ManagementoftheImpactedCanineandSecondMolarPamelaL.Alberto,DMD*DepartmentofOralandMaxillofacialSurgery,UniversityofMedicineandDentistryofNewJersey,NewJerseyDentalSchool,Newark,NJ,USAImpactedcanineandimpactedsecondmolarsareproblemsfrequentlyencounteredbyoral andmaxillofacial surgeons. Success in managementalong with the development of a satisfactorytreatment planrequiresateameort withinputfromthe orthodontist, general dentist, andsur-geon. Although the overall prevalence in thepopulationislow, theimpactedmaxillarycanineissecondonlytotheimpactedmandibularthirdmolarinitsfrequency. Wendthatthepopula-tion incidence is only between 1.7% and 2.2% [1].Secondmolarimpactionincidenceisevenless,atapproximately 0.4%. The condition is twice ascommoningirls(1%2%)asinboys(0.5%)[2].Impactedcaninesarefoundpalatallyin85%ofcases, with labial position in 15% of cases. Havingbothconditionsisrare,asseeninFig.1.Forthepurpose of this article, we discuss the managementoftheimpactedcanineandsecondmolar.ImpactedmaxillarycuspidEtiologyCalcicationof themaxillarycaninestartsatage1andiscompletedin5to6years.Itremainshigh in the maxilla above the root of the lateral in-cisor until the crownis calcied. The maxillarycuspid erupts along the distal aspect of the lateralincisor, which closes the physiologic diastemapresent between the maxillary central incisors.The maxillary canine travels almost 22 mm duringthetimeof eruption. It rst moves inapalataldirection then buccally. The maxillary canineshould erupt before 13.9 years for girls and before14.6yearsfor boys[3]. Theoriginof impactionisunclearbutmostlikelyismultifactorial. Becausethe maxillary canine has the longest path of erup-tioninthepermanentdentition,alterationinpo-sitionof the central andlateral incisor maybeafactor.Archlengthdiscrepancyandspacede-ciencymayresultinthecaninebecominglabiallyimpacted. Studieshaveshownahigherincidenceof palatally impacted canines in cases with missinglateral orpeg-shapedincisors. Failureofthepri-marycaninetoresorbmaycausepalatal move-ment of the permanent canine, althoughThilendar and Jakobsson [3] considered failureof resorption of the primary canine to be a conse-quencerather thanacauseof impaction. Age-netic predisposition has been shown in somestudies.Pirinenandcolleagues[4]foundthat pal-atally impactedcanines are genetic andrelatedto incisor-premolar hypodontia and preshapedlateralincisors.Otherpossiblecausesaretraumatotheante-rior maxillaat anearlyage, pathologic lesions,odontomas, supernumeraryteeth, andankylosis.There is also a higher incidence of impactedmaxillarycanine after alveolar bone graftinginpatientswhohaveacleft[5].LocalizationLocalizationof themaxillarycanineis akeyfactor in the comprehensive assessment of theimpacted canine. The position of the impactedcanine is important whendecidingmanagementoptionsfor patients. Localizationrequiresinspec-tion,palpation,and radiographicevaluation.The*171WoodportRoad,Sparta,NJ07871.E-mailaddress:alberto@umdnj.edu1042-3699/07/$-seefrontmatter 2007ElsevierInc.Allrightsreserved.doi:10.1016/j.coms.2006.11.001 oralmaxsurgery.theclinics.comOralMaxillofacialSurgClinNAm19(2007)5968position of the lateral incisor can give a clue to thecanine position. The crown of the lateral root maybe proclinedif the canine is lyinglabial tothelateral incisor. Occasionallytheimpactedcaninecanbepalpatedonthelabial or palatal aspect.The surgeon can take a series of periapicalradiographs alongwithapanoramicradiographtolocateits position. Whentakingtheseries ofperiapical radiographs, the cone headis shiftedhorizontally so Clarks Rule can be used todiscern the buccal or lingual position of thecanine. I ndthat 45

to60

