Anatomy of Head and Neck Nerve Supply and Lymphatic Drainage
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Transcript of Anatomy of Head and Neck Nerve Supply and Lymphatic Drainage
ANATOMY OF HEAD AND NECK NERVE SUPPLY AND LYMPHATIC SUPPLY
MADE BY-AMIT BHARGAVAMDS PROSTHODONTICS (1ST YR)
CONTENTS
NERVOUS SYSTEM• Functions of nervous tissue• Classification of nervous systems• Anatomical course of cranial nerveLYMPHATIC DRAINAGE• Structure• Anatomical distribution• Site specific drainage• Clinical correlations
INTRODUCTION TO NERVOUS SYSTEM
• The nervous system is an organ system containing a network of specialized cells called neurons that coordinate the actions and transmit signals between different parts of its body
FUNCTIONS OF NERVOUS TISSUE::• Sense stimuli in both internal and external environment.
• Stimuli are analysed & integrated to provide co-ordinated responses
• Sensory neurons transmit impulses from sense organs to CNS
• Connector neurons supply connection between sensory and motor
neurons.
• Efferent(somatic) neurons transmit impulses from CNS to a muscle.
• Efferent(autonomic) neurons transmit impulses to a involuntary
muscle or gland.
ALL THE FUNCIONS ARE ACHIEVED BY THREE NERVOUS SYSTEMS OF THE BODY:
1. Central nervous system
2. Peripheral nervous system
3. Autonomic nervous system
CENTRAL NERVOUS SYSTEM• Central nervous system composed
of brain and spinal cord
Has 4 parts:• Spinal cord• Rhombencephalon ( medulla, pons, cerebellum)• Mesencephalon (midbrain)• Prosencephalon (forebrain)
12 PAIRS OF CRANIAL NERVES31 PAIRS OF SPINAL NERVES
PERIPHERAL NERVOUS SYSTEM• The peripheral nervous system consists of the nerves and outside of the
brain and spinal cord.
• function - connect the central nervous system to the limbs and organs.
AUTONOMIC NERVOUS SYSTEMConsists of sensory and motor neurons that run in between the
central nervous system and the internal organs.
2 divisions::1. Sympathetic2. parasympathetic
LIST OF CRANIAL NERVES
I Olfactory nerve SensoryII Optic nerve SensoryIII Occulomotor nerve MotorIV Trochlear nerve MotorV Trigeminal nerve Opth.-Sensory Max.-Sensory Mand.-MixedVI Abducent nerve MotorVII Facial nerve MixedVIII Auditory nerve SensoryIX Glossopharyngeal nerve MixedX Vagus nerve MixedXI Spinal accessory nerve Motor XII Hypoglossal Nerve Motor
OLFACTORY NERVE
OLFACTORY NERVE
• Sensory in nature.
• Originates in upper nasal concha and
superior part of nasal septum.
• Ends in medial surface of cerebral
hemisphere & temporal lobe.
OLFACTORY NERVE
COURSE
• Dissolution of inhaled
aromatic molecules in the
mucous lining olfactory
epithelial cells and
stimulation of its
chemoreceptors.
• Exaggeration of the action potential by olfactory receptor cells
• Pass through cribriform plate of ethmoid bone to synapse in secondary sensory neurons in olfactory bulb
• Amygdala
OLFACTORY NERVE
APPLIED ANATOMY
• Smell is responsible for finer appreciation of taste.LOSS OF SMELL OR ANOSMIA:CAUSES
1. HEAD INJURIES: Sudden shift of cerebral hemisphere results in avulsion
of olfactory bulb from brain.
2. FRACTURE OF CRIBRIFORM PLATE: May lead to damage to olfactory
nerve and CSF rhinorrhoea.
3. TUMOURS: Tumours of the frontal lobe or those arising near the
pitutary gland may cause pressure symptoms on olfactory tract.
4. CHRONIC TUBERCULOUS MENINGITIS
ROLE IN PROSTHODONTICS
1.Cobalt–chromium–nickel damages nasal cells
due to complex of carnosine with metal
2. methyl methacrylate-methacrylic acid.
N Torbica, S Krstev World at work: Dental laboratory technicians.Occup Environ
Med2006;63:145-148
OPTIC NERVE
OPTIC NERVE
• Sensory nerve
• Not a peripheral nerve.
• Extension of the white matter of
brain
• Responsible for vision• The optic nerve is a continuation of
the axons of the ganglion cells in the
retina.
COURSE
• Begins the back of
the eye
• Joins optic
chiasma in cranial
cavity.
• Extends to lateral
geniculate nucleus in thalamus forming optic tract.
• Ends in visual cortex area in occiptal lobe
OPTIC NERVE
APPLIED ANATOMY OF OPTIC TRACT
• LESION OF OPTIC NERVE:
A) Total blindness of the corresponding eye.
B) Loss of pupillary light reflex on the affected side and consensual reflex on the
sound side.
• WHEN A TUMUOR AFFECTS THE BASE OF FRONTAL LOBE , IT MAY PRESS
UPON OPTIC NERVE:
Optic atrophy on the affected side, due to pressure.
• ARGYLL-ROBERTSON PUPIL– specific sign of neurosyphilis.
- Loss of light reflex but the near reflex is retained.
ROLE IN PROSTHODONTICS • eye prosthesis - to treat anopthalmous detailed anatomyshould be kept in mind.• Enucleation ,Evisceration
Dr. Kalavathi S.D Restoring Ocular Esthetics Using Ocular Prosthesis Journal of Dental Sciences & Research 1:2: Pages 39-44
OCULOMOTOR NERVE
OCCULOMOTOR NERVE
• Motor in nature
• Supplies all the extra ocular muscles,
except superior oblique and lateral rectus.
