PAIN & PAIN

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PAIN & PAINPAIN & PAIN

PATHWAYPATHWAY

Presented byPresented by

Dr. SantoshDr. Santosh


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1.1. IntroductionIntroduction

2.2. Definition of painDefinition of pain

3.3. Classification of painClassification of pain

4.4. Pain pathways for each type of painPain pathways for each type of pain5.5. Visceral painVisceral pain

6.6. Referred painReferred pain

7.7. Orofacial painOrofacial pain

8.8. Theories of painTheories of pain9.9. Pain modulationPain modulation

10.10. Prosthodontic considerationProsthodontic consideration


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INTRODUCTIONINTRODUCTION

PainPain isis thethe mostmost commoncommon symptomsymptom thatthat compelscompelspatientpatient toto seekseek medicalmedical andand dentaldental therapytherapyandand constitutesconstitutes aa seriousserious healthhealth andandeconomiceconomic problemproblem..

DentistDentist andand dentaldental specialistsspecialists areare concernedconcerned withwithtwotwo ofof thethe mostmost commoncommon painpain..

1)1) AcuteAcute orofacialorofacial painpain arisingarising fromfrom thethe teethteeth andandassociatedassociated structuresstructures..

2)2) ChronicChronic orofacialorofacial painpain whichwhich isis believedbelieved totoamountamount forfor4040%% ofof anan chronicchronic painpain problemsproblems..

AnAn understandingunderstanding ofof thethe pathophysiologypathophysiology ofof painpainisis needed,needed, particularlyparticularly thosethose whichwhich maymay havehave

anan importantimportant effecteffect onon patientpatient managementmanagement..


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Pain is aPain is a protective mechanismprotective mechanism of theof the

body: it occurs whenever any tissues arebody: it occurs whenever any tissues are

being damaged and it causes the individualbeing damaged and it causes the individual

toto reactreact to remove the stimulus.to remove the stimulus.


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The international association for the studyThe international association for the study

of painof pain defines pain asdefines pain as

an unpleasant sensory and emotional an unpleasant sensory and emotionalexperience associated withexperience associated with actual oractual or

potential tissue damagepotential tissue damage, or described in, or described in

terms of such damageterms of such damage


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Reaction of PainReaction of Pain

1)1) Behavioral:CryingBehavioral:Crying / moaning, on long standing,/ moaning, on long standing,

frustration and depression can be developed.frustration and depression can be developed.

22)) MuscularMuscular :: SpasmSpasm ofof thethe skeletalskeletal musclesmuscles inin

thethe affectedaffected regionregion..

33)) ReflexReflex responseresponse:: AA painfulpainful stimulusstimulus isis usuallyusually

associatedassociated withwith somaticsomatic reflexesreflexes..

4)4) InterInter relationshiprelationship betweenbetween thresholdthreshold ofof painpain andandreactionreaction:: ReactionReaction ofof thethe painpain dependsdepends uponupon

thethe environmentenvironment..


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Characteristics of PainCharacteristics of Pain

1)1) ThresholdThreshold andand intensityintensity..

2)2) AdaptationAdaptation..

3)3) LocalizationLocalization ofof painpain..4)4) EmotionalEmotional accompanimentaccompaniment..

5)5) InfluenceInfluence ofof thethe raterate ofof damagedamage onon thethe

intensityintensity ofof painpain..


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CLASSIFICATION OF NERVECLASSIFICATION OF NERVEFIBRESFIBRES

Type A fibres:Type A fibres:Alpha Alpha 7070--120m/s,120m/s, 1212--20um.20um.BetaBeta 4040--70m/s,70m/s, 55--12um12umGammaGamma 1010--50m/s,50m/s, 33--6um6umDeltaDelta 66--30m/s,30m/s, 22--5um5um

Type B fibresType B fibres 33--15m/s,15m/s,


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Classification of PainClassification of Pain

PainPain

SomaticSomatic VisceralVisceral

Eg. AnginaEg. Angina

pectoris /pectoris /peptic ulcerpeptic ulcer

intestinal coliintestinal coliSuperficialSuperficial

From skin &From skin &

subcutaneoussubcutaneoustissuestissues

Eg. SuperficialEg. Superficial

cuts, burnscuts, burns

DeepDeep

FromFrom

Muscles/Muscles/bones /bones /

joints/joints/

Eg. FractureEg. Fracture


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PAINPAIN

FAST PAIN SLOW PAINFAST PAIN SLOW PAIN


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Fast pain occurs within 0.1 second ofFast pain occurs within 0.1 second of

application of a pain stimulus, alternate namesapplication of a pain stimulus, alternate names

are sharp pain, pricking pain, acute pain andare sharp pain, pricking pain, acute pain and

electric pain.electric pain.Not feltNot felt Most of the deeper tissuesMost of the deeper tissues


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Slow pain begins only after a second or more ofSlow pain begins only after a second or more ofapplication of a pain stimulus , increases slowlyapplication of a pain stimulus , increases slowly

over many seconds and sometimesover many seconds and sometimes--eveneven

minutes. Alternate names are burning pain,minutes. Alternate names are burning pain,

aching pain, throbbing pain, nauseous pain andaching pain, throbbing pain, nauseous pain and

chronic pain.chronic pain.

