orthodontic treatment of a congenitally missing maxillary lateral incisor · 2016-02-04 ·...

Orthodontic Treatment of a Congenitally MissingMaxillary Lateral Incisor

JAE HYUN PARK, DMD, MSD, MS, PhD*

SAKIKO OKADAKAGE, DDS†

YASUMORI SATO, DDS, PhD‡

YUTAKA AKAMATSU, DDS, PhD§

KIYOSHI TAI, DDS¶

ABSTRACTClinicians agree that, regardless of gender or race, tooth agenesis has become more prominentin recent societies. The congenital absence of one or more maxillary lateral incisors poses achallenge to effective treatment planning for the restorative dentist. However, the one-sidedorthodontic approach of just moving canines mesially to eliminate restorative procedures leadsto compromise. Adult patients presenting with malocclusions, missing lateral incisors, or ante-rior crowding but who fail to get proper orthodontic treatment, requesting instead estheticsolutions that do not establish a stable occlusion, proper alignment, and proper axial inclina-tion of the teeth will have compromised esthetic and periodontal results. An evaluation of ante-rior smile esthetics must include both static and dynamic evaluations of frontal and profileviews to optimize both dental and facial appearance. This article presents how orthodontics iscombined with other specialties in treating a congenitally missing lateral incisor. One caseis used to illustrate how orthodontic treatment is progressed in collaboration withother specialists.

CLINICAL SIGNIFICANCEPatients with missing teeth, crowding, midline deviation, unesthetic gingival contours, or otherrestorative needs may require the interaction between various specialists. For the successfultreatment of orthodontic-restorative patients, an interdisciplinary team effort is vital.

(J Esthet Restor Dent 22:297–313, 2010)

I N T R O D U C T I O N

Present-day demands and expec-tations of esthetic dentistry are

growing. To provide esthetic ante-rior tooth shape and correct agen-esis, patients must be informed oftheir total dental needs, not just

those associated with a limited spe-cialty. To integrate and coordinatetreatment, patients need to beoffered a total treatment approach

*Associate Professor and Chair, Postgraduate Orthodontic Program,Arizona School of Dentistry & Oral Health, A.T. Still University, Mesa, USA and International Scholar,

the Graduate School of Dentistry, Kyung Hee University, Seoul, Korea†Private practice of orthodontics, Okayama, Japan‡Private practice of orthodontics, Okayama, Japan

§Private practice of general dentistry, Okayama, Japan¶Visiting Adjunct Assistant Professor, Postgraduate Orthodontic Program,

Arizona School of Dentistry & Oral Health, A.T. Still University, Mesa, AZ,and private practice of orthodontics, Okayama, Japan

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that maximizes function, esthetics,and oral health. In many routinedental malocclusions, just orth-odontic treatment alone may notbe enough. We must evaluate thepatient’s facial profile, smile line,buccal corridor, black triangles,lip line, and crowding. One-sided approaches to multifacetedproblems often producecompromised results.

Agenesis of one or more teeth con-stitutes one of the most commondevelopmental anomalies in man.1

Familial tooth agenesis is transmit-ted as an autosomal dominant,recessive, or X-linked condition.2

The reported incidence of perma-nent tooth agenesis varies from 1.6to 9.6%, excluding third molars,which occurs in 20% of the popu-lation.3 Studies vary on what thesecond most commonly missingteeth are. Some studies4–8 haveshown that they are the maxillarylateral incisors, whereas others9–12

indicate there is a higher incidenceof mandibular second premolaragenesis. Muller and colleagues5

found an interesting correlationthat maxillary lateral incisors arethe most frequently missing teethwhen only one or two teeth areabsent, whereas second premolarsare the most frequently missingteeth when more than two teethare absent.

