www.bjorl.org
Brazilian
Journal
of
OTORHINOLARYNGOLOGY
ORIGINAL
ARTICLE
Rapid
maxillary
expansion
in
mouth
breathers:
a
short-term
skeletal
and
soft-tissue
effect
on
the
nose
夽
Fauze
Ramez
Badreddine
∗,
Reginaldo
R.
Fujita,
Fabio
Eduardo
Maiello
Monteiro
Alves,
Mario
Cappellette
Jr.
UniversidadeFederaldeSãoPaulo(UNIFESP),SãoPaulo,SP,Brazil Received24August2016;accepted30January2017
Availableonline24February2017
KEYWORDS Maxillaryexpansion; Palatalexpansion technique; Nasalcavity; Nose Abstract
Introduction:Rapidmaxillaryexpansion canchangetheformandfunctionofthenose. The skeletalandsofttissue changescan influence theestheticsand thestability oftheresults obtainedbytheprocedure.
Objective:Theaimofthisretrospectivestudywastoevaluatetheshort-termeffectsofrapid maxillaryexpansionontheskeletalandsofttissuestructuresofthenose,inmouth-breathing patients,usingareliableandreproducible,butsimplemethodology,withtheaidofcomputed tomography.
Methods:Atotalof55mouth-breathingpatientswithmaxillaryhypoplasiawereassessedand weredividedintoanexperimentalgrouptreatedwithrapidmaxillaryexpansion(39patients, 23ofwhichweremaleand16female,withanaverageageof9.7yearsandastandarddeviation of2.28,rangingfrom6.5to14.7years)andacontrolgroup(16patients,9ofwhichweremale and7female,withanaverageageof8.8years,standarddeviationof2.17,rangingfrom5.11 to13.7years).Thepatientsoftheexperimentalgroupweresubmittedtomultislicecomputed tomographyexaminationsattwodifferentpointsintime:(T1)pre-rapidmaxillaryexpansion and(T2)threemonthsaftertheprocedure.Thecontrolgroupunderwenttothesameexams atthesameintervalsoftime.Fourskeletalandsofttissuevariableswereassessed,comparing theresultsofT1andT2.
Results:Therewasintheexperimentalgroupasignificantincreasesinalltheskeletalandsoft tissuevariables(p<0.05)butnosignificantalterationwasfoundinthecontrolgroup.When comparingtheexperimentalgroupandthecontrolgroup,themostimportantchangeoccurred inthewidthofthepyriformaperture(p<0.001).
夽 Pleasecitethisarticleas:BadreddineFR,FujitaRR,AlvesFE,CappelletteJr.M.Rapidmaxillaryexpansion inmouthbreathers:a short-termskeletalandsoft-tissueeffectonthenose.BrazJOtorhinolaryngol.2018;84:196---205.
∗Correspondingauthor.
E-mails:[email protected],[email protected](F.R.Badreddine).
PeerReviewundertheresponsibilityofAssociac¸ãoBrasileiradeOtorrinolaringologiaeCirurgiaCérvico-Facial. https://doi.org/10.1016/j.bjorl.2017.01.009
1808-8694/©2017Associac¸˜aoBrasileiradeOtorrinolaringologiaeCirurgiaC´ervico-Facial.PublishedbyElsevierEditoraLtda.Thisisanopen accessarticleundertheCCBYlicense(http://creativecommons.org/licenses/by/4.0/).
Conclusion: Rapidmaxillaryexpansion is capable ofalteringthe shapeand functionofthe nose,promotingalterationsinskeletalandsofttissuestructures.Thiskindofstudymay,inthe future,permittheproperplanningofestheticproceduresatthetipandbaseofthenoseand alsotheperformanceofobjectivemeasurementsinearlyorlatesurgicaloutcomes.
© 2017 Associac¸˜ao Brasileira de Otorrinolaringologia e Cirurgia C´ervico-Facial. Published by Elsevier Editora Ltda. This is an open access article under the CC BY license (http:// creativecommons.org/licenses/by/4.0/). PALAVRAS-CHAVE Expansãodamaxila; Técnicadeexpansão palatal; Cavidadenasal; Nariz
Expansãorápidadamaxilaemrespiradoresorais:efeitosesqueléticos etegumentaresdonarizemcurtoprazo
Resumo
Introduc¸ão: Aexpansãorápidadamaxilapodealteraraformaeafunc¸ãodonariz.Asalterac¸ões doesqueletoedostecidosmolespodeminfluenciaraestéticaeaestabilidadedosresultados obtidosatravésdesteprocedimento.
Objetivo: Avaliar,em curtoprazo, os efeitosda expansãorápidada maxilasobreas estru-turasesqueléticasetegumentaresdonarizempacientesrespiradoresoraispormeiodeuma metodologia confiável ereprodutível, porémsimples, comaajudada tomografia computa-dorizada.
Método: Foramavaliados55 pacientesrespiradoresorais comhipoplasiamaxilarque foram divididosemgrupoexperimentaltratadocomexpansãorápidadamaxila(39,23dosexo mas-culino e16dofeminino,commédiade9,7anosedesviopadrãode2,28,variac¸ãode6,5a 14,7anos)eumgrupocontrole(16pacientes,novedosexomasculinoesetedofeminino,com médiade8,8anos,desviopadrãode2,17,variac¸ãode5,11-13,7anos).Ospacientesdogrupo experimentalforamsubmetidosaexamesdetomografiacomputadorizadamultisliceemdois temposdistintos:(T1)pré-expansãorápidadamaxilae(T2)trêsmesesapósoprocedimento. Ogrupocontrolefoisubmetidoaosmesmosexamesnosmesmosintervalosdetempo.Foram avaliadasquatrovariáveisesqueléticasequatrotegumentarescomparando-seosresultadosde T1eT2.