Occurs in both skin and in almost any deepOccurs in both skin and in almost any deep

tissue or organtissue or organ


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The pain signals take 2 differentThe pain signals take 2 different

pathways to the brain.pathways to the brain.

PAIN PATHWAYPAIN PATHWAY

NeoNeo SpinothalamicSpinothalamic PaleoSpinothalamicPaleoSpinothalamic

TractTract TractTract


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NEOSPINOTHALAMIC PATHWAYNEOSPINOTHALAMIC PATHWAY

(Transnmission of fast pain)(Transnmission of fast pain)

The fast type aThe fast type a--deltadelta

painpain fibresfibres transmittransmit

mainlymainly mechanical andmechanical and

acute thermal painacute thermal pain..

They terminate mainlyThey terminate mainly

in lamia I (laminain lamia I (lamina

marginalis of themarginalis of the

dorsal horns)dorsal horns)


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PALEOSPINOTHALAMIC PATHWAYPALEOSPINOTHALAMIC PATHWAY

(Transmission of slow chronic pain)(Transmission of slow chronic pain)

The paleospinothalamic system transmits pain mainlyThe paleospinothalamic system transmits pain mainly

carried in the peripheral slowcarried in the peripheral slow--chronic typechronic type--C pain fibers,C pain fibers,

although it does transmit some signals from type Aalthough it does transmit some signals from type A--deltadelta

fibers as well.fibers as well.

The peripheralThe peripheral fibresfibres terminate almost entirely interminate almost entirely inlaminas II and IIIlaminas II and III of the dorsal horns, which together areof the dorsal horns, which together are

called ascalled as substantiasubstantia gelatinosagelatinosa..


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Most of the signals then pass through one orMost of the signals then pass through one ormore additionalmore additional shortshort fibresfibres within the dorsal hornwithin the dorsal horn

themselves before enteringthemselves before entering lamina Vlamina V throughVIthroughVI

Here the last neuron in the series give riseHere the last neuron in the series give rise

to long axons that mostly join theto long axons that mostly join the fibresfibres from thefrom the

pathway passing through the anteriorpathway passing through the anterior commisurecommisure

to the opposite side of the cord and then upwardto the opposite side of the cord and then upward

to the brain in the sameto the brain in the same anterolateralanterolateral pathway.pathway.


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Projection ofProjection of paleospinothalmicpaleospinothalmic tracttract

The slow chronicThe slow chronic paleospinothalmicpaleospinothalmic

pathway terminates widely in thepathway terminates widely in the brain stembrain stem..


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Only 1/10Only 1/10thth of theof the fibresfibres pass all the way to thepass all the way to thethalamus.thalamus. Instead tInstead they terminate principally inhey terminate principally inone of the three areasone of the three areas..

1.1. TheThe reticular nucleireticular nuclei of theof the medulla,medulla, ponsponsandand

mesencephalonmesencephalon..

2.2. TheThe tectaltectal area of thearea of the mesencephalonmesencephalon deepdeeptoto

the superior and inferiorthe superior and inferior colliculicolliculi

3. The3. The periaqieductalperiaqieductal graygray region ofregion ofsurrounding the aqueduct ofsurrounding the aqueduct of syliviussylivius..


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From the brain stem pain area, multipleFrom the brain stem pain area, multiple

shortshort fibresfibres neuronsneurons relay the pain signal upwardrelay the pain signal upward

into theinto the intralaminarintralaminar and central lateral nuclei ofand central lateral nuclei of

thethe thalamusthalamus and into certain portions of theand into certain portions of the

hypothalamushypothalamus and other adjacent regions of theand other adjacent regions of the

basal brainbasal brain


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Visceral PainVisceral Pain

CausesCauses ofof painpain areare1)1) IschemiaIschemia

2)2) ObstructionObstruction ofof aa hollowhollow viscousviscous

3)3) InflammationInflammation

4)4) DistensionDistension5)5) SevereSevere vasodilatationvasodilatation..

