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.
¨ lateral upper eyelid
Emerges from supraorbital notch ¨ up to upper eyelid, forehead, scalp up to vertex (31)
Medial to (2), ¨ central forehead up to hairline
¨ skin on medial upper lid, descends ¨ side of external nose and bridge
4 above branches also ¨conjunctiva of upper lid
¨ 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
Exits foramen rotundum ¨ pterygopalatine fossa ¨ exits infraorbital fissure
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.
From foramen on outer surface of zygomatic bone ¨ overlying skin
Emerges in temporal fossa by foramen ¨ small area of temporal skin.
Nerve of 1st pharyngeal arch, exiting foramen ovale with motor root of trigeminal nerve ¨ infratemporal fossa.
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.
Gives cutaneous twigs then pierces buccinator ¨ cheek below zygomatic bone
From inferior alveolar nerve; Breaks up into tuft of branches then ¨
enters mandibular foramen ¨ sensation to posterior 5 teeth; incisive branch ¨ remaining 3.
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
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
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.