• Supplies sphincter pupillae and cilliaris
muscle
OCCULOMOTOR NERVE
DEEP ORIGIN (NUCLEAR ORIGIN)
Ventro medial part of the
periaqueductal central grey
matter of the midbrain
OCCULOMOTOR NERVE
COURSE AND RELATIONSFrom the superficial origin, piamater (passes in between,Post. & sup. Cerebellar arteries Pierces arachnoid
Mater) duramater cavernous sinus
superior orbital fissure within tendinous ring.
OCCULOMOTOR NERVE
APPLIED ANATOMY:
COMPLETE DIVISION OF OCCULOMOTOR NERVE ON ONE SIDE
a) Ptosis or drooping of the upper eyelid- paralysis of leavator palpebrae superioris
b) External strabismus(squint)- unopposed action of lateral rectusc) Dilated or fixed pupild) Loss of accommodatione) Apparent protrusion of eyeball- flaccid paralysis of ocular muscles.f) Diplopia- where false image is higher than true image.
TROCHLEAR NERVE
TROCHLEAR NERVE
• Motor in nature
• Nerve with the longest
intracranial course.
• Supplies -superior
oblique muscle.
TROCHLEAR NERVE
DEEP ORIGIN:
• Periaqueductal grey
mater of the midbrain
at level of
inf. colliculus• Lies at level of
ventro medial nucleus
of 3rd nerve.
.
TROCHLEAR NERVE
COURSE
trochlear nucleus,
duramater,
lateral wall of cavernous sinus.
Superior orbital fissure
outside tendinous ring.
TROCHLEAR NERVE
APPLIED ANATOMY
IF TROCHLEAR NERVE IS INJURED
• Patient is unable to turn his eye downward and laterally.• NO difficulty in looking above horizontal plane.• On attempting to look down, double vision is seen.• To avoid, patient tilts his head forwards towards the sound
side.
TRIGEMINAL NERVE
TRIGEMINAL NERVE
• fifth cranial nerve• mixed in nature• It is the largest of the cranial nerves• Nuclei – 4 nuclei – 1 motor and 3 sensory
TRIGEMINAL NERVE
GASSERION GANGLION
• Also known as semilunar ganglion• Developed from neural crest.• Crescent shaped.• Located in meckel’s cavity.• Forms: Central processes Peripheral processes
TRIGEMINAL CAVE
TRIGEMINAL NERVE
SENSORY ROOT OF TRIGEMINAL NERVE Fibres arise from the semilunar ganglion. Enter brainstem through side of pons.
TRIGEMINAL NERVE
SENSORY ROOT OF TRIGEMINAL NERVE Fibres arise from the semilunar ganglion. Enter brainstem through side of pons.
CENTRAL BRANCHES (SENSORY ROOTS OF NERVE)
ASCENDING FIBRES DESCENDING FIBRES
TRIGEMINAL NERVE
SENSORY ROOT OF TRIGEMINAL NERVE Fibres arise from the semilunar ganglion. Enter brainstem through side of pons.
CENTRAL BRANCHES (SENSORY ROOTS OF NERVE)
ASCENDING FIBRES DESCENDING FIBRES
Terminate in UPPER sensory nucleusIn pons lateral to motor nucleus. DORSAL TRIGEMINO-THALAMIC TRACT
CONVEY::Light touch Tactile discrimination Sense of positionPassive movement
TRIGEMINAL NERVE
SENSORY ROOT OF TRIGEMINAL NERVE Fibres arise from the semilunar ganglion. Enter brainstem through side of pons.
CENTRAL BRANCHES (SENSORY ROOTS OF NERVE)
ASCENDING FIBRES DESCENDING FIBRES
Terminate in UPPER sensory nucleus Terminate in SPINAL nucleus extending In pons lateral to motor nucleus. Caudally from upper sensory nucleus to . 2nd cervical segment.
CONVEY:: CONVEY::Light touch PainTactile discrimination TemperatureSense of positionPassive movement
TRIGEMINAL NERVE
PERIPHERAL BRANCHES
OPTHALMIC nerve
MAXILLARY nerve
MANDIBULAR nerve
TRIGEMINAL NERVEOPTHALMIC DIVISION:Sensory in nature.
Route: Leaves the anterior medial part of the ganglion and passes forward in the lateralpart of cavernous sinus.
Fibres are afferent to:• Scalp• Skin of forehead• Upper eyelid lining the frontal sinus• Conjunctiva of eyeball• Lacrimal gland• Skin of lateral angle of the eye• sclera of eyeball• Lining of ethmoid cells
TRIGEMINAL NERVE
SUBDIVISIONS
• LACRIMAL NERVE• FRONTAL NERVE• NASOCILLIARY NERVE
TRIGEMINAL NERVE
LACRIMAL NERVE::
• Smallest of the three branches.
Passes into orbit at lateral angle of
superior orbital fissure.
• Courses anterolaterally to reach
lacrimal gland.
• SUPPLIES
Lacrimal Gland &Adjacent Conjunctiva.
TRIGEMINAL NERVE
FRONTAL NERVE: (LARGEST OF THREE)
• In middle of orbit, nerve divides into:
SUPRA ORBITAL NERVE: SUPRA TROCHLEAR NERVE:Largest branch Smallest BranchLeaves orbit through Supra orbital foramen. Pierces fascia of upper eyelid.
