orthodontic reconstruction with autotransplantation and bone grafting after a traffic accident

CASE REPORT

Orthodontic reconstruction withautotransplantation and bone graftingafter a traffic accident

Hiroshi Mimuraa and Shinho Fukuyob

Tokyo, Japan

aPrivabDirecHospiThe aproduReprin188-0Subm0889-Copyrdoi:10

This case report describes the orthodontic treatment with autotransplantation and bone grafting of the lostmaxillary alveolus for a patient injured in a traffic accident. This patient had a severe skeletal Class III relationshipbecause of the loss of 6 maxillary teeth and the adjacent alveolar bone. Autotransplantation of mandibular firstpremolars and bone grafting of the deficient alveolus were carried out to improve the occlusion and the profile.After orthodontic treatment, the transplanted premolars were reshaped and restored with composite as centralincisors. Good occlusion and cosmetic improvement were obtained. Orthodontic treatment is useful for occlusalreconstruction after a traumatic injury, and autotransplantation is an effective option for these patients. (Am JOrthod Dentofacial Orthop 2012;141:S119-29)

Traumatic maxillofacial fractures can sometimescause life-threatening neurologic injuries. There-fore, emergency treatment for these patients is

critical, and they are typically brought to a hospitalemergency room, where a general surgeon performssurgery without concern for the occlusion. If fracturedalveolar bone and displaced teeth are removed duringthe emergency surgery, subsequent occlusal reconstruc-tion can be quite difficult.

Autotransplantation has been reported as a treatmentfor anterior tooth loss. Due to the unique osteogeniccapacity of an autotransplanted tooth, this procedureis a unique treatment alternative when both the lost teethand the atrophic or missing alveolar process must bereplaced. We report here on a patient who lost heranterior maxilla and 6 maxillary anterior teeth in anaccident. The treatment involved bone grafting, auto-transplantation, orthodontic treatment, and restoration.

DIAGNOSIS AND ETIOLOGY

The patient was a 10-year-old girl who had been hitby a truck while riding her bicycle. She was transported

te practice, Tokyo, Japan.tor, Department of Oral and Maxillofacial Surgery, Showa Generaltal, Tokyo, Japan.uthors report no commercial, proprietary, or financial interest in thects or companies described in this article.t requests to: Hiroshi Mimura, 2-15-11-6, Yato-cho, Nishi-Tokyo, Tokyo001 Japan; e-mail, [email protected], August 2010; revised and accepted, September 2010.5406/$36.00ight � 2012 by the American Association of Orthodontists..1016/j.ajodo.2010.09.034

to the hospital in an ambulance. She was bruised onher face and lips, and her maxillary anterior alveolarbone and the 6 anterior teeth were lost because of thefracture. After recovering from her injuries, she visiteda general dentist because of her parents’ concernsregarding her cosmetic appearance and her difficultyin masticating food. She was referred to the clinicfor adjunctive orthodontic treatment to help in herrehabilitation.

At her initial visit, 1 month after the injury, she hadonly 2 permanent first molars and her left first andsecond deciduous molars in the maxilla (Figs 1-5). Themandibular anterior teeth were crowded and extrudedwith an excessive curve of Spee. Her molar relationshipwas Class I. The crowns of both mandibular centralincisors had also been fractured in the accident buthad no pulp exposure, so the right central incisor hadbeen restored with composite by her general dentist.Her facial profile showed severe prognathism witha retropositioned midface that resembled an elderlyperson and was exaggerated by the missing maxillaryanterior teeth. However, her facial photograph beforethe traffic accident showed excessive overjet of herrotated anterior teeth, and a slight Class III tendencywith a prominent chin (Fig 2). No other significant dam-age to the cranium and face was observed on the3-dimensional computed tomography image (Fig 4,A), and there were no other fractures of the maxilla(Fig 4, B).

The cephalometric analysis showed a skeletal Class IIIrelationship (ANB, �3.0�) with an extremely retruded

S119

Delta:1_given name

Delta:1_given name

Delta:1_given name

Delta:1_given name

Delta:1_surname

Delta:1_surname

Delta:1_surname

Delta:1_surname

mailto:[email protected]

Fig 1. Pretreatment facial and intraoral photographs.

