Functional appliances

orthodontic functional appliances are described

1. LOGO
Functional Appliances
By; Ammar A. Dae’r
Supervisor; Prof. Maher A. Fouda

2. • Introduction
• Basis for functional appliances
• Classification of functional appliances
• Cephalometric analysis
• Activator
• Bionator
• Frankel appliance (functional regulator)
• Twin-block
• Fixed functional appliances
• Conclusion
Functional appliances

3. 3
Conventionalorthodonticappliancesusemechanical
forcetoalterthepositionoftooth/teethintoamore
favorableposition.However,thescopeofthesefixed
appliancesisgreatlylimitedbycertainmorphological
conditionswhicharecausedduetoaberrationsinthe
developmentalprocessortheneuromuscularcapsule
surroundingtheorofacialskeleton.Toovercomethis
limitation,functionalappliancescameintobeing.
INTRODUCTION

4. Theseappliancesareconsideredtobeprimarily
orthopedictoolstoinfluencethefacialskeletonof
thegrowingchild.Theuniquenessofthese
appliancesliesinthefactthatinsteadofapplying
activeforces,theytransmit,eliminateandguidethe
naturalforces(e.g.muscleactivity,growth,tooth
eruption)toeliminatethemorphologicalaberrations
andtrytocreateconditionsfortheharmonious
developmentofthestomatognathicsystem
4

5. Mostofthefunctionalappliancesareintraoral
devices,andnearlyallofthemaretooth
borneorsupportedbyteeth.Withafew
exceptions,theseappliancesareremovable,
consistingprimarilyofacrylicwithwire
componentsforretentionandsupport.
5

6. Mostofthefunctionalappliancesareusedto
correctearlyClassIImalocclusionsandsome
casesofClassIIImalocclusion.About40
percentofallmalocclusionstreatedbelongto
theClassITcategory.
6

7. ThispreponderanceoftheClassII
malocclusionsseeninorthodonticpracticeis
partlyaresultofpublicawarenessofaberrant
characteristicsassociatedwiththe
malocclusionandeducationofthepublicby
theconcerneddentalpractitioners.
7

8. Toooften,ClassIImalocclusionshavebeentreated
withextra-oralforcesdirectedagainstthemaxilla.
However,abundantresearchhasshownthatmuchof
theproblemliesinthemandible,whichis
retrognathic(small)orretro-positioned(backwardly
placed)oracombinationofboth.Neverthelessthe
past30yearshaveseenanincreasingawareness
regardingthepotentialoffunctionalappliancesasa
valuabletoolinthearmamentariumofan
orthodontist.
8

9. 9

10. Althoughfunctionalapplianceshavebeen
inuseforovertwocenturies,theirscope
andpotentialhasbeenrealizedonly
recentlywiththerecognitionof
interrelationshipbetweenformand
functionandtherealizationthatneuro-
muscular involvement isvitalin
treatment.

11. Graberdescribedthe'ThreeMs:Muscles,
Malformation andMalocclusionin1963.
MelvinMoss,againvalidatedtheconceptof
formandfunctionthroughhistheory'The
FunctionalMatrixHypothesis'.

12. Anotherfactorthatgaveimpetustotheuseoffunctional
appliances(especiallymandibularhyperpropulsers)was
theidentificationofcertaincartilagesinthebodyas
'Secondarycartilages‘.
Secondarycartilageisthat'cartilagewhichisnotof
developmentaloriginbutratherdifferentiatesfromthe
bonyperiosteuminresponsetotheneedsofthebody,
e.g.condylarcartilage.

13. Among theotherfeaturesofthesecondary
cartilages(Table46.1)thecharacteristicswhich
makeitusefulforfunctionalappliancetherapy
isitsadaptivegrowthresponsetothelocal
intrinsicandextrinsicstimuli,unlikethe
primary cartilageswhichareminimally
responsivetolocalfactors/stimuli.

15. Otherfactors/theorieshavealsobeenproposedin
favoroftheuseofFunctionalapplianceswhichinclude-
hyperactivityofthelateralpterygoidandtheCybernetic
growththeory(proposedbyPetrovicandassociates)and
morerecentlythe'GrowthRelativityTheory'(Vodouris&
associates)whichwasproposedafterextensiveresearchand
showsthatsignificantremodelingintheglenoidfossaand
themandibularcondyletakesplaceinresponsetothemand
ibularhyperpropuJsers.

16. However,onequestionthatstillloomslargeis
whetherthefunctionalappliancetherapy
actuallycausesgrowthmodification(beyond
geneticpotential)orjustgrowthre-direction.

17. Althoughanswerstothesequestionsare
stillatlarge,onethingisclearthatgrowth
modificationandgrowthre-directionbothtake
placetovaryingdegreesdependingonvarious
factorsliketheageofthepatient,diagnosis
andskilloftheclinician,etc.

18. 18

19. Myofunctional appliances
are classified as:

20. I. Classification put forth by Tom Graber when
functional appliances were removable:
1.GroupA-Teethsupportedappliances,e.g.
catlansappliance,inclinedplanes,etc.
2.GroupB-Teeth/tissuesupported,e.g.activator,
bionator,etc.
3.GroupC-Vestibularpositionedapplianceswith
isolatedsupportfromtooth/tissue,e.g.Frankel
appliance,lipbumpers.

21. 1.Removablefunctionals,e.g.activator,bionator,
frankel,etc.
2.Semi-fixedfunctionalappliances,e.g.DenHoltz,
Bassappliances,etc.
3.Fixedfunctionalappliances,e.g.Herbst,Jasper
jumper,Churrojumper,Salfsprings,adjustable
corrector,Eurekaspring,mandibularanterior
repositioningappliance,(MARA),Klappersuper
spring,Sabbaghuniversalspring(SUS).
II.Withadventoffixedfunctionalappliances,a
newclassificationevolved:

22. III. With concept of hybridization by Peter Vig,
functionals were classified as:
1.Classicalfunctionalappliances,e.g.activator,
Frankelsappliance,etc.
2.Hybridappliances,e.g.propulsor,doubleoral
screen,hybridbionators,Bassappliance.

23. IV. Classification put forth by Profitt
1.Teethbornepassiveappliances-myotonicappliances,
e.g.Andresen/Hauplactivator,Herrenactivator,
Woodside,activator,Balter'sbionatoretc.
2.Tooth borne activeapplianccs-c-myodynamic
appliances,e.g.elasticopenactivator(EOA),Birnler's
appliance,modifiedbionator,stockfishappliance,etc.
3.Tissuebornepassiveappliance,e.g.oralscreen,lip
bumpers,etc.
4.Tissueborneactiveappliances,e.g.Frankelappliances.
5.Functionalorthopedicmagneticappliances(FOMA)

24. 24

25. Cephalometricanalysisattemptstodefine
normal/abnormalcraniofacialpatternby
examiningtheangularandlinear
relationshipsofclearlydefinedskeletal
landmarks.

26. However,asfaraspatientsfor
functionalappliancetherapyareconcerned,
thisseeminglysimpleapproachis
complicatedbytheunpredictabilityinthe
nature,dimension,rateanddirectionof
growth.Therefore,cephalometricdiagnostic
assessmentforfunctionalappliancepatient
include4areasofemphasis:

27. 1.Incrementofgrowthdirectionvector
2.Assessmentofmagnitudeofgrowth
change
3.Assessmentofconstantlychanging
inclinationofupperandlowerincisors
4.Radiographiccephalometries.

28. Thevariouscephalometricanalysisfor
functionalappliancetherapyfor
patientscanbedividedinto3groups
1.Facialskeleton
2.Jawbases
3.Dentoalveolarrelationships

29. 29

30. This includes three angular measurements
1. Saddle angle
2. Articularangle
3. Gonial angle
and four linear measurements
-Anterior and posterior facial height
-Anterior and posterior cranial base length
30

31. Formedbyjoiningthese3
points.Alargesaddle
anglesignifiesposterior
condylarpositionanda
mandiblewhichis
posteriorlyplacedwith
respecttocranialbase
andmaxilla..
31
SaddleAngle(N-S-Ar)

32. However,ithasbeen
seenthattheposterior
positioningofthefossais
sometimescompensated
bythearticularangleand
the ramal length.
Nevertheless,anon-
compensated posterior
positioningofmandible
causedbyalargesaddle
angleisdifficultto
influencewithfunctional
therapy
32

33. Itistheconstructedangle
betweenSella,Articulare
andGonion.Itislargeif
mandibleisretrognathic
andsmallifmandibleis
prognathic.Can be
influencedbyorthodontic
andorthopedictherapy.
33
Articular Angle (S-Ar-Go)

34. Adecreaseinthearticularangle
canbeseeninthefollowing
conditions:
•Anteriorpositioningofthe
mandible
•Closingofthebite
•Mesialmigrationofposterior
segment.
34
Anincreaseinthearticularangleis
seenin:
•Posteriorrelocationofmandible
•Openingofthebite
•Distaldrivingofposteriorteeth

35. Anangleformedbytangentstothe
bodyofthemandibleand
posteriorbodyoftheramus.
Acuteorsmallangle,signifies
the'horizontalgrowthdirection,
aconditionfavorablefor
functional appliance
therapy/anteriorpositioningof
mandible.Largegonialangle
signifiesverticalgrowth
direction.
35
GonialAngle(Ar-Go-Me)

36. Functional appliance
treatmentinsuchcasesis
generallycontraindicated,
andifattemptedshouldbe
directedtowardsreducing
theverticalfacialgrowthof
thepatient.
36

37. Thesearelinearmillimetricmeasurements:
-Anteriorfacialheight(AFH)Nasiontomenton
-Posteriorfacialheight(PFH)Sellatogonion
Themeasurementshouldbedonewithteethin
habitualocclusion.
37
Anterior and Posterior Face Height

38. TheratioofPFH/AFHwasdescribedbyJarbakin1972andis
KnownasJarbak'sratio.Itgivesanideaaboutthegrowth
directionofthepatient
38
Jarbak'sratio
Aratiolessthan62%indicatesverticalgrowth
patternwhereas,aratioofmorethan65%
indicatesmorehorizontalpatternofgrowth.
Thisgrowthdirection,asexplainedearlier,is
veryimportantinplanningthefunctional
appliancetherapyforanindividual.