anterior occlusalviews provide the shifting necessary to localize theposition of the canine. Cephalometric radiographsand CT scans are also useful in determininglocation of the impacted canine, but they aremore costly. If you need to extract the over-retained primary canine, the resorption pattern onthe root provides a clue to localization of thecrown of the impacted cuspid. Sometimes you canfeel the crown when giving your inltrationanesthesiaonthebuccalandpalatalmucosa.TreatmentoptionsAfter the patient undergoes a clinical andradiographic evaluation, a comprehensive treat-ment plan can be developed. An informed consentwithdiscussionoftreatmentoptionsandalterna-tives is important toavoidmisunderstandingorlegal problems.Treatmentoptionsinclude(1)notreatment except monitoring, (2) interceptivere-moval ofprimarycanine, (3)surgical removal ofthe impactedcanine, (4) surgical exposure withorthodontic alignment, and(5) autotransplanta-tionofthecanine.NotreatmentwithperiodicradiographicevaluationNotreatmentisrecommendedifthecanineisingoodpositionandwithout contact with thelateral incisor andrst premolar. If there is noevidence of pathology or root resorption ofthe adjacent teeth or the patient refuses treatment,thepatient canbemonitoredperiodically. If theimpactedcanineisseverelydisplacedandremotefromtheanteriorteethandisdiculttoremoveorexpose,adecisioncanbemadetomonitorthepatient radiographically. Ferguson and Pitt [6]surveyedall theUKconsultant orthodontiststoassess their opiniononmanagement of the im-pactedmaxillarycanineinpatientsforwhomnoorthodontic treatment is planned. They foundthatmostorthodontistswereinfavorofremovalof the impacted canine, with a signicant minoritysuggesting the conservative approach of radio-graphicmonitoring.InterceptiveremovalofprimarycanineExtraction of the primary canine is recommendif the patient is between 10 and 13 years, themaxillarycanineisnotpalpable,andlocalizationconrmsapalatalposition(Fig. 2).Ifthecaninepositiondoes not improveover a12-monthpe-riod, alternative treatment is indicated. Radio-graphic evaluation should be at 6-monthintervals. Figs. 3 and4 shows a case inwhichtheprimarycaninewas removedandit eruptedwithin6months.SurgicalremovalandprostheticreplacementSurgical extractionof theimpactedcanine isindicatedwhenthereispoorpositionforortho-dontic alignment, there is early evidence of re-sorptionof adjacent teeth, thepatient istoooldfor exposure, and the degree of displacement doesFig. 2. Extractionofprimarycaninetofacilitateerup-tionofimpactedcanine.Fig. 1. Impacted maxillary and mandibular canines withanimpactedmandibularsecondmolar.60 ALBERTOnot allowfor surgical repositionor transplanta-tion. Thetreatmentofchoiceforreplacementofthecanineisadental implant. Sometimesortho-dontic treatment is needed to provide enoughspaceforimplantplacement.Flapdesign. Flapdesignisdictatedbytheloca-tion of the impacted canine. If the impactedcanine is located buccally, a gingival crest incisioncan be made in the gingival sulcus. If the impactedcanineishigh,theincisioncanbemadehorizon-tally above the papillae. Vestibular incisions madeat the level of the mucogingival junction should bemade only when the impacted canine is above theroot apices. If the impacted canine is palatal,a palatal incision placed in the gingival sulcus canbe performed. Palatal incisions placed between thegingival crest and palatal vault should be avoided,because trauma to the greater palatine arterycould occur. Occasionally, the impacted caninecan be positioned transversely in the alveolus,whichwouldrequiremucoperiosteal apsonthepalatalandlabialsides.Surgical removal. Bone generally is removedusinga#8roundbur withcopious amounts ofirrigation. A 301 straight elevator is used toachievemovementof