Les revues systématiques Cochrane en orthodontie

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� 2010 CEOPublished by / Edite par Elsevier Masson SAS

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Cochrane systematic reviews inorthodontics

Les revues syst�ematiques Cochrane enorthodontie

Marie DELI�EREa,Wei YAN-VERGNESb, Olivier HAMELc, Christine MARCHAL-SIXOUd,Jean-No€el VERGNESe,*

aDocteur en chirurgie dentaire, UFR d’odontologie Paris VII, 75006 Paris, FrancebDocteur en chirurgie dentaire, d�epartement de sant�e publique, UFR d’odontologie de Toulouse,31400 Toulouse, FrancecMCU-PH, d�epartement de sant�e publique, UFR d’odontologie de Toulouse, 31400 Toulouse,FrancedMCU-PH, d�epartement d’orthop�edie dentofaciale, UFR d’Odontologie de Toulouse, 31400Toulouse, FranceeAHU, d�epartement d’�epid�emiologie, UFR d’odontologie de Toulouse, 3, chemin desMaraıchers, 31400 Toulouse, France

Available online: 26 August 2010 / Disponible en ligne : 26 aout 2010

SummaryIntroduction. – The Cochrane Collaboration is an internationalscientific not-for-profit organization the purpose of which is toproduce and distribute systematic reviews of randomized clini-cal trials. The aim of this paper is to list the different existingCochrane systematic reviews in the field of dentofacial ortho-pedics (DFO) and to analyse their main features.

Material and methods. – The choice of Cochrane systematicreviews based on dentofacial orthopedics was made from theexhaustive list published by the Cochrane Oral Health Group.

Results. – A total of 12 systematic Cochrane reviews related todentofacial orthopedics were listed. All concluded on the need toconduct randomized clinical trials using more appropriatemethodologies and comprising larger samples. None of thesesystematic reviews offered clear proof supporting any one formof treatment or treatment modality.

Discussion. – Despite the lack of relevant conclusions in the stillmeagre number of Cochrane systematic reviews related to DFO,it is essential for orthodontists to regularly consult the reviews in

R�esum�e

Introduction. – La Collaboration Cochrane est une organisa-tion internationale scientifique a but non lucratif, dont l’objetest de produire et de diffuser des revues syst�ematiquesd’essais cliniques randomis�es. L’objectif de ce travail est delister les diff�erentes revues syst�ematiques Cochrane exis-tantes en orthop�edie dentofaciale, et d’analyser leurs princi-pales caract�eristiques.Mat�eriel et m�ethodes. – La s�election des revues syst�ema-tiques Cochrane en rapport avec l’orthop�edie dento-facialeest effectu�ee a partir de la liste exhaustive publi�ee par leGroupe Cochrane pour la sant�e buccodentaire.R�esultats. – Un total de 12 revues syst�ematiques Cochraneen rapport avec l’orthop�edie dento-faciale est recens�e. Toutesconcluent a la n�ecessit�e de conduire des essais cliniquesrandomis�es avec une m�ethodologie plus adapt�ee, et r�ealis�essur des effectifs plus importants. Aucune de ces revuessyst�ematiques n’apporte des �el�ements de preuve solides enfaveur de tel ou tel traitement ou modalit�e de traitement.Discussion. – Malgr�e l’absence de conclusions pertinentesissues des revues syst�ematiques Cochrane encore peu nom-breuses en ODF, leur consultation r�eguli�ere s’av�ere un outil

*Correspondence and reprints / Correspondance et tir�es a part.

e-mail address / Adresse e-mail : [email protected] (Jean-No€el Vergnes)

International Orthodontics 2010 ; 8 : 278-292doi:10.1016/j.ortho.2010.07.012

mailto: [email protected]

mailto: [email protected]

http://dx.doi.org/10.1016/j.ortho.2010.07.012

Cochrane systematic reviews in orthodonticsLes revues syst�ematiques Cochrane en orthodontie

the framework of their daily evidence-based orthodontic prac-tice. This is true too for orthodontic researchers as clinical DFOresearch needs to be extended with the setting up of methodo-logically unquestionable randomized clinical trials. However,there exist alternatives to randomized clinical trials offering alower level of proof but which are better suited to the field ofdentofacial orthopedics.

� 2010 CEO. Published by Elsevier Masson SAS. All rightsreserved

Key-words

·Orthodontics.·Evidence-Based Dentistry.