6)6) CharacteristicCharacteristic ofof visceralvisceral painpain..a)a) VisceralVisceral painpain isis referredreferred painpain..

b)b) VisceralVisceral painpain isis veryvery oftenoften associatedassociated withwithvomitingvomiting andand fallfall ofof BB..PP..

c)c) DrugsDrugs requiredrequired toto alleviatealleviate visceralvisceral painspains areareoftenoften differentdifferent fromfrom thosethose requiredrequired toto alleviatealleviate

thethe somaticsomatic painpain..


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Referred pain:Referred pain: -- HeterotropicHeterotropic painpain

that is felt in an area innervated bythat is felt in an area innervated by

a nerve different from the one thata nerve different from the one thatmediates the primary pain.mediates the primary pain.


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InIn mammilianmammilian embryo body is divided intoembryo body is divided into

metameremetamere

A typicalA typical metameremetamere consist ofconsist of

1. Skin and subcutaneous tissue.1. Skin and subcutaneous tissue.

2. Skeletal muscles2. Skeletal muscles

3. Viscera3. Viscera


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Each metamere contains one segment ofEach metamere contains one segment of

spinal cord (corresponding)spinal cord (corresponding)a. From anterior horn of segment motora. From anterior horn of segment motor

nerve emerges and supplies skeletalnerve emerges and supplies skeletal

muscles of this segment (MYOTOME)muscles of this segment (MYOTOME)

b. Autonomic fibres of this segment supplyb. Autonomic fibres of this segment supplythe viscera (VICEROTOME)the viscera (VICEROTOME)

C. Afferent fibres from the skin enter theC. Afferent fibres from the skin enter the

dorsal horn of this segment.dorsal horn of this segment.The area of the skin supplied by one dorsalThe area of the skin supplied by one dorsal

root is called as DERMATOMEroot is called as DERMATOME


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Vicerotome,Vicerotome, MyotomeMyotome andand

dermatomedermatome ofof eacheach metameremetamere

areare suppleiedsuppleied byby thethe

correspondingcorresponding spinalspinal cordcord

segmentsegment..

InIn postpost natalnatal lifelife D,D, V,V, MM ofof aa

givengiven segementsegement ofof thethe cordcord

occupyoccupy geographicallygeographicallydifferentdifferent areaarea of of thethe bodybody ((

NEURALNEURAL CONNECTIONSCONNECTIONS

AREARE RETAINED)RETAINED)

EE..GG DermatomeDermatome ofof thethe TT11

segementsegement isis innerinner sideside ofof thetheforearmforearm andand thethe

correspondingcorresponding vicerotomevicerotome isis

partpart ofof thethe heartheart..


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Mechanism of referred pain.Mechanism of referred pain.

Following mechanism are responsible for theFollowing mechanism are responsible for the

phenomenon of referral pain.phenomenon of referral pain.

1. Convergence1. Convergence

2. Subliminal fringe effect2. Subliminal fringe effect


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CONVERGENCE


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Sympathetic afferentSympathetic afferent fibresfibres carrying paincarrying painsensation from thesensation from the viscusviscus ends at theends at the posteriorposterior

horn of the spinal cord.horn of the spinal cord.

Afferent somatic nerve, emerging from the painAfferent somatic nerve, emerging from the painreceptor, of the corresponding dermatome of thisreceptor, of the corresponding dermatome of this

viscusviscus, enters the same segment and terminate, enters the same segment and terminate

on the same cell where the sympathetic nerve ison the same cell where the sympathetic nerve isterminating. (terminating. ( i.ei.e Two different neurons convergeTwo different neurons converge

on the same next order neuron)on the same next order neuron)


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SUBLAMINAL FRINGE EFFECT


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Subliminal fringe effectSubliminal fringe effect

The afferent sympathetic nerveThe afferent sympathetic nerve bringing pain sensationbringing pain sensation

from the viscus terminates on the second order neuron,from the viscus terminates on the second order neuron,

It also gives a collateral which stimulate anotherIt also gives a collateral which stimulate anothersecond order neuronsecond order neuron

This second order neuron synapse with the somaticThis second order neuron synapse with the somatic

neuron of the corresponding dermatome.neuron of the corresponding dermatome.Therefore, when pain is felt by the patient he feel as ifTherefore, when pain is felt by the patient he feel as if

the pain is coming from the corresponding dermatomethe pain is coming from the corresponding dermatome


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Somatic inputs from the face and oral structures do notSomatic inputs from the face and oral structures do not

enter the spinal cord by way of spinal nerves. Instead,enter the spinal cord by way of spinal nerves. Instead,sensory input from the face and mouth is carried bysensory input from the face and mouth is carried byway of the fifth cranial nerve, the trigeminal nerve.way of the fifth cranial nerve, the trigeminal nerve.