thetooth. Usuallysection-ing of the crownfromthe root is requiredforremoval. Thentheremainingportionoftherootcanberemoved.Ifanimplantisplanned,abonegraft in the extraction site for ridge preservation isrecommended.SurgicalexposureSurgical exposure is the conventional treat-ment for impacted canines. There are threemethods usedfor surgical exposure andortho-donticalignment [7]: (1) opensurgical exposure,(2) surgical exposure withpacking anddelayedbonding of the orthodontic bracket, and (3) surgi-calexposureandbondingoforthodonticbracketintraoperatively.Ifthecaninehascorrectinclina-tion, theopensurgical exposureisthetreatmentofchoice.Excisionofthegingivaoverthecaninewithboneremoval issucienttoalloweruptionofthecanine[8].If surgical exposure with orthodontic align-ment has been chosen as the method of treatment,three surgical approaches canbe used. The re-placement aptechnique replaces the mucoper-iosteal ap over the exposed canine after thebracket andchainare applied. Adisadvantageofthistechniqueisthatbondingcanfail andre-exposure is necessary. The excisional exposureremoves themucosaoverlyingthecrownof theimpactedcanine.Theapicallyrepositionedapisused to preserve the attached gingiva (Fig. 5).Vermette and colleagues [9] found that apically re-positioned aps resulted in more aestheticFig.3. Extractionofprimarycanine.Fig.4. Normaleruptionofcanineafterprimarycanineextraction. Fig.5. Apicallyrepositionedap.61 MANAGEMENTOFTHEIMPACTEDCANINEANDSECONDMOLARproblems than the replacement ap technique.The goal is tochoose atechnique that exposesthe canine withinazone of keratinizedmucosawithout involvementof the cemento-enameljunc-tion. This approach minimizes potential periodon-talcomplicationsafterorthodonticalignment.If the inclination of the canine to the midline ismorethan45

thentheprognosis foralignmentworsens.Theclosertheimpactedcanineistothemidlinetheworsetheprognosis.Applicationoforthodontictractiondevices. Manydierent devices can be applied to the crown of animpacted canine, including a wire, pins, crownformers, andorthodonticbrackets. Wiresplacedaround the crowns of an impacted canine caninjure the root of the tooth. Screwing pins into theenamel of the canine can damage the crown of thetooth. Crownformers placedor cementedoverthe crown of the impacted tooth were popular formany years; however, they acted as a foreign bodyandcausedinammationanderuption. Thede-viceof choiceisanorthodonticbracket orgoldmesh disk with a gold chain bonded onto thecaninecrownsurface(Fig.6).Two types of bonding agents can be used. Oneis a two-part, self-cure bonding agent and theother is a light cure bonding agent. The advantageof the light cure materials is that most can work inapartiallyweteld(Fig.7).Thegoldmeshdisksalso work better than the orthodontic brackets orbuttons with the light cure bonding agent becausethecuringlight canget at all thebondingagentthrough the mesh. It cannot cure the bondingagentunderthebracket.Thetoothsurfacemust beacidetchedfor30seconds and then irrigated. Success improves withhemostasis. Once hemostasis is achieved, theprimercanbeplacedonthetooth. Thebondingagentisplacedonthebracketandpressedrmlyagainst the enamel surface of the tooth. If it isalightcurematerial, itshouldbelightcuredfor20to40seconds (Fig. 8). Thechainthat is at-tachedtothe bracket is thenligatedtothe pa-tients arch wire (Fig. 9). The orthodontistshouldactivatetheappliancewithinaweek. Thevector of forceusedtomovethecaninecanbechanged to move the canine away from the incisorrootsandthenmoveitverticallyandbuccally.AutotransplantationofthecanineSelected maxillary impacted canines can beautotransplanted. Thistechniquemayberecom-mendedwhenthe degree of malpositionis toogreat