SUPPLIES: SUPPLIES:• Skin of upper eyelid • Ant. Scalp region to vertex of skull
• Skin Of The Upper Eyelid• Lower medial portion of forehead
TRIGEMINAL NERVE
NASOCILIARY NERVE::• Enters the orbit through superior orbital fissure.• Supply- mucous membrane of the nose - the tip of the nose - the conjunctiva.
TRIGEMINAL NERVE
MAXILLARY DIVISION• SENSORY IN NATURE
• 2nd division of the trigeminal
nerve.
Tansmits afferent impulses from:• Upper lip
• Lower eyelid
• Tonsillar region
• Side of the nose
• Hard and soft palate
• Lining of maxillary sinus
• Opening of eustachian tubes
• All maxillary teeth and gingiva
• Mucous membrane of the nasal cavity
TRIGEMINAL NERVE
COURSE:Intracranial part::• Originates in the middle part of semilunar ganglion• Passes forward in lower part of cavernous sinus• Exits through foramen rotundum.
TRIGEMINAL NERVE
Extracranial part::• Enters pterygopalatine fossa.• Enters inferior orbital fissure to enter orbital cavity.• Runs laterally along infra orbital groove.• Emerges through infra orbital foramen.
BRANCHES OF MAXILLARY NERVEBRANCHES IN
MIDDLE CRANIAL FOSSA
BRANCHES IN PTERYGOPALATINE
FOSSA
BRANCHES IN INFRAORBITAL GROOVE
AND CANAL
TERMINAL BRANCHES ON FACE
MIDDLE MENINGEALNERVE
• ZYGOMATIC• SPHENOPALATINE
• POSTERIOR SUPERIOR ALVEOLAR
• MIDDLE SUPERIOR ALVEOLAR
• ANTERIOR SUPERIOR ALVEOLAR
• INFERIOR PALPEBRAL• LATERAL NASAL
• SUPERIOR LABIAL
BRANCHES IN MIDDLE CRANIAL FOSSA
• MIDDLE MENINGEAL NERVE• Travels with middle meningeal artery.• Sensory to the dura matter of anterior half of middle cranial fossa.
TRIGEMINAL NERVE
BRANCHES IN PTERYGOPALATINE FOSSA
A. ZYGOMATIC NERVE: Emerges in the pterygopalatine fossa.
Passes anteriorly and laterally through
inferior orbital fissure into orbit.
DIVIDES INTO 2 PARTS::
1. ZYGOMATICOFACIAL NERVE:
2. ZYGOMATICOTEMPORAL NERVE:
TRIGEMINAL NERVE
B. PTERYGOPALATINE {SPHENOPALATINE} NERVES:
• 2 short nerve trunks that unite at pterygopalatine ganglion.
Most of the fibres pass through the ganglion without synapse.
• BRANCHES: ORBITALNASAL -POSTERIOR SUPERIOR LATERAL NASAL -MEDIAL OR SEPTAL BANCH
PALATINE - GREATER OR ANTERIOR PALATINE
- MIDDLE PALATINE BRANCH
-POSTERIOR PALATINE BRANCH
TRIGEMINAL NERVE
C. POSTERIOR SUPERIOR ALVEOLAR NERVES
• Leave main branch before it enters inferior orbital fissure.• Pass downward over posterior surface of maxilla.• Enter post. superior alveolar canal along with internal maxillary artery.• Supplies-mucous membrane of sinus ,maxillary teeth and its gingivae.
P.S.A
TRIGEMINAL NERVE
BRANCHES IN INFRAORBITAL GROOVE AND CANAL::
1. MIDDLE SUPERIOR ALVEOLAR NERVE
• Leaves in posterior part of floor of
Infraorbital canal.
• Passes downward and anterior over the
anterolateral wall of maxillary sinus.
• Supplies maxillary bicuspids.
2. ANTERIOR SUPERIOR ALVEOLAR NERVE
• Descends from main trunk to emerge in
infraorbital foramen.
• Passes through fine canals in maxilla
• Supplies:
Incisors and cuspids
Anterior Part of maxillary sinus
Labial gingiva of incisors and cuspids
M.S.A
A.S.A
TRIGEMINAL NERVEAs the infraorbital nerve is about to emerge from the foramen in front of maxilla
it divides into:
3 TERMINAL BRANCHES ON FACE
INFERIOR PALPEBRAL BRANCHSupply sensory fibres to skin of
Lower eyelid and its conjunctiva.
LATERAL NASAL BRANCHPass to skin of the side of the nose.
SUPERIOR LABIAL BRANCH
Distributed to the skin & mucous membrane of the upper lip.
INF.
PALP
.
LAT. NAS.
SUP. LAB.
TRIGEMINAL NERVE
MANDIBULAR DIVISION• Largest division of trigeminal nerve.Formed by • SMALL MOTOR ROOT• LARGE SENSORY ROOT
SENSORY ROOT SUPPLIES:• Dura• External ear• Parotid gland• TMJ articulation• Lower teeth and gingiva• Scalp over temporal region• Ant. 2/3rd of the tongue. • skin and mucous membrane of chin, • cheek & lower lip.MOTOR ROOT SUPPLIES:• Muscles of mastication.• Mylohyoid• Anterior belly of digastric
TRIGEMINAL NERVE
COURSE Motor root is located in middle cranial fossa Sensory root emerges from semilunar ganglion 2 roots pass alongside in cranium. Emerging from foramen ovale,they unite.
