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Júlio A. Gurgel, D

aProfessor, Department of OrthodonState of São Paulo.bProfessor, Department of ProsthodcProfessor, Department of OrthodondGraduate student, Master Dental PeProfessor, Department of ProsthodofProfessor, Department of Prosthodo

Gurgel et al

i-implants as provisional anchoragethe replacement of missing anteriorh: A clinical report

DS, MSD, PhD,a

Rudys R. Tavarez, DDS, MSD, PhD,b

Weber J. Ursi, DDS, MSD, PhD,c Murilo G. Neves, DDS,d

Fausto S. Bramante, DDS, MSD, PhD,e andCélia R. M. Pinzan-Vercelino, DDS, MSD, PhDf

University of the State of São Paulo, Marília, São Paulo, Brazil;CEUMA University, São Luís, Maranhão, Brazil

This clinical report describes an adult patient referred for orthodontic treatment with mini-implants as anchorage to correctthe root angulation of maxillary lateral incisors. The purpose of this report was to demonstrate the versatility of mini-implantsplaced in a vertical direction in esthetic areas. During orthodontic treatment, some aspects must be observed to preserve theinterim restoration against the occlusal loads to avoid screw fracture. A fixed appliance was placed to correct the position ofthe maxillary anterior teeth and to complete the treatment. Acceptable esthetics and function were achieved. (J Prosthet Dent2014;-:---)

The absence of permanent teeth asa result of agenesis or tooth loss can befollowed by alveolar ridge reductionand migration, and by the angulationof adjacent teeth. A lack of rootparallelism is undesirable in implantprosthodontics. Frequently, insufficientspace is available to place the dentalimplant, or the space is not evenlydistributed. Thus, many patients arereferred for orthodontic treatment be-fore rehabilitation.1-3 When anteriorteeth are absent, tooth positioningmust be corrected and esthetics pre-served during orthodontic treatment.Removable appliances with dentureteeth constitute one option, but theyare generally not well tolerated by pa-tients because they can interfere withspeech and expose the edentulousspace when they are removed for eatingor cleaning. Acrylic resin veneer withbonded brackets or even with a lingualarch wire also may be considered, and,

tics, CEU

ontics, CEtics, Univrogram, Cntics, CEntics, CEU

as with removable appliances, theydo not preserve gingival contour orthickness in the edentulous region.Bone preservation in the region requirescareful analysis. Special care is requiredif the patient is still actively growing.In this situation, it is necessary towait until adulthood for prostheticrestoration, including dental implantplacement.4

Because of their biocompatibilityand ease of insertion, mini-implantshave proven to be useful as anchoringdevices for various orthodontic move-ments. These mini-implants may beinstalled in different regions of thebasal bones and alveolar maxillaryand mandibular bones, and using themto correct various combinations ofdental irregularities may be possible.5

Although commonly inserted in a hori-zontal direction, mini-implants havebeen placed vertically to upright mo-lars, to distalize maxillary molars, and

MA University; and Professor, Department of S

UMA University.ersity of the State of São Paulo, São José dos CEUMA University.UMA University.MA University.

to retain provisional restorations.5-11

The mini-implants used in these re-ports have a button-shaped head with ahexagonal base design that allowsinterim placement to enhance estheticsin the anterior regions.8-11

CLINICAL REPORT

A 19-year-old woman who reporteda history of avulsion of both centralmaxillary incisors as a result of traumawas referred for treatment. Attempts toreimplant the teeth after the accidentwere unsuccessful, presumably becausethe replantation procedures were delayedby more than 24 hours after the toothavulsion (Fig. 1). A panoramic radio-graph revealed a convergence of themaxillary lateral incisor roots, with in-sufficient space to place dental im-plants in the central incisor region. Nopathology or bone loss was noted(Fig. 2). The main treatment goals were

peech-Language Pathology, University of the

ampos.

1 Pretreatment intraoral view. 2 Pretreatment panoramic radiograph.

3 Intraoral view, showing collars and heads of mini-implants.

4 Periapical radiograph after insertionof mini-implants.

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to correct the mesiodistal angulationof the maxillary lateral incisor roots toestablish sufficient space for implants.Three treatment alternatives were pro-posed to allow for orthodontic move-ment while preserving esthetics. Thefirst option was maxillary fixed appli-ances with the simultaneous use of aHawley plate with denture teeth inthe maxillary central incisor region. Thesecond option was maxillary fixed ap-pliances with brackets bonded to den-ture teeth and tied to the orthodonticwire, and the third was a maxillary fixedappliance with 2 mini-implants placedvertically in the alveolar ridge of themaxillary central incisors to support thedenture teeth.

