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REVIEW Open Access Clinical effectiveness of Invisalign® orthodontic treatment: a systematic review Aikaterini Papadimitriou 1 , Sophia Mousoulea 2 , Nikolaos Gkantidis 3 and Dimitrios Kloukos 1,3* Abstract Background: Aim was to systematically search the literature and assess the available evidence regarding the clinical effectiveness of the Invisalign® system. Methods: Electronic database searches of published and unpublished literature were performed. The reference lists of all eligible articles were examined for additional studies. Reporting of this review was based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Results: Three RCTs, 8 prospective, and 11 retrospective studies were included. In general, the level of evidence was moderate and the risk of bias ranged from low to high, given the low risk of bias in included RCTs and the moderate (n = 13) or high (n = 6) risk of the other studies. The lack of standardized protocols and the high amount of clinical and methodological heterogeneity across the studies precluded a valid interpretation of the actual results through pooled estimates. However, there was substantial consistency among studies that the Invisalign® system is a viable alternative to conventional orthodontic therapy in the correction of mild to moderate malocclusions in non-growing patients that do not require extraction. Moreover, Invisalign® aligners can predictably level, tip, and derotate teeth (except for cuspids and premolars). On the other hand, limited efficacy was identified in arch expansion through bodily tooth movement, extraction space closure, corrections of occlusal contacts, and larger antero-posterior and vertical discrepancies. Conclusions: Although this review included a considerable number of studies, no clear clinical recommendations can be made, based on solid scientific evidence, apart from non-extraction treatment of mild to moderate malocclusions in non- growing patients. Results should be interpreted with caution due to the high heterogeneity. Keywords: Orthodontics, Invisalign, Aligner, Clinical efficiency Background Orthodontic developments, especially during the last years, have been accompanied by a significant increase in the esthetic demands of the patients. Patients often express the need to influence, or even determine, treat- ment aspects or objectives, along with the orthodontist, driven by the effects that orthodontic appliances have in their appearance. Conventional orthodontic methods have been associated with a general compromise in fa- cial appearance [1] raising a major concern among pa- tients seeking orthodontic treatment [2]. Thus, esthetic materials and techniques have been introduced in clin- ical practice aiming to overcome these limitations [3]. Since its development in 1997, Invisalign® technology has been established worldwide as an esthetic alternative to labial fixed appliances [47]. CAD/CAM stereolitho- graphic technology has been used to forecast treatment outcomes and fabricate a series of custom-made aligners using a single silicone or digital impression [6]. After its introduction, the system has been drastically developed and continually improved in many aspects; different at- tachment designs, new materials, and new auxiliaries, such as Precision Cutsand Power Ridgeswere de- signed to enable additional treatment biomechanics. According to the manufacturer, Invisalign® can effect- ively perform major tooth movements, such as bicuspid derotation up to 50° and root movements of upper cen- tral incisors up to 4 mm [8]. Despite the advocated * Correspondence: dimitrios.kloukos@zmk.unibe.ch 1 Department of Orthodontics and Dentofacial Orthopedics, 251 Hellenic Air Force General Hospital, P. Kanellopoulou 3, 11525 Athens, Greece 3 Department of Orthodontics and Dentofacial Orthopedics, University of Bern, Freiburgstrasse 7, CH-3010 Bern, Switzerland Full list of author information is available at the end of the article © The Author(s). 2018 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. Papadimitriou et al. Progress in Orthodontics (2018) 19:37 https://doi.org/10.1186/s40510-018-0235-z
24

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  • REVIEW Open Access

    Clinical effectiveness of Invisalign®orthodontic treatment: a systematic reviewAikaterini Papadimitriou1, Sophia Mousoulea2, Nikolaos Gkantidis3 and Dimitrios Kloukos1,3*

    Abstract

    Background: Aim was to systematically search the literature and assess the available evidence regarding theclinical effectiveness of the Invisalign® system.

    Methods: Electronic database searches of published and unpublished literature were performed. The reference listsof all eligible articles were examined for additional studies. Reporting of this review was based on the PreferredReporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

    Results: Three RCTs, 8 prospective, and 11 retrospective studies were included. In general, the level of evidence wasmoderate and the risk of bias ranged from low to high, given the low risk of bias in included RCTs and the moderate(n = 13) or high (n = 6) risk of the other studies. The lack of standardized protocols and the high amount of clinical andmethodological heterogeneity across the studies precluded a valid interpretation of the actual results through pooledestimates. However, there was substantial consistency among studies that the Invisalign® system is a viable alternativeto conventional orthodontic therapy in the correction of mild to moderate malocclusions in non-growing patients thatdo not require extraction. Moreover, Invisalign® aligners can predictably level, tip, and derotate teeth (except forcuspids and premolars). On the other hand, limited efficacy was identified in arch expansion through bodily toothmovement, extraction space closure, corrections of occlusal contacts, and larger antero-posterior and vertical discrepancies.

    Conclusions: Although this review included a considerable number of studies, no clear clinical recommendations can bemade, based on solid scientific evidence, apart from non-extraction treatment of mild to moderate malocclusions in non-growing patients. Results should be interpreted with caution due to the high heterogeneity.

    Keywords: Orthodontics, Invisalign, Aligner, Clinical efficiency

    BackgroundOrthodontic developments, especially during the lastyears, have been accompanied by a significant increasein the esthetic demands of the patients. Patients oftenexpress the need to influence, or even determine, treat-ment aspects or objectives, along with the orthodontist,driven by the effects that orthodontic appliances havein their appearance. Conventional orthodontic methodshave been associated with a general compromise in fa-cial appearance [1] raising a major concern among pa-tients seeking orthodontic treatment [2]. Thus, esthetic

    materials and techniques have been introduced in clin-ical practice aiming to overcome these limitations [3].Since its development in 1997, Invisalign® technology

    has been established worldwide as an esthetic alternativeto labial fixed appliances [4–7]. CAD/CAM stereolitho-graphic technology has been used to forecast treatmentoutcomes and fabricate a series of custom-made alignersusing a single silicone or digital impression [6]. After itsintroduction, the system has been drastically developedand continually improved in many aspects; different at-tachment designs, new materials, and new auxiliaries,such as “Precision Cuts” and “Power Ridges” were de-signed to enable additional treatment biomechanics.According to the manufacturer, Invisalign® can effect-ively perform major tooth movements, such as bicuspidderotation up to 50° and root movements of upper cen-tral incisors up to 4 mm [8]. Despite the advocated

    * Correspondence: dimitrios.kloukos@zmk.unibe.ch1Department of Orthodontics and Dentofacial Orthopedics, 251 Hellenic AirForce General Hospital, P. Kanellopoulou 3, 11525 Athens, Greece3Department of Orthodontics and Dentofacial Orthopedics, University ofBern, Freiburgstrasse 7, CH-3010 Bern, SwitzerlandFull list of author information is available at the end of the article

    © The Author(s). 2018 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, andreproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link tothe Creative Commons license, and indicate if changes were made.

    Papadimitriou et al. Progress in Orthodontics (2018) 19:37 https://doi.org/10.1186/s40510-018-0235-z

    http://crossmark.crossref.org/dialog/?doi=10.1186/s40510-018-0235-z&domain=pdfhttp://orcid.org/0000-0002-0665-238Xmailto:dimitrios.kloukos@zmk.unibe.chhttp://creativecommons.org/licenses/by/4.0/

  • efficiency of the treatment, its clinical potency still re-mains controversial among professionals, with advocatesbeing convinced by the successfully demonstrated treatedcases, as indicated by clinical evidence, in contrast to op-ponents who argue about significant limitations, especiallyin the treatment of complex malocclusions [5, 9–11].Despite the available body of literature pertaining to

    Invisalign® technology, its clinical performance has beenanalyzed less thoroughly and a synthesis of the results stillremains vague. Four systematic reviews about clearaligners exist in the literature: the first one was publishedback in 2005 and assessed the treatment effects of Invisa-lign; it included, nevertheless, only two studies [12]. Morerecently, another three reviews have been published. Thefirst one was last updated in June 2014; it included 11studies and evaluated the control of the clear aligners onorthodontic tooth movement [13]. The second one evalu-ated the periodontal health during clear aligner therapyand was published in the same year [14], and the most re-cent one was undertaken in October 2014 and includedfour studies, since it focused on the comparison betweenclear aligners and conventional braces [15].Therefore, the purpose of the present review was to

    systematically search the literature and summarize thecurrent available scientific evidence regarding the clin-ical effectiveness of the Invisalign® system as principalorthodontic therapy to orthodontic patients of any agetreated with this method comparing either among themor those with conventional braces and evaluating thelevel of efficacy in various malocclusions.

    Materials and methodsTypes of studiesRandomized clinical trials (RCTs), controlled clinical tri-als (CCTs), and prospective and retrospective studieswere considered eligible for inclusion in this review.These studies concerned to the clinical part of treatmentwith Invisalign, with no restrictions in language, age, sta-tus of publication, and cases with teeth extractions.

    Types of participantsOrthodontic patients of any age who were treated with Invi-salign® either as the intervention or as the control group.

    Types of interventionsInvisalign® therapy. All other aligner systems have beenexcluded.

    OutcomeAny effect on clinical efficiency, effectiveness, treatmentoutcomes, movement accuracy, or predicted toothmovement in ClinCheck® of Invisalign® treatment, in-cluding changes in alignment or occlusion, treatment

    duration, and completion rate, as primary outcomes. Ad-verse events/unwanted effects have also been recorded.

    Search methods for identification of studiesDetailed search strategies were developed and appropri-ately revised for each database, considering the differ-ences in controlled vocabulary and syntax rules. Thefollowing electronic databases were searched: MEDLINE(via Ovid and PubMed, Appendix, from 1946 to August28, 2017), Embase (via Ovid), the Cochrane Oral HealthGroup’s Trials Register, and CENTRAL.Unpublished literature was searched on ClinicalTrials.gov,

    the National Research Register, and Pro-Quest DissertationAbstracts and Thesis database.The search attempted to identify all relevant studies ir-

    respective of language. The reference lists of all eligiblestudies were examined for additional studies.

    Selection of studiesStudy selection was performed independently and in du-plicate by the first two authors of the review, who werenot blinded to the identity of the authors of the studies,their institutions, or the results of their research. Studyselection procedure was comprised of title-reading,abstract-reading, and full-text-reading stages. After ex-clusion of not eligible studies, the full report of publica-tions considered eligible for inclusion by either authorwas obtained and assessed independently. Disagreementswere resolved by discussion and consultation with thethird and the last author. A record of all decisions onstudy identification was kept.

    Data extraction and managementThe first two authors performed data extraction inde-pendently and in duplicate. Disagreements were resolvedby discussion or the involvement of two collaborators(third author and last author). Data collection forms wereused to record the desired information. The following datawere collected on a customized data collection form:

    � Author/title/year of study� Design/setting of the study� Number/age/gender of participants� Intervention and comparator/treatment duration� Type of clinical outcome� Method of outcome assessment

    Measures of treatment effectFor continuous outcomes, descriptive measures, such asmean differences and standard deviations, were used tosummarize the data from each study. For dichotomousdata, number of participants with events and total num-ber of participants in experimental and control groupswere analyzed.

    Papadimitriou et al. Progress in Orthodontics (2018) 19:37 Page 2 of 24

    http://clinicaltrials.gov

  • Unit of analysis issuesIn all cases, the unit of analysis was the patient.