·Review.Introduction

The Cochrane Collaboration is an international not-for-profitscientific body, the function of which is to produce and dis-tribute systematic reviews of randomized clinical trials in theliterature in all health-care fields [1](fig. 1). As an overabun-dance of medical and scientific information is now available, ithas become urgent to make a critical synthesis. Occasionally,this process has led to the conclusion that there is no relevantstudy providing a high level of evidence. A systematic reviewof the literature is the only scientific means of synthesizing theresults of the different clinical research studies claiming thesame research objectives [2]. Such a review differs from thetraditional review of the literature by virtue of the rigorous,transparent and reproducible methods used which aredesigned to eliminate the bias involved in study selectionand interpretation of the results [2]. In recent years, systematicreviews and metaanalyses (statistical syntheses of results fromdifferent studies) have enabled health-care professionals tointegrate the results of biomedical research in a more rationalmanner. Thanks to the methodological quality of the Cochranesystematic reviews and the output of the Cochrane organiza-tion, Cochrane systematic reviews have come to be acknowl-edged as a reference in the field of information synthesis.Cochrane Collaboration systematic reviews focus almost exclu-sively on randomized clinical trials (RCT), thus making thereviews an indispensable feature of the Evidence-BasedMedicine (EBM) concept. For the clinician, EBM involvesintegrating into his/her daily practice facts, which have beenproven in clinical research studies.In the area of modern biomedical research, RCTs are consid-ered the reference for assessing the efficacy of a treatmentprocedure. Consequently, this type of interventional study inwhich two groups of patients are randomly selected ranks firston the scale of levels of proof. However, RCTs are not alwayssuited to all forms of treatment procedures requiring evalua-tion. In orthodontics, in particular, RCTs have to overcome

International Orthodontics 2010 ; 8 : 278-292

indispensable pour l’orthodontiste dans le cadre d’uned�emarche de pratique clinique quotidienne factuelle, maisaussi pour l’orthodontiste chercheur. En effet, la rechercheclinique en ODF doit se d�evelopper, et permettre la mise enœuvre d’essais cliniques randomis�es m�ethodologiquementindiscutables. Cependant, des �etudes alternatives aux essaiscliniques randomis�es existent, a moindre niveau de preuves,mais peut-etre plus adapt�ees a la sp�ecificit�e de l’orthop�ediedento-faciale.� 2010 CEO. Edite par Elsevier Masson SAS. Tous droitsreserves

Mots-cl�es

·Orthodontie.

·Evidence-based dentistry.

·Revue.Introduction

La Collaboration Cochrane est une organisation internationalescientifique a but non lucratif, qui a pour objectif de produire etdiffuser des revues syst�ematiques d’essais cliniquesrandomis�es de la litt�erature dans tous les domaines de la sant�e[1](fig. 1). L’information m�edicale et scientifique �etant devenuepl�ethorique, il est devenu n�ecessaire d’en faire la synth�esecritique. Elle aboutit parfois a la constatation qu’il n’existeaucune �etude pertinente a haut niveau de preuves. La revuesyst�ematique de la litt�erature est l’unique moyen scientifiquede synth�etiser les r�esultats de diff�erentes �etudes de rechercheclinique partageant un meme objectif de recherche [2]. Elle sedistingue de la traditionnelle revue de la litt�erature par unem�ethodologie rigoureuse, transparente et reproductible quivise a �eliminer les biais de s�election des �etudes et d’interpr�eta-tion des r�esultats [2]. Ces derni�eres ann�ees, les revuessyst�ematiques et m�eta-analyses (synth�ese statistique desr�esultats de diff�erentes �etudes) ont permis aux professionnelsde sant�e d’int�egrer avec plus de rationalit�e les r�esultats de larecherche biom�edicale. La qualit�e m�ethodologique des revuessyst�ematiques Cochrane et la productivit�e de cette organisa-tion ont fait des revues syst�ematiques Cochrane la r�ef�erenceen mati�ere de synth�ese de l’information. Les revues syst�ema-tiques de la Collaboration Cochrane se basent de mani�erequasi-exclusive sur des essais cliniques randomis�es (ECR),faisant de ces revues syst�ematiques un �el�ement incontour-nable du concept d’evidence-based medicine (EBM). L’EBMconsiste, pour le clinicien, a int�egrer dans sa pratique quotidi-enne des faits prouv�es par des �etudes de recherche clinique.En recherche biom�edicale moderne, l’ECR est consid�er�ecomme la m�ethodologie de r�ef�erence pour �evaluer l’efficacit�ed’une intervention th�erapeutique. Par cons�equent, ce typed’�etude interventionnelle ou deux groupes de patients sontr�epartis au hasard, se retrouve au sommet de l’�echelle desniveaux de preuves. Toutefois, l’ECR n’est pas toujours adapt�ea toutes les proc�edures th�erapeutiques susceptibles d’etre

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[(Fig._1)TD$FIG]

Fig. 1: The logo of the Cochrane Collaboration.Fig. 1 : Le logo de la Collaboration Cochrane.

Marie DELI�ERE et al.

numerous difficulties [3,4], e.g. the choice of an ethicallysuitable control group, the cost of orthodontic treatment, theneed for long-term follow-up, the establishment of sufficientlylarge sample groups, and the broad diversity of evaluationcriteria. Moreover, orthodontic treatment is often performedon minors, thus rendering sample selection even more com-plex. The outcome is that RCTs in orthodontics frequently dealwith small samples with numerous dropouts and theoreticalassessment criteria, which are often far removed from thepractitioner’s treatment aims.

In such circumstances, one may well question the value andusefulness of RCTs and, even more so, of systematic reviews ofRCTs in orthodontics. The aim of this paper is to list thevarious existing Cochrane systematic reviews in dentofacialorthopedics, to highlight their main features and to discuss thevalue and usefulness of these systematic reviews for theresearcher and the practitioner.