Orofacial Pain PathwayOrofacial Pain Pathway


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Trigeminal pathway is only one of the manyTrigeminal pathway is only one of the many

pathways that carry orofacial nociception to the brain.pathways that carry orofacial nociception to the brain.

Nociceptive impulses from the face and mouthNociceptive impulses from the face and mouth

may be mediated centrally by way of afferentmay be mediated centrally by way of afferent

neurons that pass through the 7neurons that pass through the 7thth 99thth and 10and 10thth cranialcranial

nerves as well and also visceral afferents thatnerves as well and also visceral afferents thatdescend through cervical sympathetic chains.descend through cervical sympathetic chains.


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The cell bodies ofThe cell bodies of

the trigeminal afferentthe trigeminal afferent

neurons are located in theneurons are located in the

large gasserion ganglion.large gasserion ganglion.This region of theThis region of the

brain stem is structurallybrain stem is structurally

very similar to the dorsalvery similar to the dorsal

horn of the spinal cord.horn of the spinal cord.


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- Semilunar Ganglion is located in meckels cavity.

- The ganglion is unipolar neuron forms central and peripheralprocesses.

- The peripheral branch form Opthalmic; Maxillary andMandibular.

- Central branch leave the semilunar ganglion and enters thepons.

- Where they divide into ascending and descending fibers.- The ascending fibers terminate in the upper sensory nucleus of

the trigeminal nerve and convey the light touch, tactilediscrimination.

- The main nucleus gives rise to dorsal trigeminothalamic tract;which ascends upwards.

- The spinal nucleus of the trigeminal nerve gives rise to ventraltrigeminothalamic tract.

- Which extends caudally to the second cervical segment and

crosses to opposite side ascends to the thalamus.


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FromFrom thethe thalamusthalamus fibersfibers continuecontinue toto

thethe cerebralcerebral cortexcortex..

ConveyConvey painpain andand temperaturetemperature fromfrom thetheentireentire trigeminaltrigeminal areaarea..


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Theories of PainTheories of Pain

SpecificitySpecificity theorytheory (Von(Von FreyFrey ((18901890))))

-- HeHe proposedproposed thatthat freefree nervenerve endingsendings gavegave riserise toto

painpain sensationsensation inin brainbrain..

-- ThisThis theorytheory isis concernedconcerned primarilyprimarily withwith thethesensorysensory discriminationdiscrimination aspectsaspects ofof pain,pain, itsits quality,quality,

locationlocation onon skin,skin, intensityintensity andand durationduration..


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Intensives or Summation theory (Gold Sheider)Intensives or Summation theory (Gold Sheider)

HeHe proposedproposed thatthat painpain resultsresults fromfrom over over

stimulationstimulation ofof otherother primaryprimary sensationssensations..

HeHe proposedproposed thatthat painpain resultedresulted whenwhen activityactivity

exceededexceeded aa criticalcritical levellevel duedue toto excessiveexcessiveactivationactivation ofof receptorsreceptors resultingresulting inin convergenceconvergence

andand summationsummation ofof activityactivity..


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Noordenbos sensory interaction theoryNoordenbos sensory interaction theory

HeHe proposedproposed thatthat rapidlyrapidly conductingconducting largelargefiberfiber pathwaypathway inhibitinhibit oror suppressessuppresses activityactivity ininslowlyslowly conductingconducting smallsmall fiberfiber pathwaypathway thatthatconveysconveys noxiousnoxious informationinformation..

AA decreasedecrease inin thethe ratioratio ofof largelarge toto smallsmall fiberfiber

activityactivity resultsresults inin centralcentral summationsummation andand ananincreaseincrease inin painpain andand visevise versaversa..

ItIt explainsexplains differentdifferent pathologicpathologic painpain statusstatus.. HyperalgesiaHyperalgesia followingfollowing peripheralperipheral nervenerve injuryinjury..


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Gate Control theoryGate Control theory MelzackMelzackand Wall (1965)and Wall (1965)

TheThe termterm gategate refersrefers toto relativerelativeamountamount ofof inhibitioninhibition oror facilitationfacilitation..

TheThe gatinggating mechanismmechanism isis modulatedmodulatedpresumablypresumably SS..GG.. layer layer of of spinalspinalcordcord..

TheThe gatinggating mechanismmechanism isis influencedinfluencedbyby thethe relativerelative activityactivity inin largelargediameterdiameter (A(AFF)fibers)fibers activatedactivated byby lowlowthresholdthreshold nonnon noxiousnoxious stimulistimuli..

SmallSmall diameterdiameter (A(A--deltadelta ++ C)C) fibersfibers

activatedactivated byby intenseintense noxiousnoxious stimulistimuli..