1. UNDIVIDED NERVE: Nervous spinosus Nerve to internal pterygoid
2. DIVIDED NERVE: Anterior division –Branches to ext. pterygoid, masseter,Temporal, buccal posterior division –Auriculotemporal ,lingual, inferior alveolar
TRIGEMINAL NERVE
BRANCHES FROM UNDIVIDED NERVE:A.) NERVOUS SPINOSUS
Arises outside the skull and then passes in the middle cranial fossa to
supply dura and mastoid cells.
b.) NERVE TO INTERNAL PTERYGOID
A branch passes to innervate internal pterygoid muscle. A sub branch
passes for tensor veli palatini and tensor tympani muscles.
TRIGEMINAL NERVE
BRANCHES FROM DIVIDED NERVE:ANTERIOR DIVISION:A.) PTERYGOID NERVE: Enters the medial side of external pterygoid muscle for its motor supply.
B.) MASSETER NERVE: Passes above the external pterygoid to traverse the mandibular notch and enter the deep side of masseter muscle.
TRIGEMINAL NERVE
C.) TEMPORAL NERVES:Passes upwards crosses the infratemporal crest of sphenoid
bone, enters the anterior deep part of the temporalis muscle.
TRIGEMINAL NERVE
D.) BUCCAL NERVE: Passes downwards, anteriorly and laterally between the two heads
of external pterygoid muscle. At the level of occlusal plane It ramifies-
Motor innervation to cheek
Sensory innervation to cheek
Sensory fibres to retromolar pad
Sensory fibres to buccal gingivae
TRIGEMINAL NERVE
POSTERIOR DIVISIONA. AURICULOTEMPORAL NERVE:
Arises by a medial and a lateral root.
COURSE:
Passes posteriorly,Deep to external
pterygoid muscle.
Between sphenomandibular ligament &
neck of condyle.
Traverses upper deep part of parotid
Crosses posterior root of zygomatic arch
TRIGEMINAL NERVE
• BRANCHES OF AURICULOTEMPORAL NERVE
• PAROTID BRANCHES
• ARTICULAR BRANCHES
• AURICULAR BRANCHES
• MEATAL BRANCHES
• TERMINAL BRANCHES:: Supply scalp over the temporal region.
TRIGEMINAL NERVE
B. LINGUAL NERVE• Passes medially to external pterygoid muscle and descends,
• Lies between internal pterygoid muscle & ramus of mandible in
pterygomandibular space.
• In pterygomandibular space,Lingual
nerve lies parallel to inferior Alveolar
Nerve but lingual & anterior to it.
C. INFERIOR ALVEOLAR NERVE:
Largest branch of the posterior division.
Passes downwards,give branch to
mylohyoid
Enters mandibular foramen,
Distributed throughout mandible.
Reaches mental foramen,
2 terminal branches
• Mental nerve
• Incisive nerve
MYLOHYOID NERVE:
• Branch of inferior alveolar nerve
• Both sensory & motor fibres.
• Continues downward & forward in
mylohyoid groove.
Motor fibres Supply:
• Mylohyoid muscle
• Anterior Belly of digastric
APPLIED ANATOMYTRIGEMINAL NEURALGIA• It is a neuropathic disorder characterized by episodes
of intense pain in the face, originating from the trigeminal nerve
• Tic DoloureauxCLINICAL FEATURES• Pain is unilateral (rarely bilateral).• Duration of pain - few seconds to 1-2 minutes.• Pain may occur several times a day;.• patients typically experience no pain between
episodes.• Trigger zone
• CAUSE1. vascular compression –superior cerebral artery2. multiple sclerosis3. Aneurysm4. tumor 5. arachnoid cyst in the cerebellopontine angle6. by a traumatic event such as a car accident or
even a tongue piercing
Treatment
• Medical
• Surgical
Medical Treatment
• Carbamazepine Should be the initial Rx of choice for classical Trigeminal Neuralgia
If get no or only partial response to carbamazepine, add or substitute another pharmacologic agent: Baclofen : 10 m- 80 mg daily Dilantin Lamictal
Surgical Treatment
• Both percutaneous & open techniques– Glycerol injection Ballon Compression– Radio Rhizotomy Gamma knife– Partial Rhizotomy Microvascular
decompression
ROLE IN PROSTHODONTICS
• Trigger zone • Development of a chronic pain state caused by
injury to peripheral branches of the trigeminal nerve after surgical and nonsurgical procedures.
Delcanho RE Neuropathic implications of prosthodontic treatment.J Prosthet Dent. 1995 Feb;73(2):146-52
ABDUCENT NERVE
ABDUCENT NERVE
• Motor in nature
• Supplies lateral rectus muscle
• Lateral rectus muscle is responsible for visual tracking & fixing of object.
Origin:• Nucleus situated beneath floor of fourth ventricle in dorsal part of pons.
ABDUCENT NERVE
Course • From pons,
• Pierces dura mater
• Inferior petrosal sinus
• cavernous sinus
• Sup.Orbital fissure
• with in tendinous ring supply lateral rectus
ABDUCENT NERVE
APPLIED ANATOMY:
• Involvement produces paralysis of lateral rectus,resulting in medial or
convergent squint or diplopia.
