Nerves of the Face and Mouth

Innervation of Innervation of the face and the face and

mouthmouthProf St-John CreanProf St-John Crean

BDS MBBS FDSRCS BDS MBBS FDSRCS FFGDP(UK) FRCS FFGDP(UK) FRCS FRCS(OMFS) PhDFRCS(OMFS) PhD

Aims and objectivesAims and objectives

AimsAims Illustrate the nerves responsible for sensation Illustrate the nerves responsible for sensation

and motor supply of face and mouthand motor supply of face and mouth Special autonomic function of oral/facial Special autonomic function of oral/facial

structuresstructures ObjectivesObjectives

Develop applied knowledge of the nerves Develop applied knowledge of the nerves responsible for innervation of facial and oral responsible for innervation of facial and oral tissuestissues

TRIGEMINAL NERVETRIGEMINAL NERVECentral ConnectionsCentral Connections

• The cell bodies of most trigeminal sensory The cell bodies of most trigeminal sensory neurons are located in the neurons are located in the trigeminal gangliontrigeminal ganglion, , which lies in a recess of dura matter on the apex which lies in a recess of dura matter on the apex of petrous temporal bone (the cell bodies of of petrous temporal bone (the cell bodies of proprioceptive fibers are located in the proprioceptive fibers are located in the midbrain).midbrain).

• A bundle of central processes from the ganglion A bundle of central processes from the ganglion cells passes into the lateral aspect of pons where cells passes into the lateral aspect of pons where they contact the main ( common sensation) & they contact the main ( common sensation) & spinal (pain & temperature) sensory nuclei.spinal (pain & temperature) sensory nuclei.

TRIGEMINAL NERVETRIGEMINAL NERVECentral ConnectionsCentral Connections

• The motor fibers originate from neurons The motor fibers originate from neurons in a in a motor nucleusmotor nucleus adjacent to the main adjacent to the main sensory nucleus in the floor of 4sensory nucleus in the floor of 4thth ventricle.ventricle.

• However, recent evidence suggests that However, recent evidence suggests that proprioceptive information from the teeth proprioceptive information from the teeth also pass to the principal sensory nucleus.also pass to the principal sensory nucleus.

Parasympatheic ganglia of the Parasympatheic ganglia of the head and neckhead and neck

Associated with the trigeminal nerveAssociated with the trigeminal nerve Parasympathetic fibres come from Parasympathetic fibres come from

another cranial nerveanother cranial nerve Three types of fibresThree types of fibres

SympatheticSympathetic (pass straight through)(pass straight through) Somatic motor / sensory (pass straight Somatic motor / sensory (pass straight

through)through) Parasympathetic (synapse)Parasympathetic (synapse)

TRIGEMINAL NERVE (V)TRIGEMINAL NERVE (V)

NerveNerve Opening Opening passage passage from skullfrom skull

ClassificatioClassificationn

Ophthalmic Ophthalmic division (V1)division (V1)

Superior Superior orbital fissureorbital fissure

SensorySensory

Maxillary Maxillary division (V2)division (V2)

Foramen Foramen RotundumRotundum

SensorySensory

Mandibular Mandibular division (V3)division (V3)

Foramen Foramen OvaleOvale

MixedMixed

OPTHALMIC DIVISION (V1)OPTHALMIC DIVISION (V1)

• Contains only Contains only sensorysensory fibers. fibers.

• Passes anteriorly from the ganglion along the Passes anteriorly from the ganglion along the lateral wall of cavernous sinus & divides in to lateral wall of cavernous sinus & divides in to FrontalFrontal, , LacrimalLacrimal & & NasociliaryNasociliary branches branches which enter the orbit through superior which enter the orbit through superior orbital fissure.orbital fissure.

• Supplies the ;Supplies the ; Upper face including scalp, eyelids, cornea,Upper face including scalp, eyelids, cornea, Paranasal sinuses.Paranasal sinuses.

Cavernous sinusCavernous sinus

Ophthalmic nerveOphthalmic nerve

Ciliary ganglionCiliary ganglion

MAXILLARY DIVISION (V2)MAXILLARY DIVISION (V2)

• Contains only Contains only sensorysensory fibers.fibers.

• Nerve emerges in to the Nerve emerges in to the pterygopalatine fossa pterygopalatine fossa through the F.Rotundum of through the F.Rotundum of the sphenoid bone.the sphenoid bone.

• It’s subsequent branches It’s subsequent branches can be subdivided into can be subdivided into branches from ;branches from ;

The main trunk &The main trunk & Branches from the Branches from the

pterygopalatine pterygopalatine gganglion.anglion.

