BRI TI SHJOURNAL OFORAL &MAXI LLOFACI AL
SURGERYINTRODUCTIONThetreatmentof
facialfractureshastraditionallyinvolvedre-establishmentof
afunctionaldentalocclusionwithvarioustypesof
intermaxillaryfixation(IMF).1Increasinglyoverthepastthreedecades,
oralandmaxillofacialsurgeonshavedeveloped techniques of treating
facial fractures usinginternalfixation.
Champyetal.2,3laidthescientificfoundationfortheuseof atechniqueof
semirigidfixationinmandibularfracturesdescribedbyMicheletetal.4andthishasbeenpopularizedintheUK
by Cawood.5Most surgeons who treat mandibu-lar fractures with
miniplate osteosynthesis techniquesstilluseIMFasamethodof
fracturereduction, forhistorical reasons, in the belief that this
is essential toachieve a normal occlusion. Review of American
andEuropeanpapersalludetothisasbeingtheonlymethod of fracture
reduction.Itisacommonfindingthatpatientswhosefrac-tures are treated
by closed reduction and immobilizedwithIMFalonehaveafunctional,
butperhapsnotpremorbid, occlusionpostoperatively,
andthatthefractureshavenotbeenanatomicallyreducedwhenevaluated
radiographically.6With the advent of
mini-plateinternalfixationtechniquescametheoppor-tunitytoobtainboththere-establishmentofthepatientsnormalocclusionandanatomicalbonyreduction.
Thequestionarosethatif IMFdidnotoftenachieveanatomicalreduction,
wasitsusenecessaryatall,
becausefracturereductioncanbeachievedbyothermoreaccuratemeans(whichcoincidentallyalsoresultinrestorationof
normalocclusion).Wecouldfindnoreferencestomandibularfrac-tures
treated without the use of peroperative IMF, letalone a comparison
of the two methods of reduction.Despitethis,
itisbecomingcommonpracticeintheUK for some surgeons to reduce
mandibular fracturesmanually and avoid the use of IMF
altogether.Wedecidedtocomparethetwomethodsof
frac-turereductiontotrytoobtainsomeevidencetosupport our theory
that anatomical manual reductionof mandibularfractures,
whenthefracturesarealsointernally fixed with semirigid miniplates,
gives resultsthatareatleastasgoodastraditionalmethodsofreduction
with IMF.METHODWe undertook a retrospective study of a single
yearsactivity in the Catherine Cookson Maxillofacial
Unit,involvingthetreatmentof isolatedmandibularfrac-tures treated
by open reduction and internal fixation,to assess the results of
each method of reduction.Atotalof
202patientswhohadsustainedamandibularfractureduringtheperiod1July199530June1996wereidentifiedfromhospitaladminis-trativeandtheatrerecords.
Atotalof 115patients52British Journal of Oral and Maxillofacial
Surgery (1999) 37, 5257 1999 The British Association of Oral and
Maxillofacial SurgeonsIntermaxillary fixation is not usually
necessary to reduce mandibularfracturesA.M. Fordyce,* Z. Lalani,*
A.K. Songra,* A.J. Hildreth,A.T.M. Carton,* J.E.
Hawkesford**Catherine Cookson Oral and Maxillofacial Unit,
Newcastle General Hospital, Newcastle Upon Tyne;Sunderland Royal
Hospital, Sunderland, UKSUMMARY. Weundertookaretrospectivestudyof
allisolatedmandibularfractureswhichhadrequiredactivemanagement over
a 1-year period at the Maxillofacial Unit at Newcastle General
Hospital. Patients with single ormultiple fractures of the mandible
were included in the study, if there were other simultaneous
fractures of the facialskeleton, those patients were excluded. All
case notes and radiographs were reviewed by a single operator. A
total of202 cases of fractured mandible were identified of which
115 fulfilled the selection criteria of: isolated fracture,
noprevious facial fracture, treatment by open reduction and
internal fixation using titanium osteosynthesis miniplates,and all
case notes and radiographs available to
study.Sixty-sixpatientshadtheirfracturesreducedmanuallytoobtainanatomicalreductionwithouttheuseofperoperative
intermaxillary fixation (IMF). Forty-nine were treated
conventionally using peroperative IMF. The twogroups were broadly
similar in severity and type of fracture, and the method of
reduction seemed to be decided by theoperator according to their
preference. IMF was not used routinely
postoperatively.Overallthereweresignificantlyfewerocclusaldiscrepanciesintheearlypostoperativeperiodinthosepatientstreatedbyanatomicalreduction(6/66comparedwith16/49,
P =0.002)buttherewasnodifferenceinthefinaloutcome of the occlusion
between the two methods of reduction.Avoidance of the use of
peroperative IMF is more economical in time and cost, is safer for
the operator, and morecomfortableforthepatient.
