The Use of a Removable Orthodontic

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Sp oe 2555;35:131-40CU Dent J. 2012;35:131-40Original Article S ` S The use of a removable orthodontica

liance for s

ace management combinedwith anterior esthetic restorations:a case re

ortPasumon

awangnimitkul DD

1Chalerm

ol Leevailoj DD

, M

D, ABOD, FRCDT21Graduate

tudent, Esthetic Restorative and Im

lant Dentistry Program, Faculty of Dentistry,Chulalongkorn University2Esthetic Restorative and Im

lant Dentistry Program, Faculty of Dentistry, Chulalongkorn UniversityAbstract

acing in the esthetic area results in an unconfident smile. To solve this

roblem, manyalternative treatments can be used with multidisci

linary knowledge: for exam

le, orthodontictreatment and restorative treatment. The treatment

lan should be

erformed under conservativeconsideration, while the esthetic outcome should

ersist in the long term. Instead of using only

restorative treatment to close several s

aces, minor tooth movement before restorative

rocedures mayachieve a

referable result since the teeth can be realigned to the

ro

er

osition; it also requires lesstooth structure

re

aration. This case re

ort demonstrated the use of a removable orthodontic a

lianceto distribute the anterior s

ace before restoring the bilateral

eg-sha

ed lateral incisors with

orcelainlaminate veneers to close all the s

aces in the maxillary anterior area. This resulted in a naturala earance with healthy gingival tissue during the 8-month follow-u eriod. This treatment rinci le can be a lied for use in other small s acing cases.

(CU Dent J. 2012;35:131-40)Key words: esthetic; interdisci linary a roach; eg-sha ed lateral incisor; orcelain veneer;removable a

liance; s

acing132

awangnimitkul P, et al CU Dent J. 2012;35:131-40IntroductionToday, most

eo

le are concerned about theirhealth and a

earance; this includes healthy teeth anda beautiful smile, which will increase their confidencewhen out in ublic. The so-called esthetic zone in theanterior maxilla has the greatest im

act on smiledesign. Tooth anomalies occurring in this area-such asmisalignment, discoloration, or malformed and missing

teeth-can lead to unattractive smiles with non-harmonious

ink and white esthetic in the esthetic zone, whichmay sometimes reduce a

ersons confidence insmiling during their social lives.1One common esthetic roblem in the maxillaryanterior area is a

eg-sha

ed or mesiodistally deficientmaxillary lateral incisor. The definition of a

eg-sha

edlateral incisor is given in the Glossary of ProsthodonticTerms (2005) as an undersized, ta ered tooth.2Aty

ical tooth sha

e may result from an ina

ro

riate


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roliferation of the tooth bud cells during toothformation.3 Peg-sha

ed lateral incisors may causes

acing in the anterior maxilla, trans

osition ofadjacent teeth, and rolonged retention of deciduouscanines.4 The incidence of

eg-sha

ed lateral incisorsis a

roximately 2% to 5% of the

o

ulation, andoccurs more frequently in females than in males.5,6Anatomically,

eg-sha

ed lateral incisors are found

redominately on the left side of the arch.5,7There are two alternative treatments for

eg-sha

edlateral incisors. The first o

tion is to move the canineforward with a fixed orthodontic a

liance to close thes ace between the lateral incisor and canine, and thenresha

e the lateral incisor to make it a

ear morenormal. The other treatment is to maintain the caninesin Angles class I relationshi

and restore themalformed teeth with resin com

osites,

orcelainveneers or crowns. These restorations are used to closethe s

ace and change the

eg-sha

ed lateral incisorsinto their natural sha

e.8 The treatment time of thelatter method is less, and the esthetic and functionaloutcomes are satisfactorily achieved.4,9 However, insome cases the clinical situation is somewhat morecom

lex and may not be able to be corrected by only

restorative means. When teeth are severely misaligned,an orthodontic a

liance can contribute to creating the

ro

er tooth

osition

rior to any restorative treatment.Furthermore, in some cases,

eriodontal surgery maybe indicated in order to im

rove the gingival levels tocreate a more desirable symmetry and harmony of the

ink esthetic.Removable orthodontic a

liances could beconsidered as an alternative treatment for

atients witha single or a few misaligned teeth. Patients feel morecomfortable with removable a liances com ared tofixed a