Materials and methods

The choice of Cochrane systematic reviews related to dento-facial orthopedics was made from the complete list of

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�evalu�ees. En orthodontie particuli�erement, la conduite d’unECR doit faire face a de multiples difficult�es [3,4] : choixd’un groupe t�emoin �ethiquement acceptable, cout des traite-ments orthodontiques, n�ecessit�e d’un suivi a long terme,constitution d’�echantillons suffisamment importants, etgrande diversit�e des crit�eres de jugement. De plus, les traite-ments orthodontiques sont surtout r�ealis�es sur des patientsmineurs, rendant les inclusions plus complexes encore. Ils’ensuit que les ECR en orthodontie portent souvent sur des�echantillons restreints, avec de nombreux sujets perdus devue et des crit�eres de jugement th�eoriques, parfois �eloign�esdes objectifs th�erapeutiques du praticien.Dans de telles conditions, nous pouvons nous interroger sur lavaleur et l’int�eret des ECR, et a fortiori des revues syst�ema-tiques d’ECR en orthodontie. L’objectif de ce travail est delister les diff�erentes revues syst�ematiques Cochrane exis-tantes en orthop�edie dento-faciale, d’en relever les principalescaract�eristiques et de discuter la valeur et l’int�eret de cesrevues syst�ematiques pour le chercheur et le praticien.

Mat�eriel et m�ethodes

La s�election des revues syst�ematiques Cochrane en rapportavec l’orthop�edie dentofaciale est effectu�ee a partir de la liste



Cochrane systematic reviews published by the CochraneGroup for the Cochrane Oral Health Group – www.ohg.cochrane.org. Selection was performed by two independentauthors (WYV, JNV). The original versions of each selectedsystematic review were obtained from the most recent editionof The Cochrane Library, Issue 3, 2009. Critical analysis ofthese systematic reviews was based on the methodologydescribed by Wee et al. in 2008 [5].

The follow information was extracted from each systematicreview:— title of the systematic review;— author and country of affiliation;— year;— nature of the studies included;— number of studies included;— number of patients included;— pathology involved;— nature of the treatment;— type of qualitative analysis performed and conclusion ofthis qualitative analysis;— presence or not of a statistical compilation of the results(metaanalysis);— authors’ conclusions.Two authors (MD, JNV), working independently, extracted thedata using a standardized grid covering the above-mentionedcriteria. Any disparity was resolved by consensus discussion.

The French translation of the terms reported in this operationwas obtained from the French Center of Evidence-BasedDentistry – Faculty of Dentistry, at the University ofToulouse, France (http://cfebd.ups-tlse.fr).

Results

Characteristics of the systematic reviews

In all, 12 Cochrane systematic reviews related to dentofacialorthopedics were listed [6–17](fig. 2). The characteristics ofeach review are reported in Table I. All these systematicreviews took a randomized clinical trial as their main inclu-sion criterion.The first Cochrane systematic review of DFO was published in2001 [17]. Ten systematic reviews out of twelve originatedfrom the United Kingdom (essentially ManchesterUniversity), and two from Brazil [10,11]. Four systematicreviews dealt with malocclusion management [8,11,13,17],four with various treatment modalities [6,9,12,16], two withiatrogenic effects and associated preventive measures [7,15],one with posttreatment retention and one with obstructivesleep apnea in children [10]. The number of RCTs includedin each review ranged from 0 to 15. In three systematic reviews[6,7,13], no RCT met the selection criteria. Only two system-atic reviews obtained their data from more than 500 subjects


exhaustive des revues syst�ematiques Cochrane publi�ees parle Groupe Cochrane pour la sant�e buccodentaire (TheCochrane Oral Health Group – www.ohg.cochrane.org). Las�election est r�ealis�ee ind�ependamment par deux auteurs(WYV, JNV). Les versions originales de chaque revuesyst�ematique s�electionn�ee sont obtenues a partir de la plusr�ecente �edition de la Biblioth�eque Cochrane (The CochraneLibrary, Issue 3, 2009). L’analyse critique de ces revuessyst�ematiques Cochrane est bas�ee sur la m�ethodologied�ecrite par Wee et al. en 2008 [5].Pour chaque revue syst�ematique, les informations suivantessont extraites :— titre de la revue syst�ematique ;— auteur et pays d’affiliation ;— ann�ee ;— nature des �etudes incluses ;— nombre d’�etudes incluses ;— nombre de patients inclus ;— condition pathologique concern�ee ;— nature de l’intervention th�erapeutique ;— type d’analyse qualitative effectu�e, et conclusion de cetteanalyse qualitative ;— pr�esence ou non d’une compilation statistique des r�esultats(m�eta-analyse) ;— conclusion des auteurs.Deux auteurs (MD, JNV) r�ealisent de mani�ere ind�ependantel’extraction des donn�ees au moyen d’une grille standardis�eereprenant les crit�eres pr�ecit�es. Toute discordance est r�esoluepar discussion de consensus.La traduction francaise des termes report�es dans ce travail estobtenue aupr�es du Centre Francais d’Evidence-BasedDentistry - UFR d’Odontologie de l’Universit�e de Toulouse(http://cfebd.ups-tlse.fr).