Resultados: Ogrupoexperimental apresentouaumentos significativosem todasasvariáveis esqueléticasedetecidosmoles(p<0,05),masnãohouvealterac¸õessignificativasnogrupo con-trole.Aocomparar-seogrupoexperimentaleogrupocontrole,foiobservadoqueaalterac¸ão maisimportanteocorreunalarguradaaberturapiriforme(p<0,001).
Conclusão:Aexpansãorápidadamaxilaécapazdealteraraformaeafunc¸ãodonariz, pro-movendoalterac¸õesnasestruturasesqueléticasedostecidosmoles.Essetipodeestudopode, nofuturo,permitiroplanejamentoadequadodeprocedimentosestéticosnapontaebasedo narizetambémarealizac¸ãodemedidasobjetivasemresultadoscirúrgicosiniciaisoutardios. © 2017 Associac¸˜ao Brasileira de Otorrinolaringologia e Cirurgia C´ervico-Facial. Publicado por Elsevier Editora Ltda. Este ´e um artigo Open Access sob uma licenc¸a CC BY (http:// creativecommons.org/licenses/by/4.0/).
Introduction
Itiswellknownthatthenasalcavityplaysanimportantrole in respiratory physiology,1,2 exerting a fundamental
influ-ence on facialgrowth and developmentand occlusion.3,4
Inviewof thestrong relationshipthat existsbetween the nasal cavity and the maxilla, and as the maxillary bone forms around 50% of the anatomic structure of the nasal cavity,5,6 changes to the maxilla could also be the cause
of nasal obstructions, the transverse deficiencies, which include maxillary hypoplasia, being the most frequently observed.2,7
Therefore, the occurrence of maxillary hypoplasia togetherwithrespiratory problems, mainly nasal obstruc-tion,hasattractedtheattentionof variousresearchersto thepossibilityoftheseeventsharboringanintimate,mutual
relationship.8---10 RME, in addition to rectifying occlusion,
mayhave an influence on respiratory nasal activity,1,2,7,11
aswell as promotingpositive changes in cervical posture andpositionofthehead asa resultof thesmallerairway resistance.12,13
FromtheearliestevidenceoftheeffectsofRMEonthe nasalcavity8,9variousstudieshavebeenundertaken
focus-ingonskeletal changes5,7,11,14---32 thefirstspecificstudy on
therepercussionofRMEonthesofttissueofthenasal cav-itywasonlyconductedasrecentlyas1999.33Sincethistime,
fewstudieshaveassessedthemodificationstothefacialsoft tissuethathave atendency tostretch,accompanyingthe changesinthe hardtissuedue tobone expansion.9,23,33---35
The softtissue,in additionto theestheticimpact itmay haveontheface,36mayalsohaveaprimaryroleinthe
aftertheRME.Thishappensbecause,after3---4monthswith aretainer,therecouldstillbealackofadaptationofthesoft tissue,includingthatofthecheeks,whichcouldbecomea recurrencefactor.9,23,33Moreover,therecouldalsobelosses
inocclusalstabilityandrespiratoryefficiencydueto resis-tanceof the soft tissueand maxillarysutures aroundthe nose.Soitisessentialthattheprofessionalshouldconsider thepossibleconsequencesforthesofttissueasaresultof thistreatment.9,23,36
Thevastmajorityofstudiesexistingintheliteraturehave approached skeletal and soft tissue alterations by means oftwo-dimensionalexaminations5,6,11,14---18,20,21,29,30,32,33
how-ever technologicaladvancesin digital imaginghave made itpossible to performthese evaluationsin 3D. Computed tomographyisareliablemethodforrepresentingand mea-suring the thickness of facial soft and skeletal tissue37,38
providinghighlypreciseandaccuratedata,producing full-sizeanatomicalimages(1:1).Themajority ofstudiesthat use three-dimensional examinations,7,19,22---28,30,31,35,36,39,40
however,have notexplored the study of thenasal cavity in three dimensions, instead placing greater emphasis on alterationsinwidth.19---26,28,30,39
Due tothe conflictingliterature and the lack of infor-mation about three-dimensional skeletal alterations, and mainlythroughtheabsenceofamorecomprehensive liter-atureintermsofsofttissuenasalalterations,theobjective ofthepresentstudyistoevaluate,usingasimplebut reli-ableandreproduciblemethodologythe effectsof RMEon theskeletalandsofttissuestructuresofthenose,inthree dimensions, in mouth-breathing patients, with the assis-tanceofcomputedtomography.
Methods
The sample comprised55mouth-breathing individuals suf-fering from maxillary constriction, referred for RME treatment.Thepatientsweredividedintothe experimen-talgroup(EG)(39patients---23maleand16femalewithan averageageof9.7years,standarddeviationof2.28,ranging from6.5to14.7years)andaControlGroup(CG)(16patients ---9maleand7femalewithanaverageageof8.8years, stan-dard deviation of 2.17, ranging from 5 to 13.7years).All patientswereevaluatedbyamulti-disciplinaryteamandthe diagnosesweremadethroughastandardizedquestionnaire, andENTandorthodonticevaluation.Syndromicpatientsor patientswithcraniofacialabnormalitiessuchasPierreRobin andTreacherCollins,amongothers,andpatientswith den-talor periodontalchanges wereexcluded fromthe study. This study was approved by the Committee for Ethics in InstitutionalResearch.
ThepatientsoftheEGweretreatedbyusingtheHyrax maxillaryexpanderwithsix-quarterinitialactivationsand two-quarterdaily activationsuntil the necessary quantity ofexpansionwasobtainedforeachpatient,inotherwords, untilthesuperiorbuccalbonebeseemcompatiblewiththe inferiorWALA edge.Once the activationswere complete, theapplianceswerekeptinplaceforaperiodof3months, asaretainer,toenablenewbonetoformingtheregionof themid-palatalsuture.CTexaminationswereconductedat twodifferentpointsintime:(T1)pre-RMEand (T2)three monthsaftertheretainerisfitted.ThepatientsintheCG
Table1 Pointslocatedintheskeletaltissue.