liances since they can be removed occasionally.A removable a liance will not com romise the atients

oral hygiene, and it requires less clinical chair timesince the a liance is fabricated in a laboratory.10 Itcan only a

ly ti

ing force to move the misalignedtooth; therefore, the treatment needs strict su

ervisionby the dentist. Moreover, accom

lishment of thetreatment de ends on the atients coo eration. It isalso difficult to create com

lex tooth movementbecause the removable a

liance cannot achievetwo-

oint contacts on teeth, which are necessary tocontrol tooth movement in three dimensions.10,11 Inaddition, the acrylic

late may affect s

eech and causediscomfort while wearing the a

liance.10A removable a

liance with clas

s and finger

s

rings may be used for minor tooth movement in theanterior area, such as a small median diastemaa

roximately 2 millimeters or less. Palatal finger s

ringsare often used to move teeth in a mesiodistal directionin orthodontic treatment.11 O timum force forcontinuous tooth movement in a single-root anteriortooth is a

roximately 25-40 grams.10,12 Activation ofthe

alatal finger s

rings at 1.5 to 2 millimetersdistance can move the maxillary central incisor about 1millimeter in one month. Excessive force can com

licate


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Sp oe 2555;35:131-40 p p`` 133the treatment, and insufficient force can

rolong thetreatment time.10 Although removable a

liances witha finger s ring can shift the tooth to the correct osition,the tooth does not have bodily movement in the sameway as with a fixed a

liance because the finger s

ringhas only a

oint contact on the tooth. Therefore, onlythe ti

ing movement can be

erformed by removablea

liances.10Peg-sha

ed lateral incisors need restoration, suchas direct resin com

osite or

orcelain laminate veneers,to restore the tooth sha

e and close the s

ace.13,14While com osite veneers have the advantage of beinga low-cost conservative

rocedure,

orcelain laminateveneers have other advantages such as high longevity,material biocom

atibility, and a highly estheticresult.14,15 Porcelain can mimic the natural a

earanceof enamel.16 Moreover,

orcelain veneers retain lessstaining and are more durable com

ared to resincom

osite.15 Friedman and colleague re

orted that thelong-term clinical longevity of

orcelain veneers wasu

to 15 years, with only 7% failure rate due tofracture, leakage, or veneer debonding. This indicatesthat

orcelain veneers are very

redictable restorations.17

However, in order to fabricate a high-quality

orcelainveneer, teeth need to be

re

ared to allow for adequatethickness of the material. Generally a felds

athicveneer requires a minimum thickness of 0.3 millimeters.16However, the fabrication of a 0.3-millimeter-thickhigh-strength leucite-reinforced veneer is very difficult.One study revealed some cracking of 0.3-millimeter-thickveneers during cement

olymerization when the veneerswra

ed over the incisal edge.18 From these data, therecommended thickness for the veneers should be atleast 0.5 millimeter if they cover the incisal edge orinter

roximal area.18 However,

eg-sha

ed lateralincisors need minor re aration because the teeth have

enough s

ace for

orcelain veneer fabrication exce

t atthe cervical margin. ufficient tooth re aration at thecervical margin is recommended in order to avoid anovercontoured restoration.18In this case re

ort, the

atient was treated byminor tooth movement with a removable a liance todistribute the s

acing more favorably. Then estheticrestorations were

erformed by correcting the

egsha

edlateral incisors with ceramic veneers.Clinical re ortA 19-year-old male

atient was referred to theEsthetic Restorative and Im

lant Dentistry Clinic,Chulalongkorn University, for closing the s

ace in the

u

er anterior maxillary region and to change bothlateral incisors sha

e. Intraoral examination revealeds

acing between teeth 11 and 21 due to the distalmigration of tooth 21 a

roximately 0.5 millimeter,while the mesial of tooth 11 coincided with the dentaland facial midline. The shifting of tooth 21 waslikely caused by malformation of the lateral incisors.The

atient

resented with two

eg-sha

ed lateralincisors, teeth 12 and 22 (Fig. 1A). Tooth 13 wasslightly mesiolingually rotated. All of the teeth were