• unable to look laterally
FACIAL NERVE
FACIAL NERVE
• Mixed nerve • Three nuclei -1 motor and 2 sensory• Motor nucleus: it is present in the pons.• sensory –a) the superior salivatory nucleus: b)The nucleus of the tractus solitarius:
COURSE
COURSE Pons
Stylomastoid canal andforamen
Posteromedial surface of Parotid gland
Behind the neck of mandible It divides into its Five terminal branches
BRANCHESA.WITHIN THE FACIAL CANAL-1.Greater petrosal nerve2.Nerve to stapedius 3. Chorda tympaniB.AT ITS EXIT FROM STYLOMASTOID FORAMEN1.Posterior auricular2.Digastric 3.Stylohyoid C.Terminal branches within parotid gland1.Temporal 2.Zygomatic3. Buccal 4.Mandibular5.Cervical
A.WITHIN THE FACIAL CANAL
1.GREATER PETROSAL NERVEsupply mucous glands of nose, palate & lacrimal glands
A.WITHIN THE FACIAL CANAL
2.NERVE TO STAPEDIUS small motor nerve for stapedius muscle whichis attached to the stapesthe innermost of thethree auditory ossciles.
A.WITHIN THE FACIAL CANAL
3. CHORDA TYMPANIThe taste fibers follow thelingual nerve into theSubstance of the tongue & are distributed to the taste buds.
B.AT ITS EXIT FROM STYLOMASTOID FORAMEN
POSTERIOR AURICULAR NERVE Turns backwards & upwards between the mastoid process & the auricle and supplies the posterior auricular & the occipital muscles
C.TERMINAL BRANCHES WITHIN PAROTID GLAND
1.TEMPORAL -the auricular muscles,Frontalis,Orbicularis oculi,Corrugator 2.ZYGOMATIC-Orbicularis oculi3. BUCCAL-Procerus,zygomaticus,Quadratus labii superioris,muscles of the nose,buccinator and orbicularis oris4.MANDIBULAR-muscles of the lower lip and chin5.CERVICAL-Platysma.
APPLIED ANATOMY GENICULATE GANGLION• Ramsay hunt syndrome- Herpes zoster infection of ganglion Signs-• Vesicles on ear, oral mucosa, tonsil, posterior one third of
tongue• Loss of taste• Pain• Decrease salivation• Palatal paralysis
• Definition :- idopathic paralysis of facial nerve of sudden onset.
• Incidence :- 15 – 40 cases per one lac cases.
• Sex predilection :- F > M . It is 3.3 times more common in pregnant women ( especially in third trimester )
• Age :- can occur at any age. More common in middle aged people.
• Side involvement :- equally involved left & right sides. Usually unilateral but in 1% cases bilateral involvement can be seen.
BELL’S PALSY
• Causes:
• Congenital • Trauma • Iatrogenic • Idiopathic • Infection • Toxic • Neurologic • Neoplastic
CLINICAL FEATURES• Facial asymmetry• Drooping of corner of mouth• Inability to close eye• Uncontrolled tearing• Facial muscle atrophy• Eyebrow droop• Loss of forehead and nasolabial folds• Pain near mastoid process• Sensory loss• Others- Hyperacusis,Dysgeusia
• Congenital:- i) Moebius Syndrome :- Due to congenital nuclearaplasia. ii) Melkersson–Rosenthal Syndrome :- Cheilitis Granulomatosa + Facial Palsy + Scrotal Tongue
Neoplastic :-
i) Facial Nerve Tumours – Schwannoma, Neurofibroma
ii) Parotid Tumors
iii) Temporal bone or External Auditory Canal Tumours
Infectious :- i) Mastoiditis
ii) Viral causes :- Herpes zoster (Ramsay Hunt Syndrome ), mumps, infectious mononucleosis
iii) Bacterial causes :- Diphtheria, Tuberculosis
• Eighty percent of patients with Bell's palsy have normal or near-normal recovery without any treatment.
• DRUG THERAPY--CORTICOSTEROIDS-Prednisone 80 mg *5days
-ACYCLOVIR -2000 mg/day*7 days • SURGICAL NERVE GRAFTING ( Hypoglossal nerve has been a very effective
autogenous graft)
TREATMENT
ROLE IN PROSTHODONTICS Complete denture fabrication in patient with bells palsy
• primary and final impressions – excessive material is incorporated on the affected side
• The polished surface of denture base was contoured by functions of the tongue and action and tonus of affected and unaffected lips and cheek
• Occlusal wax Rims - Midline placed in the middle of the oral cavity rather than the facial midline
• Non anatomic posterior teeth are used to establish the centric occlusionSome improvement of the appearance can be achieved by:1. Placing the mesio-incisal point in the middle of the mouth rather than
the middle of the face2. keep the cant of the occlusal plane on the affected side a little low for
incisal show3. Buccal sulcus support - Placing buccal support on the affected side to
reduce the facial droop.This will also help reduce the accumulation of food in the affected buccal vestibule
Suresh S Prosthodontic management of complete edentulous patients with neuromuscular disorders - Case reports. Journal of Advanced Dental Research Vol II : Issue I: January, 2011
VESTIBULOCOCHLEAR NERVE
VESTIBULOCOCHLEAR NERVE
• This nerve is responsible for transmitting sound and equilibrium (balance) information from the inner ear to the brain.
• NUCLEUS -2 cochlear nucleii in inferior cereberal peduncle
-4 vestibular nucleii in pons and medulla
COURSE –• The cochlear nerve travels away from the
cochlea of the inner ear where it starts as the spiral ganglia.Connects organ of corti to cochlear nuclei
• The vestibular nerve travelsfrom the vestibular systemof the inner ear. The vestibular ganglion houses the cell bodies of the bipolar neurons
APPLIED ANATOMY Damage vestibulocochlear nerve may cause the following
symptoms – • hearing loss,• vertigo ,• false sense of motion ,• loss of equilibrium (in dark places) ,• nystagmus ,• motion sickness ,• tinnitus.