Asthistechniqueproducescomparableresultsinthelongtermwithfewerearlycomplications,
we conclude that IMF is not usually necessary to reduce fractures
confined to the mandibular
bone.wereselectedwhosatisfiedthefollowingcriteriaforinclusionintheanalysis:
therewasanisolatedmandibularfracture(singleormultiplebutnootherfacial
fracture); there was no previous history of facialfracture; the
fractures were treated by open
reductionandinternalfixationusingminiplateosteosynthesisprinciplesasdescribedbyChampyetal.;2,3andallcase
notes and radiographs were available for
study.Aproformawasdesignedtoextractthefollowinginformationfromtherecords:
mechanismof injury,typeof fractureandmethodof reduction;
occlusionasassessedclinicallyatthebedorchairsideonthefirst
postoperative day and at two weeks, by one of thesix specialist
registrars or university lecturers; need fortheuseof
postoperativeintermaxillaryelastictrac-tion, occlusaladjustment,
intermaxillaryfixation, orsecond operation required to correct a
malocclusion;thefinalobjectiveandthepatientssubjectiveassess-ment
of the occlusion at discharge; and complicationsof treatment,
includinginfection, wounddehiscence,sensory deficit, trismus,
malunion or nonunion.The results were collated and
analysed.RESULTSOf the 115 patients, 101 (88%) were male; the
mecha-nismof injurywasinter-personalviolencein82(71%),
fallsin16(14%), roadtrafficaccidentsin7(6%),
andsportsorotheraccidentsinafurther10(9%). A total of 113 patients
(98%) had dentate jaws.The sites of fracture are shown in Table
1.Method of
reductionAlloperationsweredonebyspecialistregistrarsoruniversitylecturers,
withtheassistanceof seniorhouse officers. In 66/115 patients (57%),
the
fractureswerereducedmanuallyassistedbyreductionforcepswhereappropriate,
andtheoccasionaluseoftemporarybridlewiresortransosseouswires,
butwithoutperoperativeIMF.
Forty-ninepatients(43%)hadtheirfracturesreducedalongconventionallineswith
IMF using eyelet wires or arch bars and tie wires(Table 2).Occlusal
outcome at two weeksA comparison was made of outcome, expressed as
theproportionof patientsineachgroupwithasatisfac-tory occlusion at
2 weeks postoperatively. The
overalldifferenceinsatisfactoryocclusaloutcomebetweenthetwoproportionswas14%(9278%).