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sound and asym

tomatic. The

atient had 2 millimetersof overjet and 2 millimeters of overbite. Radiogra

hicexamination found that tooth 21 was minorly ti

edto the distal. Teeth 13 to 23 had an intact laminadura, with no

eria

ical radiolucency observed(Fig. 1B-D).Our treatment

lan was to do minor tooth movementof tooth 21 to close the median diastema (withoutmoving tooth 11) by using a removable orthodontica

liance, and then to restore both

eg-sha

ed lateralincisors with ceramic veneer facings. The orthodonticremovable a

liance was com

osed of one finger s

ringat distal of tooth 21, which generated force to movetooth 21 mesially, and one acrylic sto

at distal oftooth 11, which hel

ed stabilize the tooth 11 whentooth 21 was moved into contact. This

rocedure neededtwo weeks of force a

lication and two weeks ofstabilizing the tooth in

osition before the finalrestorations were

erformed. The case was finished by134

awangnimitkul P, et al CU Dent J. 2012;35:131-40

lacing ceramic veneers on the two lateral incisors toclose the s

ace and change the tooth sha

e. The

atientwas asked to wear a full-time retainer for three monthsto stabilize the anterior teeth and continued to wear a

art-time retainer for a year.10With this

reliminary condition, if the s

ace wasmanaged without using a removable orthodontica

liance, the median diastema would be closed byeither resin com

osite or ceramic, which might resultin unequal size of the central incisors. Under the

ro

osed treatment

lan, the two central incisors wouldnot be

re

ared. Their alignment would be correctedby means of minor tooth movement. The two

eg-sha

edlateral incisors would be the only teeth that neededrestoration. Consequently, the atient acce ted our

ro

osed treatment

lan.Fig. 1 Pretreatment. 1A, Tooth 21 aligned distally while tooth 11 coincided with

the facial and dental midline.1B-D, Radiogra hic examination revealed sound maxillary anterior teeth and tooth21 minorly ti

ed to the distal.Fig. 2 Wax-u

model was fabricated to

resent the

ossible outcome to the

atient. Sp oe 2555;35:131-40 p p`` 135Fig. 3 Minor tooth movement with removable orthodontic a

liance and tooth

re

aration. 3A, Removableorthodontic a

liance with a finger s

ring at distal of tooth 21 and an acrylicsto at distal of tooth 11.3B, The removable orthodontic a

liance was inserted in the mouth. 3C, Frontal view after minor toothmovement was achieved. 3D, Minimal

re

aration on teeth 12 and 22 without using

local anesthesia.Clinical

roceduresOn the first visit, oral examination and smileanalysis were

erformed. Then the

atients

resentdental condition was recorded, including radiogra hsof teeth 13 to 23. Im

ressions of maxillary andmandibular teeth were taken for

re

aring the studymodels.On the second visit, a wax-u model was used tocommunicate with the

atient about the treatment

lan,


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treatment

rocedures and the outcome (Fig. 2). Thenthe removable orthodontic a

liance, com

osed of onefinger s

ring and one acrylic sto

, was fabricated.On the third visit, the s ring-activated removableorthodontic a

liance was delivered, and oral hygieneinstructions were given (Fig. 3A and B).Two weeks after a

liance a

lication, the s

acebetween teeth 11 and 21 was evaluated. The s

acewas closed com

letely, as shown in Fig. 3C. Radiogra

hicexamination showed minimal alteration of theangulation of tooth 21.

hade selection for

orcelain veneers was erformed using a Vita 3D-Master hade Guide (Vident,U

A) by selecting value, chroma and hue, res

ectively.The selected shade was 2M1. Teeth 12 and 22 were

re

ared for

orcelain veneers using a conservativea

roach by removing minimal tooth structure at thecervical margins and labial surfaces, and sha

ing theincisal edges without using local anesthesia (Fig. 3D).A final im

ression was taken with light-body and

utty

olyvinyl siloxane (Flexitime, Heraeus Kulzer, U

A)using double-mixed single-im

ression technique

riorto fabricating the working model. Bite registration wastaken using Blu-Mousse (Parkell, U