39. Cranial base length can be divided into:
1. Anterior cranial base length-Se to N
2. Posterior cranial base length-S to Ar
39
Cranial Base Length

40. Anterior cranial base length (Se-N)
Here center of superior entrance to
sellaturcica(Se) is used as
reference point. The correlation
of this criteria with the length of
jaw bases enables the assessment
of proportional averages of these
bases.
For example, in one of the longitudinal study
groups, average length of anterior cranial
base in 9 years-children was 68.8 mm for
horizontal growth pattern and 63.8 mm for
vertical growth pattern.
40

41. Posteriorcranialbaselength
(S-Ar)Thisdependsuponthe
posteriorfaceheightand
positioncifthefossa.Short
posteriorcranialbasesthat
occurinverticalgrowth
patternsandskeletalopen
bite,givepoorprognosisfor
functional appliance
.therapy.
41

42. It is done to assess the sagittal and vertical
relationships of jaw bones to each other
as well as to the cranium. appliance.
ANALYSIS OF JAW BONES

43. Indicatesthepositionof
maxillaryapicalbasewith
respecttotheanterior
cranialbase.
Alargeanglesignifiesa
prognathic maxilla
whereas,asmallangle
signifiesaretrognathic
maxilla.
SNA (Fig. 46.6)

44. However,agreatvariationinthisangle
mustbeviewedwithcautionbecause
ofpossiblevariationsintheanterior
cranialbaseitself.
Nevertheless,aClassIIDivision1
malocclusioncausedbyaprognathic
'maxillaisnotagoodcasefor
functionalappliance therapy.
However,alargedecreaseinoverjet
ispossiblewiththetwinblock
appliance..

45. Relationshipbetweenthe
mandibularapicalbase
andanteriorcranialbase.
Theangleisincreasedin
caseswithprognathic
mandibleandissmallin
retrognathicmandible.
Retrognathic mandible
(withsmallSNB)are
generallycasesindicated
forfunctionalappliance
therapy.
SNB(Fig.46.7)

46. Anotherparameterusedfortheassessmentofthe
inclination/thegrowthdirectionofthemandible.
Inhorizontalgrowthpatterns,theangleissmall(23.4°at9
years)whereasinverticalgrowthpattern,itislarger
(32.9°at9years).
BasePlaneAngle(Pal-Mp)(Fig.46.8)

47. Givesanindicationofthe
inclinationofpalatalplane
withrespecttoanterior
cranialbase.
TheangleisformedbyPN
line(perpendicularline
droppedfromN-SeatN')
andpalatalplane(Fig.
46.9A).
InclinationAngle(Fig.46.9)

48. Alargeangleindicatesan
upwardandforwardinclination
whereassmallangleindicates
downwardtippingoftheanterior
endofpalatalplaneandthe
maxillarybase(Fig.46.9B).
Although,thisangledoesnot
correlatewithgrowthpatternor
facialtype,thefunctionaland
therapeuticinfluencescanalter
theangle.
Variationintheinclinationangle
withtherotationofthemaxillary
base.Noteanincreasedanglewith
upwardtippinganddecreased
anglewithdownwardtippingofthe
maxilla

49. Thecraniofacialskeletonisadynamicentity
whereinnocephalometriclandmarkcanbetakenas
astandard.Hence,acompositeviewofallthe
previouslydescribedcephalometricmeasurements
shouldbetakenintoconsiderationbeforearrivingat
anyconclusion.Thisisparticularlytrueincaseswith
rotationofthejawbasesorthecranialbasetowards
orawayfromeachother,whichleadstoagreat
variationinthecephalometricangular
measurementsthatmayormaynotcorelatewell
withtheclinicalfindings.
RotationofJawBases(Figs46.10AtoD)

50. Rotationofthejawbases.(A)Convergentrotationofthejaw
bases.(B)Divergentrotationofthejawbases.(C)Cranialrotation
ofthejawbases.(D)Caudalrotationofthejawbases

51. EVALUATION OF THE
LENGTH OF JAW BASES

52. Notonlytheposition,butalsothelengthofjawbasesisan
importantconsiderationintheetiologyandtherapyof
functionalappliancecases.Hence,thelengthofmaxillary
andmandibularbasesandtheascendingramusis
measuredrelativetoSe-NTheidealdimensionsas
proposedbySchwarz(1958)are:
1.Se-N:Mandibularbase20:21
2.Ascendingramus:Mandibularbase5:7
3.Maxillarybase:Mandibularbase 2:3

53. ItisthedistanceGo-Pogprojectedperpendicularlyonto
themandibularplane.
Thegrowthchangesofthemandibularbaseinrelationto
anteriorcranialbase(Se-N)havebeenshowninthe
Table46.2:
MandibularBase(Fig.46.11)
Table46.2:Growthchangesinthemandibularbaseinrelationtotheanteriorcranialbase

54. Correlationbetweenthelengthandpositionofthe
mandibleshouldalsobeexamined.A
retrognathicmandiblemayeitherhavealong
baseorshortbase.Ifbaseisshort,causeof
retrognathismispossiblyagrowthdeficiency.If
afavorablegrowthdirectionispresent,
prognosisforfunctionalappliancetherapyis
good.

55. Amandibularbasethatislongandretrognathiccanresult
frommandiblethatisfunctionallyretrudedbecauseof
overclosureandocclusalguidance.Treatmentconsists
ofeliminationofforcedguidance.
Mandiblewhichismorphogeneticallybuiltintothefacial
skeletoninaposteriorposition,showspoorprognosis
forfunctionaltherapy.

56. LengthofmaxillarybaseismeasuredbetweenPNSand
pointAprojectedperpendicularlyontothepalatalplane.
MaxillaryBase(Fig.46.11)

57. Assessmentofthelengthofthemaxillarybasehastwo
idealvalues-onerelatedtothedistanceN-Se,theother
tothelengthofthemandibularbase.Adeviationfrom
themandibularbase-relatednormindicatesthatthe
maxillarybaseistoolongortooshort.Ifthemaxillary
basecorrespondstothemandibularbase-relatednorms,
thefacialskeletonisproportionallydeveloped.

58. Lengthofascendingramusis
measuredbetweengonionand
condylion.
Thislengthisimportantindetermining
theposteriorfacialheightand
consequentlythegrowthpatternof
anindividual.
Evaluationoframallengthshouldalso
bedoneinrelationtoother
proportionssoastobeableto
predictthepossiblegrowth
incrementsandconsequentlythe
efficacyofthefunctionaltherapy.
AscendingRamus(Fig.46.12)

59. Morphologyofthemandiblevariesaccordingto
differentfacialtypes.Thevariousfacialtypes
seenare:
•Orthognathic
•Retrognathic
•Prognathic
MorphologyoftheMandible

60. Inorthognathictype-Ramusandbodyofmandiblearefully
developed,widthofascendingramusisequaltoheight
ofthebodyofmandible,includingheightofthealveolar
processandincisors.
Condylarandcoronoidprocessarealmostonthesame
plane.Symphysisiswelldeveloped.

61. Intheretrognathictype-Corpusisnarrow
particularlyinthemolarregion,symphysisis
narrowandlong.Ramusisshortandnarrow.
Coronoidprocessisshorterthancondylar
process.Gonialangleisobtuseorlarge.

62. Inprognathictype-Corpusiswelldevelopedand
wideinmolarregion.Symphysisiswiderinthe
sagittalplane.Ramusiswideandlong.Gonial
angleisacuteorsmall.

63. Theprognathicmandiblegrowshorizontally.Evenifan
averageorslightlyverticalgrowthdirectionisevidentin
mixeddetention,itshiftstohorizontalpatterninfollowing
years.
Inretrognathicmandible,shiftingofthegrowthpatternin
oppositedirectionisunlikely.

64. ANALYSIS OF DENTOALVEOLAR
RELATIONSHIPS
Anassessmentofconstantlychanginginclinationand
positionofincisorswithrespecttoanteriorcranialbase,
theirapicalbases,andeachotherisanimportantfactor
indecidingthetypeandconstructionoffunctional
applianceforapatient.

65. Upperincisor:Theposterioranglebetweenthelongaxisof
upperincisorandSNlineismeasured(Fig.46.14A).
Themeasurementaverages94°-100°untiltheageof7
years.However,theangleincreasesslightlytoan
averageof102°aftertheeruptionofpermanentteeth.
Alargeangleindicatesproc1inedincisors,asmallerangle
indicatesincisorretrusion
AxialInclinationoftheIncisors(Fig46.14)
Axial inclination of the upper and lower incisors

66. Lowerincisor:Posterioranglebetweenthelongaxisof
lowerincisorandmandibularplane.
Averagemeasurementis90°-95°.Largerangleindicates
labiallytippedincisorswhichmakesthefunctional
appliancetherapydifficult.Smallerangleindicates
retroclinedincisorswhichis
advantageousforfunctional
appliancetherapy.
Axial inclination of the upper and lower incisors

67. PositionofincisorsThisisthelinearmeasurementandis
donebetweentheincisaledgesoftheincisorstoN-Pog
line.ldealpositionofmaxillaryincisorsis2-4mm
anteriortoN-Pogline(Fig.46.14B)andlowerincisors2
mmanterior/posteriortoN-Pogline(Fig.46.14C).
However,thereliabilityofthesemeasurementsin
growingindividualsisquestionablebecauseofthe
constantlychangingreferencepoints,i.e.nasionand
pogonion,themselves.

