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Oromandibular dystonia after dental treatments: a report of two cases

Soo-Mi Jang1, Yeong-Cheol Cho1, Iel-Yong Sung1, Sun-Young Kim2, Jang-Ho Son1

Departments of 1Oral and Maxillofacial Surgery, 2Neurology, Ulsan University Hospital, College of Medicine, Ulsan University, Ulsan, Korea

Abstract (J Korean Assoc Oral Maxillofac Surg 2012;38:379-83)

Oromandibular dystonia (OMD) is a rare focal form of dystonia caused by prolonged muscles spasms in the mouth, face, and jaw. OMD can develop after dental treatment, as poorly aligned dentures or multiple tooth extraction may cause an impairment of proprioception in the oral cavity, leading to the subsequent development of dystonia. These repetitive involuntary jaw movements may interfere with chewing, swallowing, and speaking. We report here two cases of OMD after dental procedures.

Key words: Tooth extraction, Dystonic disorders, Jaw, Tongue, Focal[paper submitted 2012. 10. 31 / revised 2012. 11. 27 / accepted 2012. 11. 27]

symptomsofthedisorder1,2.ThemechanismofOMDisnot

well-understood.SomecasesofOMDafterdentaltreatment

havebeenreported,althoughthecausalrelationshipbetween

theseproceduresanddystoniaisstillunclear4,5.

Thispaperdescribes2casesofperipherallyinducedOMD.

Sincetheonsetofdystoniaoccurredafteradentalprocedure,

wesoughttodiscusssomeaspectsofclinicalmanifestations,

diagnosticcriteria,mechanisms,andtreatmentoptionsfor

OMD.

II. Cases Report

1. Case 1

A59-year-oldfemalewitha12-monthhistoryofabnormal

jawprotrusivemovementandopeningwasreferredbya

localpractitioner.According toher,herproblemstarted

duringthedentalextractionofherlowerrightmolarteeth

and immediate implantation (Fig.1),and thesymptoms

worsenedovertime.Althoughthelocalpractitionertriedto

adjusttheocclusion,thesymptomwasnotrelieved.Shewas

healthy,withnosignificantmedicalhistoryorfamilyhistory

ofneurologicaldisorder.

Theintra-oralexaminationrevealedseveredentalattrition

ofher residual teethandunstableocclusion.(Fig.2)The

extraoralexaminationconfirmedtheinvoluntaryprotrusive

I. Introduction

Dystonia isaneurologicalmovementdisorderwherein

sustainedmusclecontractionscausetwistingandrepetitive

movementsorabnormalpostures.Thedisordermaybe

hereditaryormaybecausedbyotherfactorssuchasbirth-

relatedorotherphysicaltrauma,infection,poisoning(e.g.,

leadpoisoning),orreactiontopharmaceuticaldrugsparti-

cularlyneuroleptics1.

Oromandibulardystonia(OMD)isfocaldystoniainvolving

themasticatorymuscles,musclesoffacialexpression,and

thoseofthetongueandpharynx.Involuntary,inappropriate,

repetitive,orsustainedmusclecontractionscausevarying

degreesof jawopening,closing,deviation,protrusion,or

retrusionaswellasfacialgrimacing,abnormal tongueor

pharyngealmovement,oranycombinationofthese2,3.

OMDisarare,oftenmisdiagnoseddiseasethatisdifficult

tomanage.Itstreatmenthasbeenlimitedtominimizingthe

Jang-Ho SonDepartment of Oral and Maxillofacial Surgery, Ulsan University Hospital, College of Medicine, Ulsan University, 877, Bangeojinsunhwan-doro, Dong-gu, Ulsan 682-714, KoreaTEL: +82-52-250-8823 FAX: +82-52-250-7236E-mail: glycerol@naver.com

This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/), which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

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CASE REPORThttp://dx.doi.org/10.5125/jkaoms.2012.38.6.379

pISSN 2234-7550·eISSN 2234-5930

J Korean Assoc Oral Maxillofac Surg 2012;38:379-83

380

Fig. 1. Radiological examination at the initial visit.Soo-Mi Jang et al: Oromandibular dystonia after dental treatments: a report of two cases. J Korean Assoc Oral Maxillofac Surg 2012

Fig. 2. Clinical photo revealing unstable occlusion.Soo-Mi Jang et al: Oromandibular dystonia after dental treatments: a report of two cases. J Korean Assoc Oral Maxillofac Surg 2012

Fig. 3. Electromyography activity was typically reflected as significant high-frequency and high-voltage activity of motor unit potentials with either sus-tained or short-duration bursts of dis-charge patterns at rest when nor mally electrically inactive.Soo-Mi Jang et al: Oromandibular dystonia after dental treatments: a report of two cases. J Korean Assoc Oral Maxillofac Surg 2012

Oromandibular dystonia after dental treatments: a report of two cases

381

OMDwasmade.