The patient opted for an interim re-storation placed over 2 mini-implants.In addition to the esthetic advantages,this course of treatment eliminatedthe disadvantages associated with aremovable appliance, such as patientcompliance, speech changes, and riskof loss. This protocol also restored es-thetics and function, facilitated clean-ing, and attempted to preserve bonethickness and gingival contour in theedentulous space. Before the multidis-ciplinary treatment, to preserve es-thetics, the patient’s maxillary centralincisor crowns were used as interimrestorations. In the reported traumahistory, after dental avulsion, the rootswere cut off and then stabilized bybonding them to the lateral incisorsand canines in the maxillary arch. Two1.6 � 6-mm Modified Orthodontic

The Journal of Prosthetic Dentis

Skeletal Anchorage System (Dewimed)mini-implants were placed (Fig. 3). Themini-implants were inserted in thepalatal portion of the ridge, which thusallowed for greater buccal thicknessand reducing the chances of occlusalcontacts during mandibular move-ments. Denture teeth (central incisors)were attached immediately to the headsof the mini-implants with acrylic resinfor use as interim restorations. Aftermini-implant placement, a control ra-diograph was made to examine theposition of the bone site (Fig. 4).Straight-wire 0.022- � 0.028-inch slotRoth-prescription orthodontic bracketswere subsequently bonded in themaxillary dental arch.

Mini-implant stability and occlusalclearance on the interim restorationwere monitored at monthly appoint-ments. Initial leveling and alignment

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5 Gingival recontouring and interdental papilla observedimmediately after removal of mini-implants.

6 Panoramic radiograph before definitive treatment.

7 Posttreatment intraoral view. 8 Intraoral photograph at 3-year follow-up.

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were performed for 6 months. Apanoramic radiograph made at the endof this phase showed increased spacebetween the lateral incisor roots dueto the corrected angulation. Becausethe spaces were adequate, the dentalimplants were placed at this stage.When the mini-implants were removed,papillae and gingival contour forma-tion was observed in juxtapositionto the interim restoration over the mini-implants (Fig. 5). Fixed appliances wereremoved after 17 months of treatment,and ceramic crowns were then placedover the implants. Orthodontic treat-ment corrected the angulation of themaxillary lateral incisors and providedadequate space for placing dental im-plants in the maxillary alveolar ridgeto restore smile esthetics, mastication,and speech. The root divergences pro-vided sufficient interradicular space for

Gurgel et al

the insertion of dental implants toreplace the central incisors (Fig. 6). Asseen in the intra- and extraoral photo-graphs made 3 years after treatmentand after ceramic crowns, good func-tional occlusion and a pleasing estheticresult were achieved, both intraorallyand facially (Figs. 7, 8).

DISCUSSION

Placing vertical mini-implants in thealveolar bone of the edentulous ridgeprovides anchorage while promotingesthetics and normal speech, eating,and cleaning. Moreover, this type oftreatment preserves osseous tissue inthe alveolar area by stimulating bonemaintenance.8 Therefore, dental im-plants can be installed immediatelyafter removing the mini-implants. AModified Orthodontic Skeletal Anchorage

Systemetype screw was selected forthis patient because it has a horizontalcollar as a base of the head before thetransmucosal profile. This collar pro-motes gingival displacement andprevents soft-tissue inflammation ifnecessary to place partly in alveolarmucosa instead placed only on the firmattached gingiva. This type of screw wasselected because its collar reduces thecontact area between the pontic andthe gingiva, thus reducing gingival irri-tation under the pontic and maintain-ing or even recontouring the gingivalmargin and interdental papilla (Fig. 5).