Fig 2. Facial photograph before the traffic accident.

S120 Mimura and Fukuyo

April 2012 � Vol 141 � Issue 4 � Supplement 1 American

maxilla (SNA, 77.0�) because of the loss of the anterioralveolar segment, and a slightly protruded mandible(SNB, 80.0�). The mandibular incisors were inclinedlabially (IMPA, 95�; FMIA, 59.0�; L1-APo, 7.5 mm)(Fig 5, Table). The absence of the maxillary anterior teethhad caused a tongue-thrusting habit. The panoramicradiograph showed 8 permanent teeth in the maxillaand 14 in the mandible in addition to the developingthird molars (Fig 4, C).

TREATMENT OBJECTIVES AND PLAN

Planning treatment for a young patient who haslost so many teeth and alveolar bone involves a de-tailed evaluation of both the prognosis for the in-jured teeth and the prosthodontic treatment plan. Acoordinated approach, incorporating clinical andradiographic findings of the healing and potentialcomplications, must be established before orthodon-tic treatment can start. The plan should be based on

Journal of Orthodontics and Dentofacial Orthopedics

Fig 3. Pretreatment dental casts.

Mimura and Fukuyo S121

a realistic evaluation of the prognosis for the injuredteeth, the future prosthodontic treatment, and theorthodontic difficulties.

Our patient’s chronologic age was 10, so subsequentmandibular forward growth would worsen the jaw rela-tionship. Labial proclination of her mandibular incisorswas also expected because of the tongue-thrustinghabit. Therefore, chincup therapy was indispensable toinhibit mandibular advancement and to upright themandibular incisors.

There were 6 fewer teeth in the maxillary arch, andthe mandibular incisors were labially inclined andcrowded, so extraction of the mandibular first premo-lars was planned. Even with mandibular extractions,there were 4 more maxillary teeth compared with thenumber of mandibular teeth. However, if the extractedmandibular premolars could be transplanted to themaxilla, the difference in the numbers of teeth in thejaws would decrease to 2. After orthodontic treatment,the 2 missing incisors could be replaced by dental im-plants. When 2 implants are placed side by side, it isusually not possible to create a satisfactory gingival pa-pilla between the implants. So we decided to place thetransplanted premolars into the maxillary central incisorpositions.

Because of the associated bone loss, bone graftingwas necessary to obtain a normal interincisal relation-ship and to enhance midface advancement. The amount

American Journal of Orthodontics and Dentofacial Orthoped

of bone grafting to the anterior maxilla was estimated bycephalometric prediction (Fig 6). The amount of thebone graft and the tooth inclination were estimatedwithout retraction of the mandibular incisors, becausethe mandible could grow forward and worsen the ANBangle.

The panoramic radiograph showed that the rootformation of both premolars was incomplete, and theapices were open. The success of autotransplantationand the ability to maintain tooth vitality of the donorteeth are enhanced if the transplantation occurs beforethe completion of root formation.

The crown forms of the transplanted premolarswould require reshaping with composite after ortho-dontic treatment. Two single-tooth implants wouldeventually be placed in the maxilla to replace the lateralincisors after the patient had completed her facialgrowth.

TREATMENT ALTERNATIVES

Conventional prosthodontic treatment with a re-movable partial denture could have been used to re-place her missing anterior teeth and alveolar process.However, there was insufficient clearance between themandibular incisors and the maxillary alveolus to fitthe denture. Also, since the patient was 10 years old,her teeth were still erupting, so a removable denture

ics April 2012 � Vol 141 � Issue 4 � Supplement 1

Fig 4. Pretreatment radiographs: A, helical computed tomography; B, lateral cephalogram; C, pano-ramic radiograph.


would eventually not fit well. Furthermore, she did notwant a removable partial denture, so fixed prosthodon-tic treatment was the first choice of this patient and herparents.

