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Orofacial Neuropathy: Diagnosis and Treatment

AIPM:Oct19,2017JosephMa9hews,DDS,MSc

Disclosure

• Nothingtodisclose.

More than 1 in 6 adults experienced orofacial pain in the past year

JADA2015146;721

OrofacialPainPainwhichisfeltinthemouth,jawsandtheface.

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Diagnos>c Categories

• Intraoral• Muscular• Temporomandibularjointdisorders• Headachedisorders• Extracranial• Intracranial• Thoracic• Neuropathic

IntraoralpainEst.95%oforofacialpainisofdentalorigin

• Dentalcaries• PulpiRs,pulpalnecrosis,andperiapicalinfecRon• Periodontaldisease• PeriodonRum• Mucogingival• PericoroniRsassociatedwitherupRngteeth

• Mucosal• MucosiRs

CrackedtoothsyndromeMimicsneuropathicpain

Cracked tooth symptoms

• Generalized facial pain or discomfort • Severe stabbing lancina>ng pain when bi>ng • Paroxysmal pain • Sensi>vity to hot and/or cold • Sensi>vity to chemical changes (sweet or acidic) • Pain may be worse immediately aKer release of bi>ng

pressure on tooth

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Cracked tooth Imaging

• DentalX-ray• HospitalCT• HighresoluRonconebeamCTwithcustomsecRons

Cracked tooth examina>on

• Clinicalevalua3on• Visualexam• Percussion•  Sharppointexplora3on•  Thermaltes3ng• Dye• Pulptes3ng•  Transillumina3on• Chewing/bi3ngtests•  Toothsleuth

•  PalpaRonpainincharacterisRclocaRons:•  Masseter,SCM,spleniuscapitus,uppertraps,anteriortemporalis•  NegaRvelaboratoryandradiographicfindings• ClinicalpresentaRonmayresembleneuropathicpain

MusclePain

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Diagnos>c tests

• Sprayandstretchreducespain• TriggerpointinjecRons

48 year old femalewith leK side Facial Pain

Imaging•  CBCT•  Remodelingandlossof

corRcalbone•  Subchondralcysts•  OsteophyRcacRvity•  Consistentwith

osteoarthriRs

RightTMjointLe^TMjoint

TMJointdisorders• ArthriditesinTMD• OsteoarthriRs• RheumatoidarthriRs• PsoriaRcarthriRs

•  Internalderangements • DiscdisplacementwithorwithoutreducRon

Treatmentshouldbespecifictothedisorder

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AZTMJ

Intracranial•  Vascular•  Aneurism•  Hemorrhage•  Hematoma•  Edema

•  Nonvascular•  Neoplasms•  Edema

•  Other•  MSplaque•  Pos9raumaRcchanges

•  Meningioma

Intracranial facial pain disorders

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Extracranial Causes of Orofacial Pain and Headaches

• OsteomyeliRs• MulRplemyeloma•  Sicklecelldisease,• Paget’sdisease• Osteopetrosis•  Eosinophilicgranuloma• HisRocytosis• Osteoblastoma• MetastaRctumors

• CaroRdarterydissecRon• Myofascialpain• ORRs•  Salivaryglanddiseases• Nasal/paranasalsinuscomplex• GiantcellarteriRs•  ThyroidiRs• Autoimmunedisease:Lupus/MS• Viral/bacterialinfecRons

Other sources of facial pain

• Orofacialpainpresentin>25%ofpaRentswithinfarctorarterydissecRonMedPregl.2011;64:575

•  Jawpainin27%ofwomenand18%ofmenwithmyocardialinfarcRon.AmJCritCare.2008;17:14-24

Thoracic

• OrofacialpainistheONLYpresenRngsymptomin6%ofpaRentswithcardiacischemia.JAmDentAssoc.2007;138:74

Image:Voohoo.net

OrofacialNeuropathy

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Categorizing Neuropathies

• Dysesthesia,anesthesia,hyperalgesia,allodynia• Movementdisorders• Peripheralneuropathies(outsideofCNS)• Centralneuropathies(withintheCNS)• Painful/non-painful•  Episodic• ConRnuous