to make successful orthodontic alignment orinterceptivemeasureshavefailed.Thisproceduresurgicallyismoredicultthanorthodonticrepo-sitioning. Moss[10] foundthatinadultsthesuc-cess of autotransplantation of the impactedcanineispoor. CaninetransplantationshouldbeFig.6. Goldmeshdiskwithgoldchain.Fig. 7. Light cure bonding material used in partially weteld.Fig.8. Lightcurefor20to30seconds.62 ALBERTOplanned as early as possible when the root is 50%to75%formed. Thetransplantedtoothmustbeheld in place for 2 to 3 months with an orthodon-tic appliance. If endodontic treatment is neces-sary, it should be performed when theimmobilizationdeviceisremoved.ImpactedmandibularcaninesThe mandibular canine is tentimes less fre-quently impacted than the maxillary canine(Figs.10and11). Themandibularcuspidhasthelargest root of all theteeth. Themandibularca-ninefollicleformsattheleveloftheinferiorbor-der of the mandible. Because the body of themandibleislabial tothealveolus, itmayexplainthefact that most impactedmandibular caninesare labially impacted. Similar to maxillary ca-nines, mandibular canines are three times morecommoninfemalepatientsthanmalepatients.Atreatment plancanbedevelopedoncetheimpacted mandibular canine is localized andassessmentofpotential damagetoadjacentteethand involvement of the mental nerve is made.Localizationis achievedinthe same manner asimpactedmaxillarycanines.Impactedmandibularcaninesareusuallyver-ticallyimpactedclosetothelabialsurface.Occa-sionally, they can be located beneath the apices ofthemandibularincisor. Theyarerarelyfoundinahorizontalposition.Managementofimpactedmandibularcaninesincludesthefollowingtreatmentoptions:Notreatment withclinical andradiographicobservationSurgicalextractionSurgicalexposuretoaideruptionSurgicalexposurewithorthodonticguidanceTransplantationNotreatment,onlyobservationIf the impacted mandibular canine is below theapicesoftheteethandwithoutpathology, itcanbeobservedperiodically.SurgicalextractionIf the impacted mandibular canine is not in anupright position, extraction should be considered.Surgical extraction is accomplished by usinga labial or lingual mucoperiosteal ap withpossiblereleasingincisions. Theremoval ofboneoverthecrownisachievedwitharound bur.Thetooth can be luxated and removed with anelevator. If this approach is unsuccessful, thecrownis sectionedandthe crownandroot areremoved. Ifthemandibularcanineislingual, theextraction is more dicult because of poor access.SurgicalexposuretoaideruptionIf themandibularcanineimpactioniscausedbyanoverlyingimpediment,theimpedimentcanberemovedsurgically. Thenabonypathwayforeruptioncanbecreated.Fig.9. Bracketsligatedtoarchwire.Fig.10. Impactedmandibularcanines(pretreatment).Fig. 11. Mandibular canines in occlusion after 6 monthsoftreatment.63 MANAGEMENTOFTHEIMPACTEDCANINEANDSECONDMOLARSurgicalexposurewithorthodonticguidanceFour types of incisions can be used forexposing the impacted mandibular canine [11]:(1)thelabialgingivalcreviceincision,(2)alterna-tivelabialgingival creviceincision,(3)free muco-sal incision, and (4) lingual gingival creviceincision. Thelabial gingival creviceincisionisanincisioninthegingival sulcusfromtherightrstpremolartotheleftrstpremolarthatpreservestheinterdental papilla. Avertical releasinginci-sioncanbeusedif additional accessisrequired.Thealternativelabial gingival creviceincisionisa horizontal incision made at the base of the inter-dental papilla. Closure of the incision is more dif-cult. A vertical releasing incision also can be usedifmoreaccessisrequired.Thefreemucosal inci-sion is used when the impacted mandibular canineislocatedattheleveloftheapicesoftheincisorsor lingual tothem. Theincisionis placedafewmillimetersawayfromthemucogingivaljunctioninthe