A). Tem

orary

restorations were carried out using resin com

osite(shade A2, Premise; Kerr, U

A) with s

ot etching.16The tem

orary restorations were finished out ofocclusion, and the

atient was instructed to cleangently and avoid biting on these areas.A

hotogra

h with shade tab and a drawing ofthe color ma

ing were used to mimic the nature oftooth (Fig. 4A and B). Then, two Em

ress Estheticveneers (Ivoclar Vivadent, Liechtenstein) were fabricatedwith layering technique to create high translucent areasat the incisal third (Fig. 4C).Clinically, the veneers were tried in after tem

oraryveneers were removed. Resin cement (bleach shade,

NX-3 Nexus; Kerr, U

A) was used to cement both136 awangnimitkul P, et al CU Dent J. 2012;35:131-40veneers. The inner surfaces of the veneers were treatedwith 4% buffered hydrofluoric acid gel (Porcelain etchant,Bisco, U

A) for 4 minutes, and rinsed; then silane(Monobond- ; Ivoclar Vivadent, Liechtenstein) wasa

lied, and dried with warm air for 1 minute.19 Toothsurfaces were treated with 37.5%

hos

horic acid gelfor 15 seconds (Gel Etchant; Kerr, U

A) and thenrinsed. Primer and bonding agents (O tiBond FL; Kerr,U

A) were a

lied following manufacturers instruction.Bleach shade resin cement was a

lied on the innersurfaces of the veneers, which were subsequently

cemented on both teeth and light-cured for 2 minutes.After cementation, occlusal adjustment was done andexcess cement was removed. The

atient satisfied withthe result (Fig. 5). During the 8-month follow-u

eriod, the atient was recalled and the veneersmaintained their natural a

earance with healthygingival tissue (Fig. 6).DiscussionIn this case re ort, the finger s ring was designedto be used with a slightly dis

laced tooth in the mesio-distal


6/9

direction, since this s

ring has minor force that onlylasts for a short

eriod. The direction of the force fromthe s

ring should be

er

endicular to the long axis ofthe tooth, and the force should ass as close to thecenter of resistance as

ossible to reduce toothsrotation movement.11 The use of a finger s

ringgenerates a center of resistance to the tooth at the middleof the root. The movement of the tooth is

er

endicularto the tangent of the tooth surface at the contact

ointof the s

ring.12 With a finger s

ring, it is not

ossibleto move both the crown and the root simultaneouslybecause the direction of the s

rings force cannot

assthe center of resistance. As a result, the root a ex willmove in the o

osite direction com

ared to the crown.12Furthermore, the finger s

ring contacts the tooth atonly one

oint, which leads the tooth to ti

mesially ordistally.11 Minor tooth movement with a finger s

ringis acce

table in the case of tooth movement of a fewmillimeters. However, control of the root is neededwhen moving the tooth crown more than 3 to 4millimeters.10 As mentioned above, these are thelimitations of a removable a

liance with finger s

ring.However, the finger s

ring is a

ro

riate in a casewhere the tooth needs u

righting in order to move the

tooth to the right

lace, and it is ina

ro

riate in a casewhere the tooth is already angulated in the desireddirection.11Orthodontically treated teeth tend to rela

se overtime, after the a

liances are removed. A few factorsare the major causes of rela

sing. In this case re

ort,Fig. 4 Color ma

ing and shade selection of tooth 22. 4A, Drawing of tooth 22, showing color ma

ing and toothcharacteristics, was sent to communicate with the laboratory technician. 4B, Photogra

h of adjacent teeth withmatched shade tab. 4C, Veneers fabricated with translucent area and characterized to mimic adjacent teeth. Sp oe 2555;35:131-40 p p`` 137

