derived from mesoderm of the 2nd pharyngeal arch all are supplied by branches of the facial nerve

Muscles of the scalp and face 1. The muscles of the scalp 2. Extrinsic muscles of the auricle 3. The muscles of the eyelids 4. The muscles of the nose 5. The muscles of the mouth

1. The muscles of the scalp Epicranius (occipitofrontalis) - frontal belly - occipital belly

2. Extrinsic muscles of the auricle Auricularis anterior - smallest Auricularis superior - largest Auricularis posterior

3. The muscles of the eyelids 3.1 Orbicularis oculi 3.2 Corrugator supercilii

Orbicularis Oculi 3 parts : - Orbital part - Palpebral part - Lacrimal part

Actions : Orbital part - close the lids tightly Palpebral part - close the lids gently Lacrimal part - pulls the lids medially & dilate lacrimal sac

- deep to frontalis Actions : frowning - arises from medial end of superciliary arch Corrugator supercilii

4. The muscles of the nose 4.1 Procerus 4.2 Nasalis 4.3 Depressor septi

5. The muscles of the mouth 5.1 Muscles of the upper lip 5.2 Muscles of the lower lip 5.3 Platysma 5.4 Buccinator 5.5 Orbicularis oris

Muscles of the upper lip Levator labii superioris alaeque nasi Levator labii superioris Zygomaticus minor Zygomaticus major Levator anguli oris

Muscles of the lower lip Depressor labii inferioris Depressor anguli oris Mentalis Risorius

Platysma

Buccinator

Orbicularis oris

Actions of orbicularis oris 1. Close the lips 2. Compress lips against teeth (deep fibers) 3. Bring the lips together and protrude them (superficial fibers) 4. Play an important part in articulation & mastication

Buccinator

Corrugator supercilii

Depressor Anguli Oris

Depressor Labii Inferioris & Platysma

Frontalis

Levator Anguli Oris

Levator Labii Superioris,Levator Labii Superioris Alaeque Nasi & Zygomaticus Minor

Mentalis

Nasalis, Alar Portion

Orbicularis Oculi (orbital part)

Orbicularis Oris

Procerus

Risorius

Depressor Septi & Nasalis (transverse portion)

Zygomaticus Major

NERVES OF THE FACE Sensory : Trigeminal nerve & (cutaneous) Great auricular nerve Motor : Facial nerve

Cutaneous branches of trigeminal nerve main sensory nerve of the face branches from 3 divisions : Ophthalmic nerve Maxillary nerve Mandibular nerve

Cutaneous branches of Ophthalmic nerve (V1) Supply superomedial region of face 1. Palpebral branch of the lacrimal nerve 2. Supraorbital nerve 3. Supratrochlear nerve 4. Infratrochlear nerve 5. External nasal nerve

Cutaneous branches of the maxillary nerve (V2) Supply skin inferior and lateral to the eyes 1. Infraorbital nerve 2. Zygomaticofacial nerve 3. Zygomaticotemporal nerve

Cutaneous branches of the Mandibular nerve (V3) Supply skin inferior and posterior to area supplied by the maxillary nerve 1. Auriculotemporal nerve 2. Buccal nerve 3. Mental nerve

arises from inferior border of pons, lateral part of pontomedullary sulcus comprises of 2 roots : Motor root Sensory root (Nervus intermedius)

Functions & distributions Facial nerve supplies structures derived from 2nd pharyngeal arch 1.Motor fibers to : muscles of facial expression stapedius muscle stylohyoid muscle posterior belly of digastric

2. taste sensation from anterior 2/3 of tongue (chorda tympani nerve) hard & soft palate (palatine & greater petrosal nerve)

3.preganglionic parasympathetic fibers to : 3.1 Submandibular ganglion ; postganglionic fibers to submandibular gland sublingual gland lingual gland

3.2 pterygopalatine ganglion ; postganglionic fibers to - lacrimal gland - glands of nasal & palatine mucosae

4. General sensation from skin of the concha, skin behind the auricle, external acoustic meatus & external tympanic membrane

Branches of the facial nerve 1.1 Greater petrosal nerve Taste fibers to palatine mucosae Preganglionic parasympathetic fibers to the pterygopalatine ganglion 1.From the geniculum of the facial nerve

Postganglionic fibers from pterygopalatine ganglion supply lacrimal gland, nasal & palatine mucosal glands

1.3 small branch (sometimes not found) to sympathetic plexus on middle meningeal artery 1.2 small branches join the tympanic plexus of glossopharyngeal nerve

2.2 Chorda tympani nerve joins the lingual nerve - taste fibers from mucous membrane on anterior 2/3 of tongue except vallate papillae - preganglionic parasympathetic fibers to submandibular ganglion, postganglionic fibers supply submandibular, sublingual & lingual glands 2. In the descending part of the facial canal 2.1 Stapedial nerve

2.3 small branch to auricular branch of the vagus nerve ; receives sensory from external acoustic meatus

3. In the neck exits the skull through stylomastoid foramen 3.2 Posterior auricular nerve to - auricularis posterior & superior muscles - occipitalis muscle - afferent fibers to skin on mastoid process & adjacent part of the auricle 3.1 Nerve to stylohyoid & posterior belly of digastric

4. In the parotid gland enters posteromedial surface of the parotid gland, forms plexus & emerges from the anterior border of the gland to supply motor fibers to the muscles of facial expression

1. temporal branches 2. zygomatic branches - upper branches - lower branches 3. buccal branches 4. (marginal) mandibular branches 5. cervical branches

Injury to branches of CN.VII Injury to branches of the facial nerve near stylomastoid foramen or in the parotid gland results in facial paralysis (Bell’s palsy)

Inability to close the eyes (orbicularis oculi) Unable to wrinkle the forehead (frontalis) Food & fluid lodge in the oral vestibule & overflow from the mouth Loss of corneal reflex (but corneal sensation are intact) Loss of nasolabial fold Corner of the mouth droops Lower eyelid droops (falls away from the surface of the eyeball)crocodile’s tear

1. Skin incisions

2. Dissect structures ต่างๆ ดังนี้คือ 2.1 Muscles of facial expression

2.2 Superficial vessels of the face facial vessels superficial temporal vessels

2.3 Parotid gland & duct 2.4 Masseter muscle 2.5 Terminal branches of the facial nerve

2.6 Cutaneous branches of CN.V