nonkeratinizedmucosa horizontally. Theincisionshouldremainanteriortothemental fo-ramentoavoidthementalneurovascularbundle.If theimpactedmaxillarycanineislingual totheincisors, the lingual gingival crevice incisionshould be used. The incision is made in the lingualgingival sulcus fromthe mandibular right rstpremolar tothe mandibular left rst premolar.The incision should be extended to provideadequate access. Releasing incisions shouldnotbe used. If the lingually impacted mandibularcanine is belowthe level of the apices of theincisors, an extraoral approach may be necessary.TransplantationTransplantationofthemandibularcaninecanbe successful if the apex of its root has not closed.The canine can be transplanted to its correctpositioninthedental archoreventoadierentsite. The diculty is in removing the toothwithoutdamagingtherootsurfaceorapicalend.The canine must be rmly immobilized for at least2 months. The endodontic procedure can beperformedonthistoothafterimmobilization.ComplicationsandsideeectsComplicationsandsideeectswiththetreat-ment of theimpactedmaxillaryandmandibularcanineareasfollows:Ecchymosisof theupperliporlowerlipandchinInfectionParesthesiaDamagetoadjacentstructuresNoneruptionLossofsofttissueap/dehiscenceLackofattachedgingivaDevitalizationofthepulpPainEcchymosisoftheupperorlowerlipandchinAn ecchymotic area can occur in the soft tissueif proper hemostasis is not achievedbeforeclo-sure.Italsocanoccurifthepatientisonaspirinor herbal medications that increase bleeding time.InfectionAnysurgical woundcandevelopaninfectionevenwiththebest aseptictechnique. Withmax-illaryimpactedcanines,infectionscandevelopinthelip,caninespace,orpalate.Withthemandib-ular impacted canine, infections can develop in thelip, submental space, and sublingual space. Treat-ment consists of antibiotics and incision anddrainage.ParesthesiaWhenthemandibularimpactedcaninesloca-tionisneartheneurovascularbundle, paresthesiamay be a sequela of surgery. If the maxillarycanine is impacted palatally, the nasopalatinenervemaybeaected,althoughitrarelypresentsa problemfor the patient. If the mandibularcanine is locatednear the mental foramen, thepatient mayhaveaparesthesiaof the lower lipandchin. Surgeryperformedmidsymphysismayproduce altered sensation in the incisors andgingiva.DamagetoadjacentstructuresIf theimpactedcaninesareneartherootsofneighboringteeth, thesurgerycoulddamagetheimpacted tooth or adjacent teeth. Displacement ofa root into the maxillary sinus or nasal cavity canoccur during surgical removal. Rarely, an oralantral or oral nasal stula can followsurgicalremovalinthemaxilla.NoneruptionWheneruptiondoesnot occur, thetreatmentplan should be reviewed. The most commoncauses of noneruptionareankylosis, inadequateinterdentalspace,andgingivalscarring.64 ALBERTOLossofsofttissueapLoss of the soft tissue ap is the result ofinterruption of its blood supply or infection. Flapsthat are thin may have compromised bloodsupply. Allowingtheacidetchmaterial tocomeinto contact with the tissues can comprise thevitalityoftheap.LackofattachedgingivaPoorqualitygingival mucosamayoccurwithexposure of labially impactedmaxillary canine.The ap technique must preserve keratinizedtissue. Aconnectivetissuegraftcanbeplacedtocorrectthisproblem.DevitalizationofthepulpIf symptoms of pulpitis develop when theimpactedcanineisbeingorthodonticallymoved,the orthodontic therapyshouldbe stoppedandthe canine should be evaluated for possibleendodontic treatment. If adjacent teethdevelopsymptomsofpulpitis,endodontictherapyshouldbeconsidered.Thiscomplicationisrareinyoungindividuals.PainPatientsexperiencesomepainwithanysurgi-cal procedure; however, there is slightly morepostoperative