    Dealing with missing dataWe contacted study authors per e-mail to request miss-ing data where necessary. In case of no response or noprovision of the missing data, only the available reporteddata were analyzed.

    Data synthesisA meta-analysis was planned only if there were at leasttwo studies of low or unclear risk of bias, reporting simi-lar comparisons, and similar outcomes at similar timepoints. Otherwise, qualitative synthesis of the includedstudies would be performed.

    Quality assessment of included studiesThe risk of bias for RCT studies was assessed by two re-view authors, independently and in duplicate, using theCochrane risk of bias tool [16].Risk of bias was assessed and judged for seven separ-

    ate domains.

    1. Sequence generation: was the allocation sequenceadequately generated?

    2. Allocation concealment: was allocation adequatelyconcealed?

    3. Blinding of participants and investigators: wasknowledge of the allocated intervention adequatelyprevented during the study?

    4. Blinding of outcome assessors: was knowledge ofthe allocated intervention adequately preventedbefore assessing the outcome?

    5. Incomplete outcome data: were incomplete outcomedata adequately addressed?

    6. Selective outcome reporting: were reports of the studyfree of suggestion of selective outcome reporting?

    7. Other sources of bias: was the study apparently free ofother problems that could put it at a high risk of bias?

    Each study received a judgment of low risk, high risk,or unclear risk of bias (indicating either lack of sufficientinformation to make a judgment or uncertainty over therisk of bias) for each of the seven domains. Studies werefinally grouped into the following categories:

    – Low risk of bias (plausible bias unlikely to seriouslyalter the results) if all key domains of the study wereat low risk of bias.

    – Unclear risk of bias (plausible bias that raises somedoubt about the results) if one or more key domainsof the study were unclear.

    – High risk of bias (plausible bias that seriously weakensconfidence in the results) if one or more key domainswere at high risk of bias.

    Prospective and retrospective studies were graded as low,moderate, or high risk of bias according to the followingcriteria, adapted from the Bondemark scoring system [17]:

    – Low risk of bias (all criteria should be met):� Randomized clinical study or a prospective study

    with a well-defined control group.� Defined diagnosis and endpoints.� Diagnostic reliability tests and reproducibility

    tests described.� Blinded outcome assessment.

    – Moderate risk of bias (all criteria should be met):� Cohort study or retrospective cases series with

    defined control or reference group.� Defined diagnosis and endpoints.� Diagnostic reliability tests and reproducibility

    tests described.– High risk of bias (one or more of the following

    conditions):� Large attrition.� Unclear diagnosis and endpoints.� Poorly defined patient material.

    The Grading of Recommendations Assessment,Development and Evaluation (GRADE) [16] was imple-mented to assess the overall quality of evidence for thestudies included in this systematic review, according towhich the overall evidence is rated as high, moderate,low, and very low. The outcomes included in GRADEwere divided into categories regarding the different pa-rameters that had been assessed in the primary studies.

    � High quality of evidence implies that the true effectlies close to that of the estimate of the effect

    � Moderate quality of evidence implies that the trueeffect is likely to be close to the estimate of theeffect, but there is a possibility that it is substantiallydifferent

    � Low quality of evidence implies that our confidencein the effect estimate is limited: the true effect maybe substantially different from the estimate of theeffect

    � Very low quality of evidence implies that the trueeffect is likely to be substantially different from theestimate of effect.

    ResultsStudy selectionThe electronic search initially identified 227 relevant ar-ticles. One hundred fifty-eight papers remained after

    Papadimitriou et al. Progress in Orthodontics (2018) 19:37 Page 3 of 24

  • exclusion on the basis of title-reading. Five articles wereadded through hand-searching. After 49 duplicates’ re-moval, 114 papers were assessed for screening, and afterabstract-reading, 85 studies were excluded leaving 29 arti-cles to be read in full-text. After the application of specificinclusion and exclusion criteria, another seven articleswere removed. In total, 22 studies were considered eligiblefor inclusion in the final analysis (Fig. 1).

    Study characteristicsThe characteristics of each study are presented in detail inTable 1. Table 2 gives an overview of the results of the in-cluded studies regarding clinical parameters. Three studies[18–20] were RCTs, eight studies were of prospective [5,21–27], and 11 of retrospective design [28–38].

    Quality analysisThe quality assessment of the 22 studies is shown inTables 3 and 4.

    RCTsThe three RCTs [18–20] were judged to be at an overalllow risk of bias, due to the low risk of bias that appliedto each domain based on the Cochrane risk of bias tool[16] (Table 3).

    Prospective studiesThree prospective studies [21, 26, 35] were graded asmoderate and five [5, 22, 24, 25, 27] as high risk of bias.Although they were all studies of prospective design, noblinding in relation to outcome assessment was reportedin all except one [27] study, which also lacked control,among other limitations (Table 4).

    Retrospective studiesTen out of the 11 identified retrospective studies [28–38]were graded as moderate risk of bias, since all thepre-determined criteria were met. Only one retrospectivestudy [34] was of high risk of bias, because it did not

    Fig. 1 Studies’ flow diagram

    Papadimitriou et al. Progress in Orthodontics (2018) 19:37 Page 4 of 24

  • Table

    1Anoverview

    oftheinclud

    edstud

    iesprovidinginform

    ationon

    theexpe

    rimen

    tald

    esigns

    andsettings

    Autho

    r(year)

    Title

    Stud

    yde

    sign

    Setting,

    treatm

    entdu

    ratio

    nParticipants

    (num

    ber,sex)

    Age

    ofpatients

    (meanage)

    Inclusioncriteria

    Interven

    tiongrou

    pCom

    parison

    grou

    p

    Hen

    nessy

    etal.[18]

    (2016)

    Arand

    omized

    clinicaltrial

    comparin

    gmandibu

    lar

    incisorproclinationproduced

    byfixed

    labial

    appliances

    andclearaligne

    rs.

    RCT

    Setting:

    n/a

    Treatm

    entdu

    ratio

    n:fixed

    appliancegrou

    p,11.3mon

    ths;

    clearalignerg

    roup

    ,10.2mon

    ths

    44patients

    (17M

    ,27F)

    Invisaligngrou

    p:29.1±7.5years

    Fixedappliance

    grou

    p:23.7±7.0years

    -Age

    ≥18

    years

    -Nocariesor

    perio

    dontal

    disease

    -Mild

    Mncrow

    ding

    (<4mm)

    -Non

    -extractionorthod

    ontic

    treatm

    ent

    -Anterop

    osterio

    rskeletal

    patternwith

    intheaverage

    rang

    e(ANB1–4°)

    22patientstreatedwith

    Invisalign

    22patients

    treatedwith

    fixed

    appliances

    (self-ligating

    brackets)

    Liet

    al.

    [19]

    (2015)

    Theeffectiven

    essof

    the

    Invisalignappliancein

    extractio

    ncasesusingthe

    ABOmodelgradingsystem

    :amulticenterrandomized

    controlledtrial.

    RCT

    2orthod

    ontic

    clinicsat

    the

    Second

    AffiliatedHospital,

    Zhejiang

    University

    Invisaligntreatm

    entdu

    ratio

    nwas

    44%

    long

    erthan

    fixed

    appliancetreatm

    ent

    152patients

    (62M

    ,90F)

    Invisaligngrou

    p:35.2±7.3years

    Fixedappliance

    grou

    p:32.2±8.3years

    -Patientsaged

    ≥18

    years

    -Extractio

    ntreatm

    ent

    -Patientsconsen

    tedto

    the

    research

    proced

    ures

    and

    sign

    ed-Availabilityof

    pre-

    and

    post-treatmen

    tde

    ntalstud

    ymod

    elsandpano

    ramic

    filmswith

    good

    quality

    -Classified

    asbe

    ingsevere

    incomplexity

    with

    ascoreof

    25usingthediscrepancy

    inde

    x(DI)of

    theABO

    phase

    IIIclinicalexam

    ination

    -Class

    Iocclusion

    76patientstreatedwith

    Invisalign

    76patients

    treatedwith

    fixed

    appliances

    Bollenet

    al.[20]

    (2003)

    Activationtim

    eandmaterial

    stiffne

    ssof

    sequ

    ential

    removab

    leorthod

    ontic

    appliances.Part

    1:Ability

    tocompletetreatm

    ent

    RCT

    University

    ofWashing

    ton

    Region

    alClinicalDen

    tal

    Research

    Cen

    ter

    Prim

    aryen

    dpoint:

    completionof

    initialaligne

    rs’

    series

    51patients

    (15M

    ,36F)

    34years

    (rang

    e19–55)

    -Age

    ≥18

    years

    -Abilityto

    attend

    weekly

    appo

    intm

    entsandto

    pay

    forservices

    -Requ

    iremen

    tforregu

    lar

    dentalandpe

    riodo

    ntal

    mainten

    ance

    prog

    ram

    incase

    ofcariesor

    perio

    dontaldisease

    51patientsrand

    omly

    assign

    edto

    4interven

    tion

    grou

    ps;eith

    erto

    hard/soft

    plastic

    applianceand

    1week/2weeks

    activation

    time

    The4grou

    pswere

    comparedto

    each

    othe

    r

    Solano

    -Men

    doza

    etal.[21]

    (2016)

    How

    effectiveisthe

    Invisalign®

    system

    inexpansionmovem

    ent

    with

    Ex30′aligne

    rs?

    Prospe

    ctive

    Privateclinicin

    Stuttgart,

    Germany

    Meantreatm

    entdu

    ratio

    n:657.4±341.4days

    116patients

    (46M

    ,70F)

    36.57

    ±11.53

    years

    -Treatm

    entwith

    Ex30

    aligne

    rmaterial

    -Expansionof

    thepo

    sterior

    uppe

    rteeth(from

    canine

    to1stup

    permolar)

    -Presen

    ceof

    aninitialand

    finaldigitalm

    odel

    -Definition

    ofthethird

    palatalrug

    a-Nopresence

    ofattachments

    ontheinitialor

    finalmod

    el-Nomorethan

    twomod

    els

    perpatient

    Expansionwith

    Invisalign;

    4grou

    ps:

    (a)G1(n=40):expansion

    ≤1.99

    mm

    ininterm

    olar

    cuspid

    width

    (b)G2(n=45):expansion

    ≤3.99

    mm

    (c)G3(n=14):patients

    subjectedto

    expansion

    ≤5.99

    mm

    (d)G4(n=10):expansion

    ≥6mm.

