer 5

Angular Tract (Fascia)

Question 6

Anterior Boundary of Parotid fossa:

Answer 6

Masseter
Ramus and neck of mandible
Stylomandibular fascia (part of deep parotid fascia)

Question 7

Superficial parotid fascia:

Answer 7

Covering the gland on lateral side

Question 8

Medial Boundary of Parotid fascia:

Answer 8

Styloid Process

Question 9

Lateral boundary of fossa:

Answer 9

Superficial parotid fascia (layer of deep fascia)

Question 10

What forms the angular track?

Answer 10

• Stylomandibular fascia

- Fascia surrounding the stylohyoid and posterior belly of the digastric and connecting to the SCM and Styloid process

Question 11

What are the contents of the parotid fossa?

Answer 11

1. Parotid Gland
2. Facial Nerve
3. Retromandibular vein and branches
4. External carotid artery and branches

Question 12

Blood supply to Parotid gland:

Answer 12

Transverse Facial Artery,

Superficial temp. ves.

Question 13

What is the sensory innervation to the gland?

Answer 13

Great auricular Nerve: Runs across SCM. supplies skin overlying the parotid gland. (lower external ear and just in front of ear). Supplies superficial carotid fascia

Auriculotemporal nerve: Branch of V3. Goes posterior and comes out of lateral side of head. Sensory N. comes medial to parotid fossa. supplies sensation to gland

Question 14

What is the Parasympathetic innervation to the gland?

Answer 14

Fibers from the glossopharyngeal nerve- to secrete saliva, the gland must receive autonomic innervation:

Glossopharyngeal (pre) to tympanic plexus in middle ear to Lesser petrosal N. which goes through foramen ovale (so does trigeminal V3) to synapse in optic ganglion postgalnglionic fibers go with auriculotemporal nerve to supply parotid gland.

Question 15

What otters structures are passing into and out of the fossa?

Answer 15

External carotid artery:—- Posterior auricular artery: Behind ear. Parallels occipital A. Branches above the posterior digastric

External carotid ends in fossa by splitting into:
- Superficial temporal—- Transvers facial artery: on superficial/more lateral side

• Maxillary artery: Deep straight anteriorly behind ramus

Question 16

Veins of Parotid Artery:

Answer 16

Superficial temporal vein: Comes down in front of ear. Same pattern as superficial temporal artery
Maxillary vein: under ramus of mandible (deep)

Above will form retromandibular vein:

1. Anterior division joins facial to form common facial
2. Posterior division joins posterior auricular form external jugular

Question 17

Common Facial Vein:

Answer 17

Goes under the sternocleidomastoid (deep) so it can empty into the internal jugular vein

Question 18

Describe path of facial N:

Answer 18

Exits stylomastoid foramen: after exiting its a total motor N.
- It passes anteriorly between and enervates stylohyoid and the posterior digastric muscles. Will give off branches to both of those muscles. Facail N will go right through the facial gland.

Facial Nerve innervates muscles of facial expression

Question 19

In the gland VII divides into two branches:

Answer 19

Temporofacial

Cervicofacial

Question 20

What is parotitis (parotiditis)?

Answer 20

Infection of parotid gland (inflammation):
- May result from xerostomia (dry mouth): reduced salivary flow will allow bacteria from oral cavity to move retrograde through the out and infect the gland

Causes: Drugs, Radiation, Illness

Question 21

What is Mumps? (epidemic or Viral parotitis)

Answer 21

Caused by paramyxovirus: Will target all salivary glands:

• Parotid salivary gland effected and stretching of that gland will be very painful
• Will have some swelling; unilateral or bilateral

KEY ID: Infection will cause a red and swollen parotid papilla

Question 22

What is Sialolith?

Answer 22

Salivary calculus or stone:

• Parotid gland= 20% of time; 80% in submandibular gland (has higher alkaline content)
• Swelling (more isolated: Usually unilateral) of gland
• Vague pain– when eating will have increased swelling/pain while eating
• Treatment: Increase persons hydration- moist heat- more saliva more it has chance to be removed. Send to ENT

Question 23

Tumores in Parotid:

Answer 23

85% benign– Pleomorphic adenoma most common
- Will grow quite large
- occurs mainly in superficial lobe
- Will remove gland to prevent reoccurrence
Complication: have to be very careful not to damage facial Nerve

Question 24

What is Bell’s Palsy

Answer 24

Unilateral facial paralysis due to facial nerve involvement

• Lower eyelid drooping
• NO wrinkles on effected side
• drooping of mouth
• will loose all m of facial expression on effect side
• May result from viral infection… not really sure though– can be caused by dentists
• 3 weeks to several months to return to normal (may not completely go back)