painfrommaxillaryimpactedca-nine surgery than surgery of other impacted teeth.Postoperative management during the rst 24hoursshouldincludenonsteroidalanti-inamma-torydrugsandlong-actinglocalanesthesia. Nar-coticagentsoccasionallyarenecessarytorelievepostoperativepain.ImpactedsecondmolarsTheimpactionof thesecondmolar is ararecomplicationintootheruption. Theincidenceisapproximately 0.03% to as high as 3%, dependingonthestudy. It usuallyoccursunilaterallymorecommonly than bilaterally and occurs slightlymore ofteninmen. It is more commoninthemandiblethanmaxilla. Themanagement of im-pactedsecondmolars has beena challenge fororthodontists and oral and maxillofacial sur-geons. The impacted second molar is usuallyrecognizedwhenorthodontic treatment is com-plete and the roots are fully formed. Properalignment of the second molar into the dentalarch in an angle Class I position is an integral partofcompletingorthodontictherapy.Management of impacted secondmolars re-quires a teamapproach with the orthodontist,oral and maxillofacial surgeon, and generaldentist.EtiologyTherearemultiplecausesforimpactedsecondmolars. When the deciduous second molar is lost,therstpermanentmolarmustmoveforwardtoaccommodate the eruption of the second molar. Ifthis does not occur, the eruptionof the secondmolariscompromised,which canleadto tipping.If the developing third molar infringes in the spacerequiredfor the secondmolar toerupt, mesialtippingoccurs.Ill-ttingrstmolarbandsareaniatrogenic cause of the mesial impactedsecondmolar.LocalizationA panoramic radiograph is optimal to evaluatethe position of the impacted second molar.Periapical radiographsarealsouseful, especiallyusing Clarks Rule, because it tells you if theclinicalcrownistiltedbuccallyorlingually.TreatmentoptionsThedegreeof impactionandlocationof thesecond molar determine if a surgical, orthodontic,orcombinedapproachisused. Impactedsecondmolarsmust betreated. Not treatingthiscondi-tionandsimplyobservingisnotanoption.Lackof treatment causes periodontal disease with boneloss and decay of the rst and second molars. Thefollowingtreatmentoptionscanbeusedtotreattheimpactedsecondmolar.Surgical extraction of the impacted secondmolarSurgical extraction of the impacted third molarandsurgicaluprightingofthesecondmolarTransplantation of the third molar into the im-pactedsecondmolarsiteExtractionof the impactedsecondandthirdmolarandplacementofadentalimplantSurgicalextractionoftheimpactedsecondmolarOne treatment optioninvolves extractingtheimpacted second molar and allowing the thirdmolartomigrateforwardintothesecondmolarposition. The eruption of third molar is not65 MANAGEMENTOFTHEIMPACTEDCANINEANDSECONDMOLARpredictable. Often, thethirdmolaronlymigratesanteriorlyslightlyandthentips intothesecondmolarspace,whichpredisposesthesecondmolartoperiodontal problems becauseof its malposi-tion. Secondmolar extractionis contraindicatedwhen the third molars are smaller or poorlyformed, are inahorizontal position, are inthemaxillarysinus, or havea severespace deciency.It is important tomakepatients awarethat theeruptionof thethird molar isnotpredictableandthethirdmolarmayneedextraction.SurgicaluprightingofthesecondmolarwithextractionofthirdmolarUsuallythedecisiontoupright theimpactedsecondmolar is made bythe orthodontist. Thepatient is referredtoanoral andmaxillofacialsurgeon to discuss this combined orthodontic andsurgical approach. This treatment planmaynotbesuccessful if thesecondmolar root has two-thirdsrootformation.After appropriate local anesthetic blocks, anincisionis made alongthe cervical areas of therst molar along the external oblique ridge. A full-thickness mucoperiosteal ap is elevated. A