    7patientsun

    classified

    dueto

    curren

    tabsenceof

    Initialandfinal

    virtual3-D

    ClinChe

    ck®

    mod

    els

    Papadimitriou et al. Progress in Orthodontics (2018) 19:37 Page 5 of 24

  • Table

    1Anoverview

    oftheinclud

    edstud

    iesprovidinginform

    ationon

    theexpe

    rimen

    tald

    esigns

    andsettings

    (Con

    tinued)

    Autho

    r(year)

    Title

    Stud

    yde

    sign

    Setting,

    treatm

    entdu

    ratio

    nParticipants

    (num

    ber,sex)

    Age

    ofpatients

    (meanage)

    Inclusioncriteria

    Interven

    tiongrou

    pCom

    parison

    grou

    p

    oneor

    both

    1stmolars

    Buschang

    etal.[26]

    (2015)

    Pred

    ictedandactual

    end-of-treatmen

    tocclusionprod

    uced

    with

    aligne

    rtherapy

    Prospe

    ctive

    1privatepractice,Dallas,

    Texas,USA

    Treatm

    entdu

    ratio

    n:n/a

    27patients

    (n/a)

    n/a

    Con

    secutivepatients

    27consecutivepatients

    treatedwith

    Invisalign

    Finalvirtual

    3-DClinChe

    ck®

    mod

    els

    Castroflorio

    etal.[22]

    (2013)

    Upp

    er-in

    cisor

    root

    control

    with

    Invisalign

    appliances

    Prospe

    ctive

    2private

    orthod

    ontic

    clinicsin

    ametropo

    litan

    area

    ofno

    rthw

    estItaly

    Treatm

    ent

    duratio

    n:no

    trepo

    rted

    6patients

    (2M,4F)

    26.3±10.2years

    Nopatient

    hadany

    record

    ofanterio

    rcrossbite,anterior

    prosthod

    ontic

    work,

    previous

    orthod

    ontic

    treatm

    ent,craniofacial

    trauma,surgery,TM

    D,or

    orofacialp

    ain

    Invisalign

    patients

    (n=6;9Mx

    incisors)

    need

    ingpalatal

    root

    torque

    aspartof

    their

    treatm

    ent

    Initialand

    finalvirtual

    3-DClin-

    Che

    ck®

    mod

    elsfor

    each

    uppe

    rincisor

    Pavoni

    etal.[23]

    (2011)

    Self-ligatingversus

    Invisalign:analysisof

    dento-alveolar

    effects

    Prospe

    ctive

    Dep

    artm

    entof

    Ortho

    dontics

    “Tor

    Vergata,”Den

    talSchoo

    l,University

    ofRo

    me

    Treatm

    entdu

    ratio

    n:Invisalign

    grou

    p,18

    ±2mon

    ths;self-

    ligatinggrou

    p,18

    ±3mon

    ths

    40patients

    (19M

    ,21F)

    wereeq

    ually

    divide

    dinto

    2grou

    ps:

    Invisalign®

    grou

    p(8M,

    12F);self-

    ligatinggrou

    p(11M

    ,9F)

    Invisaligngrou

    p:18.4years

    Self-ligating

    grou

    p:15.6years

    -Class

    Imalocclusion

    -Mild

    crow

    ding

    inMnarch

    (mean:4.4±0.8mm)

    -Perm

    anen

    tde

    ntition

    -Verteb

    ralm

    aturationmore

    advanced

    than

    CS4

    (post-

    pube

    rtal)

    -Noprevious

    orthod

    ontic

    treatm

    ent

    Invisalign+IPR(n=20)

    Fixed

    appliances

    (self-ligating;

    n=20)

    Kravitz

    etal.[5]

    (2009)

    How

    welld

    oesInvisalign

    work?

    Aprospe

    ctive

    clinicalstud

    yevaluatin

    gtheefficacyof

    tooth

    movem

    entwith

    Invisalign

    Prospe

    ctive

    Dep

    artm

    entof

    Ortho

    dontics

    attheUniversity

    ofIllinois,

    Chicago

    Primaryendp

    oint:com

    pletion

    ofinitialaligners’series.The

    meannu

    mbero

    falignersper

    treatm

    entwas

    10Mxand12

    Mnwith

    each

    alignerw

    orn

    for2

    –3weeks

    37patients

    (14M

    ,23F)

    31years

    -Age

    ≥18

    years

    -Anteriorcrow

    ding

    /spacing

    <5mm

    andadeq

    uate

    buccalinterdigitatio

    n-Patientswith

    posterior

    eden

    tulous

    spaces

    were

    includ

    ediftreatm

    entdid

    noten

    tailspaceclosure

    (1participant

    hadmandibu

    lar

    incisorextraction)

    -Clinicians

    wereallowed

    torequ

    est/refuse

    IPR,

    proclination,attachmen

    ts,

    andovercorrectio

    nson

    ClinChe

    ck®

    37patients/401anterio

    rteeth(198

    Mx,203Mn)

    treatedwith

    Anterior

    Invisalign®

    Finalvirtual

    3-DClinChe

    ck®

    mod

    els

    Papadimitriou et al. Progress in Orthodontics (2018) 19:37 Page 6 of 24

  • Table

    1Anoverview

    oftheinclud

    edstud

    iesprovidinginform

    ationon

    theexpe

    rimen

    tald

    esigns

    andsettings

    (Con

    tinued)

    Autho

    r(year)

    Title

    Stud

    yde

    sign

    Setting,

    treatm

    entdu

    ratio

    nParticipants

    (num

    ber,sex)

    Age

    ofpatients

    (meanage)

    Inclusioncriteria

    Interven

    tiongrou

    pCom

    parison

    grou

    p

    -OnlyInvisalignattachmen

    tscouldbe

    used

    andthetray

    couldno

    tbe

    alteredwith

    scissors/the

    rmop

    liers

    Kravitz

    etal.[24]

    (2008)

    Influen

    ceof

    attachmen

    tsandinterproximalredu

    ction

    ontheaccuracy

    ofcanine

    rotationwith

    Invisalign

    Prospe

    ctive

    Dep

    artm

    entof

    Ortho

    dontics,

    University

    ofIllinois,Chicago

    Meandu

    ratio

    n:7mon

    ths.

    Primaryendp

    oint:com

    pletion

    ofinitialaligners’series

    31patients

    (13M

    ,18F)

    ≥18

    years

    Sameas

    Kravitz

    etal.[5]

    (2009)

    31patients/53

    canine

    s(33

    Mx,20

    Mn)

    treatedwith

    anterio

    rInvisalign®

    were

    divide

    din

    3grou

    ps:

    (a)attachmen

    tson

    ly(AO)

    (b)interproximal

    redu

    ctionon

    ly(IO

    )(c)ne

    ither

    attachmen

    tsno

    rinterproximal

    redu

    ction(N)

    Finalvirtual

    3-DClinChe

    ck®

    mod

    els

    Baldwin

    etal.[27]

    (2008)

    Activationtim

    eandmaterial

    stiffne

    ssof

    sequ

    ential

    removab

    leorthod

    ontic

    appliances.Part

    3:Prem

    olar

    extractio

    npa

    tients

    Prospe

    ctive

    University

    ofWashing

    ton

    Region

    alClinicalDen

    tal

    Research

    Cen

    ter

    Primaryendp

    oint:com

    pletion

    ofinitialaligners’series

    24patients

    (6M,18F)

    32.8(range18–54)

    years

    Sameas

    Bollenet

    al.[20]

    (2003)

    +at

    least1prem

    olar

    extractio

    n

    24patientstreatedwith

    either

    hard/softplastic

    applianceand1week/

    2weeks

    activationtim

    e

    Nocontrol

    grou

    p(pretreatm

    ent

    cond

    ition

    )

    Vlaskalic

    andBo

    yd[25]

    (2002)

    Clinicalevolutionof

    the

    Invisalignappliance

    Prospe

    ctive

    University

    ofthePacific

    Meantreatm

    entdu

    ratio

    n:grou

    p1,20

    mon

    ths;grou

    p2,

    27.2mon

    ths;grou

    p3,

    31.5mon

    ths

    40patients

    14–52years

    -Fully

    erup

    tedpe

    rmanen

    tde

    ntition

    (excep

    tfor3rd

    molars)

    -Den

    talh

    ealth

    with

    noim

    med

    iate

    need

    for

    restorations

    -Availabilityforeven

    ing

    appo

    intm

    ents

    -Desire

    tocomplywith

    orthod

    ontic

    treatm

    ent

    3Invisaligngrou

    psbased

    onseverityof

    crow

    ding

    :group1(n=10

    mild

    cases);

    group2(n=15

    moderate

    cases),andgrou

    p3

    (n=15

    severe

    cases)

    The3grou

    pswere

    comparedto

    each

    othe

    r

    Guet

    al.

    [28]

    (2017)

    Evaluatio

    nof

    Invisalign

    treatm

    enteffectiven

    ess

    andefficiencycompared

    with

    conven

    tionalfixed

    appliances

    usingthePeer

    Assessm

    entRatin

    ginde

    x

    Retrospe

    ctive

    Setting:D

    ivision

    ofOrth

    odontics

    atOhioStateUniversity

    College

    ofDentistry

    Treatm

    entdu

    ratio

    n:Invisaligngrou

    p,13.35mon

    ths;fixed

    appliancegrou

    p:19.1mon

    ths

    96patients

    (34M

    ;62F)

    Invisaligngrou

    p:26

    ±9.7years

    Fixedappliances

    grou

    p:22.1±7.9years

    -Availablepre-

    and

    posttreatm

    ent

    records—

    age≥16

    years

    -Noauxiliary

    appliances

    othe

    rthan

    elastics

    -Non

    -extractionpatients

    -Noorthog

    nathicsurgeryor

    synd

    romicpatients

    -Fullpe

    rmanen

    tde

    ntition

    except

    third

    molars

    Invisalign(n=48)

    Fixed

    appliances

    (straigh

    t-wire

    edge

    wise

    appliances;

    n=48)

    Khosravi

    etal.[29]

    (2017)

    Managem

    entof

    overbite

    with

    theInvisalignappliance

    Retrospe

    ctive

    Setting:

    3privateorthod

    ontic

    offices;2

    locatedinthegreater

    Seattle

    area,W

    ashand1in

    Vancou

    ver,British

    Columbia

    Treatm

    entdu

    ratio

    n:n/a

    120patients

    (36M

    ;84F)

    33years

    (interquartile

    rang

    e:17)

    -Age

    ≥18

    years

    -11

    to40

    aligne

    rsused

    for

    each

    arch

    -Amax

    useof

    3revision

    sets

    ofaligne

    rs-Non

    -extractiontreatm

    ent

    plan

    Invisalign;stratifiedstud

    ysampleas

    follows:68

    patientsintheno

    rmal

    overbite

    grou

    p,40

    patients

    inthedeep-b

    itegrou

    p,and12

    patientsinthe

    open-bite

    grou

    p

    The3grou

    pswerecompared

    with

    each

    other

    Papadimitriou et al. Progress in Orthodontics (2018) 19:37 Page 7 of 24

  • Table

    1Anoverview

    oftheinclud

    edstud

    iesprovidinginform

    ationon

    theexpe

    rimen

    tald

    esigns

    andsettings

    (Con

    tinued)

    Autho

    r(year)

    Title

    Stud

    yde

    sign

    Setting,

    treatm

    entdu

    ratio

    nParticipants

    (num

    ber,sex)

    Age

    ofpatients

    (meanage)

    Inclusioncriteria

    Interven

    tiongrou

    pCom

    parison

    grou

    p

    -NoclassIIto

    classIocclusio

    nchange

    -Not

    sign

    ificantlychange

    dpo

    sterior-transverse

    relatio

    nships

    -Nofixed

    appliances

    -Goo

    d-qu

    ality

    pre-

    andpo

    st-

    treatm

    entceph

    alom

    etric

    radiog

    raph

    s

    Hou

    leet

    al.[30]

    (2016)

    Thepred

    ictabilityof

    transverse

    change

    swith

    Invisalign

    Retrospe

    ctive

    Setting:

    Dep

    artm

    entof

    Preven

    tiveDen

    talScien

    ce,

    Divisionof

    Ortho

    dontics,

    Scho

    olof

    Dentistry,University

    ofManito

    ba-O

    rtho

    dontic

    practiceinAdelaide,Australia

    Treatm

    entdu

    ratio

    n:56

    weeks

    64patients

    (23M

    ,41F)

    31.2years

    (range18–61

    years)

    -Age

    ≥18

    years

    -Non

    -extractiontreatm

    ent

    with

    outanyauxiliariesother

    than

    Invisalignattachments

    Invisalign(n=64)

    Initialandfinal

    virtual3-D

    ClinChe

    ck®

    mod

    els

    Ravera

    etal.[31]

    (2016)

    Maxillarymolardistalization

    with

    aligne

    rsin

    adult

    patie

    nts:amulticen

    ter

    retrospe

    ctivestud

    y.