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ActivityActivity inin largelarge fibersfibers tendstends toto closeclose thethe gategate..

SmallSmall fiberfiber activityactivity tendstends toto facilitatefacilitate transmissiontransmission..


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LargeLarge fibersfibers inin particular,particular, areare postulatedpostulated toto activate,activate,

centralcentral controlcontrol mechanismmechanism relatedrelated toto cognitivecognitiveprocessing,processing, whichwhich internintern modulatemodulate gatinggating mechanismmechanism..

WhenWhen thethe outputoutput ofof thethe transmissiontransmission cellcell exceedsexceeds aa

criticalcritical layerlayer activatesactivates thethe twotwo majormajor systemssystems..

SensorySensory discriminativediscriminative system,system, involvinginvolving neospinothalamicneospinothalamic fibersfibers

projectingprojecting intointo thethe ventroposteriorventroposterior thalamusthalamus andand thethe

somatosensorysomatosensory cortexcortex..

TheThe descendingdescending controlcontrol exertedexerted byby neocorticalneocortical activityactivity isis thoughtthought

toto modulatemodulate activityactivity isis sensorysensory discriminativediscriminative andand motivationalmotivational

affectiveaffective systemssystems..

AllAll thisthis systemssystems ultimatelyultimately influenceinfluence thethe motor motor

mechanismsmechanisms responsibleresponsible forfor behaviourbehaviour elicitedelicited byby

noxiousnoxious stimulistimuli..


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MODULATIONMODULATIONThe concept of modulation is extremelyThe concept of modulation is extremely

important in understating the patientsimportant in understating the patients

experience of pain .It is based on the principleexperience of pain .It is based on the principlethat neural impulses ,rising to the higherthat neural impulses ,rising to the higher

centers that are termed painful can be alteredcenters that are termed painful can be altered

by a process called as inhibitionby a process called as inhibition


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The following areas of orofacial painThe following areas of orofacial painmodulation are as follows :modulation are as follows :1. Pain modulation in the trigeminal spinal tract1. Pain modulation in the trigeminal spinal tract

nucleusnucleus2. Transcutaneous electrical nerve stimulation2. Transcutaneous electrical nerve stimulation3. Pain modulation in reticular formation3. Pain modulation in reticular formation4. Pain modulation of the descending inhibitory4. Pain modulation of the descending inhibitory

systemsystem


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PAIN MODULATIONPAIN MODULATIONIN THETRIGEMINAL SPINAL TRACTIN THETRIGEMINAL SPINAL TRACT

NUCLEUSNUCLEUS

Tip of dorsal horn of the spinal cord is calledTip of dorsal horn of the spinal cord is called

as substantia gelatinosaas substantia gelatinosasubstantia gelatinosa neurons were proposedsubstantia gelatinosa neurons were proposed

to inhibit transmitter release from primaryto inhibit transmitter release from primary

afferent neurons, thus inhibiting the impulseafferent neurons, thus inhibiting the impulsecarried by the primary afferent neuron .carried by the primary afferent neuron .


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The myelinated afferents were proposed to excite theThe myelinated afferents were proposed to excite the

inhibitory interneuronsinhibitory interneuronsThis in turn reduce the activity of pain transmission neuronThis in turn reduce the activity of pain transmission neuron


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TRANSCUTANEOUS ELECTRICAL NERVETRANSCUTANEOUS ELECTRICAL NERVESTIMULATION [TENS]STIMULATION [TENS]

The chief product of the gate control theory wasThe chief product of the gate control theory was

the introduction of transcutaneous electricalthe introduction of transcutaneous electricalnerve stimulation as a therapeutic modalitynerve stimulation as a therapeutic modality

The rationale of TENS is based on theThe rationale of TENS is based on the

antinociceptive effect of stimulating cutaneousantinociceptive effect of stimulating cutaneoussensory nervessensory nerves


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An interrupted periodic current of very lowAn interrupted periodic current of very lowintensity at a frequency of 50 to 100Hz isintensity at a frequency of 50 to 100Hz is

usedused

The stimulation is usually below what isThe stimulation is usually below what isrequired to activate Arequired to activate A--delta and Cdelta and C

nociceptive fibersnociceptive fibers


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The effect is immediate and usually disappearsThe effect is immediate and usually disappears

rapidlyrapidly

Pain relief is localized to the segment stimulated,Pain relief is localized to the segment stimulated,

Serotonin and dynorphin are released whenSerotonin and dynorphin are released when

superficial cutaneous nerve are stimulatedsuperficial cutaneous nerve are stimulated