68. VISUALTREATMENT OBJECTIVE (VTO)
Oneoftheimportantcriteriaincaseselectionforthe
functionalappliancetherapyiselicitingapositiveVTO.
VTOissaidtobepositiveif,theprofileofthepatient
improvesnoticeablywhenthepatientadvancesthe
mandiblevoluntarilytocorrecttheoverjet.Anegative
VTO,i.e.patientwhoseprofiledoesnotimprove/
worsensonvoluntaryforwardposturingofthemandible,
arenotgoodcandidatesforthefunctionalappliance
therapy.

69. ACTIVATOR (FIGS 46.15A TO C)
Activatorisaloosefittingappliancewhichwasdesigned
byAndreasenandHaupltocorrectretrognathic
mandible.Thepresentformoftheappliancecame
throughvariousstagesofdevelopmentstartingwiththe
conceptof'bitejumping'introducedbyNormanKingsley
(1879).Heusedavulcanitepalatalplateconsistingof
ananteriorinclinedplane,whichguidedthemandible
intoaforwardpositionwhenthepatientclosedonit.
The activator (frontal view)
The activator (superior view)
The activator(lingualview) showingthe
jack screw (Photograph courtesy:
Dentaurum Germany

70. ThiswasfollowedbyHotz'sVorbissplatte
whimwasamodificationofKingsley's
plateandwasusedtocorrectretrognathic
mandiblewithdeepbite.
The activator (frontal view)
The activator (superior view)
The activator(lingualview) showingthe
jack screw (Photograph courtesy:
Dentaurum Germany

71. Monoblocwhichwasmadeupofasingleblockofvulcanite,
wasusedbyPierreRobintocorrecttheairway
obstructioninpatientswithmicrognathia
.
Laterin19013ViggoAndreasen,modifiedtheHawley's
typeofretainer,onthemaxillaryarch,towhichheadded
alowerlingualhorseshoeshapedflangewhichhelpedto
positionthemandibleforward.Hecalleditthe
biomechanicalworkingretainer.Laterheteamedwith
KarlHaupl,anddevelopedanappliancewhichthey
calledasNorwegianapplianceandlatercametobe
knownastheactivator.

72. INDICATIONS
Activelygrowingindividualwithfavorablegrowthpattern
aregoodcandidatesfortheactivatortherapy.
Varioustypesofactivatorshavebeendevisedforthe
treatmentofvariousconditionslike:
•ClassIIdivision1malocclusion
•ClassIIdivision2malocclusion
•ClassIllmalocclusion
•ClassIopenbitemalocclusion
•ClassIdeepbitemalocclusion
•Forpost-treatmentretension
•Childrenwithdecreasedfacialheight

73. CONTRAINDICATIONS
•CannotbeusedincorrectionofClassI
problemsofcrowdedteethwherethereis
disharmonybetweentoothsizeandjawsize
•Cannotbeusedinchildrenwithexcesslower
facialheight
•Cannotbegivenincaseswithlower
proclination
•Incaseofnasalstenosis
•Innon-growingindividuals

74. ADVANTAGES
Usesexistinggrowth
Minimaloralhygieneproblems
Appointmentsusuallyshort
DISADVANTAGES
Requiresgoodpatientco-operation
Cannotproduceprecisedetailingand
finishingofocclusion.

75. PHILOSOPHYOFACTIVATOR
Variousviewshavebeenputforwardtoexplainthemodeofactionofthe
activator.Someimplicatethereflexmyotactic.activityandisometric
contractionswhileothersattributetheresultstotheviscoelastic
propertiesandstretchingofthemusclesandsofttissues.
Howeverthebasicfactremainsthatmostofthechangesareinducedby
holdingthemandibleforwardandtheensuingreactionofthestretched
musclesandsofttissues,transmittedtotheperiosteum,bonesandthe
teeth.
Arestrainingeffectonthegrowthofthemaxillaandthemaxillary
dentoalveolarcomplexisalsoseenalongwiththestimulationof
mandibulargrowthandmandibularalveolaradaptation.
ResearchhasalsoshownfavorablechangesintheTMJregion.

76. COMPONENTS OF THE ACTIVATOR
itconsistsofthefollowingelements.
1.LabialbowThewireusedisspringhardened0.9mm
stainlesssteel.Theprimarywireelementoftheactivator
consistsofanupperand/orlowerlabialbow.Itconsistof
horizontalmiddlesections,twoverticalloopsandwire
extensionsthroughthecanine-deciduousfirstmolar
embrasureintotheacrylicbody.
2.JackscrewOptional(fittedtomaxillaryarch).
3.AcrylicportionThiscanbefabricatedincoldcureacrylic
directlyonthemodelsorawaxmatrixcanbemadefirst
andtheninvestedintheflask.

77. CONSTRUCTION BITE
Itisanintermaxillarywaxrecordusedtorelatethemandibletothe
maxilla.Thisisdonetoimprovetheskeletalinter-jaw
relationship.Inmostcasesbiteopeningisby2-3mmand
advancementisby4-5mm.
Generalconsiderationsforconstructionbite
1.Incasetheoverjetistoolarge,forwardpositioningisdonein2-3
stages
2.Incaseofforwardpositioningofthemandibleby7-8mm,the
verticalopeningshouldbeslighttomoderatei.e.2-4mm.
3.Iftheforwardpositioningisnotmorethan3-5mmthenthe
verticalopeningcanbe4-6mm

78. Lowerconstructionbitewithmarked
mandibularforwardpositioning
Thiskindofconstructionbiteischaracterizedbymarked
forwardpositioningofthemandiblewithminimum
verticalopening.Asaruleofthethumbtheanterior
advancementshouldnotexceedmorethan70%ofthe
mostprotrusiveposition,andverticallyitshouldbe
withinthelimitsofinterocclusalclearance.
Thiskindofanactivatorwithmarkedsagittaladvancementwith
minimalbiteopeningiscalledH-activatorandisindicatedin
personswithClassIIDivision1malocclusionwithhoriozontal
growthpattern.
CONSTRUCTION BITE

79. Highconstructionbitewithslightanterior
mandibularpositioning
Heremandibleispositionedanterioriyby3-5mmonly
andthebiteisopenedverticallyby4-6mm.Thiskind
ofactivatorconstructedwithminimalsagittal
advancementbutmarkedverticalopeningiscalleda
'V'activatorandisindicatedinClassIIDivision1
malocclusionwithverticalgrowthpattern.
CONSTRUCTION BITE

80. Constructionbitewithoutforwardpositioning
ofmandible
Itisdoneincaseswithdeepbite,andopen
bite.
CONSTRUCTION BITE

81. Constructionbitewithopeningandposterior
positioningofthemandible
InClassIIIcasesbiteistakenafterretruding
themandibletoamoreposteriorposition.
Inthisaverticalopeningof5mmanda
posteriorpositioningof2mmisrequired.
CONSTRUCTION BITE

82. FABRICATION

83. Impressionsofupper
andlowerarchesare
madetoconstruct2
pairsofmodels-study
models,workingmodelsImpressions

84. Bite
Registration
•Amountofsagittalandvertical
advancementisplanned
•Horse-shoeshapedwaxblockis
prepared.Ltshouldbe2-3mmmorethan
theverticalopeningplanned
•Patientisaskedtopracticeplacementof
mandibleatthedesiredposition
•Horse-shoeshapedwaxblockisplaced
ontheocclusalsurfaceofoneofthecast,
maxillaryormandibular(maxillary
preferred)andispressedgentlytoform
indentationoftheteethonthewax.

85. •Itisthenremovedand
placedinthepatientsmouth
andthepatientisaskedto
biteintheproposedsagittal
position
•Iffoundallrightitischilled
andonceagaintriedonthe
castandthencheckedagain
inthepatientsmouth.
Bite
Registration

86. Upperandlowercastsare
articulatedwith the
constructionbiteinplace.
Theupperandlowercasts
arearticulatedinareverse
directionfacingthehinge.
Thisistogeteasyaccessto
thepalatalsurfaceofthe
upperandUngualsurfaceof
thelowercasts.
Articulation of
the Model

87. Alabialbowisprepared
with0.8or0.9mmwire.
Theendsofthewire
entertheacrylicbody.
Thelabialbowcanbe
activeorpassive.
Preparation
of Wire
Elements

88. Fabrication of Acrylic Portions
Applianceconsistsofthreeparts(Figs46.15AandB)
•Maxillarypart
•Mandibularpart
•lnterocclusalpart
Themaxillaryandmandibularpartsaresameastheacrylic
portionsofupperandlowerHawley'splate,buttheseare
joinedbyaninterocclusaJpartwhichmakesthisappliance
intoasingleblock.Theinterocclusalportionhasthe
indentationsofupperandlowerteethandcapsthelower
anteriors,whichcontrolstheirsupra-eruptionand
proclination.