    Retrospe

    ctive

    Ortho

    donticprivatepractices

    locatedin

    Torin

    o(Italy)and

    Vancou

    ver(Canada)

    Treatm

    entdu

    ratio

    n:24.3±4.2mon

    ths

    20patients

    (9M,11F)

    29.73±6.89

    years

    -Age

    ≥18

    yearsold

    -SkeletalclassIo

    rIIanda

    bilateralend

    -to-en

    dmolar

    relatio

    nship

    -Normod

    iverge

    nceon

    the

    verticalplane

    (SN-GoG

    nangle<37°)

    -Mild

    crow

    ding

    intheup

    per

    arch

    (≤4mm)

    -Absen

    ceof

    mesialrotation

    oftheup

    per1stmolar

    -Standardized

    treatm

    ent

    protocol,

    -Goo

    dcompliance

    (wearin

    galigne

    rtim

    e,≥20

    hpe

    rday)

    -Absen

    ceor

    previous

    extractio

    nof

    theup

    per3rd

    molars

    -Goo

    dqu

    ality

    radiog

    raph

    s

    Invisalign(n=20)

    Nocontrol

    grou

    p

    Dun

    canet

    al.[32]

    (2015)

    Chang

    esin

    mandibu

    lar

    incisorpo

    sitio

    nandarch

    form

    resulting

    from

    Invisaligncorrectio

    nof

    thecrow

    dedde

    ntition

    treatedno

    nextraction

    Retrospe

    ctive

    Sing

    leorthod

    ontic

    practice

    Treatm

    entdu

    ratio

    n:1stgrou

    p,53.6±21.1weeks;

    2ndgrou

    p,63.7±20.7weeks;

    3rdgrou

    p:71.7±16.3weeks

    61patients

    (17M

    ,44F)

    Adu

    ltpatients

    (age

    n/a)

    -Non

    extractio

    ncaseswith

    orwith

    outIPR

    3interven

    tiongrou

    psaccordingto

    pre-

    treatm

    entcrow

    ding

    oflower

    dentition

    (Carey’sanalysis):(a)

    20mild

    (2.0–3.9mm),

    (b)22

    mod

    erate

    (4.0–5.9mm),and(c)

    19severe

    (>6.0mm)cases

    The3grou

    pswerecompared

    toeach

    other

    Papadimitriou et al. Progress in Orthodontics (2018) 19:37 Page 8 of 24

  • Table

    1Anoverview

    oftheinclud

    edstud

    iesprovidinginform

    ationon

    theexpe

    rimen

    tald

    esigns

    andsettings

    (Con

    tinued)

    Autho

    r(year)

    Title

    Stud

    yde

    sign

    Setting,

    treatm

    entdu

    ratio

    nParticipants

    (num

    ber,sex)

    Age

    ofpatients

    (meanage)

    Inclusioncriteria

    Interven

    tiongrou

    pCom

    parison

    grou

    p

    Grünh

    eid

    etal.[33]

    (2015)

    Effect

    ofclearaligne

    rtherapyon

    thebuccolingual

    inclinationofmandibular

    caninesandtheintercanine

    distance

    Retrospe

    ctive

    University

    ofMinne

    sota

    Meantreatm

    entdu

    ratio

    n:Invisaligngrou

    p,13.4±6.8mon

    ths;fixed

    appliancegrou

    p:20.2±5.3mon

    ths

    60patients(30

    ineach

    grou

    p;8M

    ,22F)

    Invisaligngrou

    p:25

    ±11.8years;

    fixed

    appliance

    grou

    p:26.3±13.5years

    -Fully

    erup

    tedpe

    rmanen

    tde

    ntition

    includ

    ingincisors,

    canine

    s,prem

    olars,and1st

    molars

    -Ang

    leclassIm

    alocclusion

    with

    norm

    alinterarchmolar

    relatio

    n-Nope

    riodo

    ntalattachmen

    tloss

    -Non

    -extractionorthod

    ontic

    treatm

    ent

    -Pre-

    andpo

    sttreatm

    entfull-

    field

    ofview

    CBC

    Tscans

    -Bo

    thmandibu

    larcanine

    sclearly

    visiblein

    theCBC

    Tscans

    Invisalign(n=30)

    Fixed

    appliances

    (n=30)

    Simon

    etal.[34]

    (2014)

    Treatm

    entou

    tcom

    eand

    efficacyof

    analigne

    rtechniqu

    e–regarding

    incisortorque,p

    remolar

    derotatio

    nandmolar

    distalization

    Retrospe

    ctive

    Privateorthod

    ontic

    practice

    inColog

    ne,G

    ermany

    Treatm

    entdu

    ratio

    n:n/a

    30patients

    (11M

    ,19F)

    initially,b

    ut4

    drop

    pedou

    t(n=26)

    32.9±16.3years

    Range13–72years

    -Health

    ypatients

    -1of

    the3followingtooth

    movem

    entsrequ

    ired:

    (1)Upp

    ermed

    ialincisor

    torque

    >10°

    (2)Prem

    olar

    derotatio

    n>10°

    (3)Molar

    distalizationof

    anup

    permolar

    >1.5mm

    3Invisaligngrou

    ps:

    (a)Incisortorque

    >10°

    (b)Prem

    olar

    derotatio

    n>

    10°

    (c)Molar

    distalization>

    1.5mm.

    Thegrou

    pswere

    subd

    ivided

    :inthe1st

    subg

    roup

    ,movem

    ents

    weresupp

    ortedwith

    anattachmen

    t,whilein

    the

    2ndsubg

    roup

    noauxiliarieswereused

    (excep

    tincisortorque,in

    which

    Power

    Ridg

    eswere

    used

    )

    Initialandfinal

    virtual3-D

    ClinChe

    ck®

    mod

    els

    Kriege

    ret

    al.[35]

    (2012)

    Invisalign®

    treatm

    entin

    theanterio

    rregion

    .Were

    thepred

    ictedtooth

    movem

    entsachieved

    ?

    Retrospe

    ctive

    Settingandtreatm

    ent

    duratio

    n:no

    trepo

    rted

    50patients

    (16M

    ,34F)

    33±11.2years

    Fron

    talM

    xand/or

    Mn

    crow

    ding

    accordingto

    Little’sinde

    xof

    irreg

    ularity

    Invisalign(n=50)

    Initialandfinal

    virtual3-D

    ClinChe

    ck®

    mod

    els

    Kriege

    ret

    al.[36]

    (2011)

    Accuracyof

    Invisalign®

    treatm

    entsin

    theanterio

    rtoothregion

    .Firstresults

    Retrospe

    ctive

    Settingandtreatm

    ent

    duratio

    n:n/a

    35patients

    (11M

    ,24F)

    33(rang

    e15–59)

    years

    -Ortho

    dontictreatm

    ent

    exclusivelywith

    Invisalign

    -Con

    secutivepo

    st-treatmen

    tmod

    elsandpatient

    documen

    tatio

    n-Presen

    ceof

    low-m

    oderate

    Mxand/or

    Mncrow

    ding

    Ortho

    dontictreatm

    ent

    exclusivelywith

    Invisalign

    (n=35)

    Initialandfinal

    virtual3-D

    ClinChe

    ck®

    mod

    els

    Papadimitriou et al. Progress in Orthodontics (2018) 19:37 Page 9 of 24

  • Table

    1Anoverview

    oftheinclud

    edstud

    iesprovidinginform

    ationon

    theexpe

    rimen

    tald

    esigns

    andsettings

    (Con

    tinued)

    Autho

    r(year)

    Title

    Stud

    yde

    sign

    Setting,

    treatm

    entdu

    ratio

    nParticipants

    (num

    ber,sex)

    Age

    ofpatients

    (meanage)

    Inclusioncriteria

    Interven

    tiongrou

    pCom

    parison

    grou

    p

    Kuncio

    etal.[37]

    (2007)

    Invisalignandtradition

    alorthod

    ontic

    treatm

    ent

    postretentionou

    tcom

    escomparedusingthe

    American

    Boardof

    Ortho

    donticsObjective

    Grading

    System

    Retrospe

    ctive

    Privatepracticein

    New

    York

    City

    Treatm

    entdu

    ratio

    n:Invisaligngrou

    p,1.7±0.8years;fixed

    appliancegrou

    p:2.3±0.8years

    22patients

    (11in

    each

    grou

    p;1M

    ,10F)

    34yearsin

    the

    Invisaligngrou

    p26

    yearsin

    the

    fixed

    applaince

    grou

    p

    Non

    -extractioncases

    Invisalign(n=11)

    Fixed

    appliances

    (n=11)

    Djeuet

    al.

    [38]

    (2005)

    Outcomeassessmen

    tof

    Invisalignandtradition

    alorthod

    ontic

    treatm

    ent

    comparedwith

    the

    American

    Boardof

    Ortho

    donticsob

    jective

    gradingsystem

    Retrospe

    ctive

    Privatepracticein

    New

    York

    City

    Treatm

    entdu

    ratio

    n:1.4years

    fortheInvisalign®

    grou

    p;1.7yearsforthefixed

    appliancegrou

    p

    96patients

    (gen

    dern/a)

    Invisalign®:33.6

    ±11.8years

    Fixedappliances:

    23.7±11.0years

    Non

    -extractioncases

    Invisalign(n=48)

    Fixed

    appliances

    (n=48)

    Mmale,

    Ffemale,

    m.a

    meanag

    e,Mxmaxillary,Mnman

    dibu

    lar,IPRinterproximal

    redu

    ction,

    CBCT

    cone

    -beam

    compu

    tedtomog

    raph

    y,n/ano

    tavailable

    Papadimitriou et al. Progress in Orthodontics (2018) 19:37 Page 10 of 24

  • Table

    2Overview

    oftheresults,outcomes,and

    conclusion

    sof

    theinclud

    edstud

    ies

    Autho

    r,year,

    design

    Title

    Subject

    grou

    pOutcomeassessed

    Metho

    dof

    outcom

    eassessmen

    tResults

    Con

    clusions

    Hen

    nessyet

    al.