Orofacial Neuropathic Pain

Episodic• TrigeminalNeuralgia• GlossopharyngealNeuralgia• Ophthalmoplegia• NervusIntermediusNeuralgia• SuperiorLaryngealNeuralgia

Con3nuous• PeripheralPainfulTraumaRcTrigeminalNeuropathy• PersistentIdiopathicFacialPain• PeripheralNeuriRs• PostherpeRcNeuralgia• Burningmouthsyndrome

Diagnosis

• NeurologicaltesRng•  TopicalanestheRctesRng(20%benzocaine)• AnestheRcblocks(1%lidocainewithoutvasoconstrictor)•  starRngperipherallymovingcentrally

• BrainMRI• WithandwithoutcontrastwithaddiRonalsecRonsthroughtheposteriorcranialfossaespeciallythecerebelloponRneangle.

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Trigeminal neuralgia management

• Surgical• OralmedicaRon• TopicalmedicaRons• Botox

Surgical interven>ons

• Microvasculardecompression•  WorldNeurosurg.2017;103:757•  PercutaneousballooncompressionNeurosurgClinNAm.2017;28:429

• AblaRveprocedures• RadiofrequencyablaRon• GlycerolinjecRons• Cryotherapy

•  StereotacRc•  Gammaknife(Neurosurgery.2005;56:1295)•  Linearaccelerator(Neurosurgery.2005;57:1193)

GavinDavis-Surgeon

Medica>on Management of neuralgias and painful neuropathies • BaselinebloodtesRng•  CBC•  Electrolytes•  MetabolicPanel•  RenalfuncRon•  HepaRcfuncRon

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Medica3ons Dosage SideEffects(par3allist) Notes

Carbamazepine(Tegretol)

200-800mgbid

Stevens-JohnsonSyndromeErythemamulRformeHepatotoxicityWDseizuresifabrupt

LFtesRngHLAB1502screenBehaviorchanges

Oxcarbazepine(Trileptal)

150-1200mgRd

HyponatremiaS-JSyndromeWDseizuresifabrupt

ElectrolytetesRngHLAB1502screenBehaviorchanges

GabapenRn(NeuronRn)

300-1200mgRd

FaRgue,S-JSyndromeWeightgainWDseizuresifabrupt

CratbaselineBehaviorchanges

Pregabalin(Lyrica)

150-300mgbid

Dizziness,weightgain,WDseizuresifabrupt

CratbaselineBehaviorchanges

Other oral meds for orofacial neuropathy

•  TricyclicanRdepressants•  amitriptylineornortriptyline

• Phenytoin•  Topiramate• MemanRne• Phentolamine• Clonazepam

78 year old female

• RouRnedentalexam18mos.ago•  Tooth#30waspainlessbutdx:crackedtooth• Crown#30• ConRnuousachingpainfourmonths.normalxray•  EndodonRcprocedurecompleted•  Severeburningcon3nuouspain• Wants#30extracted➛OSurg:referredtoOFP

IASP:PTTNPainfulTraumaRcTrigeminalNeuropathy

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Painful post-trauma>c trigeminal neuropathy

• Phantomtoothpain• Atypicalodontalgia• Atypicalfacialpain• Persistentdentoalveolarpain• PeripheralpainfultraumaRctrigeminalneuropathy• Persistentidiopathicorofacialpain

MoreauN,etalJournaloforofacialpainandheadache2017;31:7.

Persistent severe pain aKer root canal injury from sodium hypochlorite irriga>on

•  Startedduringrootcanaltherapy• WhileirrigaRngwithNaOClpaRentexperiencedsuddensharpburningpain• RapidfacialswellingandprofusebleedingfromendodonRcaccess•  ForoveraweekpainconRnuedunchanged

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Six months later • Painvariesinintensity5-9/10• Morepainfula^erexposuretocold

Examina>on

Rednessofle^cheekandle^earLe^eyeisasomewhatredandeffusive80%decreaseinsensaRonofle^sideCNV1andCNV2comparedtorightside20%decreaseinsensaRonofle^sideCNV3comparedtorightside

SYNAPSE!