Instinctive act of grabing, holding ,pressing orInstinctive act of grabing, holding ,pressing orrubbing exemplifies this effectrubbing exemplifies this effect

Pain reducing remedies are of this categoryPain reducing remedies are of this category

e.g.: massage analgesic balms ,counter irritantse.g.: massage analgesic balms ,counter irritants

mustard plasters, hot and cold compresses,mustard plasters, hot and cold compresses,

vibration,hydrotherapy,and vapocoolant therapyvibration,hydrotherapy,and vapocoolant therapy


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PAIN MODULATION IN RETICULARPAIN MODULATION IN RETICULAR

FORMATIONFORMATION

Reticular formation is a portion of the brainReticular formation is a portion of the brain

stem that contains a number of nuclei that canstem that contains a number of nuclei that can

either excite or inhibit the incoming impulseseither excite or inhibit the incoming impulses

Reticular formation controls the overall activityReticular formation controls the overall activity

of the brainof the brain

Pain signal in particular , increase the activityPain signal in particular , increase the activityin this area and strongly excite the brain toin this area and strongly excite the brain to

attentionattention


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PAIN MODULATION OF THE DESCENDINGPAIN MODULATION OF THE DESCENDING

INHIBITORY SYSTEMINHIBITORY SYSTEM

The neuronal mechanism in

the brain stem that appears to

balance the continuous

barrage of sensory input is

called the descending

inhibitory system

Fibers descend from the brain

stem and terminate on thesubstantia gelatinosa rolandi

Stimulation of these fibers

leads to pain inhibition


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These fibers at their terminals , secreteThese fibers at their terminals , secrete

either serotonin or enkephalin aseither serotonin or enkephalin as

neurotransmitter and they are called asneurotransmitter and they are called asserotogenic or enkephalinergic neurons.serotogenic or enkephalinergic neurons.


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Serotogenic or enkephalinergic neuronsSerotogenic or enkephalinergic neurons

synapse with the A delta and C fibersynapse with the A delta and C fiber

terminals which bring pain from periphery interminals which bring pain from periphery inthe posterior horn of the spinal cordthe posterior horn of the spinal cord

Stimulation of these descending tractsStimulation of these descending tractscauses synaptic inhibition or block at thecauses synaptic inhibition or block at the

SGRSGR

Spinothalamic tract is no more stimulated inSpinothalamic tract is no more stimulated inspite of the presence of the stimulus for painspite of the presence of the stimulus for pain

in the peripheryin the periphery

Th l di t fib hi h t hTh l di t fib hi h t h


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The large diameter fibers, which carry touchThe large diameter fibers, which carry touch

sensation from the skin to the brain ,alsosensation from the skin to the brain ,also

play a strong role to inhibit the painplay a strong role to inhibit the painsensationsensation

When touch conveying fibers of the sameWhen touch conveying fibers of the samedermatome [from which the pain is arising ]dermatome [from which the pain is arising ]

are stimulated, the intensity of the pain isare stimulated, the intensity of the pain is

reducedreduced

(A phenomenon called as Gate Control)(A phenomenon called as Gate Control)

MODULATING EFFECT OF ENDORPHINS ANDMODULATING EFFECT OF ENDORPHINS AND


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MODULATING EFFECTOFENDORPHINS ANDMODULATING EFFECTOFENDORPHINS AND

ENCEPHALINSENCEPHALINS

Endorphins revealed the inherent presence of anEndorphins revealed the inherent presence of anendogenous antinociceptive system that normallyendogenous antinociceptive system that normally

modulates painmodulates pain

Endorphins play a part in emotional states, such asEndorphins play a part in emotional states, such aschild birth ,schizophrenia is matters of addictionchild birth ,schizophrenia is matters of addiction

and in physiological activitiesand in physiological activities

Endorphins and encephalins are the two substanceEndorphins and encephalins are the two substancewhich are produced within the human body and actwhich are produced within the human body and act

like opium alkaloidslike opium alkaloids


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Two types of encephalins:Two types of encephalins:

METHIONINE ENCEPHALINSMETHIONINE ENCEPHALINS

LEUCINE ENCEPHALINSLEUCINE ENCEPHALINS

E d i id tid bi ithE d i id tid bi ith


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Endogeneous opioid peptide combine withEndogeneous opioid peptide combine with

their receptorstheir receptors

There are three receptors, mu, kappa, deltaThere are three receptors, mu, kappa, delta

Mu receptors are present most abuntantly inMu receptors are present most abuntantly in

the PAG and other brain areasthe PAG and other brain areas

Kappa are present particularly in theKappa are present particularly in the

substantia gelatinosa rolandi [SGR]substantia gelatinosa rolandi [SGR]

Combination of enkephalin or endorphin withCombination of enkephalin or endorphin withmu and kappa leads to inhibition of painmu and kappa leads to inhibition of pain

perceptionperception

Di iDi i


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DiagnosisDiagnosis

TheThe mostmost importantimportant aidaid toto thethe diagnosisdiagnosis ofofpainpain isis thethe

1)1) History,History, followedfollowed byby clinicalclinical examinationexamination &&appropriateappropriate

2)2) InvestigationInvestigation whichwhich includesincludes radiographs,radiographs,aa computerizedcomputerized oror magneticmagnetic resonanceresonancescanscan..