    [18]

    (2016)

    RCT

    Arand

    omized

    clinical

    trialcomparingmandibular

    incisorproclination

    prod

    uced

    byfixed

    labial

    appliances

    andclear

    aligne

    rs

    Invisalign

    vs.fixed

    appliances

    Mandibu

    larincisorproclination

    prod

    uced

    byfixed

    appliances

    and

    Invisalign®

    aligne

    rswhe

    ntreatin

    gpatientswith

    mild

    mandibu

    lar

    crow

    ding

    Com

    parison

    ofpre-treatm

    ent

    andne

    ar-end

    treatm

    entlateral

    ceph

    alog

    rams;themainou

    tcom

    ewas

    theceph

    alom

    etric

    change

    inmandibu

    larincisorinclinationto

    themandibu

    larplaneat

    theen

    dof

    treatm

    ent

    -Mnincisorproclination:

    fixed

    appliances,5.3±4.3°;

    Invisalign®:3.4±3.2°

    (P>0.05)

    Nodifferencein

    theam

    ount

    ofMnincisorp

    roclinationprod

    uced

    byInvisalign®

    andfixed

    labial

    appliances

    inmild

    crow

    ding

    cases

    Liet

    al.[19]

    (2015)

    RCT

    Theeffectiven

    essof

    the

    Invisalignappliancein

    extractio

    ncasesusing

    thetheABO

    mod

    elgradingsystem

    :amulticen

    terrand

    omized

    controlledtrial

    Invisalign

    vs.fixed

    appliances

    Treatm

    entou

    tcom

    esof

    the

    Invisalign®

    system

    bycomparin

    gtheresults

    ofInvisalign®

    treatm

    entwith

    that

    offixed

    appliances

    inclassIadu

    ltextractio

    ncases

    TheDIw

    asused

    toanalyze

    pretreatmen

    trecords(study

    casts

    andlateralcep

    halogram

    s)to

    controlfor

    initialseverityof

    malocclusion.TheABO

    -OGSwas

    used

    tosystem

    aticallygradebo

    thpre-

    andpo

    st-treatmen

    trecords

    -Im

    proved

    totalm

    eanscores

    oftheOGScatego

    riesafter

    treatm

    entforbo

    thgrou

    psin

    term

    sof

    alignm

    ent,marginal

    ridge

    s,occlusalrelatio

    ns,overjet,

    inter-proxim

    alcontacts,and

    root

    angu

    latio

    n-Invisalign®

    scores

    weresig

    nificantly

    lower

    than

    fixed

    appliance

    scores

    forb-linclinationand

    occlusalcontacts

    -Invisalign®

    hadlong

    ertreatm

    ent

    duratio

    n(31.5mon

    ths)

    comparedto

    fixed

    appliances

    (22mon

    ths)

    Both

    Invisalign®

    andfixed

    appliances

    weresuccessful

    intreatin

    gclassIadu

    ltextractio

    ncases,thou

    ghInvisalign®

    requ

    iredmoretim

    eandshow

    edworse

    perfo

    rmance

    incertain

    fields

    Bollenet

    al.[20]

    (2003)

    RCT

    Activationtim

    eand

    materialstiffnessof

    sequ

    entialrem

    ovable

    orthod

    ontic

    appliances.

    Part1:Abilityto

    completetreatm

    ent

    Invisalign

    grou

    psEffectsof

    activationtim

    eand

    materialstiffnesson

    theability

    tocompletetheinitialseriesof

    aligne

    rs,d

    esigne

    dto

    fully

    correct

    each

    subject’s

    malocclusion

    InitialPA

    Rscores

    calculation,

    clinicalevaluatio

    nandorthod

    ontic

    records(progressstud

    ymod

    els

    andph

    otog

    raph

    s)every4mon

    ths

    -15/51completed

    theinitial

    regimen

    ofaligne

    rs-2weeks

    activationintervalmore

    likelyto

    lead

    tocompletionthan

    1week(37%

    vs21%)

    -Nosubstantiald

    ifferen

    ces

    betw

    eensoft-andhard

    appliancein

    completionrate

    (27%

    vs32%)

    -Highe

    stcompletionrate

    (46%

    )forno

    n-extractio

    nandinitial

    PARscore<15

    -Lowestcompletionrate

    (0%)in

    patientswith

    ≥2extractio

    ns

    Greater

    likelihoo

    dfor

    completionof

    theinitialsetof

    aligne

    rsforsubjectswith

    ano

    n-extractio

    n,2weeks

    activation

    regimen

    andlow

    initialPA

    Rscores

    Solano

    -Men

    doza

    etal.[21](2016)

    Prospe

    ct.

    How

    effectiveisthe

    Invisalign®

    system

    inexpansionmovem

    ent

    with

    Ex30′aligne

    rs?

    Accuracy

    Ane

    wmetho

    dformeasurin

    gthe

    predictabilityof

    expansionob

    tained

    byInvisalign®

    treatmentand

    differences

    betweenthepredicted

    (ClinCh

    eck®

    mod

    els)andactual

    expansionattheendof

    treatment

    InitialandfinalClinChe

    ck®virtual

    modelsmeasuredwith

    ToothM

    easure®

    compa

    redto

    initialandfin

    alactual3D

    mod

    elsmeasuredwith

    Nem

    oCast®

    forevaluatio

    nof

    the

    followingvariables:canineging

    ival

    width,1stprem

    olarging

    ivalwidth,

    2ndprem

    olarging

    ivalwidth,1st

    molarging

    ivalwidth,canine

    cuspidwidth,1stprem

    olarcuspid

    width,2nd

    prem

    olarcuspidwidth,

    1stmolarcuspidwidth,canine

    -Non

    -significantdifferences

    be-

    tweentheinitial3D

    mod

    elsand

    ClinChe

    ck®forallvariables

    ex-

    cept

    for1stmolar

    cuspid

    width

    andarch

    depth

    -Statisticallysign

    ificant

    differences

    betw

    eenthefinal3D

    andClinChe

    ck®mod

    elsfor

    canine

    ging

    ivalwidth,1st

    prem

    olar

    ging

    ivalwidth,2nd

    prem

    olar

    ging

    ivalwidth,1st

    molar

    ging

    ivalwidth,canine

    -Differen

    cesbe

    tweenthefinal

    3DandClinChe

    ck®mod

    els

    show

    edthat

    planne

    dexpansionat

    theen

    dof

    treatm

    entisno

    tpred

    ictable

    Papadimitriou et al. Progress in Orthodontics (2018) 19:37 Page 11 of 24

  • Table

    2Overview

    oftheresults,outcomes,and

    conclusion

    sof

    theinclud

    edstud

    ies(Con

    tinued)

    Autho

    r,year,

    design

    Title

    Subject

    grou

    pOutcomeassessed

    Metho

    dof

    outcom

    eassessmen

    tResults

    Con

    clusions

    depth,arch

    depth,1stmolar

    rotatio

    n,1strig

    htandleftmolar

    rotatio

    n,and1stmolarinclination

    cuspidwidth,1stprem

    olarcuspid

    width,2nd

    prem

    olarcuspid

    width,1stmolarcuspidwidth

    Buschang

    etal.

    [26]

    (2015)

    Prospe

    ct.

    Predictedandactualend-

    of-treatm

    ento

    cclusio

    nprod

    uced

    with

    aligner

    therapy

    Accuracy

    Differen

    cesbe

    tweenfinalactual

    mod

    elsfro

    mthefinalvirtual

    ClinChe

    ck®mod

    elsafter

    treatm

    entwith

    Invisalign

    FinalC

    linChe

    ck®virtualm

    odels

    comparedto

    finalactual3D

    mod

    elsmeasuredwith

    MeshLab

    V1.30softwareforevaluatio

    nof

    theAmerican

    Boardof

    Ortho

    dontics(ABO

    )Objective

    Grading

    System

    (OGS)

    FinalvirtualC

    linChe

    ckmod

    els

    show

    edsign

    ificantlyfewer

    overall

    OGSpo

    intde

    ductions

    compared

    tofinalactualmod

    els(15vs

    24).

    Differen

    cesweremainlyob

    served

    inalignm

    ent(1

    vs4de

    ductions),

    buccolingu

    alinclinations

    (3vs

    4de

    ductions),occlusalcontacts

    (2vs

    3de

    ductions),andocclusal

    relatio

    ns(2

    vs4de

    ductions)

    -ThefinalvirtualC

    linChe

    ckmod

    elsdo

    notaccurately

    reflect

    thepatients’final

    occlusion,as

    measuredby

    the

    OGS,at

    theen

    dof

    active

    treatm

    ent

    Castroflorio

    etal.

    [22]

    (2013)

    Prospe

    ct.

    Upp

    er-IncisorRootC

    ontro

    lwith

    Invisalign®

    Appliances

    Accuracy

    Efficiencyof

    AlignTechno

    logy’s

    Power

    Ridg

    ein

    controlling

    theb-l

    inclinationof

    uppe

    rincisors

    ClinChe

    ck®initialandfinalvirtual

    setups

    foreach

    uppe

    rincisor

    from

    therig

    htandleftde

    fault

    view

    scomparedto

    measuremen

    tson

    3D-scans

    ofactualde

    ntalmod

    els

    -Meantorque

    values

    forthe9

    uppe

    rincisorsat

    T0:20.9°

    onthevirtualsetup

    sand21.1°on

    thescanne

    dcasts

    -AtT1,the

    torque

    values

    were

    10.5°and10.5°,respectively,and

    represen

    tedthetorque

    prescriptio

    n(10.4°)

    -Invisalign®

    controlswellthe

    uppe

    r-incisorroot

    torque,

    whe

    natorque

    correctio

    nof

    abou

    t10°isrequ

    ired

    Pavoni

    etal.[23]

    (2011)

    Prospe

    ct.

    Self-ligatingversus

    Invisalign:analysisof

    dento-alveolar

    effects

    Invisalign

    vs.fixed

    appliances

    Dentoalveolar

    effectsoftheInvisalign®

    system

    andof

    self-ligating

    bracketstreatm

    entin

    relatio

    nto

    transverse

    dimen

    sion

    ,arch

    perim

    eter

    andarch

    depthon

    Mx

    jaw

    Measuremen

    tson

    pre-

    andpo

    st-

    treatm

    entmaxillaryde

    ntalcasts

    (intercanine-,interprem

    olar-,and

    interm

    olar

    width,archde

    pth,and

    arch

    perim

    eter)

    -Nosign

    ificant

    differences

    intreatm

    entdu

    ratio

    n.-Sign

    ificant

    differences

    betw

    een

    the2grou

    pswith

    self-ligating

    causingfurthe

    rincreasesin

    the

    followingvariables

    ascompared

    toInvisalign:intercaninewidth

    (cusp),2.6mm;firstprem

    olar

    width

    (fossa),3.3mm;first

    prem

    olar

    width

    (gingiva),

    2.3mm;secon

    dprem

    olar

    width

    (fossa),2.0mm;secon

    dprem

    olar

    width

    (gingiva),

    1.8mm;archpe

    rimeter,1.3mm

    -Class

    Imild

    crow

    ding

    canbe

    treatedby

    Invisalign®

    and

    self-ligatingbracketsat

    the

    sametreatm

    entdu

    ratio

    n-Invisalign®

    caneasilytip

    crow

    nsbu

    tno

    troots

    Kravitz

    etal.[5]

    (2009)

    Prospe

    ct.

    How

    welld

    oesInvisalign

    work?Aprospective

    clinical

    stud

    yevaluatin

    gthe

    efficacyof

    tooth

    movem

    entw

    ithInvisalign

    Accuracy

    Differen

    cesbe

    tweenactual

    mod

    elsandvirtualC

    linChe

    ck®

    mod

    elsin

    theanterio

    rteeth,after

    treatm

    entwith

    Invisalign

    DIscores(overjet,overbite,

    anterio

    rop

    enbite,and

    crow

    ding

    )usingamod

    ified

    ABO

    -OGSon

    pretreatmen

    tdigitalm

    odels.