roundburisusedtoexposethecrownoftheimpactedsecondmolarandthirdmolar. Itisimportanttoavoidexposingthecemento-enamel junctionandroot surface, whichincreasesthechanceof peri-odontal defects and external resorption. The thirdmolar is sectioned and elevated fromits bonesocket.Usinga301elevator,thesecondmolarisgently elevated. If the second molar can beelevated into proper position, then an orthodonticappliance is not required. Sometimes stabilizingthe uprighted second molar can be a problem. If itis unable to self-stabilize in the surrounding bone,anorthodonticbondingmaterial isusedtobondthe second molar to the rst molar (Figs.12 and 13).This procedure is not required with maxillaryimpactedsecondmolars. Luxationof the toothstimulateseruption. InFig. 14,thesecondmolarwas exposedandluxated. Within6months, thetooth erupted. After eruption, the third molarwas removed (Fig. 15).Often an orthodontic appliance must be placedtoupright thesecondmolar. GoingandRayes-Lois [12] reported on a technique in which the sec-ondmolarisbracketedwithabandthatcontainsa buccal tube. A heavy gauge nickel titanium archwire is threaded through the tube. The arch wire isligated to the two premolars and canine and helpsto upright the second molar. Other appliances canbe used. For example, segmental springs andnickel titaniumcoil springshavebeensuccessfulinuprightingsecondmolars[13,14].Withthead-vent of endosteal implants, microimplants thatcanbeplacedinthealveolarbonehavebeende-veloped. Theyareusedas ananchoragedevice.A2-weekhealingperiodisnecessarybeforeelas-tics are placed. This method is used especiallywhen trying to upright lingually tipped lowersecondmolarsandbuccallytippeduppersecondmolars [15]. Brass wire also can be used asFig.12. Impactedsecondmolar.Fig. 13. Impacted second molar surgically uprightedwithremovalofthirdmolar.Fig.14. Impactedmaxillarysecondmolar.66 ALBERTOa separator when placed below and above the con-tact point betweentherst molar andimpactedsecondmolar. The wire canbe tightenedincre-mentallytouprightthesecondmolar. Thistech-niqueisusedinfrequentlybecauseitcausespain,swelling,andfutureperiodontalproblems.TransplantationofthethirdmolarintothesecondmolarpositionThis treatment plancanbe performedif thethird molar has two-thirds root development. Theimpactedsecondmolar must be extracted, andthen the third molar is extracted as atraumaticallyaspossible.Thethirdmolariswedgedwithinthesecond molarsocket.Ifthetooth isnot stabilizedbetweenthebuccal andlingual cortices, bondingmaterialshouldbeplacedtokeepitinitsproperposition without mobility. Transplantation is onlypossible inselect cases. Once rmmobilizationhasoccurred,endodonticsmustbeperformed.ExtractionoftheimpactedsecondandthirdmolarswithdentalimplantsIftheageofthepatientandthestageofrootdevelopment are limiting factors, one shouldconsider extracting the impacted second and thirdmolarsasanoption. Thistreatmentplanshouldbe considered with older patients who havecomplete root formation (Fig. 16). With the excel-lent success rates of dental implants, replacing thesecond molar with dental implants is a predictableoption.RiskfactorsandcomplicationsAswithanysurgicalprocedure,complicationsare possible, and they should be discussed with thepatient before surgery [16]. Risk factors andcomplications include (1) loss of teeth, (2) root in-jury, (3)external resorption, and(4) periodontaldefects.LossofteethLoss of therst, second, andthirdmolars ispossible if treatment is not performed. These teethare usuallylost todecayandacute periodontaldisease.RootinjuryUprighting a second molar can cause rootinjury andloss of vitality. If the secondmolarroots are fully formedthere is a greater chance ofroot fracture or injury. Treating the impactedsecond molar when the