Maxillary lateral incisors showthe highest genetic component of

variability in the general popula-tion, whereas the smallest geneticinfluence on size of an anteriortooth is seen in the canine.Numerous twin studies13–15 illus-trate hereditary factors in themesio-distal dimensions of theteeth, and populations with chro-mosomal aberrations, such as thosethat occur in Down’s syndrome,display a generalized reduction intooth size and number.16 Toothagenesis is more frequent in theparents and siblings of individualswith missing teeth than in thepopulation as a whole, a findingthat supports the hypothesisthat this condition isgenetically determined.17,18

T R E AT M E N T O F M I S S I N G

A N T E R I O R T E E T H

When examining the esthetics ofanterior teeth and a smile, the cli-nician should be aware of the mor-phology of the gingival contours,tooth contacts, tooth morphology,and tooth-size problems. To obtainideal esthetic results, worn incisaledges, tooth shape, incisal contact,the contours of gingival margins,and black triangles should be con-sidered before starting orthodontictreatment. The decision to reshapeor add tooth structure should beevaluated, considering the width-to-length ratios of the Golden Pro-portion.19 The length of the centralincisors should be divided into thewidth to obtain the proper percent-age, with the ideal width being 75

to 80% of the length. The longerteeth in this range are present moreoften in females while the shorterteeth tend to be found more oftenin males.20

Of interest is the question of whatdetermines the shape and thicknessof the architecture of the scallopedgingiva, the papilla, and the thick-ness of the labial and lingual alveo-lar bone. It appears clinically thatlong, tapered triangular maxillaryincisors have thin arched gingivaltissue with a longer delicate papillaand thin bone with a smallerincisal contact point. In contrast,rectangular-shaped incisors tendto have thicker gingiva with aflatter, wider free gingivalmargin. Furthermore, these latterteeth have broad contacts.Generally speaking, the more rect-angular the teeth, the thicker thealveolus and the gingiva thathouses them.21,22

The smile line and lip shape alsoshould be evaluated. The positionof the lip attachment at the nasola-bial junction has a profound effecton the esthetics of the profile. Weall need an understanding of facialproportions and facial esthetics toprovide our patients with a com-prehensive treatment plan.

There has been ongoing contro-versy in orthodontic and restor-ative dentistry over the treatmentof agenesis cases, especially of

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lateral incisors. Restorative dentistshave been opposed to mesial move-ment of the maxillary canine intothe lateral incisor space as this pre-cludes the potential for developinga canine-protected occlusionbecause it places the canine indirect opposition to the mandibu-lar lateral incisor. Stuart andStallard,23 and D’Amico24 advo-cated canine-protected occlusion inall dentitions. However, Nordquistand McNeill25 justified the mesialmovement of canines into lateralincisor space, which providedmany orthodontists with the ratio-nale for space closure. They statedthat no difference existed inadequacy of the occlusal functionbetween canine-protected andgroup function, and no relationwith periodontal status existedbetween the two groups. They alsostated that treatment should bedesigned to eliminate prostheses,which contributed to an accumula-tion of plaque and irritation.

Furthermore, studies25,26 haveshown that the two groups did notdiffer significantly in respect toocclusal function and the preva-lence of temporomandibular dys-function. Many orthodontic studieshave shown that reshaping maxil-lary canines to resemble lateral inci-sors greatly improves esthetics.27–31

When maxillary lateral incisors aremissing, there are several factors toconsider when treating patients

with a space opening or closure.These factors include the type ofmalocclusion, crowing/spacing,tooth size relationships, canineposition, shape and colorof canines, and maxillarylip length.27–33

The choice between these twomodes of treatment should notbe made empirically. In mostinstances, the presence or absenceof major occlusion problemsserves as the primary criterion foreither space closure or space open-ing.29,30 Lateral incisor spacesshould be closed in cases withmalocclusions that require theextraction of permanent mandibu-lar teeth. Mandibular extractionsmay be indicated to relieve ante-rior or posterior arch length defi-ciency, to reduce mandibulardentoalveolar protrusion, orto compensate for a Class IImolar relationship.

Some orthodontic patients may bemissing several permanent teeth,including maxillary lateral inci-sors. If teeth have been missingfor several years, the remainingteeth may have drifted. In thesepatients, orthodontists and restor-ative dentists may not know whatthe restorative requirements are orwhat the eventual restorativetreatment plan should be. Forthese types of patients, it is rec-ommended to predetermine thefinal occlusal and restorative

outcomes by creating diagnosticwax set-ups.34 In addition, thetrial set-up will allow identifica-tion of tooth surfaces that requirefunctional and esthetic reductionso that equilibration maybe initiated either at thebeginning of or during theorthodontic treatment.