    Supe

    rimpo

    sitio

    nof

    virtualm

    odels

    ofthepred

    ictedtoothpo

    sitio

    nover

    theachieved

    toothpo

    sitio

    n(Too

    thMeasure®).C

    omparison

    betweenthepredictedandachieved

    amou

    ntof

    toothmovem

    ent

    (i.e.,expa

    nsion,

    constrictio

    n,intrusion,

    extrusion,

    mesiodistal

    -Invisalign®

    meanaccuracy

    oftoothmovem

    ent,41%

    -Mostaccurate

    movem

    ent:

    lingu

    alconstrictio

    n(47.1%

    ),least

    accurate

    movem

    ent:extrusion

    (29.6%

    ;18.3%

    forMxand24.5%

    forMncentralincisors),followed

    bymesio-distaltipping

    ofthe

    Mncanine

    s(26.9%

    )-Caninerotatio

    nsign

    ificantlyless

    accurate

    than

    that

    ofallo

    ther

    teeth,except

    forthat

    oftheMx

    -Further

    research

    isne

    eded

    toun

    derstand

    theefficacyand

    biom

    echanics

    oftheInvisalign®

    system

    -Prescrip

    tionby

    clinicians

    shou

    ldbe

    madebasedon

    thepatient’s

    treatm

    entne

    eds,whiletaking

    into

    accoun

    tthelim

    itatio

    nsof

    theappliance

    Papadimitriou et al. Progress in Orthodontics (2018) 19:37 Page 12 of 24

  • Table

    2Overview

    oftheresults,outcomes,and

    conclusion

    sof

    theinclud

    edstud

    ies(Con

    tinued)

    Autho

    r,year,

    design

    Title

    Subject

    grou

    pOutcomeassessed

    Metho

    dof

    outcom

    eassessmen

    tResults

    Con

    clusions

    tip,labiolingu

    altip

    ,and

    rotatio

    n).

    Accuracy(%

    )=[(|pred

    icted-

    achieved

    |/|predicted

    |)100%

    ]

    lateralincisors,espe

    ciallyat

    rotatio

    nalm

    ovem

    ents>15°.

    -Ling

    ualcrowntip

    sign

    ificantly

    moreaccurate

    than

    labialcrow

    ntip

    -Nostatisticaldifferencein

    accuracy

    betw

    eenMxandMn

    foranymovem

    enton

    any

    specifictooth

    Kravitz

    etal.[24]

    (2008)

    Prospe

    ct.

    Influen

    ceof

    attachmen

    tsandinterproximal

    redu

    ctionon

    the

    accuracy

    ofcanine

    rotatio

    nwith

    Invisalign

    Accuracy

    Influen

    ceof

    attachmen

    tsandIPR

    oncanine

    sun

    dergoing

    rotatio

    nal

    movem

    entwith

    Invisalign®

    ToothMeasure®to

    compare

    the

    amou

    ntof

    canine

    rotatio

    nspred

    ictedwith

    theon

    esachieved

    (inde

    grees).A

    ccuracy(%)

    =[(|pred

    icted-achieved

    |/|predicted

    |)100%

    ]

    -Invisalign®

    meanaccuracy

    ofcanine

    rotatio

    nwas

    35.8±26.3%

    -Nostatisticallysign

    ificant

    differencein

    accuracy

    betw

    een

    the3grou

    ps-Nostatisticallysign

    ificant

    differencein

    rotatio

    nalaccuracy

    forMxandMncanine

    sforany

    ofthe3grou

    ps-Thevertical-ellipsoidwas

    the

    mostcommon

    lyprescribed

    at-

    tachmen

    tshape(70.5%

    )

    Theeffectiven

    essof

    the

    Invisalign®

    system

    incanine

    derotatio

    nislim

    itedandno

    tsign

    ificantlyim

    proved

    byvertical-ellipsoidattachmen

    tsandIPR

    Baldwin

    etal.

    [27]

    (2008)

    Prospe

    ct.

    Activationtim

    eand

    materialstiffnessof

    sequ

    entialrem

    ovable

    orthod

    ontic

    appliances.

    Part3:Prem

    olar

    extractio

    npatients

    Invisalign

    only

    Tipp

    ingof

    teethadjacent

    toprem

    olar

    extractio

    nspaces

    durin

    gspaceclosurewith

    aligne

    rappliances

    Den

    talcastsandpano

    ramic

    radiog

    raph

    spre-treatm

    entandat

    theen

    dof

    Invisaligntreatm

    ent

    (poten

    tially

    continuedwith

    fixed

    appliances)

    -Duringtreatm

    ent,theaverage

    radiog

    raph

    icchange

    sin

    interden

    talang

    lewere21.5°

    (P<0.0001;n

    =10)in

    the

    mandibleand16.3°(P<0.0001;

    n=19)in

    themaxilla.Onthe

    mod

    els,theaveragechange

    swere20.8°(P<0.0001;n

    =12)in

    themandibleand15.9°(P<

    0.0001;n

    =20)in

    themaxilla

    -Nosubjectcompleted

    theinitial

    seriesof

    aligne

    rsandon

    ly1

    ultim

    atelycompleted

    treatm

    ent

    with

    aligne

    rs-Theaveragetim

    ein

    theinitial

    seriesof

    aligne

    rsbe

    fore

    failure

    was

    7(rang

    e,1–17)mon

    thsand

    theaveragetotaltim

    ein

    aligne

    rs16.6(rang

    e,6–28)

    mon

    ths(treatmen

    tcontinued

    with

    fixed

    appliances)

    -In

    prem

    olar

    extractio

    npatients

    treatedwith

    Invisalign,

    sign

    ificant

    dentaltip

    ping

    occurs(it

    canbe

    corrected

    with

    fixed

    appliances)

    -Thereisatren

    dforgreater

    tipping

    ofmandibu

    larteeth

    into

    theextractio

    nspaceand

    arou

    ndsecond

    prem

    olar

    extractio

    nsitesdu

    ring

    treatm

    entwith

    aligne

    rs

    Vlaskalic

    and

    Boyd

    [25]

    (2002)

    Prospe

    ct.

    Clinicalevolutionof

    the

    Invisalign®

    appliance

    Invisalign

    grou

    psClinicalevaluationof

    theInvisalign®

    system

    basedon

    afeasibilitystud

    ycond

    uctedintheUniversity

    ofthe

    Pacific

    in1997

    Pre-,p

    rogress-,and

    post-

    treatm

    entrecordsinclud

    ing

    pano

    ramicandlateralcephalo

    metric

    radiog

    raph

    s,de

    ntalcasts,intra-,

    andextraoralp

    hotograp

    hs.

    Group

    1:aligne

    rsne

    edto

    bewornforat

    least10

    days

    each,

    patientstolerate

    aligne

    rswell,

    posteriorop

    enbite

    occursin

    somepatients,overcorrectio

    nof

    toothpo

    sitio

    nisne

    cessaryin

    -The

    Invisalignsystem

    isaviable

    alternativeto

    conven

    tionalfixed

    andremovableappliances

    -Patientsin

    thepe

    rmanen

    tde

    ntition

    with

    mild

    tomod

    eratemalocclusions

    may

    Papadimitriou et al. Progress in Orthodontics (2018) 19:37 Page 13 of 24

  • Table

    2Overview

    oftheresults,outcomes,and

    conclusion

    sof

    theinclud

    edstud

    ies(Con

    tinued)

    Autho

    r,year,

    design

    Title

    Subject

    grou

    pOutcomeassessed

    Metho

    dof

    outcom

    eassessmen

    tResults

    Con

    clusions

    initial3-Dsetup

    Group

    2:attachmentsarenecessary

    forrotations

    ofcylindricalshaped

    teeth,intru

    sion,extru

    sion,bo

    dily

    toothmovem

    ent,extractionof

    teethispo

    ssible

    Group

    3:long

    vertical

    attachmen

    tsarene

    cessaryfro

    mthestartof

    treatm

    entto

    maintain

    adeq

    uate

    root

    controlin

    extractio

    ncases,virtualtoo

    thpo

    nticsystem

    isestheticallyand

    mechanically

    advantageo

    us

    begreatly

    bene

    fited

    whe

    ntreatm

    entisplanne

    dcarefully

    -Furthe

    rinvestigationisne

    eded

    fortheultim

    ateclinical

    potentialo

    fInvisalign®

    Guet

    al.[28]

    (2017)

    Retrosp.

    Evaluatio

    nof

    Invisalign

    treatm

    enteffectiven

    ess

    andefficiencycompared

    with

    conven

    tionalfixed

    appliances

    usingthePeer

    Assessm

    entRatin

    gindex

    Invisalign

    vs.fixed

    appliances

    Effectiven

    essandefficiencyof

    the

    Invisalignsystem

    comparedwith

    conven

    tionalfixed

    appliances

    inmild

    tomod

    eratemalocclusions

    Com

    parison

    betw

    eenpatients

    treatedwith

    Invisalign®

    andfixed

    appliances

    assessingpo

    st-

    treatm

    entPA

    Rscores,p

    ost-

    treatm

    entredu

    ctionin

    PAR

    scores,treatmen

    tdu

    ratio

    n,and

    malocclusionim

    provem

    ent

    -Average

    pretreatmen

    tPA

    Rscores:20.81

    forInvisalignand

    22.79forfixed

    appliances

    (NS)

    -Not

    statisticallydifferent

    posttreatm

    entPA

    Rscores

    and

    PARscoreredu

    ctionbe

    tween

    the2grou

    ps.

    -Invisalign®

    patientsfinishe

    d5.7mon

    thsfaster

    than

    those

    with

    fixed

    appliances

    (P=0.0040).

    -Allpatientsin

    both

    grou

    pshad

    >30%

    redu

    ctionin

    PARscores.

    -Odd

    sof

    achieving“great

    improvem

    ent”in

    theInvisalign®

    grou

    pwere0.33

    times

    greater

    than

    thosein

    thefixed

    appliances

    grou

    pafter

    controlling

    forage(P=0.015)

    -Bo

    thInvisalign®

    andfixed

    appliances

    areableto

    improve

    mild

    tomod

    erate

    malocclusion

    -Fixedappliances

    weremore

    effectivethan

    Invisalignin

    providinggreater

    improvem

    ents

    -Treatm

    entwith

    Invisalignwas

    finishe

    don

    average30%

    (5.7mon

    ths)faster

    than

    treatm

    entwith

    fixed

    appliances.

    Khosraviet

    al.

    [29]

    (2017)

    Retrosp.