TheThe historyhistory shouldshould includeinclude


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TheThe historyhistory shouldshould includeinclude

1)1) ItsIts character,character, egeg.. Sharp,Sharp, dull,dull, thrombing,thrombing, burningburning ororstabbingstabbing..

2)2) TheThe sitesite oror sitessites fromfrom whichwhich itit arises,arises, andand toto whichwhichitit travelstravels..

3)3) ItsIts timing,timing, whenwhen diddid thethe firstfirst attackattack occuroccur itsitsfrequencyfrequency && durationduration..

4)4) TheThe provokingprovoking factorsfactors..5)5) TheThe relievingrelieving factorsfactors..

6)6) AssociatedAssociated phenomenaphenomena egeg..,, swelling,swelling, discharge,discharge,bruxism,bruxism, trismustrismus..

7)7) DoesDoes thethe patientpatient suffer suffer fromfrom anxietyanxiety or ordepression?depression?

8)8) TheThe currentcurrent andand previousprevious generalgeneral medicalmedical historyhistoryandand drugdrug therapytherapy..


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CLASSIFICATION OFOROFACIAL PAINCLASSIFICATION OFOROFACIAL PAIN

M th d f P i C t lM th d f P i C t l


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Methods of Pain ControlMethods of Pain Control


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Following are methods of pain controlFollowing are methods of pain control1)1) Removing the causeRemoving the cause

2)2) Blocking the causeBlocking the cause

3)3) Raising the pain thresholdRaising the pain threshold

4)4) Preventing pain reaction by corticalPreventing pain reaction by corticaldepression.depression.

5)5) Using a psychosomatic methods.Using a psychosomatic methods.

1 and 2 affect pain perception.1 and 2 affect pain perception.

4 and 5 affect pain reaction.4 and 5 affect pain reaction.

3 affect pain perception and pain reaction.3 affect pain perception and pain reaction.

Bl ki thBl ki th


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Blocking the causeBlocking the cause NerveNerve blockblock:: DepositingDepositing aa suitablesuitable locallocal

anestheticanesthetic solutionsolution withinwithin aa closeclose proximityproximity totoaa mainmain nervenerve trunktrunk..

FieldField blockblock:: DepositionDeposition aa solutionsolution inin proximityproximitytoto thethe largelarge terminalterminal nervenerve branchesbranches soso thatthat

areaarea toto bebe anesthetizedanesthetized.. LocalLocal infiltrationinfiltration:: DepositionDeposition aa solutionsolution inin

proximityproximity toto thethe smallsmall terminalterminal nervenervebranchesbranches soso thatthat areaarea toto bebe anesthetizedanesthetized..

IntraIntra ligamentaryligamentary techniquetechnique:: For For singlesingle toothtoothanesthesiaanesthesia..

TopicalTopical analgesiaanalgesia rendersrenders thethe freefree nervenerveendingsendings inin accessibleaccessible structurestructure inin capablecapable ofof

stimulationstimulation..


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Action of antiAction of anti--inflammatory analgesicsinflammatory analgesics


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HOWTO MEASURE PAINHOWTO MEASURE PAIN

Pain measurement is aPain measurement is a complex and controversialcomplex and controversial psychopsycho

physiologic subjectphysiologic subject

There isThere is no simpleno simple method of measuring pain. Pain intensitymethod of measuring pain. Pain intensity

can be measured by using ratings such ascan be measured by using ratings such as

VISUAL ANALOG SCALE (VAS).VISUAL ANALOG SCALE (VAS).

A VAS consists of a 10cm line on whichA VAS consists of a 10cm line on which

00 no pain 10no pain 10 pain as bad as it can getpain as bad as it can get

The VAS are sensitive toThe VAS are sensitive to treatment effectstreatment effects, can be, can be incorporatedincorporated

into pain diariesinto pain diaries and can be used withand can be used with children.children.