The95%confidenceinterval(CI)forthedifferenceis1%to27%, suggesting a
better occlusal outcome at 2 weekspostoperatively, for manual
reduction.Contributiontotheoveralldifferenceappearstocomepartlyfromthedifferencebetweenresultsforthesubgroupcontainingafractureof
thecondyle.However, becauseof thesmallnumbersinthissub-group,
thedifferenceinoutcomebetweentreatmentsfailstoreachsignificanceatthe95%level(Table2),althoughitisjustsignificantatthe90%level,
astheboundary is a fraction greater than
zero.Tocomparethetwogroupswithouttheskewingeffect of the subgroup
containing a fractured
condyle,wemadeasecondcomparisonwiththesecasesremoved and with
parasymphysis and body subtypesIntermaxillary fixation is not
usually necessary to reduce mandibular fractures 53Table 1 Sites of
115 mandibular fracturesCondyle and symphysis 3Condyle and
parasymphysis 12Condyle and body 5Condyle and angle 5Bilateral
condyle and parasymphysis 2Unilateral body 11Body and angle 12Body
and parasymphysis 4Unilateral angle 26Angle and parasymphysis
15Angle and symphysis 1Bilateral angle 3Unilateral parasymphysis
12Parasymphysis and ramus 2Multiple sites 2Table 2 Analysis of type
of mandibular fracture by method of reduction and occlusal outcome
expressed as the number of patients with asatisfactory occlusion 2
weeks postoperatively. Data are expressed as numbers (%) of
patientsFracture type Manual reduction IMF reduction(n = 66) (n =
49)Total Occlusion Total Occlusionsatisfactory
satisfactoryUnilateral condyle or vertical ramus andsymphyseal or
parasymphyseal or angle 10 9 (90) 17 11 (65)*Bilateral condyle and
parasymphysis 1 1 (100) 1 0 (0)Unilateral angle 18 15 (83) 8 8
(100)Unilateral body 7 7 (100) 4 4 (100)Unilateral parasymphysis 9
9 (100) 3 2 (67)Angle and body 5 5 (100) 7 7 (100)Angle and
parasymphysis 12 11 (92) 4 1 (25)Bilateral angle 2 2 (100) 1 1
(100)Body and parasymphysis 1 1 (100) 3 3 (100)Multiple sites 1 1
(100) 1 1 (100)61 (92) 38 (78)***95% C I of difference 4% to
54%.**95% C I of difference 1% to 27%, P = 0.03.combined (Table 3).
The two groups are broadly
simi-larinbothfracturesubtypesandproportionwithasatisfactoryocclusionattwoweekspostoperatively(93%
and 87%). There was no significant difference
inoutcomeforanyindividualsubtypeof fractureorinthe group as a
whole. In other words, when comparingfractures that do not include
a fracture of the condyle,thetwomethodsof
reductionseemtobeequallyeffective in terms of occlusal outcome at
two weeks.An attempt was made to deduce from the notes
thereasonfortheuseof IMFinthesecondgroup:
in18/49cases(37%)therewasafracturedcondyleinadditiontoothersitesof
fracture, anditisassumedthat this was the indication for the use of
IMF in thesecases. In two cases there was established infection;
inthe remaining 29 (59%) no other reason than
operatorpreferencecouldbeinferred.
SomesurgeonsinthisstudyhabituallyusedIMFandothersusedmanualreduction
preferentially.Occlusal assessmentItimportanttorememberthat,
asthisisaretro-spectivestudy,
theinformationobtainedabouttheassessmentof
earlyocclusaldiscrepancies, andtheprescribedtreatmentsforthem,
dependsoninfor-mationrecordedinthepatientscasenotes,
andthisisapossiblesourceof inaccuracy. However, thepresenceof
amalocclusionandthetreatmentrequired for its correction are not
likely to be omitted.Therewereproblemsrecordedof
malocclusionintheearlypostoperativephase(Table4), forwhichaperiodof
intermaxillaryelastictractionwasprescribed, in a total of 22 of the
115 patients (19%).Thiscanbesubdividedinto6/66(9%)inthegrouptreated
by manual reduction and 16/49 (33%) of thosetreated with IMF. The
occlusal discrepancies
returnedtonormalinmostpatientswiththissimplemeasurealonebutminorocclusaladjustmentwasrequiredin2/66(3%)and3/49(6%)respectively;
1/66(2%)and2/49 (4%) required reoperation for
malreduction.Thedifferenceintherateof
perceivedearlyocclusaldiscrepancies,
asmeasuredbythecliniciansdecisiontoprescribefurthertreatment,
indicatesaverydefiniteeffect, therebeing24%fewerproblemswith
fractures treated by manual reduction. We
wouldthereforeexpectthemanualreductiontechniquetoresult in between
9% and 39% fewer early
discrepan-ciesatthe95%confidencelevel(95%CIforthedifference 39% to
9%).By 2 weeks postoperatively, the difference betweenthe two
groups was much less obvious. When the sub-group containing a
condylar fracture is separated
offfromtheanalysisthereisnosignificantdifferencebetweenthetwomethodsof
reduction. Atdischargefrom outpatient follow-up no patient was
dissatisfiedwith their occlusion and objective occlusal
irregulari-ties were all minor; there was no significant
differencein the final occlusal result between the two groups.