    Managem

    entof

    overbite

    with

    theInvisalign

    applian

    ceInvisalign

    grou

    psVerticaldimen

    sion

    change

    sin

    patientswith

    various

    pre-treatm

    ent

    overbite

    relatio

    nships

    treatedon

    lywith

    Invisalignandotherd

    ental

    andskeletalchanges

    Pre-

    andpo

    st-treatmen

    tlateral

    ceph

    alom

    etric

    radiog

    raph

    s;ceph

    alom

    etric

    analyses

    byDolph

    inImaging,Ch

    atsw

    orth,Calif

    -Deepbite

    patientshada

    med

    ianoverbite

    open

    ingof

    1.5mm,w

    hereas

    theop

    enbite

    patientshadamed

    ian

    deep

    eningof

    1.5mm.The

    med

    ianchange

    fortheno

    rmal

    overbite

    patientswas

    0.3mm

    -Chang

    esin

    incisorpo

    sitio

    nwere

    respon

    sibleformostof

    the

    improvem

    entsin

    thede

    epbite

    andop

    enbite

    grou

    ps-Minim

    alchange

    sin

    molar

    verticalpo

    sitio

    nandmandibu

    lar

    planeangle

    -Invisalignisrelatively

    successful

    inmanaging

    overbite

    -Overbite

    ismaintaine

    din

    patientswith

    norm

    aloverbite

    -Deepbite

    improvem

    ent

    prim

    arily

    byproclinationof

    Mn

    incisors

    -Invisaligncorrectsmild

    tomod

    erateanterio

    rop

    enbites,

    prim

    arily

    throug

    hincisor

    extrusion

    Papadimitriou et al. Progress in Orthodontics (2018) 19:37 Page 14 of 24

  • Table

    2Overview

    oftheresults,outcomes,and

    conclusion

    sof

    theinclud

    edstud

    ies(Con

    tinued)

    Autho

    r,year,

    design

    Title

    Subject

    grou

    pOutcomeassessed

    Metho

    dof

    outcom

    eassessmen

    tResults

    Con

    clusions

    Hou

    leet

    al.[30]

    (2016)

    Retrosp.

    Thepred

    ictabilityof

    transverse

    change

    swith

    Invisalign

    Accuracy

    Differen

    cesbe

    tweentheinitial

    andfinalactualmod

    elsfro

    mthe

    initialandfinalvirtualC

    linChe

    ck®

    modelsaftertreatmentw

    ithInvisalign,

    whenplanning

    transverse

    changes

    -Com

    parison

    betw

    eenpre-

    and

    posttreatm

    entdigitalm

    odels,

    (created

    from

    aniTeroscan)and

    digitalm

    odelsfro

    mClincheck®

    (AlignTechno

    logy)

    -Digitalm

    odelsweremeasured

    with

    Geo

    magicQualify

    -In

    theMx,whe

    nde

    ntoalveo

    lar

    expansionwas

    planne

    dwith

    Invisalign®,the

    rewas

    amean

    accuracy

    of72.8%:82.9%

    atthe

    cusp

    tipsand62.7%

    atthe

    ging

    ivalmargins,w

    ithpredictio

    nworsening

    towardthepo

    sterior

    region

    ofthearch

    -FortheMnarch,the

    rewas

    anoverallaccuracyof

    87.7%:98.9%

    forthecusp

    tipsand76.4%

    for

    theging

    ivalmargins

    -Varianceratio

    sforup

    perand

    lower

    arches

    weresign

    ificantly

    different

    (P<0.05)

    -Clincheck®

    pred

    ictio

    nof

    expansioninvolves

    more

    bodilymovem

    entof

    theteeth

    than

    that

    achieved

    clinically.

    Morede

    ntaltip

    ping

    was

    observed

    -Careful

    planning

    with

    overcorrectio

    nandothe

    rauxiliary

    metho

    dsof

    expansion

    may

    help

    redu

    cetherate

    ofmidcourse

    correctio

    nsand

    refinem

    ents,especially

    inthe

    posteriorregion

    oftheMx

    Ravera

    etal.[31]

    (2016)

    Retrosp.

    Maxillarymolardistalization

    with

    aligne

    rsin

    adult

    patie

    nts:a

    multicen

    ter

    retrospe

    ctivestud

    y

    Invisalign

    grou

    pDentoalveolarandskeletalchanges

    followingmaxillarymolardistalization

    therap

    ywith

    Invisalignin

    adult

    patie

    nts

    Pre-

    andpo

    st-treatmen

    tlateral

    ceph

    alom

    etric

    radiog

    raph

    s-Distalm

    ovem

    entof

    the1st

    molar:2.25mm

    with

    out

    sign

    ificant

    tipping

    andvertical

    movem

    ents

    -Distalm

    ovem

    entof

    the2n

    dmolar:2.52mm

    with

    out

    sign

    ificant

    tipping

    (P=0.056)

    andverticalmovem

    ents

    -Nosign

    ificant

    movem

    entson

    thelower

    arch.

    -SN

    -GoG

    nandSPP-GoG

    nangles

    show

    edno

    significantdifferences

    betweenpre-

    andpo

    st-treatment

    ceph

    alog

    rams

    -Invisalignaligne

    rsareeffective

    indistalizingMxmolarsin

    selected

    end-to-end

    classII

    non-grow

    ingsubjectswith

    out

    sign

    ificant

    verticalandmesio-

    distaltip

    ping

    movem

    ents

    -Nochange

    sto

    thefacial

    height

    Dun

    canet

    al.

    [32]

    (2015)

    Retrosp.

    Chang

    esin

    mandibu

    lar

    incisorpo

    sitio

    nandarch

    form

    resulting

    from

    Invisaligncorrectio

    nof

    thecrow

    dedde

    ntition

    treatedno

    nextraction

    Invisalign

    grou

    psTreatmentoutcomesinnon-extraction

    caseswith

    loweranteriorcrowding

    treated

    with

    Invisalign®

    -Pre-andpo

    st-treatmen

    trecords

    (digitalstudy

    mod

    elsandlateral

    ceph

    alom

    etric

    radiog

    raph

    s)-Cep

    halometric

    analysisto

    determ

    inelower

    incisorchange

    s-IPRandchange

    sin

    arch

    width

    werealso

    measured

    -In

    thesevere

    crow

    ding

    grou

    p,therewerestatistically

    sign

    ificant

    change

    sin

    lower

    incisorpo

    sitio

    nandangu

    latio

    n-Nosign

    ificant

    differences

    inlower

    incisorpo

    sitio

    nand

    angu

    latio

    nin

    thethemild

    and

    mod

    eratecrow

    ding

    grou

    ps-Statisticallysign

    ificant

    increase

    inbu

    ccalexpansionin

    allthree

    grou

    ps.

    -Nochange

    inthelower

    incisor

    positio

    nor

    angu

    latio

    nin

    mild

    tomod

    eratelower

    anterio

    rcrow

    ding

    cases

    -Inno

    n-extractio

    nsevere

    crow

    d-ingcases(>

    6mm),thelower

    incisorstend

    toproclineand

    protrude

    -BuccalarchexpansionandIPR

    areim

    portantfactorsin

    crow

    ding

    resolutio

    n-In

    tercanine,interpremolar,and

    interm

    olar

    widthsdo

    notdiffer

    amon

    gthethreegrou

    psat

    post-treatmen

    t

    Grünh

    eidet

    al.

    [33]

    (2015)

    Retrosp.

    Effect

    ofclearaligne

    rtherapyon

    the

    buccolingu

    alinclination

    ofmandibu

    larcanine

    s

    Invisalign

    vs.fixed

    appliances

    Treatm

    entchang

    esinb-linclination

    ofMncaninesandintercaninedis-

    tancebetweenpatientstreated

    with

    Invisalign®

    andconventional

    Pre-

    andpo

    st-treatmen

    tCBC

    Ts-Nosign

    ificant

    pre-treatm

    ent

    differencebe

    tweenthegrou

    psregardingtheb-linclinationof

    Mncanine

    sandintercanine

    Invisalignseem

    sto

    increase

    the

    Mnintercaninedistance

    with

    little

    increase

    inb-linclination

    comparedto

    fixed

    appliances

    Papadimitriou et al. Progress in Orthodontics (2018) 19:37 Page 15 of 24

  • Table

    2Overview

    oftheresults,outcomes,and

    conclusion

    sof

    theinclud

    edstud

    ies(Con

    tinued)

    Autho

    r,year,

    design

    Title

    Subject

    grou

    pOutcomeassessed

    Metho

    dof

    outcom

    eassessmen

    tResults

    Con

    clusions

    andtheintercanine

    distance

    fixed

    appliances

    distance

    -Po

    sitivepre-

    andpo

    st-treatmen

    tb-linclinations

    ofMncanine

    s(i.e.,theircrow

    nswerepo

    sitioned

    buccalto

    theirroo

    ts)for

    both

    grou

    ps-Significantlygreaterp

    ost-treatment

    b-linclinationintheInvisalign

    group

    -Sign

    ificantlyincreased

    intercaninedistance

    inthe

    aligne

    rgrou

    pat

    theen

    dof

    treatm

    ent

    Simon

    etal.[34]

    (2014)

    Retrosp.

    Treatm

    entou

    tcom

    eand

    efficacyof

    analigne

    rtechniqu

    e–regarding

    incisortorque,p

    remolar

    derotatio

    nandmolar

    distalization

    Accuracy

    Treatm

    entefficacyof

    Invisalign®

    aligne

    rsforthefollowing3

    pred

    etermined

    toothmovem

    ents:

    incisortorque

    >10°,prem

    olar

    derotatio

    n>10°,andmolar

    distalization>1.5mm

    -Com

    parison

    betw

    eenthe

    pred

    ictedam

    ount

    oftooth

    movem

    entby

    ClinChe

    ck®and

    theam

    ount

    achieved

    after

    treatm

    ent

    -Evaluatio

    nof

    theinfluen

    ceof

    auxiliaries(attachm

    ents/Pow

    erRidg

    e),the

    staging(m

    ovem

    ent/

    aligne

    r),andthepatient’s

    compliancewith

    treatm

    ent

    -Overallmeanefficacy:59

    ±0.2%

    -Meanaccuracy

    forup

    perincisor

    torque:42±0.2%

    -Prem

    olar

    derotatio

    nshow

    edthe

    lowestaccuracy

    ofapproxim

    ately40

    ±0.3%

    -Distalizationof

    anup

    permolar

    was

    themosteffective

    movem

    ent,with

    efficacy

    approxim

    ately87

    ±0.2%

    -Bo

    dilytoothmovem

    ent(m

    olar

    distalization)

    canbe

    effectively

    perfo

    rmed

    usingInvisalign®

    aligne

    rs-Prem

    olar

    derotatio

    nsign

    ificantlyde

    pend

    son

    velocity

    andtotalamou

    ntof

    planed

    toothmovem

    ent

    -Forup

    perincisortorque

    and

    prem

    olar

    derotatio

    n,overcorrectio

    ns/case

    refinem

    entsmay

    bene

    eded

    Kriege

    ret

    al.[35]

    (2012)

    Retrosp.

    Invisalign®

    treatm

    entin

    theanterio

    rregion

    .Werethepred

    icted

    toothmovem

    ents

    achieved

    ?

    Accuracy

    Differen

    cesin

    theanterio

    rregion

    betw

    eentheinitialandfinal

    actualmod

    elsfro

    mtheinitialand

    finalvirtualC

    linChe

    ck®mod

    els

    aftertreatm

    entwith

    Invisalign

    -Electron

    icdigitalcaliper

    for

    measuremen

    tsin

    casts

    -Evaluatedparameters:up

    per/

    lower

    anterio

    rarch

    leng

    thand

    intercaninedistance,overjet,

    overbite,d

    entalm

    idlineshift,

    andLittle’sirreg

    ularity

    inde

    x-ClinChe

    ck®was

    measuredwith

    ToothM

    easure®

    -Mxanterio

    rcrow

    ding

    :initial,5.4

    (rang

    e1.5–14.5)mm;final,1.6

    (rang

    e0.0–4.5)

    mm

    -Mnanterio

    rcrow

    ding

    :initial,6.0

    (rang

    e2.0–11.5)mm;final,0.8

    (rang

    e0.0–2.5)

    mm

    -Slight

    deviations

    betw

    eenthe

    initialactualandvirtual

    ClinChe

    ck®mod

    elsin

    overjet

    (−0.1±0.3mm),up

    peranterio

    rarch

    leng

    th(−

    0.3±0.5mm),

    lower

    anterio

    rarch

    leng

    th(0.0±0.5mm),andin

    overbite

    (0.7±0.9mm)

    -Mod

    erateto

    severe

    anterio

    rcrow

    ding

    canbe

    successfully

    correctedwith

    Invisalign®

    -Wellp

    redictableresolutio

    nof

    lower

    anterio

    rcrow

    ding

    isachieved

    byprotrusion

    ofanterio

    rteeth(i.e.,

    enlargem

    entof

    theanterio

    rarch

    leng

    th)

    -In

    gene

    ral,theachieved

    tooth

    movem

    entwas

    inaccordance

    with

    thepred

    ictedmovem

    ent

    forallp

    aram

    eters,except

    for

    overbite

    Kriege

    ret

    al.[36]

    (2011)

    Retrosp.

