face lecture 2008
TRANSCRIPT
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 …