roots are two-thirdsdevelopedpreventsthiscomplication.ExternalresorptionIf the cemento-enamel junction or root surfaceisexposedordamagedwhensurgicallyexposingthesecondmolar, external resorptionispossible.Careshouldbetakentostayabovethecemento-enameljunctionandnotexposetherootsurface.PeriodontaldefectsWhen the second molar is surgically uprighted,abonedefectremainsdistaltotherstmolar. Ifbone ll is absent in that area, a periodontal defectdevelops, whichgives the secondmolar apoorprognosis. Treating the periodontal defect withguided tissue regeneration techniquesdusingabonegraftandbarrierdisanoption.Fig. 15. Impacted second molar erupts into position af-terluxation.Fig. 16. Impacted maxillary second molar fullydeveloped.67 MANAGEMENTOFTHEIMPACTEDCANINEANDSECONDMOLARSummaryManagement of impactedcanine andsecondmolarscanbedicultbutrewarding. Treatmentplanninginthesecasesshouldbemultidisciplin-ary. Thedecisiontocorrecttheseimpactedteethsurgicallyusuallyis made byorthodontists. Pa-tients then seek consultation with an oral andmaxillofacial surgeon concerning the treatmentplan.Usually the risk-to-benet ratio favors thepreservationof theimpactedcanineandsecondmolar. Generallytherecommendationissurgicalexposure of the impacted canine with orthodonticalignment into the arch. It is also recommended toupright the second molar and remove the im-pacted third molar. Close follow-up by theorthodontist and surgeon is important to thesuccess of these procedures. Preserving these teethis an important orthodontic standard of care. It isimportant thattreatment bebasedonanappro-priate diagnosis and consultation with theorthodontist.References[1] Thilander B, Myrberg N. The prevalence of maloc-clusioninSwedishschool children. ScandJDentRes 1973;81:1220.[2] DaschSF, Harrell FV. Asurveyof 3874routinefull mouthradiographs. Oral SurgOral MedOralPathol 1961;14:1165309.[3] Thilander B, Jakobsson SO. Local factors in impac-tion of maxillary canines. Acta Odontol Scand 1968;26:14568.[4] Piriren S, Arte S, Apajalahti S. Palatal displacementof canine is genetic and related to gongenital absenceof teeth. J Dent Res 1998;75:17426.[5] SembG, SchwartzO. Theimpactedtoothinpa-tientswithalveolarclefts.In:AndersonJO,editor.Textbook and color atlas of tooth impactions.Copenhagen (Denmark): Munksgaard; 1997. p.33148.[6] FergusonJW, Pitt SKJ. Management of unerup-ted maxillary canines where no orthodontictreatment is planned: asurveyof UKconsultantopinion. J Orthod 2004;31(1):2833.[7] McSterry PF. The assessment of and treatmentoptions for the buried maxillary canine. DentUpdate 1996;23:710.[8] Ferguson JW, Pervizi F. Eruption of palatal caninefollowingsurgical exposure: areviewof outcomesin a series of consecutively treated cases. Br J Orthod1997;24(3):2037.[9] Vermette ME, Kokich VG, Kennedy DB. Uncover-inglabiallyimpactedteeth:apicallypositionedapand closed eruption techniques. Angle Orthod1995;65:2332.[10] Moss JP. The unerupted canine. Dent Pract 1972;22:2418.[11] Alling C, Helfrick J, Alling R. Impacted teeth. Phil-adelphia: WB Saunders; 1993. p. 2156.[12] GoingRJr, Rayes-LoisD. Surgical exposureandbracketing techniques for uprighting impacted man-dibular second molars. J Oral Maxillofac Surg 1999;57:20911.[13] MajourauA, NortonL. Uprightingimpactedsec-ondmolar withsegmental springs. AmJ OrthodDentofacial Orthop 1995;107:2358.[14] McAboyCP, GruventJ, etal. Surgical uprightingand repositioning of severely impacted secondmolar. J Am Dent Assoc 2003;134:145962.[15] ParkJ, KwonO, SungJ, etal. Uprightingsecondmolars with microimplant anchorage. J Clin Orthod2004;38(2):1003.[16] FelsenfeldA,AghalooT.Surgicalexposureofim-pactedteeth. Oral Maxillofacial SurgClinNAm2002;14:18799.68 ALBERTO