R�esultats

Caract�eristiques des revues syst�ematiques

Un total de 12 revues syst�ematiques Cochrane en rapportavec l’orthop�edie dentofaciale est recens�e [6–17] (fig. 2). Lescaract�eristiques de chacune sont report�ees dans le Tableau I.Toutes ces revues syst�ematiques ont bien consid�er�e commecrit�ere d’inclusion principal l’essai clinique randomis�e.La premi�ere revue syst�ematique Cochrane en ODFa �et�e pub-li�ee en 2001 [17]. Dix revues syst�ematiques sur 12 provien-nent du Royaume-Uni (essentiellement de l’Universit�e deManchester), et deux proviennent du Br�esil [10,11]. Quatrerevues syst�ematiques traitent de la prise en charge desmalocclusions [8,11,13,17], quatre traitent de modalit�esdiverses de prise en charge th�erapeutique [6,9,12,16], deuxtraitent des effets iatrog�enes et mesures pr�eventivesassoci�ees [7,15], une de contention post-th�erapeutique, uned’apn�ee obstructive du sommeil chez l’enfant [10]. Le nombred’ECR inclus dans chaque revue syst�ematique se situe entre0 et 15. Dans trois revues syst�ematiques [6,7,13], aucun ECR

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[8,15} and all had fewer than 1000 subjects. In the sevensystematic reviews, which included at least two clinical trials[11,12,14–17], the RCTs were particularly heterogeneous(different types of treatment or evaluation criteria). Hence,only two systematic reviews [8,17] could be taken for inclusionin a metaanalysis.

[(Fig._2)TD$FIG]

Fig. 2: Selection process for systematic reviews.Fig. 2 : Processus de s�election des revues syst�ematiques.


The quality of the randomized clinical trialsincluded in the systematic reviews

The methodological quality of the RCTs included in the sys-tematic reviews was generally assessed by the authors of thesystematic reviews.All the systematic reviews, which included at least one RCTperformed a qualitative analysis implementing the CochraneCollaboration evaluation scale (Cochrane Handbook forSystematic Reviews on Intervention). The majority of method-ological defects reported by the authors of the systematicreviews related to the small number of participants, the lackof relevant evaluation criteria, design faults or the absence ofrandomization or of information regarding dropouts. Ethicalevaluation of the clinical trials, taking into consideration theethical criteria involved in all research into human beings, was

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n’a satisfait aux crit�eres d’inclusion. Seulement deux revuessyst�ematiques tirent leurs informations de plus de 500 sujets[8,15], et toutes incluent moins de 1000 sujets. Dans les septrevues syst�ematiques ayant inclus au moins deux ECR[11,12,14–17], les ECR sont particuli�erement h�et�erog�enes(diff�erences de nature de l’intervention th�erapeutique ou decrit�ere de jugement). Ainsi, le nombre de revues syst�ema-tiques ayant pu faire l’objet d’une m�eta-analyse n’est que dedeux [8,17].

Qualit�e des essais cliniques randomis�es inclus dansles revues syst�ematiques

La qualit�e m�ethodologique des ECR inclus dans les revuessyst�ematiques est habituellement �evalu�ee par les auteurs desrevues syst�ematiques.Toutes les revues syst�ematiques ayant inclus au moins unECR ont r�ealis�e une analyse qualitative en ayant recoursa l’�echelle d’�evaluation de la Collaboration Cochrane(Cochrane handbook for systematic reviews on intervention).Les d�efauts m�ethodologiques majoritairement rapport�es parles auteurs des revues syst�ematiques sont les faibles effectifs,l’absence de crit�ere de jugement pertinent, des d�efauts deconception, ou l’absence de randomisation ou d’informationssur les perdus de vue. L’�evaluation �ethique, portant sur la priseen consid�eration des crit�eres �ethiques inh�erents a toute


Table ICharacteristics of Cochrane systematic reviews inorthodontics.

Tableau ICaract�eristiques des revues syst�ematiques Cochrane enODF.

Author (Year,Issue)/Auteur(ann�ee, Issue)Titlea/Titre

Pathologicalcondition/Conditionpathologique

Intervention/Intervention

Numberof trialsincluded/Nombred’essais inclus

Totalnumber ofsubjects/Nombretotal de sujets

Authors’conclusions/Conclusion desauteurs

Parkin et al. (2009,I2) [6]Extraction ofprimary (baby) teethfor the treatment of apermanentunerupted canine inthe palate inchildren/Avulsiond’une denttemporaire pour letraitement d’unecanine permanenteincluse dans lepalais chez l’enfant

Uneruptedpermanent canine inyoung child/Caninepermanente inclusedans le palais chezl’enfant

Extraction of thetemporary maxillarycanine/Avulsion dela canine maxillairetemporaire

0/0 0/0 There is no evidenceproving theusefulness ofextracting thetemporary canine tofacilitate theeruption of thepermanent caninewhen the latter is inan ectopic palatalposition/Il n’y aaucun �el�ement depreuve montrantl’utilit�e de l’avulsionde la caninetemporaire pourfaciliter l’�eruptiond’une caninepermanente enposition ectopiquepalatine