GLOSSOPHARYNGEAL
• Mixed nerveMotor fibres – stylopharyngeusSensory fibres – pharynx, tonsils, posterior part of tongue,parotid glandNuclei - medulla
COURSE
COURSE Medulla
Jugular foramen
superior nucleus Inferior nucleus
Parotid gland via lesser petrosal nerve
pharynx,tonsils,tongue
BRANCHES
1.TYMPANIC NERVE2.CAROTID3.PHARYNGEAL4.MUSCULAR5.TONSILLAR6.LINGUAL
APPLIED ANATOMY
1.Tested clinically- • Tickling posterior wall of pharynx• Taste sensibility on posterior one third of tongue2.Isolated lesions- Unknown3.Neuralgia4. Involved in swallowing and gag reflex, considered to be as the taste nerve, mainly for the sweet and bitter tastes.
GLOSSOPHARYNGEAL NEURALGIADEF.-It consists of recurring attacks of severe pain
in back of throat near the tonsils and back of tongue due to malfunction of cranial nerve IX.
Cause-unknown, -artery that compresses the
glossopharyngeal nerve , -tumor in the brain or neck
CLINICAL FEATURES• Attacks are brief• Triggered by chewing,swallowing,coughing or sneezing• Pain begins at back of tongue or back of throat• Pain- unilateral,severe and paroxysmal• Older age group is affected
ROLE IN PROSTHODONTICS GAG REFLEX - Nausea manifests itself through an unpleasant feeling that precedes the sensation of vomiting
Lavinia Ardelean, et al .Gag reflex in dental practice – etiological aspects. TMJ 2003, vol. 53, no. 3-4
PHYSIOLOGICAL MECHANISMS
• Inborn reflex • Regresses in first four years of life. • It becomes more posterior after the appearance
of the first dentition(tonsil pillars)• The persistence - orofacial immaturity in forms
of dysphagia.• The sensor stimuli are detected by three types
of receptors - orofacial, digestive, blood flow level.
OROFACIAL RECEPTORS
• REAL REFLEX FIELD• palatine veil, posterior pharynx ,tonsillar
pillars , receptors,tongue papillae that carry the taste buds are rich in nociceptive
DIGESTIVE RECEPTORS
• The afferences coming from the digestive tract, conveyed mainly through the vagus nerve, reach the solitary nucleus
BLOOD-FLOW RECEPTORS
• Pathological humoral alterations, such as uremia or drug poisoning can act on the bulbar centre of vomiting.
• The hormonal changes inherent to pregnancy act through the blood flow and may induce nausea.
THE IMPORTANCE OF GAG REFLEX ETIOLOGY IN DENTAL PRACTICE
• Clinically, there are several therapeutic actssusceptible to stimulate, directly or indirectly, the areas and reflex paths, a stimulation that is manifested by triggering INBORN OR ACQUIRED, LOCAL OR GENERAL REFLEXES.
INBORN REFLEXES
Any risk of blocking the airways triggers the gag reflex. This depends mainly on two factors:• oral breathing • hypersalivation
ACQUIRED REFLEXES
GENERAL LOCAL ORIGIN
• Alcoholism• Digestive or hepato-biliary disorders• Emetic medication.
• Olfactory/taste stimuli• Mechanical stimuli• Acoustic stimuli• Visual stimuli• Psychic stimuli
MANAGEMENT OF GAG REFLEX
• Distraction techniques• Relaxation• Pharmacological Techniques Local Anesthesia• Conscious sedation
Milind Limaye, Naveen HC, Aditi Samant. The gag reflex etiology and management. International Journal of Prosthetic Dentistry.2010:1(1):10-14. 2010 International Journal of Prosthetic Dentistry
PROSTHODONTIC TECHNIQUES
Borkin recommends low-fusing wax as an impression material Webb suggests that distortion of tissue contour due to injection of anesthetic solution can be minimized by adding hyaluronidase (I-3cc) to 2 % lidocaine HCI (1cc).
MODIFICATION OF EDENTULOUS MAXILLARY CUSTOM TRAY TO PREVENT GAGGING
• The modified maxillary custom acrylic resin tray to which second layer of autopolymerising tray acrylic has been attached to original custom tray with wax spacer removed aids in removal of excess impression material as it extrudes from the posterior border of the maxillary custom tray before it can elicit a gag reflex in the patient.