89. Trimming of the Activator
Activatortherapyaimsatprovidingagoodskeletalaswell
asdentoalveolarrelationshipofupperandlowerarches.
However,thisisnotpossiblebysimplyholding/posturing
themandibleforward,inapredeterminedposition,
withoutappropriateguidancefortheeruptingteeth.
Therefore,toachieveaproperthreedimensional
relationshipofteeth,selectivetrimmingoftheactivator
iscarriedout.Trimmingcanbedoneatthetimeof
applianceinsertionorassomeclinicianssuggest,itcanbe
doneafteraboutaweek'stime.
89

90. Trimming for Sagittal Control
a.ClassIIcorrection:Trimmingisdonesoastoencourage
themesialmovementofthelowermolaranddistal
movementoftheuppermolar.Therefore,thedistopalatal
surfaceinthemaxillaryandmesiolingualsurfaceinthe
mandibularposteriorsegmentsaretrimmed.Thispattern
oftrimmingisparticularlyusefulinhorizontallygrowing
patientsasittendstoopenthebiteduetomolar
eruption.
TrimmingoftheactivatorforClassIIcorrection.Notethelowerposteriorsegmentisfreetoeruptvertically
andmesially.thushelpinginthecorrectionofdeepoverbiteandClass11relation

91. b.Protrusionofincisors
•Inthiscaselingualsurfacesofteethareloadedwith
acrylicandapassivelabialbowisgiven(Fig.46.15Ei).
c.Retrusionofincisors
•Herethelingualsurfaceismadetotallyfreeofacrylicand
anactivelabialbowisgiven(Fig.46.15Eii).
91
Activatordesignfor
protrusion of
incisors.
Notetheloadingof
theentirelingual
surfaceandlabial
bowawayfromthe
incisors to
encourage labial
movement ofthe
incisors
Activatordesign
forretrusionof
incisors.Thelabial
bowhereisactive
andthelingual
surfacesofthe
incisors are
relievedforlingual
movementofthe
teeth

92. Trimming for Vertical Control
a.lntrusionofteeth(Fig.46.15F)
•Forthistheincisalareaisloadedwithacrylic
•Labialbowisplacedbelowthegreatestconvexityattheincisal
areaforintrusion
•Incaseofintrusionofposteriorsloadthesurfacesoftheteeth
withacrylic.
92
Activatordesign for
intrusionofteeth(for
anteriorintrusionthe
labialbowisplaced
below the greatest
convexityintheupperand
above the greatest
convexityinthelower)

93. b.Extrusionofteeth(Figs46.15Giandii)
•Herethelingualsurfaceisloadedabovetheareaofgreatest
convexityinthemaxillaandbelowtheareaofgreatest
convexityinthemandible
•Alsothelabialbowcanbeplacedatthegingival1/3i.e.below
thegreatestconvexity
•Incaseofposteriorextrusionthelingualsurfacesbelowthe
greatestconvexityareloaded.
93
Trimming for Vertical Control
Activator design for extrusion of
teeth.
(i)Anteriors.(ii)Posteriors

94. For Transverse Control (Fig. 46.15H)
Jackscrewisincorporatedintotheactivatorfor
expansion(transversecontrol)asandwhen
required.
94
Activator with jack screw, for
transverse control

95. MANAGEMENT OF THE APPLIANCE
Thepatientisdemonstratedtoplaceandremovethe
applianceinmouth.Theapplianceistobeworn2to
3hoursduringthedayforthefirstweek.Duringthe
secondweekthepatientsleepswiththeappliancein
mouthandwearsitfor1-3hourseachday.
Theapplianceischeckedduringthethirdweekto
evaluatethetrimming.
Ifthepatientiswearingtheappliancewithoutany
difficultyandfollowingtheinstructions,checkup
appointmentsarescheduledevery6weeks

96. BIONATOR

97. INTRODUCTION
Thebulkinessoftheactivatoranditslimitationtonight-time
wearwasamajordeterrentinitsgreaterusebycliniciansto
obtainmaximumpotentialoffunctionalgrowthguidance.
Theappliancewastoobulkyforday-timewear.Moreover,
duringsleep,thefunctionisminimizedorvirtually
nonexistent.
BIONATOR
The bionator The activitor

98. ThisledtothedevelopmentoftheBIONATOR,alessbulky
appliance.Itslowerportionisnarrow,anditsupper
componenthasonlylateralextensions,withacrosspalatal
stabilizingbar.Thepalateisfreeforproprioceptivecontact
withthetongueandthebuccinatorwireloopsholdawaythe
potentiallydeformingmuscles.
TheappliancedevelopedbyBALTERSin1960,canbeworn
allthetime,exceptduringmeals.
INTRODUCTION
BIONATOR
The bionator (standard appliance)
Bionator (lateral view). Note that the palatal acrylic coverage has
been replaced by the palatal bow and the buccal extensions of
the labial bow which keep the deforming cheek muscles away

99. AccordingtoBalters,"theequilibriumbetweenthe
tongueandthecircumoralmusclesisresponsibleforthe
shapeofthedentalarchesandthatthefunctionalspacefor
thetongueisessentialforthenormaldevelopmentofthe
orofacialsystem"e.g.posteriordisplacementofthetongue
couldcauseClassIImalocclusion.
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PHILOSOPHYOFBIONATOR

100. Takingintoconsiderationthedominantroleofthe
tongue,Baltersdesignedanappliance,whichcouldtake
advantageoftongueposture.Thusheconstructedan
appliancewherebythemandiblewaspositioned
anteriorly,withtheincisorsinanedgetoedgeposition.
Thisforwardpositioningbroughtthedorsumofthetongue
incontactwiththesoftpalateandhelpedaccomplishlip
closure.
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101. Thustheprincipleofbionatorisnottoactivatethe
musclesbuttomodulatemuscleactivity,thereby
enhancingthenormaldevelopmentofthe
inherentgrowthpatternandeliminateabnormal
andpotentiallydeformingenvironmentalfactors.
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102. Threebasicconstructionsarecommonin
bionator
•Standardappliance
•Open-biteappliance
•ClassIIIorreversebionator
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BIONATORTYPES

103. Itconsistsofalowerhorse-shoeshapedacryliclingual
plateextendingfromthedistalofthelasteruptedmolar
tothecorrespondingpointontheotherside.
Fortheupperarchtheappliancehasonlyposteriorlingual
extensionsthatcoverthemolarandpremolarregions.
Theanteriorportionisopenfromcaninetocanine.The
upperandlowerparts,whicharejoinedinterocclusally,
extend2mmabovetheuppergingivalmarginand2mm
belowthelowergingivalmargin.
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StandardAppliance;-

104. Thepalatalbarisformedof1.2mmhardstainlesssteel
wireextendingfromthetopedgesofthelingualacrylic
flangesinthemiddleareaofthedeciduousfirstmolars.
Thepalatalbarformsanoval,posteriorlydirectedloop
thatorientsthetongueandmandibleanteriorlyto
achieveaClassIrelationship.
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105. Thelabialbowismadefrom0.9mmhardstainless
steel.Itstartsabovethecontactpointbetweenthecanine
anddeciduousupperfirstmolar/premolar.Itthenextends
vertically,makingarounded90°bendtothedistalalong
themiddleofthecrownsoftheposteriorteethand
extendsasfarastheembrasurebetweendeciduous2nd
molarandpermanent1
st
molar.Itthenmakesagentle
downwardandforwardcurverunninganteriorlytillthe
lowercanine.Fromthere,itformsasharpcurveextending
obliquelytilltheuppercanine,bendstoalevelat
approximatelytheincisalthirdoftheincisorsandextends
tothecanineontheoppositeside.
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106. Thisisusedtoinhibitabnormalpostureandfunction
ofthetongue.Theconstructionbiteiskeptaslowas
possiblewithacrylicbiteblocksbetweentheposterior
teethtopreventtheirextrusion.Theacrylicportionofthe
lowerlingualpartextendsonto/uptotheupperincisor
regionaslingualshield,topreventtonguemovements.
Thepalatalbarhasthesameconfiguration.Thelabial
bowisquitesimilarwiththeexceptionthatthewireruns
approximatelybetweentheincisaledges.
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OpenBiteAppliance
Labial bow for the open bite appliance

107. Thistypeofapplianceisusedtoencouragethe
developmentofmaxilla.Thebiteistakeninmostpossible
retrudedposition,toallowlabialmovementofthemaxillary
incisorsandreciprocallyaslightrestrictiveeffectonthe
lowerarch.Thebiteisopenedabout2mmonlyinthe
interincisalregion.Thepalatalbarconfigurationruns
forwardinsteadofposteriorly,withtheloopextendingas
farasthedeciduous1stmolarorpremolar.Thelabialbow
runsinfrontofthelowerincisorsratherthaninfrontofthe
upperincisors.
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ClassIIIorReverseBionator

108. INDICATIONSFORBIONATORTHERAPY
BionatorisindicatedforthetreatmentofClassIIDivision1
malocclusioninthemixeddentitionusingthestandard
bionatorunderthefollowingconditions:
•Wellaligneddentalarches.
•Functionalretrusion
•Mildtomoderateskeletaldiscrepancy
•Noevidenceoflabialtippingseen
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109. CONTRAINDICATIONS
•ClassIIrelationshipcausedbymaxillary
prognathism
•Verticalgrowthpattern
•Labiallytippedlowerincisors.
www.themegallery.com
6/29/2021

110. ADVANTAGES OFBIONATOR
1.Applianceislessbulky.
2.Canbewornfulltime,exceptduringmeals.
3.Applianceexertsaconstantinfluenceonthe
tongueandperioralmuscles.
DISADVANTAGE OFAPPLIANCE
Themaindisadvantageliesinthedifficultyof
correctlymanagingit.
www.themegallery.com
6/29/2021

111. THE FRANKEL
FUNCTION
REGULATOR

112. THE FRANKEL FUNCTION REGULATOR
FunctionregulatorappliancesweredevelopedbyRolf
Frankel(Germany).Frankelbelievedthattheactive
muscleandtissuemassi.e.,thebuccinatormechanism
andtheorbicularisoriscomplexhaveamajorroleinthe
developmentofskeletalanddentofacialdeformities.
Hencehedevelopedfunctionregulatorsasorthopedic
exercisedevices,toaidinthematuration,trainingand
reprogrammingoftheorofacialneuromuscularsystem.

113. FRANKEL PHILOSOPHY
1..Vestibularareaofoperation
-Shieldsoftheapplianceextendtothevestibuleand
thispreventstheabnormalmusclefunction.
2.Sagittalcorrectionviatoothbornemaxillaryanchorage
-Applianceisfixedontheupperarchbygroovesmesial
tothe1stpermanentmolaranddistaltothecaninein
themixeddentitionperiod.
-Presenceofthelingualpadactsasproprioceptive
stimulusandhelpsintheforwardposturingofthe
mandible.

114. FRANKEL PHILOSOPHY
3.Differentialeruptionguidance
-Frankelisplacedontheupperteeth.
-Mandibularposteriorteetharefreetoeruptandtheir
unrestrictedupwardandforwardmovementcontributesto
bothverticalaswellashorizontalcorrectionofthe
malocclusion.
4.Periostealpullbybuccalshieldsandlippad
-Presenceofbuccalshieldsandlippadsexertthe
periostealpullwhichhelpsinboneformationandlateral
expansionofthemaxillaryapicalbase.
5.Minimalmaxillarybasaleffect
-Downwardandforwardgrowthofmaxillaseemstobe
restricted,eventhoughlateralmaxillaryexpansionin
seen.