Maxillary nerve (V2)Maxillary nerve (V2)

Pterygopalatine ganglionPterygopalatine ganglion

MAXILLARY DIVISION (V2)MAXILLARY DIVISION (V2)

• Supplies theSupplies the ; ; Maxillary teeth & the Maxillary teeth & the

supporting structures, supporting structures, The palate, The palate, The maxillary air The maxillary air

sinus, sinus, Much of the nasal Much of the nasal

cavity, &cavity, & The skin overlying the The skin overlying the

middle part of the middle part of the face. face.

MANDIBULAR DIVISION (V3)MANDIBULAR DIVISION (V3)

• Largest division of Largest division of trigeminal nerve & trigeminal nerve & only only division that contains division that contains motor as well as sensory motor as well as sensory fibers.fibers.

• Emerges into infratemporal Emerges into infratemporal fossa through foramen ovale.fossa through foramen ovale.

• It lies deep to the lateral It lies deep to the lateral pterygoid muscle, where it pterygoid muscle, where it gives off all its branches gives off all its branches dividing into ;dividing into ;

Anterior (mainly motor) &Anterior (mainly motor) & Posterior (mainly sensory) Posterior (mainly sensory)

trunkstrunks..

Mandibular nerve V3Mandibular nerve V3

Mandibular nerve (V3)Mandibular nerve (V3)

Otic ganglionOtic ganglion

MANDIBULAR DIVISION (V3)MANDIBULAR DIVISION (V3)

• Proximal to posterior division, it Proximal to posterior division, it gives off thegives off the ; ;

Meningeal branchMeningeal branch: passes back into the : passes back into the middle cranial fossa through Foramen middle cranial fossa through Foramen Spinosum.Spinosum.

The nerve to medial pterygoidThe nerve to medial pterygoid: through : through the Otic Ganglion (without synapsing) &, the Otic Ganglion (without synapsing) &, after supplying the muscle, continues on after supplying the muscle, continues on to supply the tensor veli palatini & tensor to supply the tensor veli palatini & tensor tympani muscles.tympani muscles.

MANDIBULAR DIVISION (V3)MANDIBULAR DIVISION (V3)

• Sensory fibers supplySensory fibers supply ; ; Mandibular teeth & Mandibular teeth &

their supporting their supporting structures,structures,

Mucosa of the Mucosa of the ant.2/3ant.2/3rdrd of tongue, of tongue,

Floor of mouth,Floor of mouth, Skin of lower part of Skin of lower part of

face, &face, & Parts of temple & Parts of temple &

auricle.auricle.

• Motor fibers supplyMotor fibers supply ; ; Muscles of Muscles of

mastication,mastication, Mylohyoid,Mylohyoid, Anterior belly of Anterior belly of

digastric,digastric, Tensor veli palatini, Tensor veli palatini,

&& Tensor tympani Tensor tympani

muscles.muscles.

TRIGEMINAL NEURALGIATRIGEMINAL NEURALGIA

• A distressing condition characterized by A distressing condition characterized by brief paroxysms of sharp, piercing pain in brief paroxysms of sharp, piercing pain in the territory of one or two divisions of the territory of one or two divisions of trigeminal nerve (not usually ophthalmic trigeminal nerve (not usually ophthalmic division).division).

• Frequently the paroxysms can be Frequently the paroxysms can be provoked by touching a specific area of provoked by touching a specific area of skin “trigger area” or by eating or talking.skin “trigger area” or by eating or talking.

• Little is known of its cause.Little is known of its cause.

FACIAL NERVE (VII)FACIAL NERVE (VII)

• VII contains VII contains motormotor, , sensorysensory & & secretomotorsecretomotor (preganglionic (preganglionic parasympathetic) fibers. parasympathetic) fibers.

• The motor & secretomotor neurons lie in The motor & secretomotor neurons lie in pons of brainstem.pons of brainstem.

• Cell bodies of the sensory fibers form the Cell bodies of the sensory fibers form the geniculate gangliongeniculate ganglion in the petrous in the petrous temporal bone.temporal bone.

FACIAL NERVE (VII)FACIAL NERVE (VII)

• VII suppliesVII supplies ; ; Stapedius,Stapedius, The muscles of facial expression,The muscles of facial expression, Taste to the anterior 2/3Taste to the anterior 2/3rdrd of the tongue, & of the tongue, & Secretomotor fibers to the lacrimal gland, Secretomotor fibers to the lacrimal gland,

nose, palate & salivary glands in the floor nose, palate & salivary glands in the floor of the mouth.of the mouth.

FACIAL NERVE WITHIN THE FACIAL NERVE WITHIN THE SKULLSKULL

• Facial nerve leaves the brain Facial nerve leaves the brain near the cerebellum & near the cerebellum & passes laterally into the passes laterally into the internal acoustic meatus.internal acoustic meatus.