The diagnosis and treatment ofgrowing children with missinglateral incisors can be a problemfor many clinicians. If the patientand his/her parents plan on havingimplants in the future, it is impor-tant that the majority of verticalfacial growth and tooth eruptionbe completed before implant place-ment.32 Girls mature faster thanboys, and their adolescent growthspurt occurs sooner. After comple-tion of growth in stature (height),sequential cephalometric and hand-wrist radiographs verify the cessa-tion of facial growth over a timeframe of approximately 6 monthsto 1 year. The sequence of treat-ment in cases of agenesis of ante-rior teeth must be thoroughlyexplained to both the patient andhis/her parents. They must realizethat orthodontic treatment is thebeginning of a process, with thescheduling of periodontal therapyand final restorations to follow. Alltreatment options should be dis-cussed with the interdisciplinaryteam, just as all the options areexplained in the orthodontictreatment phase.

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M A X I L L A RY L AT E R A L I N C I S O R S

In a long-term clinical and radio-graphic follow-up study by Thord-arson and colleagues,31 adolescentpatients who had extensive remod-eling of the permanent canineswere evaluated. The canines wereground to the shape of lateral inci-sors as part of the orthodontictreatment and the patients wererecalled after 10 to 15 years forclinical examination. The studydemonstrated that extensive cuspal,labial, lingual, and interproximalrecontouring by the grinding ofyoung teeth associated with orth-odontic treatment can be per-formed without discomfort to thepatient and with only minor or nolong-term clinical and radiographicreactions. They stated that thisfinding is encouraging, as betterlong-term esthetic results andhealthier periodontal conditionsmay be achieved by recontouringcanines, rather than byreplacing missing incisors withprosthetic appliances.

However, many esthetic dentistsdisagree with this conclusion.Isler,35 discussing facial beauty,stated that the bone is the under-structure, the scaffolding, and themajor determinant of facial beauty.He also mentioned that a goodsmile is only partly about the teeth;it is primarily about the way inwhich the teeth appear to be

placed in the face. Therefore, thedesign foundation of the smile isthe very foundation of the teeththemselves, that is, the maxillaryalveolar arch. Obviously, if apatient has a bilateral agenesis ofmaxillary lateral incisors, the bonevolume of the maxilla will bedecreased. By erupting maxillarycanines into the lateral incisorspace, alveolar bone is developed,and by distalizing the buccal seg-ments for the restoration of thelateral incisors, we can maintainthe volume of the maxillarybone.32,36 In the canine substitutioncase, the alveolar canine buttress-ing of the canine roots is displayedanteriorly where the lateral incisorsshould be, and the dental archnarrows distally. With spaceclosure, the arch form is condensedand constricted. Obvious gingivaland tooth esthetics may beimproved with gingival margin rec-ontouring, and the reshaping of themaxillary canines. However, even ifthe canines are recontoured estheti-cally, the dentoalveolar arch curva-ture cannot be changed. Thepatient in full smile displays buccalcorridor, because arch circumfer-ence is diminished with the closureof the lateral incisor spaces. Thereis less dentoalveolar bone to workwith to create an esthetic smile.37

On the other hand, Zachrisson38,39

showed that buccal corridor can beeliminated in extraction cases byadding labial crown torque tolingually inclined canines and

premolars during treatment.Gianelly40 reported a similar con-clusion that extraction treatmentsdo not constrict arch form.

Henns41 reported that the canineeminence is lost from its normalposition when canines are used aslaterals because the eminenceaccompanies the canine as it ismoved. However, his study showedthat the difference of the canineeminence did not exceed 1.5 mmwhen the mean arch form record-ings of the Class I extraction groupand the canine substitution groupwere superimposed. According tohis evaluation, using the upperstudy casts, the poor estheticappearance of the canine eminencemay have been exaggerated.