• PALATE LESS DENTURES: A cast metal denture base of aluminum or chrome nickel alloy is recommended
• THE MARBLE TECHNIQUE• SYSTEMATIC DESENSITIZATION• ERRORLESS LEARNING- The patient is
instructed to set aside time to position the denture closer each day and eventually into the mouth in successive approximations
• Training bases - A thin acrylic denture base, without teeth is fabricated and the patient is asked to wear it at home, gradually increasing the length of time the training base is worn
VAGUS• Mixed nerve• Nuclei-located in medulla
VAGUSCOURSEMedulla
jugular foramen,
carotid sheath
neck, chest and abdomen
viscera
BRANCHES
IN HEAD AND NECK-A.IN JUGULAR FORAMEN-1.Meningeal2.Auricular – skin of ear
B.IN NECK
1.Pharyngeal-muscles and mucous membrane of the pharynx (except the stylopharyngeus) and the muscles of the soft palate, except the Tensor veli palatini
2.Carotid
3.Superior laryngeal
ExternalLaryngeal(cricothyroid)
4.Right recurrent laryngeal –all muscles of larnyx5.Cardiac
Internal laryngeal(mucous membrane of the pharynx and larynx)
APPLIED ANATOMY1.Tested clinically- Comparing palatal arches2.Paralysis- • Nasal regurgitation-pharyngeal branch• Nasal twang in voice - recurrent laryngeal nerve• Hoarseness of voice – recurrent laryngeal nerve• Flattened palatal arch - pharyngeal branch• Dysphagia – pharyngeal branch
ACCESSORY NERVE• Motor nerve• Nucleus – nucleus ambiguus• Formed by spinal and cranial roots
COURSE OF ACCESSORY NERVE
Jugular foramen
Cranial root spinal root
muscle of soft palate and pharynx
sternocleidomastoid and trapezius
APPLIED ANATOMY
• IT IS TESTED CLINICALLY-1.ASKING PT. TO SHRUG HIS SHOULDERS2.TURN FACE TO OPPOSITE SIDE• WRY NECK
HYPOGLOSSAL NERVE
• Motor nerve• Nucleus- hypoglossal nucleus in medulla
COURSE OF NERVEhypoglossal nucleus
hypoglossal canal It spirals behind the vagus nerve and passes between the internal carotid artery and internal jugular vein (carotid sheath)
submandibular region to enter the tongue
BRANCHES1. Meningeal branch2. Descending ramus-
Omohyoideus,Sternohyoideus, the Sternothyreoideus, and the inferior belly of the
Omohyod.3. Thyrohyoid 4. Geniohyoid
APPLIED ANATOMYTested clinically- Protrude tongueLesion of nerve- Paralysis of tongueA.Infranuclear lesions• Gradual atrophy• In motor neuron disease ,syringobulbia
B.Supranuclear lesions• Paralysis without wasting• Seen in pseudobulbar palsy
LYMPHATIC DRAINAGE OF THE HEAD AND
NECK
THE LYMPHATIC SYSTEM
• The lymphatic system is a part of the circulatory system, comprising a network of conduits called lymphatic vessels that carry a clear fluid called lymph unidirectional towards the heart
FUNCTION
• To provide an accessory route for the excess plasma to get returned to the blood.
• Secondly the lymphatic organs play an important part in the immune system
LYMPH
• Lymph is the fluid that circulates throughout the lymphatic system. The lymph is formed when the interstitial fluid is collected through lymph capillaries.It is then transported though lymph vessels to lymph nodes before emptying ultimately into the right or the left subclavian vein, where it mixes back with blood.
FUNCTION OF LYMPH
• Lymph returns protein and excess interstitial fluid to the circulation. Lymph may pick up bacteria and bring them to lymph nodes where they are destroyed. Metastatic cancer cells can also be transported via lymph. Lymph also transports fats from the digestive system
LYMPH NODE
SURFACES
SUBCAPSULAR SINUS
OUTER CORTEX
INNER MEDULLA
• CLASSIFICATION OF HEAD & NECK LYMPH NODES
Classification of Head & Neck Nodes
WALDEYER’S INTERNAL RING • Adenoid• Lingual• Palatine• Posterior pharyngeal wall lymphoid aggregate
WALDEYERS CLASSIFICATION
WALDEYER’S EXTERNAL RING The ring in the head constitues Skull base nodesOccipital nodesPostauricular nodesParotid nodes and Buccal lymph nodes .
The ring in the neck constitutesSuperficial Cervical nodesSubmandibular nodesSubmental and Anterior cervical nodes
SUPERFICIAL LYMPH NODE
• Located at junction of head and neckINCLUDES• occipital• Post auricular• Parotid• Buccal• Superficial cervical• Submental• Submandibular• Anterior cervical
DEEP LYMPH NODE
located along internal jugular vein within carotid sheath INCLUDES• Upper• Middle• LowerIn general lymph flows from superficial to deepand from superior to inferior
SITE SPECIFIC DRAINAGE IN HEAD & NECK
SUPERFICIAL PAROTID LYMPH NODES
• Location-anterior to the tragus superficial or deep to the parotid fascia.
• Drainage
POSTERIOR AURICULAR LYMPH NODES• Location-superficial to the
mastoid attachment of sternocleidomastoid muscle
• Drainage – Strip of Scalp above Auricle Posterior Wall of external
auditary meatus(Upper half of Auricle)
OCCIPITAL NODES
• Location - the superior angle of the posterior triangle superficial to the upper attachment of trapezius
• Drainage - the occipital scalp
SUPERFICIAL CERVICAL LYMPH NODES
• Location - along the external jugular superficial to the sternocleidomastoid muscle.
• Drainage - Floor of the EAM Lobe of the Auricle Skin over Angle of Mandible Lower Parotid region.
SUBMANDIBULAR LYMPH NODES
• Location - internal to the investing layer of the deep fascia of the neck in the submandibular triangle
• Afferents - facial nodes (nasolabial and buccal ) , submental & Parotid nodes may drain
SUBMENTAL LYMPH NODES
• Location - on the mylohyoid muscle between the anterior bellies of digastric.
• Drainage -- Mandibular Anterior Alveolar ridge
Anterior 1/3rd of floor of the mouth
Lower Lip (except lateral thirds)
UPPER DEEP CERVICAL NODES
• Located - upper third of the internal jugular vein deep to the sternocleidomastoid muscle .
• Jugulodigastric node- in triangular region bounded by the posterior belly of digastric , facial vein and IJV.