Itseemsthereforethat, irrespectiveof themethodofreduction,
perceivedearlymalocclusionsrapidlyreturned to normal in the
postoperative phase.Other
complicationsAllpatientsreceivedprophylacticantibiotics,
despitewhichfivepatients(4%)developedminorwoundinfections.
Fivepatientsdevelopedadegreeofrestrictedmandibularopeningof
whomthreehadinjuriesthatincludedacondylarfracture. Record54 British
Journal of Oral and Maxillofacial SurgeryTable3 Analysisof typeof
mandibularfracture, excludingcaseswithfracturesof
thecondyleintheinjurycomplex, bymethodof
reductionandocclusaloutcomeexpressedasthenumberof
patientswithasatisfactoryocclusion 2 weeks postoperatively. Data
are expressed as numbers (%) of patientsFracture type Manual
reduction IMF reduction(n = 55) (n = 31)Total Occlusion Total
Occlusionsatisfactory satisfactoryUnilateral angle 18 15 (83) 8 8
(100)Unilateral body or parasymphysis 16 16 (100) 7 6 (86)Angle and
body or parasymphysis 17 16 (94) 11 8 (73)Bilateral angle 2 2 (100)
1 1 (100)Body and parasymphysis 1 1 (100) 3 3 (100)Multiple sites 1
1 (100) 1 1 (100)51 (93) 27 (87)**95% CI of difference 8% to
20%.Table 4 Management of early postoperative occlusal
discrepancies by method of reduction (all fractures)Manual
reduction IMF used for reduction(n = 66) (n = 49)Elastic traction
alone 3 11Elastic traction and occlusal adjustment 2 3Reoperation 1
26 (9%) 16 (33%)95% CI of the difference: 39% to
9%.keepingwasinadequatetofindouttheincidenceofneurosensorydeficitresultingfromtheoperations,
acommonprobleminretrospectiveanalyses. Therewerenocasesof
malunionornonunion. Themeanlength of inpatient stay was 2 days,
with most patientsbeing discharged home on the first postoperative
dayand without the need for a period in an intensive careward.
Themeandurationof out-patientfollowupwas 3 months and involved four
out-patient visits.DISCUSSIONThe obvious difference between the two
groups, whichaffectsthecomparisonof theproportionof
casestreatedineachgroup, isthatthenumberof caseswhich included a
fractured condyle in the injury com-plex is much greater in the IMF
group. There are twomain reasons for this: first, many operators
prefer tohave cleats attached to the teeth to which elastic
bandscan be attached postoperatively if intermaxillary
trac-tionisindicatedforaminormalocclusion.
Somethinkthatitismorelikelythatafracturedmandiblewhichincludesafracturedcondylewillrequirethistreatment,
andsoallsuchpatientsshouldhavearchbars attached to their teeth at
the time of operation asaprecaution. Second, oneof
thesupervisingconsul-tants stipulated that all of his patients with
a
fracturedcondylemusthavearchbarsoreyeletwiresattachedtotheteethatthetimeof
fracturereduction.
Thesetwofactorsinevitablyresultedinmorecaseswhichincluded a
fracture of the condyle having IMF placedperoperatively,
andthisaffectedtheanalysisof theproportions in each subtype of
fracture.Why use intermaxillary fixation?Perioperative IMF has a
number of indications, whichinclude: apreferredmethodof
fracturereductionbytheoperatororsupervisingconsultant; lackof
anadequately trained assistant at operation; the presenceof a
unilateral or bilateral condylar fracture that
mayrequirepostoperativeIMForelasticintermaxillarytraction;
andplannedpostoperativeIMFtoimmo-bilizethemandibleandprotectthefixation,
whichmay be because of poor-quality internal fixation (softbone or
comminuted fractures), established infection,orpossiblelackof
patientscompliancewithpost-operative care of the fracture sites
(such as adopting asoft diet).The overall complication rates
compare favourablywithotherstudies,
reviewedrecently.7Infectionrateshave been reported from 0% to
14.6%, with a mean of6.7%, compared with 4% in the present study.
Overallourearlymalocclusionratewas19%,
with3%earlyreoperationsformalreduction, 4%of whomeventually
required minor occlusal adjustment. Thesefigures compare with 17%,
0.5%, and 8%, respectively,in the review by Renton et
al.7Ourmainaimwastodiscoverif
thereisadiffer-enceinoutcomebetweenthetwomethodsof treat-ment.