Fig. 5 Pretreatment and

osttreatment of both

eg-sha

ed lateral incisors. 5A and B, Equal s aces of teeth 12 and22 were accom

lished after tooth 21 was ti

ed mesially by using removable orthodontic a

liance. 5C andD, Natural a

earance of teeth 12 and 22 was achieved after veneer cementation.Fig. 6 Com arison hotos of retreatment (left), and 8-month follow-u (right).6A and B, The change in thefacial a

earance and the new smile refreshed the whole facial com

osition. 6C and D, The veneers gavethe atient more confidence which showed in new natural smile. 6E and F, The veneers remained innatural a

earance with healthy gingival tissue.138

awangnimitkul P, et al CU Dent J. 2012;35:131-40

the

rimary cause was

eriodontal and gingival tissuereorganization. A

revious study demonstrated that the

eriodontal ligament needs 3 to 4 months to reorganizeitself, but the collagenous and elastic fibers in thegingival tissue need 4 to 6 months to do so. Thesu

racrestal fiber can remodel extremely slowly, and maycause the tooth to dis

lace within 1 year after treatment.This is why every

atient needs to wear a full-timeretainer for at least a few months, and this should becontinued for 12 months as a

art-time retention.10


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Daily oral hygiene maintenance of the veneers issimilar to that for natural teeth. Normal toothbrushingtwice a day and flossing are recommended for dailycare. One advantage of a orcelain surface is that thereis less

laque and calculus de

osition com

ared to anatural tooth surface.16 Therefore, it is not necessary touse an ultrasonic scaler to clean the veneers. Dentistsshould also be aware that the ultrasonic scalers ti

may create roughness, scratches or chi

s on the

orcelainsurface.20 Patients should take s

ecial care when bitingon hard foods.20 The gingival margin area is im

ortant;if gingival recession occurs, the veneer margin will beex osed and contribute to unesthetic outcomes. Inaddition, the veneers should be ins

ected regularly.20For veneer

re

aration, the

eg-sha

ed lateralincisors are already undersized. They only need minor

re

aration because there is already enough s

ace forcreating the

orcelain veneers. However,

re

arationof the teeth is necessary to define the veneer marginsduring fabrication, so that they can be created with the

ro

er thickness. In addition to mimicking the translucentarea of the natural teeth, incisal reduction may be needed.Thus, restoring the

eg-sha

ed lateral incisors withveneers is a

ro

riate due to the conservative

treatment as

ect, longevity, and highly esthetic resultscom

ared to resin com

osite filling.16Communication between the dentist and laboratorytechnician is an im

ortant issue.

im

ly selectinga shade tab is inadequate for creating the desiredrestorations.21 In addition to effective communicationwith the laboratory technician, a drawing describing allthe characteristics and color ma

ing should be sentto the laboratory in combination with

ictures of theadjacent teeth and matched shade tab.16 In our case,a drawing of tooth 12, which also simulated thecharacteristics of tooth 11, was sent to the laboratorytechnician. Pronounced vertical and horizontal lines

with some white s

ots were indicated in the drawing.Highlighted edges with gray area at the incisal thirdshowed the translucent area of the teeth. A

hotogra

hwith shade tab 2M1 from the Vita 3D-Master

hadeGuide was sent at the same time.Marginal gingival recession is caused by manyfactors, including inflammatory

eriodontal disease,ageing, faulty tooth alignment, traumatic toothbrushinginjury, orthodontic forces,

ressure (bands, arch wires,clas s or denture bars) and deleterious habits.22 Themost common cause is traumatic toothbrushing injury.23The defect dominantly occurs on left canine area inright handed

atients.22 And it was found more

frequent at facial surface than

alatal side.23 Moreover,the traumatic toothbrushing habits often relate to goodoral hygiene.23 In the

resent case, small gingivaldefects were shown at marginal gingiva of teeth 22 to 24.Faulty toothbrushing technique may be the cause, asnoticed by good oral hygiene and the area of the defects.Pro

er oral hygiene instruction was given, however,the defects

ersisted after the treatment was com

leted.The atient was reinstructed and informed aboutdisadvantages of toothbrush injury. The

atient understood


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and attem

ted to follow the oral hygiene instruction.Although the restorations look natural and achievea highly esthetic result, their function and the