Since there were 6 missing teeth, orthodontic spaceclosure was excluded. Also, the edentulous space wastoo great to be restored with fixed bridgework. So,replacement with single implants was the third alterna-tive. However, the anterior alveolar process was also lostin the accident, so it would be difficult to create estheticartificial teeth on implants without rebuilding the ante-rior alveolus. Implants are contraindicated in growingpatients, because they result in infraocclusion. Implanttreatment must therefore be postponed until facialgrowth is complete. During this waiting period, there isa risk of further atrophy of the alveolus.

Atrophy of the width and height of the alveolus issometimes seen in growing patients with missingpermanent teeth. Autotransplantation of premolarsto replace missing incisors can contribute to favorable


development of the alveolar bone due to its osteo-genic potential.

TREATMENT PROGRESS

A chincup appliance was used to restrict mandibulargrowth and to control the mandibular growth direction.The chincup also has an effect on the mandibular inci-sors to incline them lingually and resists tongue pressureproduced by the tongue-thrusting habit.

About 1 3 5 cm of cortical and medullary bone wastaken from the patient’s ileum and grafted to theatrophied anterior maxilla. The crushed medullary andcortical bones were placed on the anterior alveolus,covered with a titanium micromesh plate (Alveolar CrestReconstruction System; MONDEAL Medical Systems,M€uhlheim, Germany) and fixed with 3 microscrews.

After the bone graft, all mandibular teeth werebanded and bonded (Fig 7). Brackets were also placedon the mandibular first premolars to increase the


Fig 5. Pretreatment cephalometric tracing. Fig 6. Paper prediction for the autotransplantation.

Table. Cephalometric measurements

Measurement Standard Initial FinalSNA angle (�) 82.3 77 77SNB angle (�) 78.9 80 75ANB angle (�) 3.4 �3 2MP to FH (�) 28.8 26 26Y-axis (�) 65.4 61.5 64FMIA (�) 54.9 59 60L1 to MP (�) 96.3 95 94L1 to APo (mm) 3 7.5 1U1 to FH (�) 111.1 Unmeasurable 115U1 to SN (�) 104.5 Unmeasurable 109.5Interincisal angle (�) 124.1 Unmeasurable 125


mobility of these donor teeth. The titaniummesh was re-moved after 7 months, and we confirmed that new bonehad formed. After 11 months of treatment, the mandib-ular first premolars were transplanted to the recipientsites of the maxillary central incisors (Fig 8).

For accurate positioning, a surgical stent wasprepared, and a modified lingual arch was placed inthe maxillary arch for stabilization. The transplantedteeth were not bonded to the lingual arch, becausethe teeth would not fit on the bonding base of the lin-gual arch. On the day after the surgery, the bracketswere placed, a nickel-titanium wire was used for tem-porary fixation, and an orthodontic force was appliedto prevent ankylosis of the transplanted teeth. Thoughthe alveolar bone graft had been successful, thegrafted alveolar process did not have sufficient height.So, the donor teeth could be placed deep and high,and their extrusion could help to create alveolarbone (Fig 9).


The labial attached gingiva was also lost with thefractured alveolar process, so the presurgical labialsurface of the alveolar crest was covered with alveolarmucosa. The transplanted teeth were so deep that theyhad no attached gingiva or vestibule. After extrudingthe transplanted teeth, vestibular expanding surgeryand a gingival graft were performed.

After 23 months of treatment, a Class I ideal occlu-sion had been established, so all brackets and bandswere removed (Fig 10), and the general dentist reshapedthe transplanted premolars and restored them withcomposite resin (Fig 11). After facial growth is com-plete, single dental implants will be placed in the lateralincisor sites. A circumferential retainer with 2 artificialteeth was provided for use until the implants could beplaced.