Goh and FernandezMauleffinch (2007,I3) [7]/Goh etFernandezMauleffinch (2007,I3)[7]Inter-dentalbrushing for oralhygiene in patientstreated with a fixedorthodonticappliance/Brossageinterdentaire pourl’hygi�enebuccodentaire chezles patients trait�espar un appareilorthodontique fixe

Dental plaquefollowing wearing ofan orthodonticappliance/Plaquedentairecons�ecutive au portd’un appareillageorthodontique

Use of interdentalbrushes and/orspecial toothbrushesfor fixed orthodonticappliances/Utilisationde brossettesinterdentaires et/oude brosses a dentssp�eciales pourappareilorthodontique fixe

0/0 0/0 The currentrecommendationadvocating the use ofinterdental brushesin addition totraditionaltoothbrushes is notbased on clinicalstudies/Larecommandationactuelle pr�econisantl’utilisation debrossettesinterdentaires enaddition des brossesa dents classiquesne s’appuie pas surdes investigationscliniques

Harrison et al.(2007, I3) [8]Orthodontic

Prominent anteriormaxillary teeth inchildren/Dents

An orthodonticappliance and/orEOF/Appareillage

8/8 592/592 There is scientificevidence suggestingthat early

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Table ICharacteristics of Cochrane systematic reviews inorthodontics. (following)

Tableau ICaract�eristiques des revues syst�ematiques Cochrane enODF. (suite)







treatment forprominent upperfront teeth inchildren/Traitementorthodontique pourles dents maxillairesant�erieures enproalv�eolie chezl’enfant

maxillairesant�erieures enproalv�eolie chezl’enfant

orthodontique et/ouforces extra-orales

orthodontictreatment (7-9 years)is no more effectivethan orthodontictreatment initiatedduring adolescence/Il existe des�el�ements de preuvescientifiquesugg�erant que letraitementorthodontiquepr�ecoce (7–9 ans)n’est pas plusefficace qu’untraitementorthodontiquecommenc�e pendantl’adolescence

Skeggs et al. (2007,I3) [9]Reinforcement ofanchorage duringorthodontic bracetreatment withimplants or othersurgical methods/Renforcement del’ancrage durant untraitementorthodontique pardes implants oud’autres m�ethodeschirurgicales

Insufficientanchorage/Insuffisanced’ancrage

Placement of apalatal implant,miniscrew, onplant,spider screw,titanium plate orzygomatic wire/Miseen place d’implantpalatin, minivis,onplant, spiderscrew, plaque entitane, ou zygomaticwire

1/1 51/51 Slender evidenceindicates thatosseointegratedpalatal implantscould be effective inreinforcinganchorage/Defaibles �el�ements depreuve indiquentque les implantspalatins ost�eo-int�egr�es pourraientetre un moyenefficace de renforcerl’ancrage

Carvalho et al.(2007, I2) [10]Oral appliances andfunctionalorthopedicappliances forobstructive sleepapnea in children/Appareils buccaux

Obstructive sleepapnea in children/Apn�ee obstructivedu sommeil chezl’enfant

Various appliances:Bimler, Herbst,Frankel, Harvold,Andresen, bionator,bite block, or Herrenor Woodsideactivator/Appareillages de :Bimler, Herbst,

1/1 32/32 There is insufficientevidence to claimthat oral orfunctionalorthopedic devicesare effective in thetreatment ofobstructive sleepapnea in children/Il

284 International Orthodontics 2010 ; 8 : 278-292










et appareilsorthop�ediquesfonctionnels pourl’apn�ee obstructivedu sommeil chezl’enfant

Frankel, Harvold,Andresen, bionator,bite block, ouactivateur de Herrenou Woodside

n’y a pas assezd’�el�ements depreuve pouraffirmer quedes appareilsbuccaux ou desappareilsorthop�ediquesfonctionnelspuissent etreefficaces dans letraitement del’apn�ee obstructivedu sommeil chezl’enfant

Lentini-Oliveira etal. (2007, I2) [11]Orthodontic andorthopedictreatment foranterior open bite inchildren/Traitementorthodontique etorthop�edique de lab�eance ant�erieurechez l’enfant

Anterior open bite inchildren/B�eanceant�erieure chezl’enfant

Functionalorthopedicappliance or fixed orremovableorthodonticappliance/Appareillageorthop�ediquefonctionnel ouappareillageorthodontique fixeou amovible

3/3 120/120 There is inadequateevidence toestablishrecommendationsfor clinical practice/Il n’y a pas assezd’�el�ements depreuve pour �etablirdesrecommandationspour la pratiqueclinique

Millett et al. (2007,I2) [12]Adhesives for fixedorthodontic bands/Syst�emes decollage pour baguesorthodontiques enappareillage fixe

Bracket loss/Pertedes bagues

Choice of bondingsystem fororthodontic molarbands/Choix dusyst�eme de collagepour les baguesorthodontiques surmolaires

8/8 488/488 There is insufficientevidence todetermine the bestsystem for bondingorthodontic bands ina fixed appliance/Les �el�ements depreuve sontinsuffisantspour juger dumeilleur syst�emede collagedes baguesorthodontiques enappareillage fixe











