L10: Superficial Face Flashcards
Explain embryological development of facial structures.
- Facial structures develop during 4th – 8th week
- Develop around upper part of primitive pharynx known as primordial stomodum
- Five prominences appear around large stomodeum during 4th week: single frontonasal prominence, paired maxillary prominences and paired mandibular prominences
- Frontonasal prominence: Frontal part forms from forehead, nasal part forms from upper part of stomodeum
- Maxillary / mandibular prominence: result from fusion of 1st pharyngeal arches with neural crest cells migrating from neural fold into maxillary prominence
What are the divisions of the trigeminal nerve, CN V, and their branches?
- V1 (ophthalmic division): supraorbital, supratrochlear, infratrochlear
- V2 (maxillary division): infraorbital
- V3 (mandibular division): mental, buccal, auriculotemporal nerve
From what areas of the face do the trigeminal nerve and its branches carry sensory skin innervation for?
- Lateral forehead and upper eyelid (V1 supraorbital)
- Medial forehead and upper eyelid (V1 supratrochlear)
- Medial part of eye and root of nose (V1 infratrochlear)
- Lower eyelid, cheek, lateral nose, upper lip, anterior temporal fossa (V2 infraorbital)
- Lower lip, skin of chin (V3 mental)
- Oral mucosa of cheek (V3 buccal)
- Scalp anterior to the ear and posterior part of temporal fossa (V3 auriculotemporal)
What provides sensory innervation to skin inferior to ear and over parotid? Is it trigeminal?
- Not trigeminal
- Great auricular nerve from cervical plexus
What is trigeminal neuralgia?
- Aka tic douloureux
- Disorder of sensory root of CN V
- Sudden sharp excruciating pain on the face, lasting 15-20 minutes
- Involves maxillary nerve typically
- Unknown cause
See Netter’s flashcards and identify muscles of facial muscles.
Just do it!
Characteristics of facial expression muscles.
- Lie in superficial fascia
- Attached partly to the skin
- Enable us to move skin of the face and change our facial expressions
- Don’t move bones
- Motor innervation by facial nerve
- Arranged around natural openings of the face and act as sphincters typically
Why do facial lacerations gape widely?
- Lie in superficial fascia and are attached partly to skin, no deep fascia present
What nerve controls facial expression?
- Facial nerve, CN VII
Branches of facial nerve, course of facial nerve.
- Exits skull through stylomastoid foramen
- Enters parotid gland and gives off 5 branches (mnemonic: To Zanzibar by motor car)
1. ) Temporal: proceeds superiorly slightly anterior to the ear
2. ) Zygomatic: courses towards corner of the eye
3. ) Buccal: courses over muscles of cheek
4. ) Mandibular: courses inferomedially across mandible
5. ) Cervical: courses below mandible to supply platysma
What is Bell’s palsy?
- injury to CN VII or its branches produce paralysis to some or all muscle expression on one side.
What can damage to CN V and CN VII or their branches cause?
- to CN V: trigeminal neuralgia
- to CN VII: Bell’s palsy
Course of facial artery, branches of facial artery, supplies what?
- Facial artery is 4th branch of external carotid artery usually
- It crosses mandible (anterior to angle, can find ridge by palpation) and then is tortuous across face to medial angle of eye
- Inferior labial: for lower lip
- Superior labial: for upper lip
- Angular: for medial corner of the eye (terminal branch)
What does compression of facial artery not stop bleeding?
- There are anastomoses with facial artery branches supplying the other side of the face
What main arteries supply blood to superficial face/scalp?
- Facial artery
- Superficial temporal