TREATMENT RESULTS

A Class I ideal occlusion was obtained, and ideal over-jet and overbite were achieved; the posttreatment facialphotographs show an acceptable and balanced profile(Figs 10-13). The posttreatment panoramic radiograph(Fig 13, B) shows that the transplanted mandibularfirst premolars remained vital, and the apices closednormally. The crowns were reshaped and restored withcomposite. The mandibular right central incisor crownhad been damaged during the accident and was end-odontically treated because of the loss of pulpal vitality.Circumferential retainers with artificial teeth for bothmaxillary lateral incisors were placed in the maxillaryarch, and a lingual bonded retainer between themandibular second premolars was attached to themandibular arch (Fig 11).


Fig 8. Intraoral photographs after the autotransplantation.

Fig 7. Intraoral photographs after the alveolar bone graft.


Cephalometric analysis showed a decreased SNBangle with clockwise rotation of the mandible. Thealveolar bone graft and the autotransplanted teethcreated bone apposition at A-point. The ANB angleimproved from �3� to 2�. Articulare moved backwardwith a slightly rotated ramus, but the FMA angle wasmaintained at 26� (Figs 14 and 15, Table).

The occlusion remained stable at 2 years posttreat-ment.

DISCUSSION

Dental injuries in themixed andpermanent dentitionsare most frequent in children from 8 to 9 years of age,


and most injuries involve the maxillary incisors.1-6 Boysare injured twice as often as girls. Patients with anincreased overjet have a significantly greater risk ofdental injury. The maxillary central incisors are mostcommonly involved; however, traffic accidents cancause other types of maxillofacial injuries.

Trauma to the face often creates orthodontic prob-lems that require immediate treatment. Displacementof a traumatized tooth occurs because the alveolarbone moves and takes the tooth with it, since fracturesoccur within the alveolar process. In addition to possibleroot fractures and loss of pulp vitality, trauma to incisorscarries with it a significant risk of ankylosis. The crown of


Fig 9. Intraoral photographs during treatment.


the mandibular incisor was fractured and then lostpulpal vitality. Fortunately, this tooth did not ankyloseand could be moved orthodontically. However, the teethwere so damaged in the maxillary anterior region thatthe emergency team removed all 6 anterior teeth andthe fractured alveolar bone. This unfortunate treatmentmade the subsequent rehabilitation of this youngpatient quite difficult.

Loss of multiple anterior teeth results in significantlyincreased esthetic problems. This is primarily due to theassociated alveolar bone loss, which might require bothhorizontal and vertical bone augmentation. The mainreason for this patient’s acquired severe skeletal ClassIII relationship was the lack of maxillary anterior alveolarbone around A-point. Therefore, bone grafting wasnecessary to correct the skeletal discrepancy, especiallythe retropositioned maxilla, and to gain alveolar boneheight for tooth autotransplantation and dentalimplants in the maxillary incisor region.

The loss of the anterior teeth and the alveolar pro-cess in our patient resulted in an anterior open biteand an acquired tongue-thrusting habit. When thereis an anterior open bite, it is more difficult to sealoff the front of the mouth during swallowing to pre-vent food or liquids from escaping. Bringing the lipstogether and placing the tongue between the spacesof the missing anterior teeth is a successful maneuverto close off the front of the mouth and form an ante-rior seal. Profitt7 concluded that, from the point ofequilibrium, light but sustained pressure by the tongueagainst the teeth would be expected to have a signifi-cant effect on the anterior teeth. However, he alsoadded that tongue-thrust swallowing simply has too


short a duration to produce an impact on tooth posi-tion. This patient had only her mandibular anteriorteeth and no maxillary alveolar process, so the tonguecould also procline the mandibular anterior teeth. Fur-thermore, this patient had an acquired skeletal Class IIIrelationship.

Chincup therapy alters the direction of mandibulargrowth, rotates the chin down and back, and produceslingual tipping of the mandibular incisors as a result ofthe pressure of the appliance on the lower lip and den-tition. So chincup therapy was necessary for this growingClass III patient to correct the skeletal pattern andprevent labial movement of the mandibular anteriorteeth.8-13 The cephalometric superimposition showsthe effectiveness of the chincup at producingdownward and backward rotation of the mandible.Also, the superimposition shows how the mandibularincisors were uprighted to produce a normal incisorrelationship as well as the effects of the bone graft andthe autotransplantation on maintaining the position ofA-point. The ultimate goal of autotransplantation ingrowing patients is the potential of not onlymaintaining bone, but also creating new alveolar boneby periodontal ligament induction and tooth eruption.Autotransplantation in our patient was quite successful.