• Runs through the meatus to Runs through the meatus to the medial wall of middle the medial wall of middle ear, where it is enlarged by ear, where it is enlarged by the geniculate ganglion.the geniculate ganglion.

• On reaching the posterior On reaching the posterior wall the nerve makes a wall the nerve makes a right-angled bend, passes right-angled bend, passes downwards & exits skull downwards & exits skull through through stylomastoid stylomastoid

foramenforamen..

FACIAL NERVE WITHIN FACIAL NERVE WITHIN THE SKULLTHE SKULL

• In the middle ear facial nerve gives offIn the middle ear facial nerve gives off ; ; Greater petrosal branchGreater petrosal branch: carries : carries

parasympathetic fibers to the parasympathetic fibers to the pterygopalatine pterygopalatine ganglionganglion..

In the posterior wall of the middle ear the VII In the posterior wall of the middle ear the VII supplies supplies stapediusstapedius & gives off the & gives off the chorda chorda tympanitympani..

The Chorda tympaniThe Chorda tympani: which joins the lingual : which joins the lingual nerve & is distributed with it. ( submandibular nerve & is distributed with it. ( submandibular ganglion)ganglion)

Submandibular ganglionSubmandibular ganglion

EXTRACRANIAL COURSE OF EXTRACRANIAL COURSE OF FACIAL NERVEFACIAL NERVE

• VII leaves the stylomastoid VII leaves the stylomastoid foramen & suppliesforamen & supplies ; ;

Stylohyoid,Stylohyoid, Posterior belly of digastric &Posterior belly of digastric & Occipital belly of occipitofrontalis.Occipital belly of occipitofrontalis.

EXTRACRANIAL COURSE OF EXTRACRANIAL COURSE OF

FACIAL NERVEFACIAL NERVE • VII then enters parotid gland & divides in to VII then enters parotid gland & divides in to

the following terminal branches,the following terminal branches,• temporal, temporal, • zygomatic,zygomatic,• buccal, buccal, • mandibular mandibular • cervical.cervical.

• They spread out in a fan-like pattern on the They spread out in a fan-like pattern on the side of the face & supply the side of the face & supply the muscles ofmuscles of facial expressionfacial expression, including buccinator & , including buccinator & platysma platysma

EXTRACRANIAL COURSE & EXTRACRANIAL COURSE & DISTRIBUTION OF VIIDISTRIBUTION OF VII

FACIAL NERVE (VII)FACIAL NERVE (VII)

• CLINICAL CONSIDERATION:CLINICAL CONSIDERATION:

The The cervical branchcervical branch, which supplies , which supplies muscles that control the angle of the muscles that control the angle of the mouth, loops down over the sub-mouth, loops down over the sub-mandibular region below the angle of the mandibular region below the angle of the jaw.jaw.

Surgery (e.g. biopsy of lymph nodes) in Surgery (e.g. biopsy of lymph nodes) in this region must preserve this branch this region must preserve this branch carefully. carefully.

FACIAL NERVE (BELL’S) FACIAL NERVE (BELL’S) PALSYPALSY

• Facial nerve can be damaged by swelling Facial nerve can be damaged by swelling in the facial canal, which is probably in the facial canal, which is probably caused by a viral infection.caused by a viral infection.

• The condition usually regresses The condition usually regresses spontaneously, but on occasion it may be spontaneously, but on occasion it may be necessary to decompress the nerve within necessary to decompress the nerve within the canal. the canal.

Submandibular glandSubmandibular gland

mucocelemucocele

stonesstones

anatomyanatomy

Use patients as revisionUse patients as revision Read up as go alongRead up as go along Clinical applicationsClinical applications

Thank youThank you

REFERENCESREFERENCES• Trigeminal Trigeminal NNerve erve aanatomy:natomy: illustrated usingillustrated using examples of abnormalities.examples of abnormalities. Kamel HA,TolandKamel HA,Toland

• The trigeminal nerveThe trigeminal nerve. . Shankland WE 2nd.Shankland WE 2nd.

• The trigeminal nerve.The trigeminal nerve.Go JL, Kim PE, Zee CSGo JL, Kim PE, Zee CS..

Anastomoses between the cervical branch of the Anastomoses between the cervical branch of the facial nerve and the transverse cervical cutaneous facial nerve and the transverse cervical cutaneous nerve.nerve.Domet MA, Connor NP, Heisey DM, Hartig GK.Domet MA, Connor NP, Heisey DM, Hartig GK.

• Oral anatomy, Histology & Embryology,3th Ed. B.K.B. Oral anatomy, Histology & Embryology,3th Ed. B.K.B. Berkowitz, G.R. Holland, B.J. MoxhamBerkowitz, G.R. Holland, B.J. Moxham