115. MODE OF ACTION OF FR
1.Increaseintransversesagittaldirection
-byuseofbuccalshieldsandlippads
2.Increaseinverticaldirection
-byallowingthelowermolartoeruptfreelybecause
applianceisfixedtotheupperarch
3.Muscleadaptation
-Theformandextensionofthebuccalshieldsandlip
padsalongwiththeprescribedexcercisescorrects
theabnormalperi-oralmuscleactivity.

116. ORAL EXERCISES WITH FRANKEL
-Frankel-fulltimewearappliance.
-Lipstobeclosedatalltimesorkeepapaper
betweenthelips
-Swallowing,speaking,etc.withtheappliance
inmouth,itselfservesasanexercise

117. TYPES OF FUNCTION REGULATORS
1.FRl-usedforClassIandClassII,Division1.
FRla-usedforClassI,moderatecrowdinganddeepbite.
PRlb-usedforClass[JDivision1overjetlessthan7mm.
FRlc-usedforClassIIDivision1overjetmorethan7mm.
2.FRIl-usedforClassIIDivision2andDivision1(Figs
46.17AandB)
3.FRIll-usedforClassUI(Figs46.17CtoE)
4.FRIV-usedforcaseswithopenbiteand
bimaxillaryprotrusion.
5.FRV-FRwithheadgear.

118. FR Il -used for Class II Division 2 and
Division 1
Frankel11 (superior view showing
parts of the appliance
Frankel II (frontal view showing
parts of the appliance)

119. FR Ill -used for Class III
Frankel III (for Class III cases Frankel lll in mouth
Patient with Frankel lll

120. FABRICATION OF FUNCTION REGULATOR
PARTS OF THE APPLIANCE (FIGS 46.17A,B
AND F TO I)
Acrylic part
Buccal shields
Lip pads
Lower lingual pads
Wire parts
Palatal bow
Labial bow
Canine extensions
Upper lingual wire (only in FR Il)
Lingual cross over wire
Lip pads
Lower lingual springs

121. BasiccomponentsasdescribedforaFAIIappliance.
(F)Buccalshields,lippads,labialWire,
(G)Buccalshields,lippads,canineclasp,labialarch,andlabialarchloop,
(H)Applianceonthemaxillarycast,
(I)Lingualacrylicpad,lingualwiresandlingualsprings

122. IMPRESSIONS
Theimpressionsshouldreproducethewhole
alveolarprocesstothedepthsofthesulci,includingthe
maxillarytuberosities.Thesofttissuesandthemuscle
attachmentsshouldnotbedistorted.Acustomtraycan
alsobefabricatedbasedonthestudymodels,if
desired.Sincetheapplianceisanchoredinthe
maxillaryarchbetweenthedeciduoussecondmolar
andthepermanentfirstmolar,separatorsshouldbe
placedbetweentheseteethpriortoimpressions;
otherwise,diskingofthedistalsurfaceoftheprimary
secondmolar,canalsobedoneafterfabricationof
appliance.

123. WORKINGMODELPOURINGANDTRIMMING
-Modelbasemustextendawayfromalveolar
processbyatleast5mm
-Correctmodeltrimmingisnecessary
beforeappliancefabrication
-Thedesiredamountofstonetobecutis
outlinedwithapencilbeforetrimming.
-Thenitshouldbecutwitharoundbur

124. -Finaldetailingisdonewithplasterknife.
-Notrimmingrequiredforbuccalshieldson
mandible.
-Buttrimmingisrequiredinthemaxillary
buccalshieldareaandlowerlippadarea.
-Caremustbetakennottodisturbthe
muscleattachments.
WORKING MODEL POURING AND TRIMMING

125. TRIMMING FOR LIP PADS
-5mmfromgreatestcurvatureofalveolar
basetoensureoptimumextension.
-Lowerreliefshouldbe12mmbelow
gingivalmargin.

126. TRIMMING FOR LIP PADS CONSTRUCTION BITE
Forminorsagittalproblems,theconstructionbiteis
takenatandend-to-endincisorrelationship,withthe
mandiblepositionforwardnotmorethan2.5to3mm.A
clearanceofatleast2.5to3.5mminthebuccalsegments
isnecessarytoallowthecrossoverwirestopassthroughin
theFrankelappliance.
Dentalmidlinediscrepanciesshouldnotbecorrectedinthe
bitebymanipulationduringforwardposturing.The
constructionbiteshouldbecheckedonthecastsandthe
casesshouldbemountedwiththebite.
ConstructionbiteforFR11.Notethatthe
dentalmidlinedeviationshouldnotbe
correctedintheconstructionbite
unlesstheskeletalmidlinesare
deviatingaswell

127. WAX RELIEF (FIGS 46.17K TO M)
Reliefisplacedsuchthatthebuccalshields
andlippadsstayawayfromteethandtissuesto
achievethedesiredexpansion.Thicknessofwax
dependsontheexpansionrequiredbutshould
notexceed4-5mminthetoothareaand2.5-3
mminthealveolarareainthemaxilla.
Wax relief in the maxillary arch. Note the
Configuration of the palatal bow as well

128. In the mandible, only 0.5 mm of relief is
given (Fig. 46.17L). Thickness of relief wax is
greater in maxilla because of arch narrowing in
case of Class II Division 1 malocclusions
Wax relief on the mandibular cast
Complete wax up of the Frankel. Ready for
the fabrication of the buccal shields in cold
cure acrylic

129. WIRE COMPONENTS (FR Ib)
Consistsof:
•Stabilizingwires
•Toothmovingwires

130. Lower Lingual Support Wire
-Madeof1.25mmwire
-Canbeoneunitor3separateparts
-Horizontalreinforcingwireelementcontourstothe
lingualapicalbase1-2mmawayfromthemucosaand
3-4mmbelowthegingivalmarginsoastopermitadding
acrylictothepad.
-Crossoverwirepassbetweendeciduousfirstand2nd
molar
-Endsarethenbentat90°toinsertintothebuccal
shields.Theendsmustbeparalleltoeachotherandthe
occlusalplanetoallowforadvancementoftheanterior
sectionlaterifneeded.

131. Lower Lingual Springs
-Madeof0.8mmwire.
-Rightabovethecingulathewireiscurvedabout3
mmbelowtheincisalmargin
-Function-istopreventextrusionoflowerincision
-Shouldnotbeactiveonlypassive
-Iftoothmovementisrequiredthespringismade
active.

132. Lower Labial Wires
-Madeof.9mmwire
-Actsasaskeletonforlowerlippads
-Itcanbeonepieceorthreepiece
-Itshouldbe1mmawayfromthetissue.
-Wireframe-workshouldbe7mmbelowthe
gingivalmargin
-Middlepartshouldbeinverted'V'shapedfor
labialfrenumrelief.

133. Palatal Bow
-Madeof1mmwireShouldhaveacurveinthecenterfor
lateralexpansion
-Wireshouldpassintothegroovebetweendeciduous2nd
andIstpermanentmolar
-Wireemergesoutofwaxreliefmakesaloopinthebuccal
shieldandliesbetweenmaxillaryIstmolarbuccalcusp
endinginthefossaasanocclusalrest.
-ThisprovidesapositiveseattotheFRaswellasprevents
eruptionoftheupper1stpermanentmolar.

134. Labial Bow
Madeof0.9mmwire
-Originatesinbuccalshieldcurvesupwardsandliesinthe
depressionbetweencanineandlateral.Itisinthe
middleoflabialsurfaceofincisorsandleavestheacrylic
withslightbendtowardsthesulcus.
-Shouldbe2mmawayfrommucosaPermitscanine
eruptionandexpansionwithoutcontactingthelabialwire
-Loopsshouldbewideenoughtoallowactivationlaterto
closeanteriorspaceifrequired.

135. Canine Loops (For FR la)
-Madeof0.9mm.
-Embeddedinbuccalshieldatocclusalplanelevel.
-Turnedsharplytowardsgingivalmarginofupper
deciduous1stmolarandfitinembrasurebetween
deciduousfirstmolarandcanines.
-Wirewrapsaroundthelingualsurfaceofthecanine
emergeslabiallyatthecanine-lateralembrasure
curvesdistallyoverthecaninecusps.Freeendscan
bebentocclusallyifrequired.

136. Canine Loops (For FR II)
-Madeof0.8mmwire.
-Originateinbuccalshield
-Contactcaninesonbuccalsurfaceasrecurved
loop.
-Servesasextensionofbuccalshieldinthe
canineareawhimisnormallynarrowedbythe
peri-oralmuscles.
-Shouldbe2-3mmawayfromcaninestoprevent
restrictivemusclefunction,

137. Upper Lingual Wire (Protrusion Bow)
-Madeof0.8mmwire
-MostlyseeninFRlIandFRIII.
-Lingualbowbehindthemaxillaryincisorsservesto
maintainpro-functionalappliancealignmentachieved
andalsostabilizestheFRbylockingitontothemaxillary
arch
-0.8wireisusedifthecentralsareretroclined,butifthe
anterioralignmentisa!readyachievedastifferwirecan
beusedi.e.0.9mmwire.
-Itoriginatesinthevestibularshieldandpassestothe
lingualthroughthecanine-deciduous1stmolar
embrasure.
-Wireformsloopsatthepalatalmucosaandcurvevertically
tocontacttheincisorattheembrasurebetweencanine
andlateralincisor.