When all missing teeth are replaced with singleimplants, a significant esthetic problem will occur. If2 or more implants are placed next to each other, it isusually not possible to create a satisfactory gingivalpapilla between the implants, and an esthetic compro-mise must be accepted. A treatment principle to reducethis problem is to combine orthodontic space closureand autotransplantation.


Fig 11. Intraoral photograph after composite restorations.

Fig 10. Posttreatment facial and intraoral photographs.


Slagsvold and Bjercke14 developed a method of trans-planting teeth with partially formed roots. Aftertransplantation, root growth continues, and the teethmaintain their potential for functional adaptation sothat endodontic treatment is usually not necessary.Andresen et al15 reported that second premolars,canines,mandibularfirst premolars,maxillary second pre-molars, and small third molars are suitable for the maxil-lary central incisor region, because of their dimensions atthe cervical aspect of the graft. Furthermore, they recom-mended that transplantation should be performed whenthe root has three quarters to full root formation witha wide-open apex. At this stage of development, the graftis easy to remove, and periodontal and pulpal healing willbe predictable. The prognosis for complete periodontalhealing at this stage of root development is greater than90%.14,16 Patients suited for autotransplantation ofpremolars to the maxillary anterior region are between 9and 12 years of age; this corresponds with the period of


their most serious traumatic injuries. It is remarkablethat tooth transplants have the inherent potential forbone induction and reestablishment of a normalalveolar process.14

This Class III situation included mandibular ante-rior crowding that required uprighting of those teeth,so the mandibular first premolars required extraction.In this patient, the mandibular first premolars had half


Fig 13. Posttreatment radiographs: A, lateral cephalo-gram; B, panoramic radiograph.

Fig 14. Posttreatment cephalometric tracing.

Fig 12. Posttreatment dental casts.


of their root formation and wide-open root apicesthat had been developing beneath the deciduousteeth.


Experimental studies have shown that rigid splintingis detrimental to both pulpal and periodontal healing,and this procedure should be avoided.17 Andresenet al15 recommended placing a suture over the occlusalsurface of the graft to prevent vertical displacementduring healing after a single-tooth transplantation.However, in this patient, the missing span was too


Fig 15. Superimposition of the cephalometric tracingsbefore (black line) and after (red line) treatment.


long, and there were no abutments for temporary fixa-tion of the transplanted teeth. A tight ligated gingivalflap held both premolars at the maximum contour ofthe crown. Therefore, prompt fixation with bracketsand an orthodontic wire were required. The grafted alve-olar process did not have sufficient height to transplantthe premolars, so the autotransplanted teeth looked as ifthey were impacted. Slow extrusion of the premolarshelped to create the alveolar bone that was necessaryfor a normal overbite. Because the root of an autotrans-planted premolar continues to develop, a normal peri-odontal ligament is established, so that teeth can bemoved orthodontically like any other tooth that haserupted into occlusion.

Clinical studies have indicated that orthodontic treat-ment is possible 3 to 6 months after autotransplantationwithout significant risk of progressive resorption.18,19

However, this patient had lost 6 anterior teeth, sotemporary fixation after transplantation requiredbrackets and orthodontic wires. Light orthodontic forcewith a long interbracket distance produced a lightcontinuous extruding force on the autotransplantedpremolars. As a result, normal overjet and overbite wereobtained, and the alveolar bone volume was restored.Furthermore, the autotransplanted teeth maintainedtheir pulpal vitality. Finally, the transplanted premolar


crowns could be reshaped to resemble incisors withdirect composite resin buildup.