Millett et al. (2006,I4) [13]Orthodontictreatment for deepbite and retroclinedupper front teeth inchildren/Traitementorthodontique de lasupraclusion et de lapalato-version desdents sup�ero-ant�erieures chezl’enfant

Deep bite andpalatal tipping ofupper front teeth inchildren/Supraclusion etpalato-version desdents sup�ero-ant�erieures chezl’enfant

Any orthodonticappliance orextraoral force/Toutappareillageorthodontique ouforce extra-orale

0/0 0/0 Judging from theclinical trials it isimpossible torecommend orcontraindicate theuse of any given typeof orthodontictreatment to correctClass II, 2malocclusions inchildren/En sebasant sur les essaiscliniques, il n’est paspossible derecommander ou decontre-indiquerl’emploi d’un typeparticulier detraitementorthodontique pourcorriger lamalocclusion deClasse II.2 chezl’enfant

Littlewood et al.(2006, I1) [14]Retentionprocedures forstabilizing toothposition aftertreatment withorthodontic braces/Proc�edures decontention pourstabiliser la positiondes dents apr�estraitement avec unappareilorthodontique

Relapsedmalocclusion/R�ecidive demalocclusion

All fixed orremovable retentionsystems/Toutsyst�eme decontention fixe ouamovible

5/5 170/170 There is insufficientevidence toestablishrecommendationsregarding retentionin clinical practice/Iln’y a pas assezd’�el�ements depreuve pour �etablirdesrecommandationsvis-a-vis de lacontention pour lapratique clinique

Benson et al. (2004,I3) [15]Fluorides for theprevention of white

Enameldemineralization/D�emin�eralisationam�elaire

All types of topicalfluoride or fluoride-containing material/Tout type de fluor

15/15 723/723 Using topicalfluoride or fluoride-containing bondingmaterial during











spots on teeth duringfixed bracetreatment/Utilisationde fluor pour lapr�evention de lad�emin�eralisationam�elaire pendant letraitementorthodontiquemultibagues

topique ou demat�eriau contenantdu fluor

orthodontictreatment reducesthe risk and severityof demineralizationof the enamel (whitespots). However,there is insufficientevidence toestablish whichmethod orcombination ofmethods for therelease of fluoride ismost effective/L’utilisation de fluortopique ou demat�eriau de collagecontenant du fluordurant le traitementorthodontique r�eduitle risque et la gravit�edesd�emin�eralisationsde l’�email (whitespots), mais il n’y apas assezd’�el�ements depreuve pour �etablirquelle m�ethode oucombinaison dem�ethodes pour lerelargage de fluorest la plus efficace

Mandall et al. (2003,I2) [16]Adhesives for fixedorthodonticbrackets/Syst�emesde collage pour lesbrackets enappareillageorthodontique fixe

Bracket loss/Pertedes brackets

Choice of bondingsystem fororthodonticbrackets/Choix dusyst�eme de collagepour les bracketsorthodontiques

3/3 157/157 There is inadequateevidence to developrecommendationsfor clinical practice/Il n’y a pas assezd’�el�ements depreuve pour �etablirdesrecommandationspour la pratiqueclinique











Harrison and Ashby(2001, I1) [17]/Harrison et Ashby(2001, I1)[17]Orthodontictreatment forposterior crossbites/Traitementorthodontique pourles articul�es crois�espost�erieurs

Posterior crossbites/Articul�es crois�espost�erieurs

All types oforthodontictreatment/Tout typede traitementorthodontique

12/12 402/402 Grinding prematurecontacts betweenmilk teeth iseffective for theprevention ofposterior crossbitein mixed or adultdentition. If thegrinding isinsufficient, the useof a removableexpander iseffective/Lemeulage descontactspr�ematur�es sur lesdents lact�eales estefficace pour lapr�evention del’articul�e crois�epost�erieur endenture mixte ouadulte. Lorsque lemeulage n’est passuffisant,denturemixte ou adulte.Lorsque le meulagen’est pas suffisant, lerecours a unappareillageamovibled’expansion estefficace

a The original title and complete reference are given in the bibliography.




reported in only one systematic review [11]. All the systematicreviews mentioned the need to conduct RCTs using appropri-ate methods and performed on sufficiently large cohorts.Indeed, calculation of the number of subjects performed priorto any clinical research study constitutes one of the essentialscientific criteria most frequently omitted from protocols.

Discussion

This study identified and analyzed the twelve systematicreviews published by the Cochrane Collaboration in connec-tion with dentofacial orthopedics. A quarter of these system-atic reviews found no RCT. None of the systematic reviewsprovided sufficient evidence in favour of any treatment ortreatment modality. Several reasons can account for this.Firstly, it is clear that relatively few RCTs are conducted inorthodontics. Secondly, when such trials are performed, theygenerally run a high risk of methodological bias due to thedifficulty involved in randomizing subjects, the long follow-upand the large number of drop-outs. Lastly, the lack of aninternational consensus regarding the aims of orthodontictreatment in terms of its functional, esthetic and psychosocialobjectives makes comparison between the clinical trialsextremely complex and any overall assessment of the benefitsor unwanted side-effects of treatment almost impossible. Thus,Cochrane DFO systematic reviews can appear to be rathervain exercises given the paucity, weakness and heterogeneityof randomized clinical trials in this field.

