UnitThirtyOneAnanalysisof80casesofmandibularfracturestreatedwithminiplateosteosyntltesisL.RixA.R.LStevenson,A.Punnia-Moorthy:Ananalysisof80casesofmandibularfracturestreatedwithminiplateosteosynthesis.Int.J.OralMaxillofal.Surg.1991;20:337-341Abstract.Astudyof80consecutivecasesofmandibularfracturestreatedutilizingminiplateosteosynthesisisreported.Analysisofthedatacollectedfrom2innercityhospitalsrevealedahighincidenceofmales(90%),alcoholabusers(44%),smokers(77%)andunemployed(36%).Assaultwastheaetiologicalfactorin72.5%ofcases,withalcoholimplicatedin58%.Theinjurieswerepredominantlynoncomplexinnature,94%havingoneor2mandibularfracturesandonly11%havingadditionalfacialfractures.Theresultscomparedfavourablywiththosefoundinpreviousstudieswith8%havingcomplications.Theefficacyandadvantagesofminiplateosteosynthesisasamethodoftreatmentofmandibularfracturesisdiscussed.Osteosynthesisofmandibularfracturesutilisingnpm-compressionmonocorticalminiplateswasintroducedbyMICHELETetal.anddevelopedandrefinedbyCHAMPYetal.Thissystemisnowwellrecognisedandpracticedinmanycountries.HoweveritsintroductionintoAustraliahasbeenrecentandasyetnoresultshavebeenreported.TheaimofthisstudywastoanalyzedatacollectedfrompatientssufferingmanclibularfractureswhopresentedtotheUniversityofSydneyDepartmentofOralSurgery.Thenatureoftheirinjurieswasassessedandtheeffectivenessorthistechniqueintreatingthesefractureswasexamined.MaterialandmethodsEightyconsecutivecasesofmandibularfracturestreatedduringtheperiodJuly1987tomarch1991wereincludedinthisstudy.ThepatientsweretreatedatSydneyHospitalandUnitedDentalHospital,bothofwhicharelocatedintheinnercityareaofSydney.Datawascollatedfromthepatientrecords,radiographsandfromclinicalexaminationwheneverpossible.TheoperativetechniquesemployedfollowedthatdescribedbyCHAMPYetal.withsomeminormodifications.Thepatientsweretreatedundergeneralanesthesiainallbut4cases.Anintra-oralapproachwasusedin90%ofcaseswiththeoccasionalneedtoplacescrewstransbuccally.Intermaxillaryfixation,intheformofeyeletwiresorarchbarswasusuallyappliedintra-operativelyinordertostabilisethefracturewhilsttheplatedwereadaptedandscrewedintoposition.Twoplateswereusedforfracturedanteriortothementalforamenandoneplateforfracturesatothersitesexceptforcondylarfracturedwhichweremanagedconservatively.Amodificationwasoccasionallyusedforfracturesincloseproximitytothementalforamentoavoidtraumatothenerve.Insteadofthecustomary2plates,onlyoneplatewasplaced,abovetheforamen,andsupplementedwithloopwiringwhichincluded2ormoreteethoneithersideofthefractureline.Theloopwirewasleftinplaceforapproximately4-6weeks.Stainlessteelplates(Champyplates.GebruderMartinCo.)wereusedinallbut7caseswheretitaniumplateswereused.Theoperatorsrangedfromspecialiststotraineeswithvaryinglevelsofexperience.Prophylacticantibiotics(predominantlypenicillinand/ormetronidazole)wereadministeredeitherintravenouslyororallyfromthetimeofpresentationuntilthe7thpost-operativeday8mgofdexamethasonewasadministeredintra-operatively,with2furtherdosesthefollowingdayincertaincases.Anantisepticmouthwash.0.2%cblorhexidinewasroutinelyissuedfor7days.Minivacdrainswerealsousedforthefirst24hwhenindicated.Post-operatively,patientswereexaminedonaregularbasisforupto