FracturereductionusingIMFalone, usingtractiononthebuccalaspectsof
theteeth, tendstoapproximatebuccalsurfacesof maxillaryandmandibular
teeth. This has the effect of establishing afunctional,
thoughnotthepremorbidocclusion, butwithoutanatomicalreductionof
thefracture,6whichcommonlybecomesmoredisplacedattheinferiorborderintheparasymphysialregion.
Itisprobablethatafterbonyhealingandremodellingthereareminor tooth
movements under the influence of muscleforces in the lips, cheeks,
and tongue, which repositiontheteethinanareaof musclebalance,
ashappensduringtootheruption.8Accurateanatomicalreduc-tion,
however, resultsinimmediatere-establishmentof the patients normal
occlusion.Assessment of early occlusionTheassessmentof
postoperativeocclusioncanbedifficultwithapatientinsomediscomfort.Malocclusionmayresultfrommalreductionof
anyinternallyfixedfractures, failureof
thefixation,artefactual(voluntaryorinvoluntaryguardingwiththepatientposturing
theirmandibleintoamorecomfortableposition),
ortheremaybeshorteningoftheramusrelatedtoaconservativelymanagedcon-dylar
fracture.Malreduction and fixation failure should be
appar-entonclinicalandradiographicexaminationbutmany early apparent
occlusal irregularities result frommuscleguardingandposturing of
themandiblebythepatientandtheseresolvespontaneously.
Theassessmentinthesecasescanbedifficultandmayimprovewithexperience.
Assixdifferentspecialistregistrarsorlecturersof
varyingexperiencewereinvolved in these management decisions, it is
probablethatdecisionsabouttheuseof elastictractionwerenot
standard.Assessing the contribution of the fractured condy-lar
element to perceived malocclusion and separatingthis effect from
malreduction or guarding, is the mostdifficultaspectclinically.
Allcondylarfractures, aspartof theinjurycomplex,
weremanagedconserva-tively in this study.AscanbeseenfromTable5, 2of
the11patientswith condylar fractures in the manual reduction
grouprequiredintermaxillaryelastictractionpostopera-tively,
compared with 10 out of 18 in the IMF group.The difference shows
that patients with condylar
frac-turesareslightlybutnotsignificantlymorelikelytorequireintermaxillaryelastictractionprescribedifthey
have had other fractures in the mandible reducedby IMF.Arch bars
may influence treatment
decisionsElastictractionmaybeprescribedmoreoftenforthosepatientswitharchbarsoreyeletwiresinplacepostoperatively(theIMFgroup),
simplybecausetheelasticsareeasiertoapplywhenloopsorcleatsarealready
attached to the teeth. This may have the effectof increasing the
apparent early occlusal complicationIntermaxillary fixation is not
usually necessary to reduce mandibular fractures
55rateintheIMFgroup, forcaseswithorwithoutafracture of the condyle.
The actual difference in earlyocclusal outcome between the two
groups may there-fore be less than it looks from these
results.Results from this study, although not always
statis-ticallysignificantandwiththecaveatthatthenum-bersanalysedaresmall,
suggestthatpatientsdonotneedtohavearchbarsroutinelyfittedtotheirteethmerely
because they have a fractured condyle as partof
theirmandibularfracture. Atotalof 55%of theIMFgroup,
about40%overall, andlessthan20%ifthe fracture is treated by manual
reduction, will havepostoperativeintermaxillaryelastictraction.
Itmaybe that prescribing arch bars and elastic traction
onlytothosepatientswhorequirethempostoperatively,rather than
applying them to all cases regardless, is themost appropriate
course of action. This treatment
canbesimplyprovidedwithoutasecondgeneralanaes-thetic, in
outpatients.The role of elastic tractionItisnotclearif
elastictractionachievesabeneficialeffect in mandibular fractures,
as correction of majorocclusalirregularitiesisunlikely.
Minorapparentmalocclusions seem to resolve rapidly with or
withoutelastictraction.