Nasion(N) Intersectionofthefrontal boneandtwonasalbones. AnteriorNasalSpine(ANS) Mostanteriorpointofthe
maxilla’snasalspine. PosteriorNasalSpine(PNS) Mostposteriorpointofthe
maxilla’snasalspine.
weresubjectedtothesameCTexaminations(T1andT2)on similarperiodstothosein theEG (threemonths between them).All thepatientsin theCG wereduly treatedusing thesamestandardprocedureemployedintheEG,oncethe studywasover.AlltheCTscanswereperformedinthesame locationandwiththesameequipment,namely: Multislice (PhilipsBrillianceCT64channelscanner).Forthese exami-nations,aFOVof20cmandVoxelof0.25mmwereused.All patientswereundermedicaltreatment,allTCscanswere partof thediagnosisprocessand bymedicalprescription, respectingtheALARAprincipleaccordingtotheskullsizeof eachpatient.
Theskeletalandsofttissuestructuresofthenosewere dulymanipulatedandmeasuredinthreedimensionsbased onanatomicalpointsdefinedinthegloballiterature36,40---42
(Tables 1and 2),withthe aidof OsiriXMD software(FDA approved, version 1.4.2; Pixmeo, Geneva, Switzerland), which, by means of specific tools, permittedthe acquisi-tionofmultiplanarslices(sagittal,axialandcoronal)ofCT images,throughwhichthedatawerecollected.Inorderto assurethecorrectlocalizationoftheanatomicalpoints,41,42
good reproducibility and reliable measurements, prior to measuring, therepositioning of the head wascarried out foralltheCTmages,followingthemethodologyadvocated byCevidanesetal.43(Fig.1A---C).
The skeletal structures were measured in the sagittal andcoronalimagesofthemultiplanarslices.Inthesagittal image(Fig.2A),thenasalheightismeasuredviathe mea-surementoflineardistance(mm)betweenpointsNandANS andthetotallengthofthenoseviathedistance,in millime-ters, betweenthe pointsANSandPNS. As for thecoronal image, the height of the pyriform aperture is measured, obtained via thelineardistance (mm) betweenthe upper andlowertangentsofthisstructureabovethemidsagittal
Table2 Pointslocatedinthesofttissue.
Nasion(N) Pointofthemidlineofthesoft tissuethatliesdirectlyover thehardtissue,inthedirection oftheskeletalNasion(N). Pronasal(Prn) Mostprominentpointofthe
noselocatedonthemedian. Alar(Al) Themostlateralpointofthe
contourofeachnostril. AlarCurvature(Ac) Pointlocatedatthesofttissue
insertionofeachalarbase. Subnasal(Sn) Mid-pointbetweenthemeeting
oftheloweredgeofthenasal septumandupperlip,located onthemedian.
Figure1 Finalrepositioningoftheheadwiththesagittal(A), axial(B)andcoronal(C)slicesdulyorientedinrelationtothe Frankfurtplaneandthemidsagittalplane.
A
NANS
PNS Length: 2.1
B
C
Figure2 (A)Measurementofthenasalheight(N-ANS)andtotallength(ANS-PNS)inthesagittalslice.(B)Measurementofthe heightofthepyriformapertureinthecoronalslice.(C)Measurementofthewidthofthepyriformapertureinthecoronalslice.
plane (Fig. 2B)and the nasal width through the distance (mm)betweentheoutermostpointsofthelateralwallsof thelowerthirdofthepyriformaperture(Fig.2C).
The soft tissue measurements were measured in the sagittal and axial images of the multiplanar slices. The heightwasobtainedinthesagittalimageviathelinear dis-tance(mm)betweenthepointsNandSn(Fig.3A)andthe length, alsoin the sagittal image,via the lineardistance (mm) betweenthepointsPrn andSn (Fig.3A).The width ofthenasalsofttissuewasobtainedfromtheaxialimage viathelineardistance(mm)betweenthepointsAlr andAlL (alarwidth)andbetweenthepointsAcr andAcL (widthof thesofttissueinsertion)(Fig.3BandC).Fig.4shows the samepointsreferredto3Dreconstruction.
Statisticalanalysis
Thestatisticalanalysisanddatatreatmentwasperformed using the program Statistical Package for the Social Sci-ences (SPSS),version 22 for Windows. The measurements
areshowninmillimeters(mm)anddescribedviathemean (M)andstandarddeviation(SD),theresultsbeingdisplayed intheformatM±DP.
In order toverify the adequacy of the sample for the study, Student’s t-tests were performed for paired sam-ples.The calculationswerecarriedoutusingtheprogram G*Powerandshowedasample(n=55)withpowerof80%at a5%levelofsignificance,demonstratingthatthesampleis sufficienttoassurethecredibilityoftheresultsobtained.
Thesignificance values(p)oftheShapiro---Wilktest for the analysis of normality of data were greater than or equal to 0.05 for all variables. These results with a 5% level of significance permit us to assume that the data haveanormaldistribution,guaranteeingtheprerequisites for the performance of parametric tests for the statisti-calanalysis andtreatment of theresults obtained in this study.
Inordertocheckforthepossibilityofpotential interfer-encefromgender andage,intheresultsofthestudy,the Fisher’sexacttestwasusedforthegendervariable(58.2% male and 41.8% female) and the independent Student’s
A
N′ Alr AlL Acr AcL Prn SnB
C
Figure3 (A)Measurementoftheheightofthenasalsofttissue(N---Sn)andlengthofthenasalsofttissue(Prn---Sn)inthesagittal slice.(B)Measurement ofthe alarwidth (Alr---All)intheaxial slice.(C) Measurementofthewidth ofthe softtissueinsertion
(Acr---Acl)intheaxialslice.
AIr Acr AIr AII AII AcI Ac I Sn Prn Acr Prn N′
Figure4 Pointsin3Dsofttissuereconstruction.
t-testfor the age variable(inthe global sample the ages
rangefrom5.92to14.17years,withM=9.45andSD=2.26). The test results demonstrate there were no significant differences either in terms of gender (p=1.000) or age (p=0.191).Basedontheseresults,it maybestatedthat, despitetherebeing moremales thanfemales anda large agevariationbetweenthesample elements,therewasno interferencefromeitherofthesetwofactorsintheoutcome ofthestudy.