2. Case 2

A57-year-oldfemalewithnoprevioushistoryofmove-

mentdisordersandwhowastakingnorelevantmedication

experiencedsuddenonsetofinvoluntaryjawtremor, limi-

tationofmouthopening,andprotrusivetonguemovements

following theextractionofboth lowermolar teethand

immediatepartialdenture6monthsago.(Fig.5)Thesym-

ptomsworsenedovertimeandinterferedwithherspeaking

andeating.

The clinical examination revealed thedenture to be

generallyunstable.Shehadspontaneoustonguemovements

evenwhenshewasnotspeaking.Themovementsworsened

whenherdentureswereremoved.

Shehadnoother relevantmedicaland familyhistory.

Shewas referred to theneurologist for aneurological

exam.Thecranialmagneticresonanceimagingrevealedno

abnormalities,andtheresultoftheneurologicalexamination

wasnormalsaveforthepresenceofabnormalmovement.A

diagnosisoflingualprotrusiveOMDwasmade.

Shewasprescribedbaclofen,analgesics,andocclusal

stabilization appliance.Afteroralmedication andoral

appliancetherapyfor1month,thesymptomimproved,and

shewasreferredtoaprosthodontistfortherepairofherold,

ill-fittingdenture.

Atthefollow-up1monthlater,mildtonguetremorwith

protrusionandjawtremorwereobserved.BTXinjectioninto

thegenioglossusmusclewasrecommended,butthepatient

refusedbecauseoffinancialproblemsandthesymptomsdid

notcauseanydisability.Onlytheoralmedicationofbaclofen

wascontinued.

andopeningmovementwithslightdeviationtowardtheright

side.

Shewasprescribedbaclofen(Baclan;YooyoungPharma-

ceuticalCo.,Ltd.,Seoul,Korea)10mgthreetimesadayand

analgesicsfor thereliefofchronicmusclespasm.Despite

the treatmentwithamusclerelaxantfor threeweeks, the

symptomspersisted.

Shewasreferredtoaneurologistforelectromyography

(EMG).(Fig.3)TheEMGrecordingsrevealedthatherproblem

wasduetoaspasmofthelateralpterygoidmuscle.Botulinum

toxin(BTX)A(Meditoxin;PacificPharma,Seoul,Korea)

wasinjectedatadoseof30unitspermuscleviaanextraoral

approach.(Fig. 4)Aweek later, she showedadefinite

reductionof thedystonicmovement,becomingsymptom-

free.Nosideeffectwasobservedsavefor26mmofactive

rangeofmotion.Adiagnosisofjawopeningandprotrusive

Fig. 5. Radiological examination at the initial visit.Soo-Mi Jang et al: Oromandibular dystonia after dental treatments: a report of two cases. J Korean Assoc Oral Maxillofac Surg 2012

Fig. 4. Botulinum toxin injection was done via the extraoral approach.Soo-Mi Jang et al: Oromandibular dystonia after dental treatments: a report of two cases. J Korean Assoc Oral Maxillofac Surg 2012

J Korean Assoc Oral Maxillofac Surg 2012;38:379-83

382

Thepathophysiologyofdystoniaisunclearbutisthought

tooriginate in the centrallymediateddysregulationof

movementduetodefectinthebasalgangliaparticularlyin

thesensorymotorregionsoftheputamen.Themechanism

ofperipherallyinduceddystonia-asillustratedbyOMD-is

alsobasedonthetheoryofsensorypathwaydisruptionatthe

levelofthebasalganglia15-17.

Dentalinterventioncanberegardedasperipheraliatrogenic

injury.TherehavebeenseveralreportsofOMDfollowing

dentalprocedures3,7,18.Thompsonetal.reportedonewoman

whodevelopedOMDfollowingdentalextraction8.Traumatic

situations in themouth-suchaspoorlyaligneddentures

ormultipleextractions-maycausean impairmentof the

proprioceptionoftheoralcavity,leadingtothesubsequent

developmentofdystonia8,19.Themuscleconditionworsened

over theyear.Note,however, that thecausalrelationship

betweentheseproceduresanddystoniaisstillunclear4.

OMDisdifficult tomanage,andits treatmenthasbeen

limitedtominimizingthesymptomsofthedisorder.Note,

however, that thereareseveral treatmentoptions thatcan

relievesomeof thesymptomsofdystonia,sophysicians

canselectatherapeuticapproachbasedoneachindividual’

s symptoms12,13.Treatment approachesused tomanage

OMDincludemedication,BTX, localanestheticblocks,

dentalappliances,behavioralmodificationandpsychological

support, andsurgicalprocedures12,13.Oralmedication is

theusualfirstlineoftreatment,butthereisnomedication

topreventdystoniaorslowitsprogression.Tetrabenazine,

clonazepam,orotheroraldrugshavebeenassessed in

a systematicway in large studies.The results of oral

medicationforOMDhavebeenlargelydisappointing.Some

authorsfindtheoralmedicationofbaclofentobeusefulfor

OMD10,13,18.