The mini-implants described in thisclinical report were 6 mm in length.For the interim restoration to inducethe gingival recontouring describedabove, the mini-implant should beinserted into the palatal aspect of thealveolar area. The greater thickness of

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the palatal mucosa tissue in this regionreduces the depth of screw insertion intothe bone. In this clinical report, themini-implant inserted in the left side (Fig. 4)was quite anteriorly positioned in rela-tion to the palatal aspect because oftechnical limitations. However, beforeinsertion an accurate positioning of themini-implant in mesiodistal, buccolin-gual, and apicocoronalmust be carefullyconsidered when determining theplacement direction of themini-implant.Therefore, using 10-mm mini-implantsis currently recommended becauseit avoids the increased chance ofdisplacement associated with smallerscrews. Moreover, by using a 10-mmscrew, a 1:1 ratio is possible betweenthe crown length and implant length,which also favors implant stability.8

After installing a mini-implanteinterim-restoration combination, im-ages must be obtained to check thescrew location relative to the roots andother surrounding anatomic structures.Positioning the mini-implant in thepalatal aspect of the alveolar ridgeprevents fenestration of the corticalbone and helps adapt the provisionalrestoration to the gingival contour.Mandibular movements were checkedfor any incisal and/or occlusal contactinterference with occlusal film (Accu-Film S053; Parkell) after adapting thedenture teeth to the mini-implant headsand at every appointment thereafter.This precaution prevented mini-implantfracture and/or breakage of the dentureteeth. Moreover, stripping the proximalsurfaces of the denture teeth to providespace for the movement of adjacentteeth also is recommended. To facilitate

The Journal of Prosthetic Dentis

orthodontic movement to correct rootangulation, the spaces between theinterproximal surfaces should be eval-uated at all appointments.

Placing orthodontic mini-implantsfor provisional esthetics and functionalrehabilitation in young patients withcongenitally missing maxillary lateralincisors requires long-term assessmentto maintain regularity in the alveolarridge height after age-related boneremodeling. The follow-up visits shoulddetermine the need for provisional cer-vical recontouring and mini-implantrepositioning. They can be unscrewedfor repositioning, which can preventchanges in the height of the alveolarridge relative to the adjacent teeth. Pa-tients should be advised that the mini-implant is a short-term element andthat, after orthodontic treatment, itmust be replaced with a dental implant.In this patient, upon the completionof orthodontic treatment, the mini-implant was removed and the dentalimplant was placed during the sameappointment. This treatment protocolhelps maintain the gingival contour, andthe mini-implant bone site can be usedas a guide for the insertion of the dentalimplant.

REFERENCES

1. Van der Weijden F, Dell’Acqua F, Slot DE.Alveolar bone dimensional changes ofpost-extraction sockets in humans: asystematic review. J Clin Periodontol2009;36:1048-58.

2. Armbruster PC, Gardiner DM, Whitley JB Jr,Flerra J. The congenitally missing maxillarylateral incisor part 1: esthetic judgment oftreatment options. World J Orthod 2005;6:369-75.

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3. Kinzer GA, Kokich VO Jr. Managingcongenitally missing lateral incisors, part II.Tooth-supported restorations. J Esthet RestorDent 2005;17:76-84.

4. Fudalej P, Kokich VG, Leroux B.Determining the cessation of verticalgrowth of the craniofacial structuresto facilitate placement of single-toothimplants. Am J Orthod Dentofacial Orthop2007;131:59-67.

5. Cornelis MA, Scheffler NR, De Clerck HJ,Tulloch JFC, Nyssen-Behets C. Systematicreview of the experimental use oftemporary skeletal anchorage devices inorthodontics. Am J Orthod DentofacialOrthop 2007;131:52-8.

6. Park HS, Kyung HM, Sung JH. A simplemethod of molar uprighting withmicro-implant anchorage. J Clin Orthod2002;36:592-6.

7. Lim SM, Hong RK. Distal movement ofmaxillary molars using a lever-arm and mini-implant system. Angle Orthod 2008;78:167-75.

8. Graham JW. Temporary replacement ofmaxillary lateral incisors with miniscrews andbonded pontics. J Clin Orthod 2007;41:321-5.

9. Ritto AK. Skeletal anchorage: differentapproach. In: Nanda R, Uribe FA, editors.Temporary anchorage devices in orthodon-tics. St Louis: Mosby; 2009. p. 238-59.

10. Jeong DM, Choi B, Choo H, Kim JH,Chung KR, Kim SH. Novel applicationof the 2-piece orthodontic C-implantfor temporary crown restorationafter orthodontic treatment. Am JOrthod Dentofacial Orthop 2011;140:569-79.

11. Bidra AS, Almas K. Mini implants fordefinitive prosthodontic treatment: asystematic review. J Prosthet Dent 2013;109:156-64.

Corresponding author:Dr Júlio de Araújo GurgelCel José Braz, 480Centro Marília - SP - 17501-570BRAZILE-mail: jagurgel@marilia.unesp.br

Copyright ª 2014 by the Editorial Council forThe Journal of Prosthetic Dentistry.

Gurgel et al