The Face


Sensory supply of face (116)

Trigeminal nerve

3 zones by 3 branches of V; meet at margins of eyelids & angles of mouth junction lines curve out from there.  Angle of mandible = only part of facial skin not supplied by V (gr auricular nerve). 

-           pattern of facial haemangioma and distribution of herpes zoster vesicles often go with these.

-           Brainstem representation of these inputs onion skin model with central areas highest.

(A) Ophthalmic division 5 cutaneous branches (31)

 (1) Lacrimal

lateral upper eyelid

(2) Supraorbital

Emerges from supraorbital notch up to upper eyelid, forehead, scalp up to vertex (31)

(3) Supratrochlear

Medial to (2),  central forehead up to hairline

(4) Infratrochlear

skin on medial upper lid, descends side of external nose and bridge

4 above branches also conjunctiva of upper lid

(5) External nasal

midline skin of nose down to tip

Supraorbital and supratrochlear are branches of the frontal nerve

Infratrochlear and external nasal are from nasociliary (latter via anterior ethmoidal branch)

-           when these are involved in herpes zoster, cornea may also become infected ulceration

 

(B) Maxillary division 3 cutaneous branches (40)

Exits foramen rotundum pterygopalatine fossa exits infraorbital fissure

(1) infraorbital nerve

Emerges from infraorbital foramen to lie b/n levator labii superioris and levator anguli oris

Tuft of branches radiate palpebral, nasal & labial (from midline to 2nd premolar tooth) branches. 

(2) zygomaticofacial

From foramen on outer surface of zygomatic bone overlying skin

(3) zygomaticotemporal

Emerges in temporal fossa by foramen small area of temporal skin.

 

(C) Mandibular division 3 cutaneous branches

Nerve of 1st pharyngeal arch, exiting foramen ovale with motor root of trigeminal nerve infratemporal fossa. 

(1) auriculotemporal

Passes back around neck of mandible ascends over posterior zygomatic arch behind sup temp a.

-           Auricular branch EAM & external surface of auricle,

-           Temporal branch scalp, skin of temple. 

(2) buccal

Gives cutaneous twigs then pierces buccinator cheek below zygomatic bone

(3) mental

From inferior alveolar nerve; Breaks up into tuft of branches then

enters mandibular foramen sensation to posterior 5 teeth; incisive branch remaining 3. 

Blood supply to face

Facial artery (63)

Highest of anterior branches of ECA. 

Hooks over inferior border of mandible at anterior border of masseter muscle

tortuous course toward medial eye on buccinator deep to lip dilators.

sizeable inferior and superior labial arteries, anastomose across midline (superior nasal septum)

Branches of ophthalmic artery forehead (supraorbital and supratrochlear) & dorsal nasal to nose root

Branches of superficial temporal artery temple (transverse facial)

-           supraorbital anastomoses with superficial temporal = ICA ECA communication

Venous return (64)

Blood from temple collected by superficial temporal vein, joined by maxillary vein from pterygoid plexus to form retromandibular vein.

-           its posterior branch and post-auricular vein form EJV.

Supraorbital and supratrochlear veins unite at medial canthus angular vein, becomes facial vein

straight course behind artery to angle of mandible

pierces investing fascia and joined by anterior branch of retromandibular vein (and sometimes superior thyroid); empty together into IJV

Note that facial vein connects with cavernous sinus via ophthalmic vein and deep facial vein; obstruction of facial vein between these flow via cavernous sinus. 

-           danger are of infection of upper lip, nearby cheek and up to between angular veins

Lymphatics

Three superficial groups (66)

Chin & tip of tongue submental nodes

Central face submandibular nodes

Lateral face preauricular nodes

Eventually all of this reaches deep cervical nodes.