C A S E R E P O RT

A 38-year-old Japanese female haddifficulty biting and desired toimprove her facial esthetics. Shehad facial symmetry with a convexprofile (Figure 1). She presentedwith an end-on Class II molar rela-tionship on the right side and amutilated molar relationship onthe left side because of the loss ofthe mandibular left first molar. Themissing area was replaced by athree-unit bridge. The patient wasalso missing the maxillary leftlateral incisor and the maxillarydental midline was deviated to theleft by 3 mm relative to the facialmidline. Because of the loss of themaxillary left lateral incisor, there



were severe gingival marginal dis-crepancies between the maxillaryleft central incisor and canine. Thelingually displaced madibular rightlateral incisor also showed gingivalmarginal discrepancy. The maxil-lary arch had mild crowding andthe mandibular arch had severeanterior crowding. The maxillaryleft first premolar and madibularleft first premolar were in cross-bite, and the maxillary rightseocnd premolar and the mandibu-lar right second premolar were inBrodie bite. The patient hadseveral restorations in both archesand had 2 mm overjet and 70%overbite. The maxillary left centralincisor showed discoloration. Themaxillary right lateral incisor andthe first premolar exposed metalmargins of porcelain-fused-to-metalrestorations because of gingival

recession. The maxillary right firstmolar also showed gingival reces-sion (Figure 2).

The panoramic radiograph showedno caries or pathologies. Thepatient recevied root canal treat-ments on the maxillary right andleft first molars, maxillary rightfirst premolar, maxillary rightlateral incisor, maxillary left centralincisor, mandibular central incisors,and mandibular right first molar.The maxillary and mandibularthird molars were missing(Figure 3A). The cephalometricanalysis revealed that the patienthad a skeletal Class II pattern(ANB = 6.4°). The maxillary inci-sors were slightly proclined (U1 toFH: 113.5°) and the mandibularincisors showed normal inclination(IMPA: 94.1°). The upper and

lower lips were slightly protrusive(Figure 3B). The etiology of themalocclusion was determined to bea combination of heredity andenvironmental factors.

Before orthodontic treatment, thepatient was referred to a generaldentist for restorative dentistryconsultation as well as a periodon-tist for the evaluation of the exist-ing periodontal condition,especially thin attached gingiva onthe mandibular canines. One treat-ment option was to open space toreplace the missing maxillary leftlateral incisor. However, this treat-ment plan was not chosen becauseof the potential to procline themaxillary incisors and increaseprotrusive lips. Furthermore, thepatient was reluctant to undergo arestoration for a single tooth space

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Figure 1. Initial facial photographs.

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after orthodontic treatment. Theother treatment option was toextract the maxillary right firstpremolar and mandibular rightsecond premolar, which had resto-rations. In addition, there wereplans to remove the three-unitbridge on the left posteriorsegment to mesialize the leftmandibular second molar using a

temporary anchorage device(TAD). However, the patient didnot want to extract a tooth in themandibular arch and did not wantto install a TAD during treatment.The last treatment option was toextract the maxillary right lateralincisor to correct the maxillarydental midline and slenderize themandibular incisors to relieve the

crowding. It was explained to thepatient that the mandibular firstmolar would be replaced afterorthodontic treatment. However,severe gingival marginal discrepan-cies would result in a compromisedgingival architecture. Thepatient agreed to choose thistreatment plan.

Full-fixed .022″ Tip-Edge (TPOrthodontics, Inc., LaPorte, IN,USA) appliances were placed onboth arches. Before placing theappliances, the left mandibularthree-unit bridge was removed andtemporary crowns were delivered.This preadjusted edgewise appli-ance permitted crown tipping inone direction yet created ananchorage through bodily

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Figure 2. Initial intraoral photographs.