12months.ResultNinetypercentofmandibularfracturesoccurredinmen.Thepeakincidencewasinthe20-30yearagegroupwithagesrangingfrom16to83years(Fig.l).Assaultaccountedfor72.5%oftheinjurieswhilemotorvehicleaccidentswereresponsiblefor7.5%,theremainderbeingduetosports,industrialaccidents,epilepticfits,spontaneousfractureandfollowingexodontia(Tablel).Fifty-eightpercentofpatientsadmittedtoconsumingalcoholwithinashorttimeofbeinginjured.BasedontheclassificationusedbytheRoyalCollegeofPsychiatdstsl8,44%ofpatientswereclassedasalcoholabuserswith11patientsdiagnosedasalcoholic,10ofwhomwerealsovagrant.Seventy-sevenpercentofthepatientsweresmokersand7.5%wereintravenousduringusers.Thirty-sixpercentofpatientswereunemployedandtherewasapreponderanceofnon-professionalsamongstthe46%employed.Theremaining18%werecomposedofstudents,oldagepensionersandthoseonsicknessbenefits.Acomparisonofsocialcharacteristicsofthestudygroupwiththatofthegeneralpopulationindicatedmarkeddifferences(Table2).Asthestudygroupwaspredominantly(90%),onlythestatisticsforadultmalesinthestateofNewSouthWalewereusedforcomparison.Twenty-fivepercentofpatientshadmedicalconditionsofsignificancewhichincludedheartdisease,respiratorydisease,chirrosisoftheliver,epilepsyandanaemia.Twopatientswereclassedasinfectious,onebeingHIV-positiveandtheotherhepatitisCcarrier.Table1.ClassificationaccordingtoetiologyEtiologyNo.patients(%)Assault58(72.5)MVA*6(7.5)Sports5(6)Fall4(6)Industrial3(4)Epilepticfit2(2.5)Spontaneous1(1.25)Iatrogenic1(1.25)Total80Table2SocialcharacteristicsofthestudygroupcomparedtothemalepopulationofthestateofNSWStudygroup(90%make)Adultmales(NSW)*Alcoholabusers(%)443.6Tobaccosmokers(%)7733IVdruguser(%)7.52Unemployed(%)368.7Fig.1AedistributionFig.2Distributionofthe125fracturesaccordingtositeTherewereatotalof125fractures,withtheanglebeingthemostcommonsite(Fig.2).Thisisconsistentwithotherstudieswhichhaveshownthatassaulttendstoresultinmoreangleandbodyfractures,whilstmotorvehicleaccidentscausemorecondylarandsymphysealfractures.Themajorityoffracturesoccurredontheleftside,whichwouldcorrespond,tomostassailantsbeingright-handed.Ninety-fourpercentoftheinjurieswerenon-complexhavingonlyoneor2fracturesofthemandibleandonlyafewcasesbeingcomminuted.Atotalof12.5%hadadditionalfacialfracturesinvolvingthenose,zygomaticcomplexorthemaxilla.Ninepatientshadassociatedinjuriesofsignificance,whichincludedfracturedhips,legs,hands,skullandvertebrae.Itwasthesepatientsthatrequiredlongerperiodsofhospitilisation.Sixty-sevenpercentofcaseswereplatedwithin4daysoftheinjury;however,asmallproportionwastreatedafteraconsiderabledelay(Fig.3).Thiswasduetoeitherthelatepresentationofthepatient,thenatureoftheirotherinjuries,orwhenthefracturehadinitiallybeeninadequatelytreated.Atotalof139plateswereplacedinadistributionindicatedinTable3.Intermaxillaryfixationwasrequiredpost-operativelyin9cases,usuallynecessitatedbythepresenceofadisplacedcondylarormaxillaryfracture.Table3.Distributionofthe139platesplacedPositionofplatesAngle45Body35Parasymphysis51Symphysis8Theamountoftheatretimerequiredrangedfromlto5hwith73%ofcasescompletedin2horless(Flg.4).Longeroperativetimeswereassociatedwithcasesofmultiplefacialinjuries.Theperiodofhospitalisationrangedfromlto