Disadvantage: the multidimensional aspects of pain are not wellDisadvantage: the multidimensional aspects of pain are not well

measuredmeasured


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2)2) SomatopsychicSomatopsychic problemsproblems


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2)2) SomatopsychicSomatopsychic problemsproblems

ItsIts overover reactionreaction ofof dentaldental procedureprocedure toto moremoreaggressiveaggressive conditionsconditions.. Anxious,Anxious, depresseddepressed statestate of of

mindmind willwill amplifyamplify thethe painpain andand createcreate agitationagitation afterafterwhatwhat appearsappears toto bebe aa normalnormal dentaldental proceduresprocedures..

TheThe procedureprocedure maymay bebe fittingfitting ofof newnew denturedenture..

TreatmentTreatment

NewNew denturesdentures mustmust bebe carefullycarefully adjustedadjusted replicasreplicas ofofthethe previousprevious setset oror if if possiblepossible ofof thethe naturalnatural teethteeth..

CostensCostens syndromesyndrome

ClinicalClinical featurefeature

-- PainPain usuallyusually unilateralunilateral andand isis describeddescribed asas aa dulldull acheacheinin earear oror preauricularpreauricular areaarea whichwhich maymay radiateradiate toto angleangleofof mandiblemandible

-- MuscularMuscular tendernestendernes

--

ClickingClicking ofof TMJTMJ

EtiologyEtiology


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MasticatoryMasticatory muscle spasm:muscle spasm:

a)a) Muscular over extensionMuscular over extension

b)b) Muscular over contractionMuscular over contractionTreatmentTreatment

1)1) Anti inflammatory drugsAnti inflammatory drugs

2)2) Correction of occlusion and replacement of old dentureCorrection of occlusion and replacement of old denture

with new one.with new one.AtypicalAtypical OdontalgiaOdontalgia

Patient may present with pain without any obviousPatient may present with pain without any obviouscause.cause.

The pain is severe and throbbing in character and theThe pain is severe and throbbing in character and theteeth are hypersensitive to any stimulus.teeth are hypersensitive to any stimulus.

Some time appears to have been precipitated by aSome time appears to have been precipitated by adental procedure. Such as fitting of a bridge or andental procedure. Such as fitting of a bridge or anextraction but they are made worse by any furtherextraction but they are made worse by any further

active treatment.active treatment.


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TreatmentTreatmenta)a) PulpalPulpal and periodontal inflammationand periodontal inflammation

must be excludedmust be excluded

b)b) Reassurance is importantReassurance is important

it responseit responsewell to the explanation.well to the explanation.

c)c) MedicationMedication mustmust bebe combinedcombined withwith

regularregular reviewsreviews toto provideprovide reassurancereassurance

andand toto activeactive drugdrug compliancecompliance..


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Burning mouth syndromeBurning mouth syndrome

AnAn intraoralintraoral painpain disorderdisorder unaccompaniedunaccompanied byby

clinicalclinical sciencescience oror idiopathicidiopathic causescauses inin whichwhichthethe mainmain symptoms,symptoms, beingbeing describeddescribed asas aaburning,burning, painfulpainful oror etchingetching sensationsensation..

ThereThere isis aa decreaseddecreased painpain tolerancetolerance ofof oraloral

mucosa,mucosa, tonguetongue..TreatmentTreatment

1)1) CorrectionCorrection ofof malocclusionmalocclusion

2)2) MuscleMuscle relaxantsrelaxants suchsuch asas diazepamdiazepam

3)3) TreatmentTreatment ofof systemicsystemic diseasedisease suchsuch diabetesdiabetesmellitusmellitus..

4)4) TopicalTopical analgesicsanalgesics


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ConclusionConclusion

NotNot onlyonly isis understandingunderstanding thethe neurologicalneurological

mechanismmechanism ofof orofacialorofacial painpain isis vitalvital butbut alsoalso

itit equallyequally importantimportant toto consider consider thethe

psychosocialpsychosocial && psychophysiosocialpsychophysiosocial

dimensiondimension ofof painpain && THENTHEN proceedproceed toto

managemanage andand or or controlcontrol thethe diversediverse

manifestationmanifestation ofof thethe painpain ACCORDINGLYACCORDINGLY..


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ReferencesReferences

GuytonGuyton Textbook of Medical Physiology.Textbook of Medical Physiology.

MonheimMonheim Local anesthetic and painLocal anesthetic and paincontrol.control.

DCNADCNA

Timothys MilesTimothys Miles Clinical Oral PhysiologyClinical Oral Physiology

Malcolm HarrisMalcolm Harris Clinical Oral ScienceClinical Oral Science

Bells Oro facial pain.Bells Oro facial pain. ChaudhariChaudhari Concise Medical Physiology.Concise Medical Physiology.


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Thank youThank you

PAIN & PAIN

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