Inordertoanalyzemethoderror,intra-examiner reliabil-itywasassessedusingtheStudent’st-testforpairedsamples andtheIntraclassCorrelationCoefficient(ICC).Allthe pre-andpost-RMECTexaminationsweremeasuredagain30days aftertheinitialmeasurements,assuming alevelof signifi-cance of 5% for the decision with regard tothe outcome ofthe statisticaltests. Theresults showedthat thereare nosignificant differences(p>0.05) betweenthemeans of thefirstandsecondmeasurementsinanyofthesofttissue orskeletalvariables,norinthepre-andpost-RME tomog-raphy. The ICC values were above 0.05 for all variables, indicatingan excellentconsistencybetweentheresultsof thefirstandsecondmeasurements,assuringexcellent intra-examinerreliability.
For the analysisof the inter-examiner method error a totalof 27patients were selectedat random(totalof 54 CTs) out of the 39 patients in the EG sample who were measured by a second examiner. The Student’s t-test for paired samplesdetected nostatistically significant differ-ences (p>0.05)between the means of the firstexaminer andthemeansofthesecondexaminerforanyofthe varia-bles nor in the pre- and post-RME tomography. The ICC valueswere in excessof 0.95 for all variables, indicating
excellent consistencybetween theresults ofthe firstand second measurements, assuring excellent inter-examiner reliability.
FortheanalysisofthecomparisonbetweenT1andT2 val-uesinbothgroups,fortheskeletalandsofttissuevariables, andforthecomparisonbetweenthegroups,theStudent’s
t-testforpairedsampleswasused.
Results
AlltheCTimagesweremeasuredtwicebythesame exam-ineratan intervalof 30days.TheCT’swerenumberedso that the examiner would not know if he was measuring imagesfromthepre-orpost-RMEimages.AftertheCT mea-surement, theCT’s werearrangedinto(T1)pre- and(T2) post-RME.ThesameprocedurewasusedfortheCTscansof theCG.
The evaluation of the results on the skeletal and soft tissue structures in both groups was conducted using the valuesoftheT1andT2measurementsandtheresultsforthe skeletalalterationsaredisplayedinTable3andtheresults forthesofttissuevariablesareshowninTable4.
Fortheskeletalvariables,intheEG,asignificantincrease (p<0.05) was observed in all the structures. The largest increasewasfoundwiththewidthofthepyriformaperture (+9.15%),followed bythe heightofthepyriformaperture (+4.00%),nasalheight(+3.37%)andthetotallengthofthe nose(+1.12%).AmongthepatientsoftheCG,nosignificant changeswere observed.When comparingtheEG withthe CG,themostsignificantdifferencewasfoundinthewidthof thepyriformaperture,post-RME(p=0.001).Changesintotal
Table3 Comparisonbetweenpre-RMEandpost-RMEvalues,andbetween theExperimentalGroup (EG)andControlGroup (CG),oftheskeletalvariables(valuesdisplayedinmm).
Variable Group Pre-RME
M±DP (Min---Max) Post-RME M±DP (Min---Max) Pre-RMEpost-RME alteration(average) pa (pre-RME---post-RME) mm % Nasalheight EG 44.81±4.01 (38.37---57.34) 46.32±3.94 (40.23---57.14) +1.51 +3.37% <0.001 CG 44.93±4.35 (38.01---52.13) 45.05±4.21 (38.41---52.91) +0.12 +0.27% 0.537 pb(betweengroups) 0.920 0.003 Heightof pyriform aperture EG 31.52±3.42 (22.66---37.15) 32.78±3.40 (24.72---39.33) +1.26 +4.00% <0.001 CG 31.24±3.51 (25.05---37.26) 31.14±3.24 (25.40---37.98) −0.10 −0.32% 0.776 pb(betweengroups) 0.790 0.003 Widthof pyriform aperture EG 21.64±1.73 (17.83---25.34) 23.62±2.45 (18.19---31.39) +1.98 +9.15% <0.001 CG 21.28±1.98 (17.52---24.55) 21.28±1.88 (17.83---24.41) 0.00 0.00% 0.985 pb(betweengroups) 0.503 0.001 Totallengthof thenose EG 47.25±3.35 (37.76---54.61) 47.78±3.53 (37.18---54.87) +0.53 +1.12% 0.002 CG 47.50±3.09 (41.22---53.16) 47.71±2.83 (42.08---52.75) +0.21 +0.44% 0.444 pb(betweengroups) 0.796 0.938
a p,significancevalueofStudent’st-testforpairedsamples(differencebetweenpreandpost).
b p,significancevalueofStudent’st-testforindependentsamples(differencebetweentheEGandtheCG).
noselengthwerenotsignificantinthecomparisonbetween groups.
With regard to the soft tissue variables, it was also found,intheEG,asignificantincrease(p<0.05)inallthe analyzedstructuresbetweenthepointsintimeT1andT2. Inpercentageterms,theincreasewas+4.39%inthewidth ofthesofttissueinsertion,+3.46%inthealarwidth,+3.73% intheheightofthenasalsofttissueand+4.28%inthelength ofthenasalsofttissue.Among thepatientsoftheCG,no significantchangeswereobserved.WhencomparingtheEG withtheCG,thegreatestdifferencewasfoundinthewidth ofthesofttissueinsertion(p=0.002)andthelengthofthe nasalsofttissuedidnotshowsignificantchanges.
Theanalysisoftheratiosbetweentheskeletalandsoft tissuemeasurements,intheEG,showedthatthealterations occurinaproportioncloseto1:1.The meanofthe alter-ationsofthe4softtissuevariableswasdividedbythemean ofthealterationsinthe4skeletalmeasurements.The out-comeallowsustostatethat,foreachmillimeterincrease intheskeletalvariables,thesofttissuevariablesincrease 0.95mm. In percentage terms, for each percentage unit increaseintheskeletalmeasurement,thesofttissue mea-surementsincrease0.9%.