• Efferents from these nodes drain to the middle deep cervical nodes or directly to the jugular trunk.
Afferents from the parotid posterior-auricular , occipital , superficial cervical , submandibular , retropharyngeal and prelaryngeal lymph nodes
Drains wide areas of face , oral cavity , tongue , tonsils , nose , nasal cavity , nasopharynx , parotid and submandibular gland and supraglottic larynx .
MIDDLE DEEP CERVICAL NODES
Located around middle third of the internal jugular vein
The Juguloomohyoid lymph node lies just on or above the tendon of omohyoid muscle.
Efferents from these nodes drain to the inferior deep cervical nodes or directly to the jugular trunk.
afferents from the upper deep cervical nodes , submental nodes , suprahyoid nodes , prelaryngeal nodes , paratracheal nodes
LOWER DEEP CERVICAL
Location- lower1/3rd of the internal jugular vein
Afferents- middle deep cervical nodes , anterior superficial cervical , spinal accessory nodes and transverse cervical nodes
CLINICAL CONSIDERATIONS
PALPATION OF LYMPH NODES
• Use the pads of all four fingertips
• Examine both sides of the head simultaneously
• Applying steady, gentle pressure
• Evaluated in a systematic fashion
PREAURICULAR NODES
• Stand behind the patient• Gently tilt the head to
the opposite side of node being palpated
• Roll your finger in front of the ear, against the bone.
POSTAURICULAR NODES
• Stand behind the patient
• Gently tilt the head to the opposite side of node being palpated
• Roll your finger behind the auricle , against the mastoid process.
SUBMANDIBULAR NODES
• Stand behind the patient • Gently tilt the head to
the same side of node being palpated
• Roll your fingers against inner surface of mandible applying pressure against the bone.
SUBMENTAL NODES
• Stand behind the patient
• Gently tilt the head in front .
• Roll your fingers against inner surface of symphysis applying pressure against the bone.
SUPERFICIAL CERVICAL NODES
• Stand behind the patient
• Palpate using four fingers above the sternocleidomastoid muscle using rolling motion
DEEP CERVICAL NODES
• They are located deep to the sternocleidomastoid muscle and are often inaccessible
• Palpate by standing behind the patient and hooking thumb and fingers around either side of the muscle.
PATHOLOGIES ASSOCIATED WITH LYMPHATIC SYSTEM
• DEVELOPMENTAL
• NEOPLASTIC
• INFLAMMATORY
CAVERNOUS HEMANGIOMAGIANT CELL LYMPHOMALYMPHOEPITHELIOMALYMPHOENDOTHELIOMALYMPHANGIOSARCOMAUNDIFFRENTIATED LYMPHOMAHODGKINS DISEASENON-HODGKINS DISEASE
CYSTIC HYGROMACONGENITAL LYMPHEDEMA
LymphangitisLymphadenitis LymphoedemaLymphadenopathy
DEVELOPMENTAL PATHOLOGY
• CYSTIC HYGROMA - A cystic hygroma is a congenital multiloculated lymphatic lesion that can arise anywhere, but is classically found in the left posterior triangle of the neck. This is the most common form of lymphangioma
• CONGENITAL LYMPHEDEMA - Congenital lymphedema is a blockage of fluid in the developing fetal lymphatic system.
INFLAMMATORY PATHOLOGIES • LYMPHANGITIS - Lymphangitis is an inflammation of the
lymphatic channels that occurs as a result of infection at a site distal to the channel. The most common cause of lymphangitis in humans is Streptococcus pyogenes
• LYMPHADENITIS is an infection of the lymph nodes. Causes are– Viral -Common upper respiratory infections,Infectious
mononucleosis ,cytomegalo virus,Acquired immunodeficiency syndrome,Rubella,Varicella,Measles
– Bacterial –Septicemia , Typhoid fever, Tuberculosis, Syphilis, Plague
– Protozoal - Toxoplasmosis– Fungal - Coccidioidomycosis
• LYMPHOEDEMA - Lymphedema is a condition characterized by swelling in one or more extremities that results from impaired flow of the lymphatic system. Causes are most commonly filariasis in india, and after breast cancer surgery.
REFERENCES1. N Torbica, S Krstev World at work: Dental laboratory technicians.Occup Environ
Med2006;63:145-1482. Lavinia Ardelean, et al .Gag reflex in dental practice – etiological aspects. TMJ 2003, vol.
53, no. 3-43. Dr. Kalavathi S.D Restoring Ocular Esthetics Using Ocular Prosthesis Journal of Dental
Sciences & Research 1:2: Pages 39-444. Delcanho RE Neuropathic implications of prosthodontic treatment.J Prosthet Dent. 1995
Feb;73(2):146-52 5. Suresh S Prosthodontic management of complete edentulous patients with
neuromuscular disorders - Case reports. Journal of Advanced Dental Research Vol II : Issue I: January, 2011
6. Lavinia Ardelean, et al .Gag reflex in dental practice – etiological aspects. TMJ 2003, vol. 53, no. 3-4
7. Milind Limaye, Naveen HC, Aditi Samant. The gag reflex etiology and management. International Journal of Prosthetic Dentistry.2010:1(1):10-14. 2010 International Journal of Prosthetic Dentistry
8. Grays Anatomy9. Oral Anatomy – Sichers10. B. D. Chaurasia's human anatomy11. Netters Atlas of Human Anatomy12. Clinically Oriented Anatomy – Moore & Dalley13. Development of Human Body– Moore & Persaud14. Medical Physiology- Ganong
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