Itmaybethatthistechniquemerelyovercomesthereflexmusclecontractionthatresultsfrom
the discomfort associated with the fracture anditstreatment.
Aperiodof
timetoallowguardingtoresolvebeforeprescribingelastictractionmayavoidsome
unnecessary treatment.Intermaxillary fixation compared with
manualreductionWhilst there are some definite indications for the
use ofIMF, thereareobviousadvantagestomanualreduc-tion and avoiding
the need for IMF. Arch bars or eyeletwires, themethodof
IMFusedinthisstudy, takeatleast 40 min to apply and there is a risk
of injury to thesurgeon and nursing staff from wires puncturing
theirgloves. The presence of circumdental wires mean that itis
difficult for the patient to maintain a high standardof
oralhygiene, theymaydamagetheperiodontium,and they cause discomfort
during removal. The cost ofmanufacturingandapplyingarchbars,
increasedlengthof generalanaesthesia(costof
personnelandanaestheticagents),
personnelandoutpatienttimerequiredinremovingthemetalworkpostoperatively,all
militate against this method of fracture
reduction.Manualreductionismuchmoreoperator-dependent than IMF and
requires a greater degree ofexperience and skill. A comprehensive
understandingof thevagariesof
thehumanocclusionisessential.Foroptimumpatientcare,
itisessentialthatjuniorsurgeonsarecloselysupervisedandthatoperatingsurgeonsareadequatelytrainedbeforeembarkingonit.
Intheabsenceof acompetentassistantitismoredifficult,
andIMFmaybeindicatedinsuchcircumstances.
Manualreductiontechniquesworkwell if the most senior surgeon
establishes the occlusionand holds the fracture reduced, whilst the
less experi-enced surgeon fixes the fracture with
miniplates.Therearealternativemethodsof applyingIMF,such as placing
transgingival screws and using these
aspointstoattachintermaxillarywires.
Thismethodreducesthetimetakenandthenumberof wiresrequired to
establish IMF but there will be a compli-cation rate associated
with screw placement and use oftie wires. The disadvantage of
applying traction onlytothebuccalaspectof thedentalarches,
withthedisplacingeffectthatthishasatthelowerborderofthemandible,
isnotovercomeandthismethodinevitablycostsmorethanmanualreduction.
SinceIMF seems to offer no short- or long-term
advantagesovermanualreductiontheredoesnotseemtobeaneed for its
routine use. A prospective study is clearlyrequired, and this is
now being undertaken.AcknowledgementsWethankthedepartmentof
MedicalAuditatNewcastleGeneralHospital for obtaining case records
and Mr K.R. Postlethwaite forpermission to report the results of
treatment of his patients.References1. Rowe NL, Killey HC.
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synthesis. Placement of thesynthesis as a function of mandibular
stress. Rev StomatolChir Maxillofac 1976; 77: 971976.4. Michelet
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Livingstone, 1994, Vol 2:352353.56 British Journal of Oral and
Maxillofacial SurgeryTable5 Comparisonof
needforelastictractionbymethodof reductioninpatients whose injury
included a fractured condyleManual reduction IMF reduction
TotalElastic traction 2 10 12No elastic traction 9 8 17Total 11 18
29P = 0.06 (Fishers exact test).Intermaxillary fixation is not
usually necessary to reduce mandibular fractures 577. Renton TF,
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AuthorsA.M. Fordyce FRCS, FDSRCSSenior RegistrarZ. Lalani MDS,
FFDRCSISenior House OfficerA.K. Songra BSc, MBBS,
FFDRCSIRegistrarA.T.M. Carton MA, FRCS, FFDRCSI, FDSRCSSenior
RegistrarJ.E. Hawkesford FDSRCSConsultantCatherine Cookson Oral and
Maxillofacial UnitNewcastle General HospitalWestgate RoadNewcastle
Upon Tyne NE4 6BE, UKA.J. Hildreth MPhil, FSSMedical
StatisticianSunderland Royal HospitalKayll RoadSunderland SR4 7TP,
UKCorrespondence and requests for offprints to: A.M.
FordyceConsultant Oral and Maxillofacial Surgeon, Torbay
Hospital,Lawes Bridge, Torquay TQ2 7AA, UKPaper received 12 June
1997Accepted 3 December 1997