CONCLUSIONS

Autotransplantation of mandibular premolars is aneffective option for orthodontists to replace traumati-cally avulsed maxillary incisors. The best solution couldbe a combination of bone augmentation, premolarautotransplantation, direct composite buildup, andorthodontic space closure when all maxillary anteriorteeth are traumatically lost in young patients. Auto-transplantation is a biologic approach to tooth replace-ment; the transplanted tooth germ retains the potentialto induce alveolar bone growth and can prevent atrophyof the augmented bone.

REFERENCES

1. Malmgren O, Malmgren B. Orthodontic management of thetraumatized dentition. In: Andresen JO, Andresen FM,Andresen L, editors. Textbook and color atlas of traumatic injuriesto the teeth. 4th ed. Copenhagen, Denmark: Blackwell Munks-gaard; 2007. p. 669-715.

2. Hardwick JL, Newman PA. Some observations on the incidenceand emergency treatment of fractured permanent anterior teethof children. J Dent Res 1954;33:730.

3. Lewis TE. Incidence of fractured anterior teeth as related to theirprotrusion. Angle Orthod 1959;29:128-31.

4. Hallet GEM. Problems of common interest to the pedodontist andorthodontist with special reference to traumatized incisor cases.Eur J Orthod Soc Trans 1953;29:266-77.

5. O’Mullane DE. Some factors predisposing to injuries of per-manent incisors in school children. Br Dent J 1973;134:328-32.

6. J€arvinen S. Incisal overjet and traumatic injuries to upper perma-nent incisors. A retrospective study. Acta Odontol Scand 1978;36:359-62.

7. Proffit WR. The etiology of orthodontic problems. In: Profitt WR,Fields HW, editors. Contemporary orthodontics. 3rd ed. St Louis:Mosby: 1999. p. 113-44.

8. Sakamoto T, Iwase I, Uka A. A roentogeno-cephalometric study ofskeletal changes during and after chincup treatment. Am J Orthod1984;85:341-50.

9. Mitani H, Sakamoto T. Chin cap force to a growing mandible.long-term clinical reports. Angle Orthod 1984;54:93-122.

10. Irie M, Nakamura S. Orthopedic approach to severe skeletal Class IIImalocclusion. Am J Orthod 1975;67:377-92.

11. Mitani H, Fukazawa H. Effects of chincap force on the timing andamount of mandibular growth associated with anterior reversedocclusion (Class III malocclusion) during puberty. Am J OrthodDentofacial Orthop 1986;90:454-63.

12. Sugawara J, Asano T, Endo N, Mitani H. Long-term effectsof chin cap therapy on skeletal profile in mandibularprognathism. Am J Orthod Dentofacial Orthop 1990;98:127-33.

13. Asai Y. Growth changes of maxillofacial skeleton of Japanesefrom 12 to 20 years of age. A longitudinal study by means ofcephalometric roentgenograms. J Jpn Orthod Soc 1973;32:61-98.



14. Slagsvold O, Bjercke B. Applicability of autotransplantation in caseswith missing upper anterior teeth. Am J Orthod 1978;74:410-21.

15. Andresen JO, Andresen L, Tsukiboshi M. Autotransplantation ofteeth to the anterior region. In: Andresen JO, Andresen FM,Andresen L, editors. Textbook and color atlas of traumatic injuriesto the teeth. 4th ed. Copenhagen, Denmark: Blackwell Munks-gaard; 2007. p. 740-60.

16. KristersonL. Autotransplantationof humanpremolars. A clinical andradiographic study of 100 teeth. Int J Oral Surg 1985;14:200-13.


17. Bragger U, Lauchenewer D, Lang NP. Surgical lengthening of theclinical crown. J Clin Periodontol 1992;19:58-63.

18. Andresen JO, Paulsen HU, Yu Z, Schwartz O. A long term studyof 370 auto transplanted premolars. Part III. Periodontalhealing subsequent to transplantation. Eur J Orthod 1990;12:25-37.

19. Kristerson L, Lagerstr€om L. Autotransplantation of teeth in caseswith agenesis or traumatic loss of maxillary incisors. Eur J Orthod1991;13:486-92.


orthodontic reconstruction with autotransplantation and bone grafting after a traffic accident

Documents