BTXinjectioninto theaffectedmusclewithorwithout

EMGguidanceisasecond-linetherapy7,13.Botoxhasbeen

proventobesuperior tomedical treatmentparticularly in

focaldystonias20.Injectionsofsmallamountsofthischemical

intotheaffectedmusclespreventmusclecontractions,and

they canprovide temporary improvement in abnormal

postures andmovements characterizingdystonia7.The

toxindecreasesmusclespasmsbyblockingthereleaseof

theneurotransmitteracetylcholine,whichnormallycauses

musclestocontract.Theeffectistypicallyseenafewdays

aftertheinjections,anditcanlastforseveralmonthsbefore

theinjectionsneedtoberepeated2,7.

Physical therapy,useofsplints,stressmanagement,and

biofeedbackmayalsohelpindividualswithcertainformsof

III. Discussion

Dystoniaisapersistentposturefromtheco-contraction

ofagonistsandantagonistsand isgenerallyconsidered

partofthespectrumofdyskinesia2,6.Dyskinesiaconsistsof

adverseeffectsincludingdiminishedvoluntarymovements

andpresenceof involuntarymovements,similar toticsor

chorea1.Dystoniaisaneurologicalmovementdisorderrarely

seenbyoralandmaxillofacialsurgeons7whereinsustained

musclecontractionscausetwisting,repetitivemovements,or

abnormalpostures1,2,5.Themovementsmaybepainful,and

someindividualswithdystoniamayhavetremororother

neurologicalfeatures.Severaldifferentformsofdystonia

mayaffectonlyonemuscle,groupsofmuscles,ormuscles

throughoutthebody1,8,9.Thecauseofmajorityofthecases

isnotknown.Hereditaryorother factors suchasbirth-

related,otherphysicaltrauma,infection,poisoning(e.g.,lead

poisoning),andreactiontopharmaceuticaldrugsparticularly

neurolepticsarepresumedtobethepossiblecauses8-10.

Therearedifferentwaysofdystoniaclassification-itcan

beclassifiedbyetiologyintoprimary(alsoreferredtoas

idiopathic,inherited,orfamilial)andsecondaryforms(also

referredtoasacquired).Primarydystoniareferstodystonia

thatdoesnothaveaclearcause.Manyinstancesofdystonia

are idiopathic.Thesecondaryformofdystoniadevelops

duetoenvironmentalfactors, long-termneurolepticdrugs

(tardivedystonia),neurologicaldisease,braininjury,Wilson’

sdisease,andperipheraltrauma.Themostcommonformis

tardivedystonia,whichdevelopsasasideeffectoflong-term

treatmentwithantipsychoticdrugs11.

Dystoniacanalsobeclassifiedbyageofonset,anatomically

byregionofdistributionsuchasfocal,segmental,multifocal,

andgeneralized,andfurtherintotheaffectedbodyparts2,12,13.

OMDisfocaldystoniainvolvingthemasticatorymuscles,

musclesoffacialexpression,andthoseof thetongueand

pharynx.Involuntary,inappropriate,repetitive,orsustained

musclecontractionscausevaryingdegreesofjawopening,

closing,deviation,protrusion,orretrusionaswellasfacial

grimacing,abnormaltongue,orpharyngealmovementorany

combinationofthese,withthemuscleconditionworsening

over theyear2,3.OMDisclassifiedas jawopening, jaw

closing,jawdeviating,lingualdystonia,orcombinationsof

these2,4,8.

FocalOMDisextremelyrare.TheprevalenceofOMD

varies,reportedlyashighas6.9casesper100,000.Women

seemtobeaffectedmorefrequentlythanmen,withtheonset

typicallybetweentheageof45and70years14.

Oromandibular dystonia after dental treatments: a report of two cases

383

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dystonia12,13.Surgicaltherapiesincludeperipheralandcentral

surgery.Peripheraldenervationormyectomy is seldom

neededsinceOMDusuallyrespondswelltoBTXandmust

bedelayedwhileothertreatmentoptionsareeffective12,13.

These2peripherallyinducedOMDcasesfolloweddental

procedure,withnofamilyhistoryofmovementdisorders,

organicbrainlesion,orexposuretoneurolepticdrugs.The

onlypredisposingfactorwastherecentdentalextractionand

prosthetic treatment.These2patientsexperiencedashort

latencyperiodbetweentheextractionandonsetofdystonia,

andthesymptomsworsenedovertime.Thecloseassociation

oftime,locationoftheprocedure,andonsetofsymptoms

suggeststhattheonsetofdystoniamayhavebeencausedby

thedentalintervention.

Becauseof its rareoccurrence,patientswithOMDare

probablyoftenmisdiagnosed,or theirdiagnosismaybe

delayed.Consequently, thesepatientsmayalso receive

incorrectdental treatment,andthesymptomsmayworsen

overtheyears.

OMDmaybe caused or aggravated by someof the

otherdentalandprostheticproblems.Thus, inplanning

thedental treatmentandprocedure, thesubtypeofOMD

andthepossibledystonicmovementsandforcesshouldbe

considered.

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