Nevertheless, Cochrane systematic reviews remain valuabletools for researchers. Nowadays, for scientific and ethicalreasons, any piece of clinical research must be grounded ina methodical synthesis of the extant literature. By “extantliterature” is meant all the published articles in the field, allthe published research protocols (eg. in the specialized reviewTrials) as well as all the studies listed in the internationalregisters of clinical trials (ClinicalTrials.gov, ISRCTN).Cochrane systematic reviews are useful since they guideresearchers in their clinical methodological choices (and nota-bly choices regarding evaluation criteria) regarding methods,which have been tried and tested by their peers, even when noclinical trials have been conducted in the field. During theproduction process of a Cochrane systematic review, the cor-responding, peer-reviewed protocol is published in advance.So far (The Cochrane Library, Issue 3, 2009), eleven protocolsof Cochrane systematic reviews related to dentofacial ortho-pedics have been published [18–28].

Practitioners may find the information provided up to thepresent by Cochrane systematic reviews somewhat


recherche sur l’etre humain des essais cliniques inclus n’estreport�ee que dans une seule revue syst�ematique [11]. Toutesles revues syst�ematiques �evoquent la n�ecessit�e de conduiredes ECR avec une m�ethodologie plus adapt�ee, et r�ealis�es surdes effectifs suffisants. En effet, le calcul du nombre de sujetseffectu�e pr�ealablement a toute �etude de recherche clinique,est un des crit�eres scientifiques essentiels le plus souventomis dans les protocoles.

Discussion

Ce travail a permis d’identifier et d’analyser les douze revuessyst�ematiques de la Collaboration Cochrane en rapport avecl’orthop�edie dento-faciale. Un quart de ces revues syst�ema-tiques n’ont pas trouv�e d’ECR. Aucune de ces revuessyst�ematiques n’apporte des �el�ements de preuve suffisantsen faveur de tel ou tel traitement ou modalit�e de traitement. Acela, plusieurs explications peuvent etre avanc�ees. En pre-mier lieu, force est de constater qu’il n’existe que relativementpeu d’ECR en orthodontie. Ensuite, lorsqu’ils existent, lesECR sont g�en�eralement a haut risque de biaism�ethodologique (randomisation difficile, longue p�eriode desuivi et nombre de perdus de vues important). Enfin, l’absencede consensus international sur la finalit�e du traitement ortho-dontique (en termes d’objectif fonctionnel, esth�etique et psy-chosocial) rend la comparaison entre les essais cliniquesextremement complexe, et l’�evaluation globale du b�en�eficeou des effets ind�esirables des traitements impossibles.Ainsi, les revues syst�ematiques Cochrane en orthop�edie den-tofaciale peuvent-elles sembler vaines, de par la raret�e, lafaiblesse et l’h�et�erog�en�eit�e des essais cliniques randomis�esdans le domaine.Les revues syst�ematiques Cochrane restent n�eanmoins tr�espr�ecieuses pour les chercheurs. Aujourd’hui, pour des raisonsscientifiques et �ethiques, tout travail de recherche clinique doitse baser sur une synth�ese m�ethodique de la litt�erature exis-tante. Par litt�erature existante, nous devons consid�erer a lafois l’ensemble des articles publi�es dans le domaine, maisaussi l’ensemble des protocoles de recherche publi�es (parexemple, dans la revue sp�ecialis�ee Trials), et l’ensemble des�etudes r�epertori�ees dans les registres internationaux d’essaiscliniques (ClinicalTrials.gov, ISRCTN). Les revues syst�ema-tiques Cochrane sont utiles car elles permettent au chercheurde guider ses choix m�ethodologiques (et notamment celui,difficile, des crit�eres de jugement) vers unem�ethodologie d�ejavalid�ee par des pairs, et ce, meme en l’absence d’essaiscliniques dans le domaine. En effet, durant le processus der�ealisation d’une revue syst�ematique Cochrane, intervient lapublication pr�ealable du protocole correspondant, lui-memevalid�e par des pairs. A ce jour (The Cochrane Library, Issue 3,2009), 11 protocoles de revues syst�ematiques Cochrane enrapport avec l’orthop�edie dento-faciale ont �et�e publi�es [18–28].Pour le praticien, l’information apport�ee a ce jour par lesrevues syst�ematiques Cochrane peut sembler d�ecevante.

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disappointing. However, regular consultation of the Cochranelibrary has numerous advantages. Firstly, regular updating ofCochrane systematic reviews enables practitioners to keep intouch with recent and proven scientific information and data.Second, a systematic review relaying an evidence-based con-clusion in favor of a given type of procedure constitutes anindispensable factor to be taken into account alongside thespecific characteristics of both patient and practitioner whendeciding on the most appropriate treatment. Furthermore,even in the absence of an evidence-based conclusion in asystematic review, the full text, and notably the“Discussion”, can provide practitioners with relevant anduseful information. Such information enables readers to basetheir treatment decisions on studies with a lower level ofevidence than the RCT but can still provide equivalent results[29]. It is very important to emphasize here that the mainpitfall to be avoided when interpreting a non-evidence-basedsystematic review is to conclude that the treatment is ineffec-tive. “Lack of evidence of efficacy” does not signify “evidenceof lack of efficacy”! Finally, it should be noted that the firstCochrane systematic review dates from 2001 and that therecent burst of activity is destined to develop considerablyin the coming years, as witnessed by the number of publishedprotocols [18–28].