138. ACRYLIC PARTS
-Afterthewiresarefabricatedandadaptedtheyaresecured
inplacewithstickywax.
-Thelippad,buccalshields,lowerlingualpadsare
fabricatedincoldcureacrylic.
-Totalthicknessoftheacrylicshouldnotexceed2.5mm
-Lippadslooklikeparallelogram(teardropshapein
longitudinalcross-section)
-Lippadsshouldbe5mmfromthegingivalmargin
-Presenceoflippadseliminatesmentalishyperactivityand
abnormalfunctionalliptrap,therebyhelpscorrectingthe
overjet.
-Buccalshieldsshouldextendpastthecaninedeciduous
firstmolarembrasuretothemiddleofthecanine.

139. COMPONENTS OF VARIOUS FR APPLIANCES
FRla
-Notpopular.ReplacedbyFRIb
-UsedforClassImoderatecrowdinganddeep
bite
-Lingualwireloopsaregiveninsteadofacrylic
lingualpadstoposturethemandibleforwards
-Thecrossoverwire(passingbetweenupper
andlowerocclusalsurface)isanextensionof
thelingualloops.

140. FRlc
-usedinClassIIDivision1withoverjetgreaterthan7mm
-Ithasbeenobservedthatposturingthemandibleforwardintoa
ClassIrelationshipandeliminatingexcessiveoverjetinonestep
foraFrankelapplianceisneitherfeasiblenornecessary.Because
tissueresponseislessfavorableandthereisincreasedpatient
discomfortorcompliance.
-Somandibularprotractionisdonein2or3steps.
-Horizontalandverticalcutsaremadeonthebuccalshieldandthen
madetoslidealongthehanger.
-Thecutsarethenfilledwithcoldcureacrylic.
-FRTcisseldomusedbecauseFRlband
FR!1canbemodifiedinthesameway.
Mandibularadvancementdoneinstages.Horizontalandvertical
cutsaremadeintheacrylicandthelowerlingualpadandlip
padsareadvanced.Thegapislaterfilledwithacrylic

141. FRII
-UsedforClassIIDivision2andDivision1
-ProtrusionbowismadeunlikeinFRI
-Canineloops
•Itisonlyarecurvedloop
•Itoriginatesinthebuccalshieldandcontactsthebuccal
surfaceofthecanineasarecurvedloop.
•Itshieldsthecanineagainstthebuccinatoraction.
•Itisplaced2-3mmawayfromthedeciduouscanines

142. FRIII
-UsedforClassIIIcorrection
-Lippadsareinthemaxillaryarch
-Labialbowrestingagainstmandibularteeth.
Protrusionbowisontheupperteethandismadeof0.8mmwirefor
forwardmovementofmaxillaryincisiorsifdesired.
-Theocclusalrestisonthemandibularmolarunlike
inFRIIwhereitisonthemaxillarymolar.

143. FRIV
-Usedforopenbiteandbimaxillaryprotrusion
-Hasnocanineloops
-Hasnoprotrusionbow
-Fourocclusalrestspresenti.e,ondeciduous1
st
molar
andpermanent1stmolaroneachsidetoprevent
eruptionofposteriorteeth.
-PalatalbarresemblesFRIIIi.e.itdoesnotcontactthe
teeth
-ThebuccalshieldinFRIVshouldbewaferthintoenable
lipclosureandexercisewithoutwhichtheappliancewill
beafailure.

144. FRV
Frankelapplianceusedalongwithhead
gear.

145. TREATMENT TIMING
ThebesttherapeuticeffectoftheFrankel
applianceisachievedduringthelatemixed
andtransitionaldentitionperiod,whenboth
thesoftandhardtissuesareundergoingtheir
greatesttransitionalchanges.
TreatmentforClassIIIandopenbitecases
shouldusuallystartsoonerthanforClassII
problems.

146. TWIN-BLOCK

147. EVOLUTION OF TWIN-BLOCK
Thetwinblockappliancewasdevelopedby
Clarkin1977,anditconsistsofanupperand
lowerdevicewithsimplebiteblocksthat
engageonocclusalinclinedplanes.
Introduction

148. The appliance became popular due to a number of
advantages over other functional appliances namely:
1.Thefunctionalmechanismisverysimilarto
thatofthenaturaldentition.
2.Theocclusalinclinedplanesgivegreaterfreedom
ofmovementinlateralandanteriorexcursionand
causelessinterferencewithnormalfunction.
3.Appearanceisnoticeablyimproved.
4.Lessbulk,therefore,betterpatient
compliance.

149. 5.ItCanbeusedinlaterstagesofgrowth(latemixed,/
dentition/earlypermanentdentition)
6.Theappliancecanbecementedinmouth,without
disruptingthenormaloralfunctions,toimprove
patientcompliance.
7.Absenceoflippadsandbuccalshields,
allowpatientamuchbettercomfort,however,
modificationscontaininglippadscanbe
incorporatedasandwhenrequired.

150. Thetwinblockapplianceevolvedinresponsetoaclinical
problemthatpresentedwhenayoungpatient,thesonof
adentalcolleague,fellandcompletelyluxatedanupper
centralincisor.Theincisorwasreimplantedanda
temporarysplintwasconstructedtoholdthetoothin
position.
DEVELOPMENT OFTWIN-BLOCK

151. After6monthswithastabilizingsplint,thetoothhad
partiallyreattached,buttherewasevidenceofsevere
rootresorptionandthelong-termprognosisforthe
reimplantedincisorwaspoor.

152. TheocclusalrelationshipwasClassIIDivision1withan
overjetof9mmandlowerlipwastrappedlingualtothe
upperincisors.Adverselipactiononthereimplanted
incisorwascausingmobility,androotresorption.To
preventthelipfromtrappingintheoverjetitwas
necessarytodesignanappliancethatcouldbewornfull
timetoposturethemandibleforward.Atthattimeno
suchappliancewasavailableandsimplebiteblocks
weretherefore,designedtoachievethisobjective.

153. Theappliancemechanismwasdesignedtoharness,the
forcesofocclusiontocorrectthedistalocclusionand
alsoreducetheoverjetwithoutapplyingdirectpressure
totheupperincisors.Thefirsttwinblockappliances
werefittedon7thSeptember1977.Theupperandlower
biteblocksengagedmesialtothe1stpermanentmolar
at90°totheocclusalplane,whenthemandible
posturedforward.Thispositionedtheincisorsedge-to-
edgewith2mmverticalseparationtoholdtheincisors
outofocclusion.Thepatienthadtomakeapositive
efforttoposturethemandibleforwardtooccludethebite
blocksinprotrusivebite.

154. CASE SELECTION
FOR TWIN-BLOCK
APPLIANCE

155. Case selection for clinical use of twin-block should,
display the following criteria:
1.Angle'sClassITDivision1malocclusion
withgoodarchform.
2.Alowerarchthatisuncrowdedor
decrowdedandaligned.
3.Anupperarchthatisalignedorcanbe
easilyaligned.
4.Anoverjetof10-12mmandadeep
overbite.

156. 5.Afullunitdistalocclusioninthebuccal
segments.
6.Onexaminationofmodelsinocclusionwiththelower
modeladvancedtocorrecttheincreasedoverjet,the
clistalocclusionisalsocorrectedanditcanbeseenthata
potentiallygoodocclusionofthebuccalteethwillresult.
7.Onclinicalexaminationtheprofileshouldbenoticeably
improvedwhenthepatientadvancesthemandible
voluntarilytocorrecttheoverjet.
8.Toachieveafavorableskeletalchange,duringtreatment,
patientshouldbeactivelygrowing.Amorerapidgrowth
responsemaybeobservedwhenthetreatmentcoincides
withthepotentialgrowthspurt.

157. APPLIANCE DESIGN AND
CONSTRUCTION

158. Thepresentformoftheapplianceevolvedoveraperiodfollowingclinical
experiencewiththeappliance.Theearliestdesignofthetwin-block
consistedof:
1.Amidlinescrewtoexpandtheupperarch
2.Occlusalbiteblock(at90°toocclusalplane)
3.Claspsonuppermolarsandpremolars(Adams‘clasp)
4.Claspsonlowerpremolarsandincisors.
5.Springstomovetheindividualteeth
6.Provisionforextra-oraltraclioninsomecases.(esp.maxillary
protrusioncases)
EVOLUTION OF THE APPLIANCE
DESIGN

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160. DELTACLASPS
AfterinitialuseoftheAdams'clasp,Clarkintroduced
thedeltaclaspin1985.Thebasicpremisewasto
reducetheincidenceofbreakages(asseenwiththe
Adams‘clasp)duetorepeatedadjustmentsand
consequentmetalfatigue.

161. LABIALBOW
Theuseoflabialbowintheupperplatewasdiscontinued
afteritwasnoticedthatitcausesunwantedretroclination
ofupperincisorswithconsequentdeepeningofthebite.
Thisisturn,limitedthescopeofmandibularcorrection
possible.However,incertaincaseswithsevereupper
proclination,labialbowintheupperarchmaybeplaced.

162. BASEPLATE
ThedesignissimilartoupperandlowerHawley'splate
andcanbepreparedinheatcureorcoldcureacrylic.
Themainadvantageofheatcureacrylicisitsadditional
strength.Coldcureacrylichastheadvantageofspeed
andconvenience,however,strengthandaccuracyis
slightlycompromised.

163. Positionofthebiteblocksandtheangulationofitsinclined
planesareimportantfactorsinthesuccessofthetwin-
blocktherapy.Thepositionoftheinclinedplaneis
determinedbythelowerblockandiscriticalinthe
treatmentofdeepoverbite.
OCCLUSALBITEBLOCKSWITHINCLINEDPLANES
(FIG.46.18F)
Biteblockswiththeincline.Thelowerbiteblockdoesnotextendbeyondhalfoftheprimarysecondmolar!2
nd
premolar,which
allowsfreeeruptionofthelowermolarforthecorrectionofClassIIocclusionanddeepoverbite.Alsonotetheangulationof
theinclinedplanes

164. Theinclinedplaneonthelowerbite-blockisangledfrom
themesialsurfaceofthesecondpre-molarorsecond
deciduousmolarat70°totheocclusalplane.This
placestheleadingedgeoftheinclinedplaneonthe
upperappliancemesialtothelowerfirstpermanent
molar,thuskeepingaprovisionfortheunhindered
eruptionofthelower1stpermanentmolar.