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Figure 3. Initial radiographic images: A, panoramic view; B, lateralcephalometric view.



movement in the other direction. Itoffered easy rotation and angula-tion control by using auxiliarieslike rotating springs and uprightingsprings. The Tip-Edge bracket wasderived from a single .022″straight-wire bracket, merely bycutting away two diametricallyopposed corners from the archwireslot. The addition of rotationwings and a vertical slot enhancedboth rotational and tip controls.This unique arch slot was able toclose the extraction space withoutextruding incisors, by tipping inthe mesiodistal direction early inthe treatment. The brackets hadappropriate torque and in-outcompensation to assure controlledfinishing with rectangular arch-wires and upright springs.42

To substitute canines in the positionof missing laterals, special bracketplacement was necessary for bothmaxillary canines and the first pre-molars. The lateral incisor bracketswere bonded to the canines and thecanine brackets were placed on thefirst premolars. Before bondingthe lateral incisor bracket on thecanine, the labial surface wasreshaped for the bracket adapta-tion. It is necessary to positionthese brackets gingivally to permitthe recontouring of the caninesrequired for esthetics and function(Figure 4A). To make the canineappear less curved and more like alateral incisor, the bracket wasplaced more distally in the center ofthe canine rather than at the heightof contour (Figure 4B). In addition,

a canine bracket was placed on thefirst premolar in the same mesiodis-tal position (more distally) as it wasplaced on the canine.

Maxillary and mandibular archesstarted with .016″ high tensilestainless steel archwires with mildbite opening bends mesial to thefirst molars. To make room for thelingually displaced mandibularright lateral incisor and to preventproclination of the mandibularanterior teeth, interproximal reduc-tion was performed in the anteriorsegment. At the leveling stage,.016″ nickel titanium archwire wasused in conjunction with the main.016″ high tensile stainless steelarchwire to speed the alignment ofthe mandibular anterior teeth. Inthe maxillary arch, space wasclosed using a .022″ round arch-wire. While protracting the maxil-lary right canine, the maxillarydental midline was slightly overcor-rected because the patient did notwear elastics (Figure 5). During thetreatment, enamel was recontouredto flatten and create an incisaledge on the canine cusp tip(Figure 6A). To eliminate traumaticocclusion of the mandibular lateralincisors with the lingual surfaces ofthe canines and to establish a bal-anced occlusion, the lingual cuspsof the maxillary canines and firstpremolars were recontoured(Figures 4A and 6B).28 In the fin-ishing stage, .0215″ ¥ .028″ arch-wires were used for torque control.

BA

Figure 4. A, Recontouring (red area) of the prominent labial ridge of a caninebefore bonding a bracket. During finishing stage, the lingual surface is reduced(blue area) to establish a balanced occlusion. B, To make the canine look lesscurved and more like a lateral incisor, the bracket is positioned more distally.

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In addition, to improve the inter-proximal contact points, offsetbends (in-out) were neededbetween the central incisor andcanine (Figure 7).

At this stage, the patient wasreferred to the restorativedentist to evaluate space forthe three-unit bridge on theleft posterior segment. The

patient was instructed to use elas-tics all the time to correct dentalmidline. Uprighting springs wereused to exert continuous, upright-ing, and torquing forces on theanterior teeth to ideal angulations.

Total treatment time was 23months. Following the treatment, a0.0175-in twistflex wire fixedretainer was bonded from first pre-molar to the first premolar on themandibular arch. The mandibularcentral incisors could not bebonded successfully with the fixedretainer because of ceramic crownswhich were fabricated after deb-onding. A mandibular Essixretainer was also delivered as aremovable retainer. On the maxil-lary arch, an Essix retainer wasdelivered. The patient was

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Figure 5. Intraoral progress after 10 months of treatment.

BA

Figure 6. A, Recontouring (red area) of the maxillary canine to resemble alateral incisor. B, Enamel recontouring (blue area) of the maxillary firstpremolar for canine substitution.



instructed to wear them 24 hoursper day for 1 year, and then atnighttime only after 1 year. Recallvisits for retainer checks weremade at 1, 3, and 6 months for thefirst year. To ensure continued sat-isfactory posttreatment alignmentof the mandibular and maxillaryanterior dentition, the use of fixedor removable retainers is recom-mended indefinitely. At the end oforthodontic treatment, the patientwas referred to her general dentistfor the restorative treatment andthe periodontist for gingivalmargin discrepancies.