Discussion
SinceRMEwasintroducedin1860,becomingestablishedin the period between the end of the 1860s8 and beginning
ofthe1870s,9orthodontistshaveextensivelyevaluatedthis
procedurewithregardtodentoskeletalalterationsandthe repercussions for the nasal cavity. The close relationship between themaxilla and the nasalcavity5,6 may have an
influence on the physiology1,2 and format of the nose,10
increasingthechancesofindividualswithmaxillary hypopla-siaacquiring aclinical mouth-breathing condition10 which
mayhaveseriousconsequencesforthegrowthand develop-mentofthefaceandocclusion,2---4,7besides problemsofa
medicalnature,andonthedevelopmentofthebody.3,12,13
Accordingly,variousresearchershave sought toshedlight onthepossiblebenefitsofRMEforthenasalcavityandon theincreaseinnasalbreathingcapacity.1,2,7,11
In recent years, the soft tissue of the nose has been citedbysomeresearchersasbeingastructureofextreme importance for maintaining the stability of the results obtainedwithRME,23,33 inadditiontothe estheticimpact
thatmayensueaftertheprocedure.36Evenso,studies
deal-ingwiththesestructuresarescarce,andthemainfocusof almostall the works citedin the literature is onskeletal alteration.
Theproposalinourstudywas,usingCT,toevaluatethe repercussionsofRMEontheskeletalandsofttissue struc-turesofthenoseinmouth-breathingpatientswithmaxillary hypoplasia. CT has been shown to be an excellent diag-nosticresourceprovidingconditionsfor locating anatomic pointswithahigh degree ofreliability, aswellas provid-ingmeasurementsofsoftandskeletaltissuewithextreme precision.38
Table4 Comparisonbetweenpre-RMEandpost-RMEvaluesandbetweentheExperimentalGroup(EG)andControlGroup(CG), ofthesofttissuevariables(valuesdisplayedinmm).
Variable Group Pre-RME
M±DP (Min---Max) Post-RME M±DP (Min---Max) Pre-RMEPost-RME alteration(average) pa (pre-RME---post-RME) mm % Widthofthe softtissue insertion EG 32.59±2.84 (28.73---39.95) 34.02±2.85 (29.58---41.99) +1.43 +4.39% <0.001 CG 32.71±1.72 (30.09---35.44) 32.78±1.89 (29.88---36.19) +0.07 +0.21% 0.758 pb(betweengroups) 0.876 0.002 Alarwidth EG 32.68±3.27 (27.13---40.59) 33.81±3.32 (27.43---42.75) +1.13 +3.46% <0.001 CG 32.69±1.74 (30.16---35.81) 32.29±2.08 (29.13---36.31) −0.40 −1.22% 0.085 pb(betweengroups) 0.990 0.003 Heightofthe nasalsoft tissue EG 47.95±4.07 (41.27---58.77) 49.74±4.39 (41.70---59.14) +1.79 +3.73% <0.001 CG 47.49±4.69 (40.16---55.89) 47.69±4.67 (40.41---55.86) +0.20 +0.42% 0.101 pb(betweengroups) 0.714 0.003 Lengthofthe nasalsoft tissue EG 15.89±1.62 (12.17---18.84) 16.57±1.67 (12.38---20.68) +0.68 +4.28% <0.001 CG 15.41±1.38 (13.30---17.74) 15.66±1.57 (12.05---18.29) +0.25 +1.62% 0.161 pb(betweengroups) 0.301 0.068
ap,significancevalueofStudent’st-testforpairedsamples(differencebetweenpreandpost).
b p,significancevalueofStudent’st-testforindependentsamples(differencebetweentheEGandtheCG).
PatientstreatedwithRMEpresentwithtransverse defi-cienciesofthemaxillaand,therefore,additionaltransverse alterationscanbeexpected.Theresultsshowed,however, thatafterRME,changesoccurredinthe3dimensionsofthe noseandnotjustthewidth,whichhasbeenthemainfocus ofthemajorityofthestudiesreviewed.
With regard to skeletal alterations, our studies found larger alterations in the width of the pyriform aper-ture with a significant average increase (p<0.001) of 1.98mm (+9.15%). Similar results were obtained by Her-shey et al. (+2.12mm),15 Sila Filho et al. (+2.07mm),16
Chung and Font (+1.75mm),5 Garret et al. (+1.89mm),18
Iwasakietal.(+2.09mm),25Bargazanietal.(1.4---2.7mm),27
Hakan and Palomo (+1.5mm),30 and Leri and Basciftci
(+1.97mm).32 Larger increases innasal width, also
signif-icant, were observed by Wertz (+4mm),14 Basciftci and
Karaman(+3.47mm),18Christieetal.(+2.73mm),21Görgülü
etal.(+5.28mm),22Smithetal.(+3.15mm)23andTokuetal.
(+2.54mm).31 Thestudies conductedbyCross and
McDon-ald(+1.06mm),17Ballantietal.(+1.22mm),20Ribeiroetal.
(+1.28mm),26 Kanomi etal.(+1.36mm)28 andC¸örekc¸iand
Göyenc¸(+0.81mm)29 alsoshowedincreasesinnasalwidth,
howeveronlythestudybyCrossandMcDonald17 exhibited
any statistical significance. The largest differences noted occurredinstudiesthatadoptedmethodologieswhichused two-dimensional diagnosis.14,29 Of the three-dimensional
methodologiesemployed,onlythestudybyGörgülüetal.22
found larger deviations than the means of the other studies.