165. Mesially,thelowerbiteblockextendsuptothecanine
regionwithaflatocclusalsurface.Theupperinclined
planeisangledfromthemesialsurfaceoftheupper
secondpremolartothemesialsurfaceoftheupperfirst
molar.Theflatocclusalportionthenpassesdistallyover
theremainingupperposteriorteethinawedgeshape,
reducingmthickenasitextendsdistally.

166. Theheightofthebiteblocksisdeterminedbythevertical
openingplannedandrecordedintheconstructionbite.
Foratwinblocktherapy,itisrecommendedthatthe
verticalopeningintheconstructionbitebebeyondthe
freewayspace.Thisimpliesthattheheightofthebite
blockshouldbe4-6mmsothatthemandibledoesnot
gobackeveninphysiologicrestposition.

167. initially,inclinedplaneswereat90°toocclusalplane.However,
adjustmenttothissortofinclinedplanewasdifficultforalotof
patients.
Therefore,forpatientconvenienceinclinedplaneswerereducedto45°
butsince,thisangulationcausedequalverticalandhorizontal
movement,theangulationwasfurtherchangedto70°,sothatmore
horizontalvectorofforcewouldbeproduced.
Nevertheless,theinclinedplaneangulationcanvarybetween45°and
70°dependinguponthepatientcomfortlevels.
ANGULATIONOFTHEINCLINEDPLANES

168. Constructionbitefortwin-blockcanbetaken
istheconventionalmanner,bymeansof
aninter-occlusalwaxbite,asdescribed
earlier,fortheactivator,orbytheuseof
an'Exactobite‘.
CONSTRUCTION BITE
BITEREGISTRATION FORCONSTRUCTION OFTWIN-BLOCKSFOR
CLASSIIDIVISION1MALOCCLUSION

169. Exactobiteorproject-bitegaugeisahorse-shoe
shapeddevicewithananteriorhandlewithvarious
grooves,designedforaccuratecontrolmregisteringa
protrusivebiteforconstructionoftwinblock.Theblue
bitegaugeregisters2mmverticalclearancebetween
theincisaledgesoftheupperandlowerincisors,which
aremappropriateinterincisalclearanceforbite
registrationinmostClassIIDivision1malocclusionswith
increasedoverbite.

170. InaClass11Division1malocclusionaprotrusivebiteis
registeredtoreducetheoverjetanddistalocclusionon
average5-10mmoninitialactivation,dependingonthe
freedomofmovementinprotrusivefunctions.Thelength
ofthepatient'sprotrusivepathisdeterminedby
recordingtheoverjetincentricocclusionandfully
protrusiveocclusion.Theactivationshouldnotexceed
70%ofthemaximumprotrusivepath.

171. ingrowingchild,withanoverjetofupto10mm,
providedthepatientcanposturecomfortably
forwards,bitemaybeactivateduptoedge-to-
edgeontheincisorswitha2mminterincisal
clearance.Largeroverjetrequirespartial
correction.

172. Itisbest,firsttorehearsetheprocedureofbiteregistration
withthepatientusingamirror.Thepatientisinstructed
toclosecorrectlyintothebitegaugebeforeapplyingthe
wax.Oncethepatientunderstands,whatisrequired,
softenedwaxisappliedtothebitegaugefromahot
waterbath.

173. Thecliniciancanthenplacethebitegaugeinthe
patient'smouthtoregisterthebite.Midlines
shouldbecoincident,however,ifdentalmid
linesaredeviating,skeletalmidlinesshouldbe
takenintoconsideration.

174. Oneimportantaspectoftheconstructionbiteforthetwin-
blockapplianceistoestablishthecorrectvertical
dimension,Thebiteshouldbeopenslightlybeyondthe
clearanceofthefreewayspacetoencouragethepa
tienttocloseintotheapplianceratherthanallowthe
mandibletodropoutofcontactintorestposition.

175. Hence,aninter-incisalclearanceofabout2-3mm
isestablished,whichisequivalenttoan
approximately5-6mmclearancemthe1st
premolarregionandabout3mmclearance
distallymthemolarregion.

176. Thisamountofverticalclearanceensuresthatthe
mandibledoesnotdropbackatrestandthat
enoughspaceisavailableforthevertical
developmentoftheposteriorteethtoreduce
theoverbite.

177. ESTABLISHING THE CORRECT VERTICAL DIMENSIONS -
THE INTERGINGIVAL HEIGHT
Asimpleguideisusedtoestablishthecorrectvertical
dimensionduringthetwinblockphaseoftreatment.
Theintergingivalheightismeasuredfromthegingival
marginoftheupperincisortothegingivalmarginof
thelowerincisorwhentheteethareinocclusion.

178. The'comfortzone'forintergingivalheightforadult
patientsisabout17-19mm.Thisisequivalentto
combinedheightsoftheupperandlowerincisors
minusanoverbitewithintherangeofnormal.
Patientswhose intergingivalheightvaries
significantlyfromcomfortzoneareatagreaterriskof
developingTMD.Thisappliesbothtothepatients
withadeepoverbitewhoseintergingivalheightis
reduced,andtopatientswithananterioropenbite
whohaveanincreasedintergingivalheight.

179. Theintergingivalheightisausefulguidelinetocheck
progressandtoestablishthecorrectvertical
dimensionsduringtreatment.Measurementof
intergingivalheightisdonebyusingammrulerand
dividerorwithaVernierscaletomeasurethe
distancebetweentheupperandlowergingival
margins.

180. In twin block treatment the correct intergingival height
is achieved with great consistency. Deep overbite
may be corrected to an intergingival height of 20 mm
to allow for a slight settling in with a resultant overbite
increase after treatment.
In the younger patient's a range of 15-17 mm is
normal and allowance should be made for the
diminutive height of the clinical crowns.

181. Patientmotivationisanimportantfactorinallremovable
appliancetherapy.Theprocessofpatienteducationand
motivationcontinueswhenthepatientattendstohave
twinblockfitted.Itisoftenhelpfultothepatientifthe
cliniciandemonstratestwinblocksonmodelstoconfirm
thatitisasimpleappliancesystemandiseasytowear
withnovisibleanteriorwires.
FITTINGTWIN·BLOCKS:
INSTRUCTIONSTOPATIENT

182. Simplybitingtheblockstogetherguidesthelowerjaw
forwardtocorrectthebite.Theappliancesystemis
easilyunderstoodevenbyyoungpatients,whoseethat
bitingtheblockstogethercorrectsthejawposition.Itis
importanttoemphasizepositivefactorsandtomotivate
thepatientbeforetreatment.

183. Thepatientisshownhowtoinsertthetwinblockswiththe
helpofamirror,pointingouttheimmediateimprovement
infacialappearancewhenthetwinblocksisinsertedand
explainingthattheappliancewillproducethischange,in
afewmonths,providedtheyarewornfulltime.A
removableapplianceonlycorrectstheteethwhenitisin
mouth,andnotinthepocket.Bothappliancesmustbe
wornfulltime,especiallyduringeatingwithsole
exceptionbeingremovedforcleaningandduring
swimmingandcontactsports.

184. Atfirsttheappliancemayfeellargeinthemouth,butwithin
afewdays,itwillbeverycomfortableandeasytowear.
Twinblockscausemuchlessinterferencewithspeech
thanother,onepiecefunctionalappliances.Forafirst
fewdays,speechwillbeaffected,butwillimproveand
shouldreturntonormalwithinaweek.

185. Aswithanynewappliancesitisnormaltoexpectalittle
initialdiscomfort.Butitisimportanttoencouragethe
patienttopreserveandkeeptheapplianceinmouthat
alltimesexceptforhygieneprocess.

186. Thepatientshouldbeadvisedtoremovetheappliance
duringeatingforfirstfewdays.Thenitisimportantto
learntoeatwiththeappliance.Theforceofbitingonthe
appliancecorrectsthejawposition,andlearningtoeat
withtheapplianceisimportanttoacceleratethe
treatment.Inafewdayspatientshouldbeeatingwith
thetwinblockandwithinaweekshouldbemore
comfortablewiththeapplianceinthemouththanthey
arewithoutit.

187. Itisnecessarytochecktheinitialactivationandconfirm
thatthepatientclosesconsistentlyontheinclinedplane
withthemandibleprotrudedinnewposition.Theoverjet
ismarkedwithamandiblefullyretrudedandthis
measurementshouldberecordedandcheckedatevery
visittomonitorprogress.

188. Twin-blocktreatmentisdescribedintwostages.Twin
blocksareusedintheactivephasetocorrectthe
anteroposteriorrelationshipandestablishthecorrect
verticaldimension.Oncethisphaseiscompleted,the
twin-blocksarereplacedwithanupperHawley'stypeof
appliancewithananteriorinclinedplanewhichisthen
usedtosupportthecorrectedpositionastheposterior
teethsettledfuJ1yintotheocclusion.
Stages of Treatment (Figs 46.19A and B)

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191. Twin-blocksachieverapidfunctionalcorrectionof
mandibularpositionfromaskeletalretrudedClassIIto
ClassIocclusionusingocclusalinclinedplanesoverthe
posteriorteethtoguidemandibleintocorrect
relationshipwiththemaxilla.Inailfunctionaltherapy,
sagittalcorrectionisachievedbeforevertical
developmentofposteriorteethiscomplete.
StageI-ActivePhase

192. Theupperblockistrimmedocclusodistallytoleavethe
lowermolars1-2mmclearoftheocclusiontoencourage
lowermolarstoeruptandreducetheoverbite,By
maintainingaminimalclearancebetweentheupperbite
blockandthelowermolars,thetongueisprevented
fromspreadinglaterallybetweentheteeth.Thisallows
molarstoeruptmorequickly.