atientsoral health are the most im ortant issues. The atientmust be informed of the entire treatment

lan

rior tothe beginning of the treatment, including oral hygieneinstruction. The

atient must be aware that the focusneeds to be not only on the restored area, but also onthe entire mouth, in order to maintain the esthetica

earance and the longevity of the veneers. Sp oe 2555;35:131-40 p p`` 139ConclusionThe use of a sim le removable orthodontica

liance combined with

orcelain laminate veneerscan be used to manage s

acing in the maxillaryanterior area with

eg-sha

ed lateral incisors. Thisconservative treatment can achieve a highly estheticoutcome, with healthy gingival tissue. The treatment

rinci

les described in this case re

ort can be extendedto the treatment of other small s

acing issues

resentin other cases.References1. Van der Geld P, Oosterveld P, Van Heck G,Kuij

ers-Jagtman AM.

mile attractiveness:

self-

erce

tion and influence on

ersonality. AngleOrthod. 2007;77:759-65.2. Academy of Prosthodontics. The glossary of

rosthodontic terms. J Prosthet Dent. 2005;94:10-92.3. Arte

, Nieminen P, Pirinen

, Thesleff I, PeltonenL. Gene defect in hy

odontia: exclusion of EGF,EGFR, and FGF-3 as candidate genes. J Dent Res.1996;75:1346-52.4.

chmitz JH, Coffano R, Bruschi A. Restorativeand orthodontic treatment of maxillary

egincisors: a clinical re ort. J Prosthet Dent. 2001;85:330-4.5. Meskin LH, Gorlin RJ. Agenesis and eg-sha ed

ermanent maxillary lateral incisors. J Dent Res.1963;42:1476-9.6. Alvesalo L, Portin P. The inheritance

attern ofmissing,

eg-sha

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cand.1969;27:563-75.7. Kook YA, Park

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ameshima GT. Peg-sha

edand small lateral incisors not at higher risk for rootresor

tion. Am J Orthod Dentofac Ortho

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Am J Orthod Dentofac Ortho

. 1987;92:249-56.9. Kokich VO Jr., Kinzer GA. Managing congenitallymissing lateral incisors. Part I: Canine substitution.J Esthet Restor Dent. 2005;17:5-10.10. Proffit W, Fields H. Contem orary orthodontics.3rd ed.

t. Louis: Mosby, 2000:418-48.11. Cobourne MT, DiBiase AT. Handbook oforthodontics. 1st ed.

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133-56.13. Izgi AD, Ayna E. Direct restorative treatment of

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ed maxillary lateral incisors with resincom osite: a clinical re ort. J Prosthet Dent.2005;93:526-9.14. Peumans M, Van Meerbeek B, Lambrechts P,Vanherle G. Porcelain veneers: a review of theliterature. J Dent. 2000;28:163-77.15. McLaren EA. Luminescent veneers. J Esthet Dent.1997;9:3-12.16. Gurel G. The science and art of

orcelain laminateveneers. Hanover Park IL, U

A: QuintessencePublishing, 2003:19-58, 302-9.17. Friedman MJ. A 15-year review of

orcelainveneer failure-a clinicians observations. Com

endContin Educ Dent. 1998;19:625-36.18. Roulet JF,

oderholm KJM, Longmate J. Effectsof treatment and storage conditions on ceramic/com

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re

arations: to

re

or not to

re

. Inside Dent. 2006;May:76-9.20. Goldstein RE. Change your smile: discover how anew smile can transform your life. 4th ed. HanoverPark IL, U

A: Quintessence Publishing, 2009:26-43.

21. Parker RM.

hade matching for indirect restorationsin the esthetic zone. J Cosmetic Dent. 2008;23:98-104.22. Grant DA,

tern IB, Listgarten MA. Periodontics.6th ed.

t. Louis: Mosby, 1988:460-8.23. Newman MG, Takei HH, Carranza FA. Carranzasclinical

eriodontology. 9th ed. U

A: W.B.

aunders,2002:851-75.140

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The Use of a Removable Orthodontic