Theanalysisofpossiblealterationsintheheightofthe nasalcavity,showedthatinsagittalform(multiplanar sagit-talimage)nasalheightincreasedsignificantly(p<0.001)by 1.51mm (+3.37%)andinfrontalform(multiplanarcoronal image)theheightofthepyriformapertureshowed signifi-cantaverageincreases(p<0.001)of1.26mm(4%).Theonly works thatevaluated skeletalalterations in the height of thenasalcavity,post-RME,werethoseofCrossand McDon-ald(+1.26mm)17andC¸örekc¸iandGöyenc¸(+1.35mm).29Both
usedtwo-dimensionalmethodologiesinfrontalform. Wealsoevaluatedthetotallengthofthenasalskeleton, notingasignificantincrease(p<0.002)of0.53mm(+1.12%). None of the evaluated works researched potential alter-ationsintheskeletallengthofthenasalcavity.
All the studies surveyed in the literature performed short-termevaluations(between3 and6 monthson aver-age) and,aswiththeresultsof ourstudy,alarge part of them found thereto benoinfluence on growthby virtue of the short space of time between pre- and post-RME evaluations,7,10,11,14,20,30,32contradictingthefindingsofSilva
Filho et al.,16 Cross andMcDonald,17 Kanomi etal.28 who
determinedthat,evenintheshortterm,thegrowthfactor couldaffectthestructuresbeingmeasured.
Inmakingashort-termstudy,thegoalwastoanalyzethe realnasalalterationsfromspecificallytheactionsoftheREM attheevaluatedstructures,avoidingthatthegrowthfactor wouldinterfereintheresultsifevaluatedinlongterm.
Some authors checked for skeletal modifications by means of ENT examinations,1,2,7,11 with the aim of
evaluatingtherealbenefitsofRMEonthenasalphysiology and found that,in the main, thealterations in the width ofthenasalcavitycontributesignificantlytoincreasedflow andnasalairwayvolumeinpatientswithmaxillary hypopla-siawhohadbeensubjectedtoRMEtreatment.
Intheevaluationofthesofttissuestructuresofthenose, intheEG,thelargestincreasesfoundinourstudyoccurred inthewidthofthesofttissueinsertionwithanaverageof +1.43mm(+4.39%)(p<0.001).Thealarwidthincreasedon aslightlylowerscaleat1.13mm(+3.46%),thoughwiththe samestatisticalsignificance(p<0.001).Severalofthealbeit few studies found in the literature that deal with alter-ationsinthewidthofthesofttissueofthenose,post-RME, havefoundvaluessimilartothoseinthepresentstudy,for exampleBergeretal.(+2mm),33Johnsonetal.(+1.5mm)37
andYlmazetal.(+1.19mm),40andothersexhibitedhigher
valueslike the studies of Kulbersh et al.(+3.2mm)39 and
Magnusson etal.(+2.88mm)36 or muchlowervalues,asis
the case withKim etal.(+0.96mm),35 though all
demon-stratedstatisticallysignificance.
By evaluating the length of the nasal soft tissue, we foundasignificantaverageincrease(p<0.001)of0.68mm (+4.28%) in the EG, post-RME. The studies by Karaman etal.(+2.53mm)34andMagnussonetal.(+3.09mm)36
exhib-ited greater increaseswhile Ylmaz et al. detected lower increases(+0.31mm),40 howeverall weresignificant,
con-tradicting the results of Kilic¸ et al.6 whose increase of
0.23mminthesofttissuelengthwasdeemedinsignificant (p>0.05).
In a study ofthe potential alterationsin the heightof thenasalsofttissue,post-RME,wefoundintheEGa signif-icantaverageincrease(p<0.001)of1.79mm(+3.73%).The onlystudythatdealtwiththeheightofthenasalsofttissue wasthatofMagnussonetal.36withaninsignificantaverage
(p>0.05)of+0.18mm,buttheseauthorsanalyzedthe alter-ationsoccurredaftersurgerydisjunctionandnotaRMEas inourstudy.
Theonlystudyonsofttissuealterationswhich,likethe present study,studied modifications to the nose in three dimensions, was that of Magnussen et al.36 as previously
dimensioned, a work based on surgical expansion which makesourstudythefirsttotakethisapproachwithpatients whohavebeenexclusivelytreatedwithorthopedicRME.
Aswiththosestudiesthatevaluatedskeletalalterations, all the workson soft tissue wereperformed over a short period of time,6,33,37,40 showing all alterations occurred
exclusivelybytheeffectoftheRMEwithouttheinfluence ofthegrowthfactorduetotheshortintervalbetweenT1 andT2.
According to Berger et al.33 and Kulbersh et al.,39 the
softtissuetendstoaccompanyRMEskeletalalterationsin a1:1proportion(100%).Thesevaluesclosely approximate theresults ofourstudy whichfound that,for every1mm ofskeletalincrease,0.5mm ofsofttissuealterationtakes place(0.90%),contradictingthestudiesofKaramanetal.,34
whichstatethatthereisonly18%ofsofttissuealteration duringskeletalmodifications.
An essential factor in performing a correct analysis is the reliability of the measurements, i.e., the preci-sion of the selected points41---43 and the analysis of the
method error in the measurements. Our study demon-stratedahighreliabilitywithICCvaluesinexcessof0.95,
both for the intra-examiner and the inter-examiner eval-uations. For the most part, the studies quoted in the literature did not display method error and several did not present a sampling calculation, to validate the size ofthe sample, which may lead tobias in theresults and interpretation.
TheresultsobtainedintheEG madeitclearthat post-RME nasal changes occur in the three dimensions, both in soft tissues and in skeletal tissues, but the compari-sonbetweentheEGwiththeCGshowedthatthechanges in length are those that have the less significant impact amongthe evaluatedstructures. In addition, the statisti-calresultsobtainedintheCG,whencomparingT1andT2 times,showedthattherewasnointerferenceofthegrowth factorbetweentheevaluationperiods.
We should remember again that all patients that took partofthisresearchwereundermedicaltreatmentin hos-pitallevelandallCTexams,antheintervalsbetweenthem wereundertakenbyexclusivemedicalneeds,respectingthe ALARAprincipletoeachpatient.Furthermore,itisalso nec-essary to clarify that no medical conduct was performed priortoRME,i.e.,themedicalconductsweredetermined onlyafterRME,therefore,noneofthesepatientsinthe sam-plewereunderwenttoanymedical/surgicalprocedurethat couldchange the characteristics of the nasal soft tissues withinthistimeinterval.