As a result of treatment, thepatient’s profile has improved(Figure 8). The severe mandibularcrowding has been relieved. Dentalmidlines were aligned with thefacial midline, and overbite and

overjet have improved (Figures 9and 10). The panoramic radio-graph showed proper space closureand acceptable root parallelism,with no signs of bone or rootresorption (Figure 11A). Cephalo-metric analysis revealed nosignificant skeletal changes(ANB = 5.9°). The maxillaryincisors showed decent inclination(U1 to FH: 108.9°) and the man-dibular incisors showed nosignificant changes (IMPA: 92.4°).Her upper and lower lip profilehas improved (Figures 11Band 12, Table 1). After 6 yearsof retention, the patientshowed pretty stable occlusion(Figures 13–15).

D I S C U S S I O N

From an esthetic viewpoint,observing the natural anatomy of

the maxillary lateral incisor andthe maxillary canine, the markedprominence of the canine roots atthe corner of the mouth is quiteobvious. The natural topographyshows labial root prominence ofthe central incisor, labial concavityof the lateral incisor root, andlabial prominence of the canineroot. The next natural observationis the gingival scalloping heightcontours of the natural dentition.The gingival tissue is higher on thecentral incisors, drops down on thelateral incisors, is higher again forthe canines, and again drops downon the first premolar. These heightsof contour are critical for theesthetic smiles of our patients.43

When a patient has a high smileline with excessive gingival display,esthetic consideration must beweighed against additional

AB

Figure 7. A, To improve the interproximal contact points in the archwire design, the 1st order (in-out) bends wereperformed on the maxillary canines. B, Maxillary occlusal view of canine substitutions.

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restorative needs. Kokich44 andZachrisson45 outlined steps onhow to accomplish this withextrusion of the canines andintrusion of the first premolars to

obtain the ideal gingivalheight. However, this protocolrequires prosthetic build-up onboth the substituted lateralsand canines.44,45

Placing the dentition into an idealocclusion when there is agenesis,especially in cases involving thelateral incisors, is critical to obtainan ideal esthetic result. With

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Figure 8. Final facial photographs.

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Figure 9. Final intraoral photographs.



ectopic canine positions in agenesisof unilateral or bilateral maxillarylateral incisors, the objective is tocreate space or to allow the perma-nent canines to erupt mesially adja-cent to the maxillary centralincisors. The periosteal matrix (thetooth and periodontal ligament) isresponsible for the form, size, andshape of the skeletal unit (thealveolar bone), and its mainte-nance. Basically, the alveolar boneexists if the tooth and periodontalligament exist.

If there is no tooth to erupt into anarea of the dental arch, alveolarbone cannot be formed. As aresult, a large defect in the alveolarprocess can make future implantplacement almost impossible. Asthe canine erupts into the lateralincisor space, alveolar bone will

form in a 2 to 4 mm area adjacentto the erupting tooth. It is there-fore important for a tooth to eruptin the area where the eventualimplant will be.

Carlson46 has shown that, aftertooth extraction, the maxillaryanterior labio-lingual width isreduced by 23% in the first 6months and, after 5 years,an additional 11% loss inridge-width occurs. After toothextraction, the ridge-width willnarrow by approximately 34%over 5 years.

When canines erupt in close prox-imity to central incisors, spaceclosure is the best treatment.However, cases presenting withClass I buccal occlusions andneither mandibular arch length

deficiencies nor dentoalveolar pro-trusions favor treatment by orth-odontic space opening andsubsequent prosthetic lateralincisor replacements. In thesepatients, when maxillary lateralincisors are congenitally absent,spaces are created to allow ectopiccanines to erupt adjacent to thecentral incisors. As the permanentcanine is moved distally to createspace for a lateral incisor implantor bridge, an alveolar ridge iscreated. The labio-lingual ridgewidth of bone over time in orth-odontic cases of canines moveddistally was addressed by a studyby Kokich.36 The amount of boneloss was less than 1% over 4 years,compared with the Carlson studyof extracted teeth which showed34%. Kokich concluded that, if theedentulous alveolar ridge wascreated by orthodontic separationof two teeth, little resorptivechange will occur over time.