SilbersteinSD,etal.HeadacheinClinicalPracRce.Oxford,UK

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Addi>onal Tes>ng

•  Co9onRppedapplicator•  LightlytouchgingivainlabialvesRbule•  LightlystokegingivainlabialvesRbule

•  20%topicalbenzocaine•  ShallowinfiltraRonwith9mglidocaine2%withoutepinephrine

StaRcmechanicalallodynia

PeripheralsensiRzaRon

Dynamicmechanicalallodynia

CentralsensiRzaRon

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Anesthe>c Tes>ng

Topicalbenzocainedecreasedpainfrom8to6/10LidocaineinjecRondecreasedpainfrom6to3/10

Diagnoses • PeripheralsensiRzaRon•  StaRcmechanicalallodynia• PainreducRona^eranestheRcDxtesRng

• CentralsensiRzaRon• Dynamicmechanicalallodynia• Residualpaina^eranestheRcDxtesRng

•  SympatheRcallymediatedpain• Autonomicfeatures• Morepaina^erexposuretocold• Residualpaina^erlidocaineinjecRon

• Post-Trauma3cTrigeminalNeuropathy

Ma9hewsJ,MerrillR.JAmDentAssoc;145:914RentonT,YilmanZ.JOrofacPain2011;25:333-344

Plan

• Neurosensorystent• Capsaicin0.025%• Orabase(Benzocaine20%)

LewisM,Shankar,etal.OralSurgOalMedOralPatholOralRaiolEndod.2007;103(supplS32):e1-e24

PadillaM,ClarkGT,MerrillRL.JAmDentAssoc.2000Feb;131(2):184-95.

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Stent fabrica>on

Fabricated stent

Stent delivery

Ptwasinstructedtowearthestent

FullRmeandre-applymedicaRonEvery3hours

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Stent delivery

Capsaicin

h9ps://www.researchgate.net/publicaRon/51581406_Topical_capsaicin_for_pain_management_TherapeuRc_potenRal_and_mechanisms_of_acRon_of_the_new_high-concentraRon_capsaicin_8_patch[accessedJun12,2017]

•  RepeatedapplicaRonofcapsaicincanproduceapersistentlocaleffectonnociceptors

•  SubstancePdepleRonordefuncRonalizaRon.

•  ReducesspontaneousneuronalacRvity

•  LossofresponsivenesstoawiderangeofsensorysRmuli.

54 year old female with persistent gingival pain 11 months aKer implants placed

• Twoimplants-mandibularle^• ConRnuous“Burning”gingivalpain• SensiRvetotouchbetween#19implantandtooth#20(StaRcmechanicalallodynia)• DxTest:90%decreaseinpainwithtopical20%benzocaine.

Painwaseliminateda^er8weekswearingneurosensorystentandtopicalmedicaRon.

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Treatment and prognosis

• UptoonethirdofnerveinjuriesresulRngfromimplantplacementneverrecoverfully.

AgbajeJO,etal.JMaxillofacOralSurg.2016;15:321

• TopicalmedicaRons• Microsurgicalrepair• Implantremoval(whenappropriate)• OralmedicaRonmanagement

IMPLANT NEUROPATHY

Various Mechanisms and symptoms

• Anesthesia• Paresthesia• Dysesthesia• Allodynia• Hyper-orHypoalgesia

•  Secondarytoneuronalinjury• MagnitudeandduraRonoftheinjury• MechanicaldeformaRon•  TransecRon• ParRal• Complete

•  TraumaRcNeuromaformaRon•  Ischemia• Vascularcompression• Compartmentsyndrome

Neuroanatomy and gene expression

• AmandibularcanalintheinferioraspectofthemandiblemaybemorelikelytohaveextensivearborizaRonoutsidetheinferioralveolarcanal• GeneRcdimorphismincludingepigeneRcphenomena