Itisalsoimportanttoclarifythat,aftertheendofthe study,thepatientsintheCGwereproperlytreatedwiththe sameproceduresoftheEG,withoutanyprejudicetothem, duetothesmalltimeofthreemonthsbetweenT1andT2 times.
Ourstudyutilizedanalreadyexistingdatabasewiththe pertinentauthorizationsandsoughttofollowallthesteps requiredtoguaranteemaximumcredibilitywiththeresults obtained, ranging from the use of a simple methodology thatisreliableandeasilyreproducibletotheperformance ofallthenecessary statistical studiestodiminish therisk ofbias,therebyincreasingthereliabilityofthestudy,duly approvedbytheresearchethicscommitteeandbythe Clini-calTrials(ID:CRB-ORTO-3).Thiskindofstudymaypermitin thefuture,throughtheevaluationofsofttissue,adequate planningofestheticproceduresatthetipandbaseofthe noseandalsotheperformanceofobjectivemeasurements inearlyorlatesurgicalresults.
Conclusion
1. In the shortterm, RME caused significant skeletal and softtissuealterationsinallthevariablesstudiedwhen analyzingpre-andpost-RMEmeasurements.
2. The soft tissues of the nose accompany the skeletal alterationsinaproportioncloseto1:1,andforevery mil-limeterofskeletalincreasethereisasofttissueincrease of0.95mm(0.90%).
3. Thiskindofstudymaypermitinthefuture,throughthe evaluationofsofttissue,adequateplanningofesthetic proceduresatthetipandbaseofthenoseandalsothe performanceofobjectivemeasurementsinearlyorlate surgicalresults.
Conflicts
of
interest
Theauthorsdeclarenoconflictsofinterest.
References
1.CappelletteMJr,CruzOLM,CarliniD,WeclxLL,PignatariSSN. Evaluationofnasalcapacitybeforeand afterrapidmaxillary expansion.AmJRhinol.2008;22:74---7.
2.HaliciogluK,Kilic¸N,YavuzI,AktanB.Effectsofrapidmaxillary expansionwithamemorypalatalsplitscrewonthemorphology ofthemaxillarydentalarchandnasalairwayresistance.EurJ Orthod.2010;32:716---20.
3.Subtelny JD. Oral respiration: facial maldevelopment and corrective dentofacial orthopedics. Angle Orthod. 1980;50: 147---64.
4.McNamaraJuniorA.Influenceofrespiratorypatternon cranio-facialgrowth.AngleOrthod.1981;51:269---300.
5.ChungCH,FontB.Skeletalanddentalchangesinthesagittal, vertical,andtransversedimensionsafterrapidpalatal expan-sion.AmJOrthodDentofacialOrthop.2004;126:569---75. 6.Kilic¸N,Kiki A, OktayH,Erdem A.Effects ofrapidmaxillary
expansiononHoldawaysofttissuemeasurements.EurJOrthod. 2008;30:239---43.
7.De FelippeNLO, Bhushan N, DaSilveira AC, Viana G, Smith B.Long-termeffectsoforthodontictherapyonthemaxillary dentalarchandnasalcavity.AmJOrthodDentofacialOrthop. 2009;136:490e1---8e.
8.Haas AJ. Rapid expansion of the maxillary dental arch and nasalcavitybyopeningthemidpalatalsuture.AngleOrthod. 1961;31:73---90.
9.HaasAJ.Palatalexpansion:just thebeginningofdentofacial orthopedics.AmJOrthod.1970;57:219---55.
10.HaralambidisA,DemirkayaAA,AcarA,Küc¸ükkelesxN,Mustafa A, ÖskayaS.Morphologychangesofthenasalcavityinduced by rapid maxillary expansion: a study on 3-dimensional computed tomography models. Am J Orthod Dent Orthod. 2009;136:815---21.
11.BaratieriA,AlvesMJr,SouzaMMG,AraújoMTS,MaiaLC.Does rapid maxillary expansion have long-term effects on airway dimensions and breathing? AmJ Orthod Dentofacial Orthop. 2011;140:146---56.
12.TeccoS,FestaF,TeteS,LonghiV,D’AttilioM.Changesinhead posture after rapid maxillary expansion in mouth-breathing girls:acontrolledstudy.AngleOrthod.2005;75:171---6. 13.TeccoS,CaputiS,FestaF.Evaluationofcervicalposture
follow-ingpalatalexpansion:a12-monthfollow-upcontrolledstudy. EurJOrthod.2007;29:45---51.
14.WertzRA.Skeletalanddentalchangesaccompanyingrapid mid-palatalsutureopening.AmJOrthod.1970;58:41---63.
15.Hershey HG, Stewart BL, Warren DW. Changes in nasal air-wayresistanceassociatedwithrapidmaxillaryexpansion.AmJ Orthod.1976;69:274---84.
16.Silva FilhoOG,Prado MontesLA, Torelly LF.Rapid maxillary expansion in the deciduous and mixed dentition evaluated throughposteroanterior cephalometricanalysis.AmJOrthod DentofacialOrthop.1995;107:268---75.
17.Cross DL, McDonald JP. Effect of rapid maxillary expansion on skeletal, dental,and nasal structures: a postero-anterior cephalometricstudy.EurJOrthod.2000;22:519---28.
18.Basciftci FA, Karaman AI. Effects of a modified acrylic bonded rapid maxillary expansion appliance and vertical chin cap on dentofacial structures. Angle Orthod. 2002;72: 61---71.
19.GarrettBJ,CarusoJM,RungcharassaengK,FarrageJR,KimJS, TayloreGD.Skeletaleffectstothemaxillaafterrapidmaxillary
expansionassessedwithcone-beamcomputedtomography.Am JOrthodDentofacialOrthop.2008;134,8e1---e11.
20.Ballanti F, Lione R, Baccetti T, Franchi L, Cozza P. Treat-ment and posttreatment skeletal effects of rapid maxillary expansioninvestigatedwithlow-dosecomputedtomographyin growingsubjects.AmJOrthodDentofacialOrthop.2010;138: 311---7.
21.Christie KF, Boucher N, Chung CH. Effects of bonded rapid palatal expansion onthe transverse dimensions of the max-illa:a cone-beamcomputed tomographystudy.Am JOrthod DentofacialOrthop.2010;137:S79---85.
22.Görgülü S, Gokce SM, Olmez H, Sagdic D, Faith O. Nasal cavity volume changes after rapid maxillary expansion in adolescentsevaluatedwith3-dimensionalsimulationand mod-eling programs. Am JOrthod Dentofacial Orthop. 2011;140: 633---40.
23.Smith T, GhoneimaA, StewartK, Liu S, Eckert G, Halum S, etal.Three-dimensionalcomputedtomographyanalysisof air-way volume changes after rapid maxillary expansion. Am J OrthodDentofacialOrthop.2012;141:618---26.
24.Cordasco G, NuceraR, Fastuca R, Matarese G, Lindauer SL, Leone P, et al. Effects of orthopedic maxillary expansion on nasal cavity size in growing subjects: a low dose com-putertomographyclinicaltrial.IntJPediatrOtorhinolaryngol. 2012;76:1547---51.
25.IwasakiT,SaitohI,TakemotoY,InadaE,KanomiR,HayasakiH, etal.Improvementofnasalairwayventilationafterrapid max-illaryexpansionevaluatedwithcomputationalfluiddynamics. AmJOrthodDentOrthod.2012;141:269---78.
26.RibeiroANC,DePaivaJB,Rino-NetoJ,Illipronti-FilhoE, Triv-inoT,FantiniSM.Upperairwayexpansionafterrapidmaxillary expansionevaluated withcone beam computedtomography. AngleOrthod.2012;82:458---63.
27.Bazargani F, Feldmann I, Bondemarkc L. Three-dimensional analysis of effects of rapid maxillary expansion on facial sutures and bones. A systematic review. Angle Orthod. 2013;83:1074---82.
28.Kanomi R, Deguchi T, Kakuno E,Yamamoto TT, Roberts WE. CBCTofskeletalchangesfollowingrapidmaxillary expansion toincreasearch-lengthwithadevelopment-dependentbonded orbandedappliance.AngleOrthod.2013;83:851---7.
29.C¸örekc¸iB,Göyenc¸YB.Dentofacialchangesfromfan-typerapid maxillaryexpansionvstraditionalrapidmaxillaryexpansionin earlymixeddentition:aprospectiveclinicaltrial.AngleOrthod. 2013;83:842---50.
30.ElH,PalomoJM.Three-dimensionalevaluationofupper air-wayfollowingrapidmaxillaryexpansion:aCBCTstudy.Angle Orthod.2014;84:265---73.
31.TokluMG,Germec-CakanD,TozluM.Periodontal, dentoalveo-lar,and skeletaleffectsoftooth-borneandtooth-bone-borne expansion appliances. Am J Orthod Dentofacial Orthop. 2015;148:97---109.
32.LLeriZ,BasciftciFA.Asymmetricrapidmaxillaryexpansionin trueunilateralcrossbitemalocclusion:aprospectivecontrolled clinicalstudy.AngleOrthod.2015;85:245---52.
33.Berger JL, Pangrazio-Kulbersh V, Thomas BW, Kaczynski R. Photographicanalysisoffacialchangesassociatedwith max-illaryexpansion.AmJOrthod DentofacialOrthop. 1999;116: 563---71.
34.KaramanAI,Basc¸iftc¸IFA,GelgörIE,DemirA.Examinationofsoft tissuechangesafterrapidmaxillaryexpansion.WorldJOrthod. 2002;3:217---22.
35.KimKB,AdamsD,AraújoEA,BehrentsRG.Evaluationof imme-diatesofttissuechangesafterrapidmaxillaryexpansion.Dental PressJOrthod.2012;17:157---64.
36.MagnussonA,BjerlinK,KimH,NilssonP,MarcussonA. Three-dimensionalcomputedtomographicanalysisofchangestothe externalfeatures of the nose aftersurgically assisted rapid
maxillary expansion and orthodontic treatment: a prospec-tive longitudinal study. Am J Orthod Dentofacial Orthop. 2013;144:404---13.
37.JohnsonBM,McNamaraJA,BandeenRL,BaccettiT.Changesin softtissuenasalwidthsassociatedwithrapidmaxillary expan-sioninprepubertaland postpubertalsubjects.AngleOrthod. 2010;80:995---1001.
38.PalaisaJ, Ngan P, Martin C, Razmus T. Use of conventional tomography to evaluate changes in the nasal cavity with rapid palatal expansion. Am J Orthod Dentofacial Orthop. 2007;132:458---66.
39.KulbershVP,Wine P,HaugheyM,PajtasB,KaczynkiR. Cone beam computed tomography evaluation of changes in the
naso-maxillarycomplexassociatedwithtwotypesofmaxillary expanders.AngleOrthod.2012;82:448---57.
40.Yilmaz BS, Kucukkleles N. Skeletal, soft tissue, and airway changesfollowingthealternatemaxillaryexpansionsand con-strictionsprotocol.AngleOrthod.2015;85:117---26.
41.RhineJS,CampbellHR.ThicknessoffacialtissuesinAmerican blacks.JForensicSci.1980;25:847---58.
42.StephanCN,SimpsonEK.Facialsofttissuedepthsin craniofa-cialidentification(PartI):ananalyticalreviewofthepublished adultdata.JForensicSci.2008;53:1257---72.
43.CevidanesL,OliveiraAEF,MottaA,PhillipsC,BurkeB,Tyndall D.HeadorientationinCBCT---generatedcephalograms.Angle Orthod.2009;79:971---7.