55dayswith2patientsmanagedasoutpatientsand72%ofpatientsdischargedwithin5days(Fig.5).Thelengthyinpatienttimeswereassociatedwithcasesofmultipleinjuries.Fiveofthe80patientsfailedtoattendreviewappointmentsandcouldnotbecontacted.TheincidenceofcomplicationsintheremainingpatientsisillustratedinTable4,withonly8%havingpersistentcomplications.Duringtheearlypost-operativeperiod(<lmonth)aconsiderablenumberoftransientcomplicationswereinevidence.Therewere32casesofhypoaesthesiaoftheinferioralveolarnerve,aresultoftheinitialtraumaplusmanipulationofthenerveduringtheplatingprocedure.Only2failedtoresolve(2.5%),oneofwhichwasalsotheonlycaseofdelayedunion.Occlusaldisturbanceswerereportedby13patientsintheinitialpost-operativephase.Minorocclusaladjustmentwascarriedinafewcases;however,themajorityofthesecasesresolvedspontaneously.Only2cases(2.5%)hadresidualocclusalcomplications,onewithananterioropenbiteandonewitharesidualocclusalstepdefect.Bothofthesecaseshadassociatedcondylarfractures.Transientweaknssofthemandibularbranchofthefacialnerveoccurredin3ofthe8patientswhereanextraoralapproachhadbeenusedtoplacetheplates.Theseallresolvedaftersomemonths.Twodentalcomplicationsoccurredbothinvolvingatoothinthefractureline.Inonecaseaperiodontaldefectdevelopedandintheotherresorptionoftheapicalportionoftherootwasdetected,althoughthetoothremainedasymptomatic.Table4.IncidenceofcomplicationsComplicationslMonth6MonthsMalocclusionl32Dysaesthesia322Delayedunion-1InfectionnilnilWounddehiscence2nilFacialnerveweakness3NilPeriodontaldefect-1Resorptionoftoothinfractureline-1Totalcomplications=6patients(8%)5patientsunabletobereviewed(n=75)Theincidenceofcomplicationsinthisstudycomparedfavourablewiththatinsimilarstudiesonminiplateosteosynthesis(Table5).Theseresultsarealsosimilartothoseachievedwithtraditionalmethodsoffracturetreatmentdisignintermaxillatyfixations.Table5.Comparisonofresultswithotherstudies.ComplicationCawood1985n=5Champy1978n=100Ikemura1988n=66Wald1988n=61Sydneyn=75Maloccluson84.831.92.6Infection63.837.4nilDehiscence12-7.6-2.6Delayedunion-0.5--1.3Sensorydisturbance8--3.72.6FiguresexpressedaspercentagesDiscussionDuringthelast10yearstherehavebeenanumberofpaperspublishedonthepatternsoffacialtraumaindifferentcountries.Thepatientgroupanalyzedinthiscurrentstudyhowever,showssomeinterestingfeatures.Themostobviousoftheseisthehighproportion(72.5%)ofmandibularfracturesthatwerecausedbyassault,whichisoneofthehighestfiguressofarreported.Thenumberofpatientsconsideredalcoholabusers(44%)andthoseconsumingalcoholpriortobeinginjured(58%)werealsomarkedlyhigh.Thisgivesfurtherevidencetotherelationshipbetweenalcoholandinterpersonalviolence.Thelargeproportionofsmokersinthisstudymayalsobeareflectionofthesocialbehaviorofthisgroup.Thehighpercentageofunemployedpatients(36%)wasalsosignificant,contributingtotheevidenceofalinkbetweenunemployment(orincreasedleisuretime)andviolence.Theprofilepresentedbythepatientsinthisstudyepitomizeswhatonewouldexpectinhospitalslocatedwithinaninnercityareaofalarge,modemcity.Insuchanareathereisaconcentrationoflicensedpremisesandentertainmentvenues,withminimalopportunityforhigh-speedmotorvehicleaccidents.Fig.3TimeelapsedbetweentheinjuryandtheoperationFig.4Theadvantagesofplatingtechniquesforthetreatmentofmandibularfractures,overmoretraditionalmethods,havebeenhighlightedbyanumberofauthors.Theseincludetherapidreturntonormalmasticatoryfunctionandmouthopening,resultinginleftdisturbancetobodyweightandlesstimelostfromemployments.Inaddition,earlymobilizationhasbeenrecognisedasasignificantadvantagewhenconcurrentcondylarfracturesarepresent.Directvisualisationalsoallowsforamorepreciseanatomicalreduction,withthefragmentssubsequentlyheldinamorestablepositionbytheplategs.Thisstabilityisofparticularadvantageforedentulousmandiblesandinanglefracturesdistaltothelastteethwherethemasticatorymusclestendtocausedisplacement.Forcomminutedfractureslongerplatescanbeusedtospanallfragments,thuscompletelystabilizingtheareaoffeature.Fig.5Periodofhospitalisationindays.Plateshavegreatlyreducedtheneedforpost-operativeintermaxillaryfixation,asindicatedby89%ofpatientsinthisstudynotrequiringthisadditionalfixation.Intermaxillaryfixationisassociatedwithanumberofproblems,themostimportantbeingtherestrictedaccesstotheairwayinunconsciouspatients.Itisalsounsuitableforepileptics,alcoholanddrugabusers,patientswithchronicobstructiveairwaydisease,thoseunabletoattendforregularreview,pregnantwomenandpatientswhosehealthwouldbeadverselyaffectedbythedecreasednutritionassociatedwithaliquiddiets.Intermaxillaryfixationfrequentlyrequiresadjustmentorreplacementofwires,whichsuggeststhestabilityofthefixationmaybecompromisedaswellasrequiringanincreasednumberofoutpatientvisits.Periodontalproblemsandresidualtrismusmayalsobeundesirablesequelae.Ithasbeensuggestedthattheuseofmetalplatesformandibularfracturesincreasestheincidenceofinfections.Conversely,anumberofstudieshaveshownlowratesofinfectionassociatedwiththeuseofminiplateosteosynthesis.Alcoholicshavebeenshowntohaveanincreasedincidenceofpost-operativeinfectionsanddelayedhealingfollowingfacialfractured.Inthisstudy,however,therewerenocasesofpost-operativeinfectionsdespitethehighproportionofalcoholabuserstreated.TherewasalsoevidencetosupportJOHANSSONetal.whoshowedaneffectivenessofminiplateosteosynthesisintreatingmandibularfracturesthatwereinitiallyinfected.Reporteddisadvantagesincludethenecessityforhospitaladmission,generalanaesthesia,increasedoperatingtimeandgreatercostofmaterials.JOHANSSONstatedthatitispossibletoperformminiplateosteosynthesiswithlocalanaesthesiaaloneandthusreducehospitalisationtime.Inthecurrentstudy4patientsweretreatedinthismanner,with2managedonanout-patientbasis.Followingadmission,in-patienttimewasgenerallyfoundtobebrief,3daysbeingthemostcommon.Innocasewasanextendedperiodofhospitalisationrelatedtothemandibularfractureoritstreatment.Thecostefficiencyofplatingversustraditionaltechniquesisalsoanimportantissue.Thetimeinthemajorityofcasesvariedbetweenland2h,whichisonlyslightlylongerthanusuallyrequiredforclosedreductiontechniques.However,themajorityofpatientsdonotrequirepost-operativeintermaxillaryfixation,thereforeintensive-carenursingisnotrequiredintheimmediaterecoveryperiod.TAYLORetal.havequantifiedtheaveragecostofmanagingafracturedmandiblewithminiplateosteosynthesisandfoundthatitisapproximately25%lessthanfortreatingafracturewithintermaxillaryfixation.Someauthorshaveraiseddoubtsastothefunctionalst