The absence of decisive conclusions in Cochrane systematicreviews is more a pointer to inadequate clinical research thana sign of the non-validity of the undertaking. Systematicreviews of randomized clinical trials remain the most reliablemeans of assessing the efficacy of a treatment intervention, afact which health professionals should be aware of. It is theresponsibility therefore of each medical specialty to identifythe problems related to the conduct of randomized clinicaltrials in order to adapt research methods to the nature of thespecific medical field. In orthodontics, new research strate-gies could be developed in order to facilitate the implemen-tation of randomized clinical trials. Among the different prom-ising solutions, one could mention the development ofinternational networks of research-workers, the supervisedinvolvement of freelance practitioners in high-quality clinicalresearch (Practice-Based Research Networks), the logisticalcontribution made by Contract Research Organizations(CROs), the adoption of new technologies designed to assistclinical research [30] and the establishment of solid profes-sional consensuses regarding the purpose of orthodontic treat-ment in terms of assessment criteria. Orthodontists should alsobear in mind that there exist alternatives to randomized clin-ical trials and that observational studies involving cohort,case-control or cross-sectional studies are frequently moreappropriate than clinical trials and supply equally relevantresults for the clinical setting [31].

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Pourtant, la consultation r�eguli�ere de la biblioth�equeCochrane apporte de nombreux avantages. Tout d’abord, lamise a jour r�eguli�ere des revues syst�ematiques Cochranepermet au praticien de rester au contact d’une informationscientifique conforme aux donn�ees av�er�ees et actuelles.Ensuite, une revue syst�ematique qui apporterait une conclu-sion probante en faveur d’une intervention serait un �el�ementincontournable, a conjuguer avec les caract�eristiques propresdu patient et du praticien, pour prendre la meilleure d�ecisionth�erapeutique qu’il soit. Par ailleurs, meme en cas d’absencede conclusion probante d’une revue syst�ematique, le textecomplet, et en particulier la partie « Discussion », fournitdes informations pertinentes et utiles a la pratique clinique.Ces informations permettent au lecteur de baser sa prise ded�ecision th�erapeutique sur des �etudes situ�ees a un niveau depreuve inf�erieur a l’essai clinique randomis�e,mais qui peuventparfois apporter des r�esultats tout a fait �equivalents [29]. Il esttr�es important de souligner ici que le principal �ecueil a �eviterlors de l’interpr�etation d’une revue syst�ematique non probanteest de conclure a l’inefficacit�e du traitement : « absence depreuve d’efficacit�e » ne signifie pas « preuve d’absenced’efficacit�e »! Enfin, notons que la premi�ere revue syst�ema-tique Cochrane date de 2001, et que cet essor r�ecent estamen�e a largement se d�evelopper dans les ann�ees futures,comme l’atteste le nombre de protocoles publi�es [18–28].L’absence de conclusions fortes �emanant des revuessyst�ematiques Cochrane est davantage le signe d’unerecherche clinique insuffisante que le signe de l’inutilit�e de lad�emarche. La revue syst�ematique d’essais cliniquesrandomis�es reste le moyen le plus fiable pour �evaluerl’efficacit�e d’une intervention th�erapeutique, et les profession-nels de sant�e doivent en prendre conscience. D�es lors, ilappartient a chaque sp�ecialit�e m�edicale d’identifier lesprobl�emes li�es a la r�ealisation d’essais cliniques randomis�espour adapter les modalit�es de recherche aux sp�ecificit�es dudomaine. En orthodontie, de nouvelles strat�egies derecherche pourraient etre d�evelopp�ees pour faciliter la miseen place d’essais cliniques randomis�es. Parmi les solutionsprometteuses, citons le d�eveloppement de r�eseaux de cherch-eurs internationaux, l’implication encadr�ee des praticienslib�eraux a une recherche clinique de qualit�e (Practice-BasedResearch Networks), l’apport logistique des ContractResearch Organization (CRO – entreprises priv�ees d’essaiscliniques), le recours aux nouvelles technologies d’aide a larecherche clinique [30] et l’�etablissement de consensus pro-fessionnels forts sur les finalit�es du traitement orthodontiqueen termes de crit�eres de jugement. L’orthodontiste doit aussigarder a l’esprit que des alternatives a l’essai cliniquerandomis�e existent, et que les �etudes observationnelles detype cohorte, cas-t�emoins ou transversales sont, dans denombreuses situations, plus indiqu�ees que l’essai clinique etfournissent des r�esultats tout aussi pertinents pour la pratiqueclinique [31].


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International Orthodontics 2010


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Documents

Les revues systématiques Cochrane en orthodontie