193. Ateachsubsequentvisit,theupperbiteblockis
reducedprogressivelytocleartheocclusionwith
thelowermolarstoallowtheseteethtoerupt,
untilfinallyalltheacrylichasbeenremovedover
theocclusalsurfacesoftheuppermolars
allowingthelowermolarstoeruptfullyinto
occlusion.

194. Throughoutthistrimmingsequence,itis
importantnottoreducetheleadingedgeofthe
inclinedplane,sothatadaptivefunctional
occlusalsupportisgivenuntila3pointocclusal
contactisachievedwithmolarsinocclusion.
Averagetime6-9monthstoachievefull
reductionofoverbitetoanormalincisor
relationshipandtocorrectthedistalocclusion.

195. Theaimofthesupportphaseistomaintainthe
correctedincisorrelationshipuntilthebuccal
segmentocclusionisfullyinterdigitated.To
achievethisobjectiveanupperremovable
applianceisfittedwithananteriorinclinedplane
toengagethelowerincisorsandcanine.
195
Stage II—Support Phase

196. Thelowertwin-blockisleftoutatthisstageand
removaloftheposteriorbiteblocksallowthe
posteriorteethtoerupt.Fulltimeappliancewear
isnecessarytoallowtimeforinternalbony
remodelingtosupporttheocclusionasthe
buccalsegmentssettleintoocclusion.
196

197. Treatmentisfollowedbyretentionwiththeupper
anteriorinclinedplaneappliance.Appliancewearis
reducedtonighttimewearonlyoncetheocclusionis
fullyestablished.Agoodbuccalsegmentocclusionis
thecornerstoneofstabilityaftercorrectionofarch-to-
archrelationship.Theapplianceaffectedadvanced
mandibularpositionwillnotbestableuntilthefunctional
supportofafullbuccalsegmentocclusioniswell
established.
RETENTION

198. FIXED
FUNCTIONAL
APPUANCES

199. Successfulorthodontictreatmentoftenrelies
heavilyonpatient'scooperationinthe
wearingofremovablefunctionalappliances,
elasticsorheadgears.Eliminatingtheneed
tousetheseplacesthetreatmentresultmore
underthecontroloftheorthodontist.Thisled
tothedevelopmentof"non-compliant
appliances".

200. Theappliancesin"noncompliance"treatment
haveacoupleoffeaturesincommon.
Forcesareappliedusingauxiliaries
betweenthearches.
Mostoftenmulti-bandedfixedappliances
areusedwithlingualarchesandpalatalbars.
Mostofthemusesuperelasticsnickel
titaniumandTitan-molybdenumalloysprings.

201. 1.Herbstappliance
2.JasperJumper
3.Adjustablebitecorrector
4.Eurekaspring
5.Saifsprings
6.Mandibularanteriorrepositioningappliance(MARA)
7.Klappersuperspring
8.Forsusfatigueresistantdevice
9.Sabbaghuniversalspring(SUS)
The commonly used fixed functional appliances are:

202. LOGO
202

203. The1sttrulyfixedfunctional
appliancedevelopedbyEmil
Herbstin1909.Itwaslater
popularizedbyPancherz(1979).
Itconsistsofabilateral
telescopicmechanism that
maintainsthemandibleina
protrudedposition.TheHerbst
canbe:
—Banded
—Cast
—Acrylicsplintorcantileverbitejumpe.
(FIGS 46,20A AND B)
Banded Herbst appliance (Photograph
courtesy Dentaurum.Germany
Acrylic splint Herbst appliance

204. Indications
Dental Class II malocclusions
Skeletal Class II mandibular deficiency
Deep bite with retroclined mandibular incisors.
Contraindications
Dental and skeletal open bites
Vertical growth with high maxillomandibula plane angle
Excess lower facial height.
Cases prone to root resorption.
Disadvantages
Appliance is prone to breakage.
Lateral movement is restricted

205. 205

206. TheJasperJumper (AmericanOrthodontics)consists
consistsofaheavycoilspringencasedin
vinylcoating.
Theflexiblespringsareattachedtothe
maxillary1
st
molarposteriorlyanddistalto
themandibularcanine,eitherdirectlyonto
thelowerarchwireorbymeansofanout-
rigger.

207. Indications
Dental Class IT malocclusion
Deep bite with retroclined mandibular incisors.
Contraindications
Dental and skeletal open bites.
Min.imu.m buccal vestibular space.
Vertical growth pattern with increased lower facial height.
Cases prone to root resorption.

208. Advantages
Ease of insertion and activation
Generation of intrusive forces on molars and incisors.
Disadvantages
Frequent breakages
Compromised oral hygiene
Externally perceivable bulge in the cheeks
CompromisedoralhygieneduetoJasperJumper.
AlsonotethetearingoffofthevinylsleeveoftheJasperJumper
Externally perceivable bulqe in the cheeks
due to Jasper Jumper

209. 209

210. TheMARAconsistsofcamsmadefrom0.060
squarewireattachedtotubes(0.062square)on
upperfirstmolarbandsorstainlesssteelcrown.
Alowerfirstmolarcrownhasa0.059arm
projectingperpendiculartoitsbuccalsurface,
whichengagesthecamoftheuppermolar.
The mandibular anterior positioning appliance

211. Indication
SkeletalClassITwithmandibulardeficiency.
Contraindications
•Casespronetorootresorption
•Dentalandskeletalopenbite
•Verticalgrowthpattem.

212. Theapplianceisadjustedsothatwhenpatient
closesthemouth,thecamonuppermolar
guidesandrepositionsthemandibleintoa
ClassIrelationship.Itsmaindisadvantageis
thattemporarystainlesssteelcrownsare
neededonallfirstmolars.

213. 213

214. DevelopedbyJayCollinsin1997consistsof
buccalattachmentonupperandlowermolar
crownswhichincludesthestandardedgewise
tubesandalarge.070inchmolartube.
Largerodspassthroughthesetubes.The
mandibularrodinsertfrommesialofthemolar
tubeandisfixedatthedistalbyitsscrewclamp.
Activationisdonebymovingtherodmesially.

215. Maxillary rod inserts from distal of the tube and
is fixed at the mesial by screw clamp. Two
rods are connected by a rigid shaft and have
pivotal regions at their ends.

216. 216

217. DevelopedbyDe-vincenzoin1996.Oneofthe
firstinterarchappliancestoutilizethe
compressiveforces.

218. Advantages
-Goodpatientacceptance
-CanbeusedforClassIlandClassillcorrectionaswell
asinconjunctionwithextraoralforce.
-Possibilityofalterationintheamountanddirectionof
forceduringtreatment.
-Componentsareavailableseparately
-Significantlylessexpensivethanotherappliances.
Disadvantages
-Techniquesensitiveinsertionprocedure
-Frequentbreakagesofintervalspring
-Lessforcelevelsthanforsusandtwinforcecorrector.
-Tissueirritation.

219. 219

220. IntroducedbyArmstrong,consistsoftwoNi-Ti
coilsprings,oneinsidetheotherwith
solderedloopsonbothends.UsedforClass
IlandClassIllcorrectionandavailablein2
lengths:7and10mm.Deliverstheforceof
200-400gm

221. Disadvantage
-Bulky, therefore oral hygiene maintenance
is problem.
-Large inventory
-Oral hygiene is compromised
-Breakages are often seen.

222. 222

223. IntroducedbyLewisKlapperin1997.Resemblesjasper
jumperexceptthatinsteadofcoilspring,cableisused.
In1998,thecablewaswrappedwithacoilandKlappcr
superspringITcameintobeing.
Advantages
-Moreverticalforcevector,thereforeusefulforintrusion.
Disadvantages
-Unlike,jasperJumperitentersthemolartubefrommesial
andrequiresspecialmolartubeforengagement.

224. 224

225. Theapplianceconsistsof:
•Springmodule
•Lbailpin
•Pushrodinstallation.Thepushrodsareavailableinfollowing
sizes25,29,32and35mmwhichareavailableforrightandleft
side.
•TheLpinwiththespringmoduleisattachedtoupperfirstmolar
afterselectingtheappropriatepushrod.
Itsloopisattachedtoarchwirebetweenthecuspidandfirst
bicuspidandtheotherendisinsertedintothe
compressedspringmodule.

226. Advantages
•Unequalpushrodscanbeusedformidlinecorrection
•Springcanbereactivatedbyplacingcrimpsplitringbushingsonpushrod
•Relativeeaseofinstallationandremoval.

227. 227

228. Itisthelatestinterarchcompressivespringtobe
introducedandhasanumberofuniquefeaturesas:
-Slottedscrewforpartialadjustmentofdistalaspectofthe
plungerassembly(upto4mm)
-Thesecondcoilspringinsertedatthetimeofplacement
whichincombinationwiththeinternalspringpermitsa
greateractiveextensionofforcethananyother
appliance.
-Availableinonestandardlink
-Nodifferenceinappliancefortherightandleftsides.
-Lateral mandibular movement possible.
-More resistant to fatigue fracture.

229. Sabbagh universal spring (Photograph courtesy Dentaurum. Germany)
Disadvantages
-Unsuitability for Class ill treatment
-Limitations in patients with maximum opening of less than 48
mm.
-Increased force levels
-Considerably greater cost

231. Thepurposeofthischapterwastodiscussthe
biologicalbasisandclinicalmanagementofthe
variousfunctionalappliances.
Today,withthisimportanttoolinthehandsofthe
orthodontist,thespecialityhastrulyevolved
fromjusttheabilitytomoveteethtotheabilityof
influencingandtransformingthedentofacial
structures,thus,permittingtheattainmentofthe
achievableoptimum.
CONCLUSION

232. However,aswithanyotherspecialityofmedicine,the
importanceofproperdiagnosisandtreatmentplanning
inthesuccessofthefunctionaltherapycannotbeover
emphasized.Onemustnotforgettheimportanceof
correcttimingforachievingthebestresultswith
functionalappliances.

233. THANK YOU