    Accuracyof

    Invisalign®

    treatm

    entsin

    the

    anterio

    rtoothregion

    .Firstresults

    Accuracy

    Differen

    cesbe

    tweentheinitial

    andfinalactualmod

    elsfro

    mthe

    initialandfinalvirtualC

    linChe

    ck®

    mod

    elsaftertreatm

    entwith

    Invisalign

    -Electron

    icde

    ntalcaliper

    tomeasure

    pre-

    andpo

    st-

    treatm

    entmod

    els

    -ToothM

    easure®to

    measure

    the

    ClinChe

    ck®

    -Exam

    ined

    parameters:overjet,

    overbite,and

    dentalmidline

    shift

    -Slight

    deviations

    inoverjet

    (0.1±0.3mm),overbite

    (0.3±0.4mm),andde

    ntal

    midlinede

    viation(0.1±0.4mm)

    betw

    eeninitialactualandvirtual

    mod

    els

    -Larger

    deviations

    inoverjet

    (0.4±0.7mm),overbite

    (0.9±0.9mm),andde

    ntal

    -Accep

    tableaccuracy

    ofInvisalign®

    techno

    logy

    durin

    gcompu

    terized

    transfer

    ofmalaligne

    dteethinto

    the

    ClinChe

    ck®presen

    tatio

    n.-Toothcorrectio

    nsin

    the

    verticalplaneweremore

    difficultto

    achieve.

    -Overcorrectionin

    thefinal

    Papadimitriou et al. Progress in Orthodontics (2018) 19:37 Page 16 of 24

  • Table

    2Overview

    oftheresults,outcomes,and

    conclusion

    sof

    theinclud

    edstud

    ies(Con

    tinued)

    Autho

    r,year,

    design

    Title

    Subject

    grou

    pOutcomeassessed

    Metho

    dof

    outcom

    eassessmen

    tResults

    Con

    clusions

    midlineshift

    (0.4±0.5mm)

    betw

    eenfinalactualandvirtual

    mod

    els

    ClinChe

    ck®,case

    refinem

    entat

    treatm

    enten

    dor

    additio

    nal

    measures(e.g.,ho

    rizon

    tal

    beveledattachmen

    tsor

    verticalelastics)aresugg

    ested

    tomeetindividu

    alized

    therapeutic

    goals,espe

    ciallyin

    verticalcorrectio

    ns

    Kuncio

    etal.[37]

    (2007)

    Retrosp.

    InvisalignandTradition

    alOrtho

    donticTreatm

    ent

    PostretentionOutcomes

    comparedusingthe

    American

    Boardof

    Ortho

    donticsObjective

    Grading

    System

    Invisalign

    vs.fixed

    appliances

    (retention)

    Post-retentio

    ntreatm

    entou

    tcom

    esinpatientstreatedwith

    Invisalign

    andthosetreatedwith

    tradition

    alfixed

    appliances

    -ABO

    -OGSanalysison

    pano

    ramic

    radiog

    raph

    sandde

    ntalcasts

    -Investigated

    parameters:total

    alignm

    ent,Mxanterio

    rand

    posterioralignm

    ent,Mnanterio

    randpo

    sterioralignm

    ent,

    marginalridge

    s,b-linclination,

    occlusalcontacts,occlusalrelations,

    overjet,interproximalcontacts,root

    angulations

    -Evaluatio

    nafterappliance

    removal(T1)

    andat

    apo

    st-

    retention(T2)

    (3yearsafter

    applianceremoval).

    -Efficacyin

    retentionin

    comparison

    toEssixretainer

    afterfixed

    appliances

    -Po

    st-reten

    tionworsening

    oftotalalignm

    entandMnanterio

    ralignm

    entforbo

    thgrou

    ps-Highe

    rpo

    st-reten

    tionchange

    sin

    totalalignm

    ent(ABO

    -OGS

    score)

    forInvisalignpatients

    (−2.9±1.6)

    than

    patients

    treatedwith

    fixed

    appliances

    (−1.4±1.2)

    -Po

    st-reten

    tionworsening

    ofMx

    anterioralignm

    entintheInvisalign

    grou

    pon

    ly.

    Greater

    relapsein

    theInvisalign®

    grou

    pforthisob

    servation

    perio

    d(app

    roximately3years)

    forInvisalignthan

    forfixed

    appliancegrou

    p

    Djeuet

    al.[38]

    (2005)

    Retrosp.

    Outcomeassessmen

    tof

    Invisalignandtradition

    alorthod

    ontic

    treatm

    ent

    comparedwith

    the

    American

    Boardof

    Ortho

    donticsob

    jective

    gradingsystem

    Invisalign

    vs.fixed

    appliances

    Treatm

    entou

    tcom

    eof

    Invisalign

    comparedto

    conven

    tionalfixed

    appliancetreatm

    ent

    -Pretreatmen

    trecords(den

    tal

    castsandlateralcep

    halogram

    s)assessed

    with

    theDI

    (measuremen

    ts:overjet,

    overbite,anteriorop

    enbite,

    lateralo

    penbite,crowding

    ,occlusion,lingu

    alpo

    sterior

    crossbite,b

    uccalp

    osterio

    rcrossbite,cep

    halometrics,and

    othe

    r)-Po

    sttreatm

    entrecords(den

    tal

    castsandpano

    ramic

    radiog

    raph

    s)scored

    byABO

    -OGS(m

    easuremen

    ts:alignm

    ent,

    marginalridge

    s,b-linclination,

    occlusalcontacts,occlusal

    relatio

    ns,overjet,interproximal

    contacts,roo

    tangu

    latio

    n)

    -Lower

    OGSpassingrate

    for

    Invisalign®

    (27.1%

    )than

    that

    for

    fixed

    appliances

    -Invisalign®

    scores

    were

    sign

    ificantlylower

    than

    fixed

    appliancescores

    forb-linclin-

    ation,occlusalcontacts,occlusal

    relatio

    nships,and

    overjet(P

    <0.05)

    -Invisalign®

    OGSscores

    negativelycorrelated

    toinitial

    overjet,occlusion,andbu

    ccal

    posteriorcrossibite

    -Treatm

    entdu

    ratio

    non

    average

    4mon

    thsshorterwith

    Invisalign®

    than

    with

    fixed

    appliances

    (P<0.05)

    -Treatm

    entresults

    offixed

    appliances

    aresupe

    riorto

    thoseof

    Invisalign®

    (13OGS

    pointson

    average)

    -Redu

    cedability

    ofInvisalignto

    correctlargeA-P

    discrepancies

    andocclusalcontacts

    Prospect.,prospe

    ctive,Retrosp.,retrospective,DId

    iscrep

    ancy

    inde

    x,AB

    OAmerican

    Boardof

    Ortho

    dontics,OGSObjectiv

    eGrading

    System

    ,Mxmaxilla(ormaxillary),M

    nman

    dible(orman

    dibu

    lar),N

    Sno

    tstatisticallysign

    ificant,

    b-lb

    uccolingu

    al

    Papadimitriou et al. Progress in Orthodontics (2018) 19:37 Page 17 of 24

  • Table

    3Qualityassessmen

    tof

    theinclud

    edRC

    Tstud

    ies

    Autho

    r-year

    ofpu

    blication

    Stud

    yde

    sign

    Sequ

    ence

    gene

    ratio

    n(selectio

    nbias)

    Allocatio

    nconcealm

    ent

    (selectio

    nbias)

    Blinding

    ofparticipants

    andpe

    rson

    nel

    (perform

    ance

    bias)

    Blinding

    ofou

    tcom

    eassessors(detectio

    nbias)

    Incompleteou

    tcom

    edata

    (attritionbias)

    Selectiverepo

    rting

    (repo

    rtingbias)

    Other

    sourcesof

    bias

    Overall

    risk

    Hen

    nessyet

    al.

    [18]

    (2016)

    RCT

    Aj:Low

    risk

    Sfj:Alth

    ough

    not

    explicitlystated

    ,sequ

    ence

    gene

    ratio

    nisvery

    likelydu

    eto

    referenceof

    rand

    ompicking

    upof

    sealed

    opaque

    envelope

    s

    Aj:Low

    risk

    Sfj:Sealed

    opaque,

    envelope

    s

    Aj:Low

    risk

    Sfj:Incompleteblinding

    ,bu

    tthereview

    authors

    judg

    ethat

    theou

    tcom

    eisno

    tlikelyto

    beinfluen

    cedby

    lack

    ofblinding

    Aj:Low

    risk

    Sfj:Noblinding

    ofou

    tcom

    eassessmen

    t,bu

    tthereview

    authorsjudg

    ethat

    theou

    tcom

    emeasuremen

    tisno

    tlikelyto

    beinfluen

    cedby

    lack

    ofblinding

    Aj:Low

    risk

    Sfj:Missing

    outcom

    edata

    balanced

    innu

    mbe

    rsacross

    interven

    tiongrou

    ps,

    with

    similarreason

    sfor

    missing

    data

    across

    grou

    ps

    Aj:Low

    risk

    Sfj:Thestud

    yprotocol

    isavailableandallo

    fthestud

    y’spre-

    specified

    outcom

    esthat

    areof

    interestin

    thereview

    have

    been

    repo

    rted

    inthepre-

    specified

    way

    Aj:Low

    risk

    Sfj:Thestud

    yappe

    ars

    tobe

    freeof

    othe

    rsourcesof

    bias

    Low

    Liet

    al.[19]

    (2015)

    RCT

    Aj:Low

    risk

    Sfj:Use

    ofa

    compu

    terrand

    omnu

    mbe

    rge

    nerator

    Aj:Low

    risk

    Sfj:Sequ

    entially

    numbe

    red,

    opaque,sealed

    envelope

    s

    Aj:Low

    risk

    Sfj:Blinding

    ensuredand

    unlikelythat

    the

    blinding

    couldhave

    been

    broken

    Aj:Low

    risk

    Sfj:Blinding

    ofou

    tcom

    eassessmen

    ten

    suredandun

    likely

    that

    theblinding

    couldhave

    been

    broken

    Aj:Low

    risk

    Sfj:Nomissing

    outcom

    edata

    Aj:Low

    risk

    Sfj:Thestud

    yprotocol

    isavailableandallo

    fthestud

    y’spre-

    specified

    outcom

    esthat

    areof

    interestin

    thereview

    have

    been

    repo

    rted

    inthepre-

    specified

    way

    Aj:Low

    risk

    Sfj:Thestud

    yappe

    ars

    tobe