In many of Class II malocclusioncases with mesial eruption of thecanines into the lateral incisorposition, extensive distalization ofthe buccal dentition is required tocreate the mesial-distal space andto provide an alveolar ridge foresthetic lateral incisor pontic place-ment. The second molars have tobe distalized into a Class I posi-tion; the first molars, the secondpremolars, the first premolars and,finally, the maxillary canines aredistalized into a Class I occlusion,

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Figure 10. Intraoral lateral close-up views before (A) and after (B) treatment.

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to provide the mesial-distal spacenecessary for achieving ideal restor-ative dentistry. It is obviously mucheasier to move the canines mesially,but in some cases, if space openingis required, it is mechanicallydifficult and sometimes limited by

the relative alveolar concavitybetween the canine and firstpremolar roots.29

In creating the proper mesial-distal space for lateral incisor res-toration, the clinician should

properly position the central inci-sors with respect to the midpointof the cupid’s bow of the phil-trum of the upper lip and upperface, and to have maxillary andmandibular midlines coincident.The more important of the two isthe maxillary midline to the upperlip and face. After the alignmentis complete, radiographs should betaken of the created ridge androot positions of the central inci-sors and the canines. For implantor restorative cases, the rootposition must be evaluatedby both the orthodontist andthe surgeon.

If patients will requirerestorations after orthodontics, therestorative dentist should beinvolved during the final stage oforthodontic treatment. In thisway, the patient will benefit fromthe evaluation of the final resultsby the restorative dentist. Inaddition, the orthodontist and

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Figure 11. Final radiographic images: A, panoramic view; B, lateral cephalometric view.

Figure 12. Superimposition of cephalometric tracings: pretreatment (black) andposttreatment (red).



restorative dentist will bemore aware of the treatmentpossibilities for theorthodontic-restorative patient.34

C O N C L U S I O N

In treating congenitally missinglateral incisors, the two major

alternatives, orthodontic spaceclosure or space opening for pros-thodontic replacements, can bothcompromise esthetics, periodontalhealth, and function. If orthodon-tists and restorative dentistsestablish realistic objectives,communicate the sequence of

treatment, interact during treat-ment, evaluate dental and gingivalesthetics, and position teeth tofacilitate proper restorative treat-ment, the esthetics and long-termdental health of the patientafter all treatment will begreatly enhanced.

TA B L E 1 . C E P H A L O M E T R I C M E A S U R E M E N T S .

Japanese Norm Pretreatment Posttreatment 6 years posttreatment

SNA angle (°) 82.3 85.1 84.2 84.7SNB angle (°) 78.9 78.7 78.3 78.9ANB angle (°) 3.4 6.4 5.9 5.8FMA (°) 28.8 31.1 31.5 31.6U1 to FH (°) 111.1 113.5 108.9 110.9IMPA (°) 96.3 94.1 92.4 95.0Interincisal angle (°) 124.1 121.4 128 122Upper lip (mm) 0 1.5 –0.5 0.3Lower lip (mm) 0.8 2 1.7 1.9

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Figure 13. Postretention facial photographs after 6 years.

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Figure 14. Postretention intraoral photographs after 6 years.

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Figure 15. Postretention radiographic views after 6 years: A, lateral cephalometric view; B, a volume-rendering3-dimensional computed tomography.



D I S C L O S U R E S TAT E M E N T

The authors have no financialinterest in any of the companieswhose products are included inthis article.

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Reprint requests: Jae Hyun Park, DMD,MSD, MS, PhD, Postgraduate OrthodonticProgram, Arizona School of Dentistry &Oral Health, A.T. Still University, 5855East Still Circle, Mesa, AZ 85206, USA;Tel.: 480.248.8165; Fax: 480.248.8117;email: [email protected] article is accompanied by commentary,“Orthodontic Treatment of a CongenitallyMissing Maxillary Lateral Incisor,” TungNyguyen, DMD, MS, DOI 10.1111/j.1708-8240.2010.00357.x



orthodontic treatment of a congenitally missing maxillary lateral incisor · 2016-02-04 ·...

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