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Other medica>ons for the NS stent

Lidocainesodiumchannelblocker

Imagecredit:CorryResearchGroup

Imagecredit:WikipediaCommons

CarbamazepineSodiumchannelBlocker• Membranestabilizer•  renderstheNa+channelmoresuscepRbletoblockade

RizzoM.JNeuroSci1997:152;103

• ReducesNMDAsignaling• GABAreceptoragonistbyinhibiRonofGABA-AandGABA-Breceptors.MagnaghiV.J.Mol.Neurosci2006;28:89

GABA

Glutamate

Other medica>ons for the NS stent Chasing neuro receptors

• Gabapen3n–•  IncreasesnoradrenergicdescendinginhibiRon•  HirokiT.AnesthAnalg2017

• Ca++Channelblocker,α2-δsubunit•  DhandA.Brain2014;137:313

• Protectsinterneurons•  PengB.NeurosciLe92011;494:19

• Reducesallodyniaandhyperalgesia•  Go9rupH.etal.Anesthesiology2004;101:1400.

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Other medica>ons for the NS stent Chasing receptors

• Clonidine0.01-0.02%• Alpha2receptoragonist•  ImportantwherethereisevidenceofsympatheRcallymediatedpainandAlpha-2Csubtypeexpressedonc-fibers.MalmbergAB,etalBritJPharm2001;132:1827.

Other medica>ons for the NS stent Chasing receptors

• Ketamine(1-2%)•  NMDAreceptorantagonist•  DecreasescentralsensiRzaRonbyinhibiRngcentraltemporalsummaRon(Arendt-NielsenLetalAnesthAnalg1995;81:63)

•  Decreasessecondarymechanicalhyperalgesia(KoppertW.etal.Anesthesiology2001;95:395.

•  Reduceseffectsofsubstance-P(TamE.OpenNeurolJ2012;6:58)

Advantages of topicals

•  Evadefirst-passmetabolism•  TargeteddistribuRon•  NoRtraRon,minimalsystemicdruglevels,li9leabusepotenRal

• MedicallycompromisedpaRents

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Pilot study of oral topical in neurosensory stent

•  39paRents•  DeafferentaRonpain(PTTN)•  TraumaRcneuroma•  Trigeminalneuralgia

• Assignedintothreegroups•  Topicaltreatmentonly(12)•  Systemictreatmentonly(10)•  Combinedtopical+systemic(17)

HeirG,etal.OralSurgOralMedOralPatholOralRadiolEndod2008;105:466

Results

Star3ngVAS ANerTreatmentVAS

WeekstoMaxbenefit

CombinedTopicalandSystemic

7.5+0.403 3.6 5.5

SystemicOnly

8.6+0.611 5.1 4

TopicalOnly

6.1+0.716 3.6 3

HeirG,etal.OralSurgOralMedOralPatholOralRadiolEndod2008;105:466

Conclusions

•  TopicalmedicaRons•  UsedaloneorincombinaRonwithsystemicmedicaRons•  HighlyeffecRveinprovidingrapidreliefwhencomparedtosystemicmedicaRonsalone

HeirG,etal.OralSurgOralMedOralPatholOralRadiolEndod2008;105:466

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Other medica>ons for Neuro-sensory stents

5%Ketoprofen5%GabapenRn2%Carbamazepine1%Lidocaine1%Ketamine0.01%Clonidine

Thecarrieriscrucial,workwithyourcompoundingpharmacisttoachieveopRmalabsorpRonrate

BOTOX for trigeminal neuralgia

•  InjecRonofbotulinumtoxintypeAintotriggerzoneoftrigeminalneuralgiaasameanstocontrolpain.NgeowWC.OralSurgOralMedOralPatholOralRadiolEndod2010;109:47.•  BeneficialeffectsofbotulinumtoxintypeAintrigeminalneuralgia.ZuñigaC,etalArqNeuropsiquiatr2008;66:500.

Orofacial Pain

Thefirststeptowardsuccessfultreatmentisaccuratediagnosis