face lecture 2008

Face & Parotid Gland

Medical Science 531Spring 2008D. M. Conley

Face: Regions and Landmarks

Nasolabial sulcus

Skeletal framework = The facial skeleton:

Mandible

Maxillae

Zygomatic bones

Nasal bones

Lacrimal bones

Inferior nasal conchae

VomerNote also the frontal bone contributes greatly to

skeletal framework of the face.

LeFort Fractures(Midface fractures)

Fascia of the Face

Superficial fascia is

copious and loose –

however, there is no

discrete layer of

deep fascia of the face except …

Deep fascia does exist in the

regions of the parotid glands

and the masseter muscles. It forms capsules around these structures.

The other regions of the face have

much subcutaneous

tissue, but no deep fascia.

Facial skin

Aging of facial skin

Loss of elastic fibers in skin cause permanent wrinkles (e.g., “Crow’s feet” and “worry lines”.

Dynamic duo: Botox & collagen

Before

After

Muscles of Facial Expression(Mimetic muscles)

Muscles of facial expression: Associated with (1) the forehead, (2) orbit, (3) mouth, and (4) nose.

We will study these muscles in lab, for now think of the facial muscles in groups:

Buccal fat pat & Buccinator muscle

Buccal fat pad

Buccal pad reduction

Before After

Cutaneous innervation of

the face

Blood supply to the face

Facial artery Transverse facial a. (from the superficial

temporal a.)

Venous drainage of the face

Facial vein = A tributary of the internal jugular vein

Lymphatic drainage of the face/scalp

Vessels carrying lymph from the

face pass through nodes arranged like a “collar”

around the base of the head.

• Occipital

• Retro-auricular (Mastoid)

• Parotid

• Submandibular

• Submental

Parotid gland: Surface anatomy

The parotid has a

triangular profile when

viewed externally

AND in cross-

section!

Kewl!

Parotid Gland: Relationships

Note: (1) External structures bordering the parotid (2) Structures coursing WITHIN the parotid.

Structures coursing within the parotid gland

• Facial nerve

• Retromandibular vein

• External carotid artery

• Auriculotemporal nerve (from V3)

Superficial

Deep

Parotid Gland: Relationship to the facial nerve

Facial nerve: Deep and superficial course

Bell’s Palsy

Paralysis of muscles of facial expression

due to damage/inflammation

of the facial nerve.

Retromandibular vein

Superficial temporal vein

Maxillary vein

Posterior division

Anterior division

Joins posterior auricular v. to form external

jugular v.

Joins facial v. to form common facial v. A

tributary of the internal jugular

v.

External carotid artery

Gives off its terminal branches within the

parotid

Maxillary a. Superficial temporal a.

Auriculotemporal nerve (from V3)

Supplies scalp & external ear

Carries postganglionic PS fibers that are secretomotor to the parotid.

Parotid (Stensen’s) Duct

Penetrates buccal fat pad and buccinator open into the

oral cavity opposite the 2nd maxillary molar

toothNote: Its surface

anatomy – coursing parallel to the tip of the ear

lobule.

Development of the Face

[Continued .. From pharyngeal apparatus lecture]

5 primordial structures are crucial to facial development

Frontonasal prominence (1)

Maxillary prominences (2)

Mandibular prominences (2)

Primitive mouth (stomodeum)

5 Facial Primordia

Frontonasal prominence

Maxillary prominences

Mandibular prominencesFrom 1st

pharyngeal arch

Observe:

The 2 medial nasal prominences fuse = produce the bridge of the nose and the intermaxillary segment.

The 2 mandibular prominences fuse = complete the lower jaw.

The 2 lateral nasal prominences fuse with the 2 maxillary prominences (but not with each

other)= form the sides (alae) of the nose.

The maxillary prominences do not fuse with themselves – they form upper jaw and cheeks.

Intermaxillary segment

Gives rise to the:

• Philtrum of the upper lip.

• Upper incisor teeth & their gums.

• Primary palate (region of hard

palate just posterior to

the upper incisors).

The lower portion of the fused medial nasal

prominences

Facial clefts Failure of the embryonic

facial prominences to fuse properly

Mesenchyme – ectoderm interaction problems = failure of neural crest to migrate properly?

Cleft lip coupled with clefts of the anterior palate or entire palate.

First Arch Syndromes

Treacher-Collins Pierre-Robin

Cheekbone and mandible hypoplasia, down-slanting

palpebral fissures

Severe mandibular hypoplasia & cleft

palate

What matters most is how you see yourself …