CASE REPORT

Orthognathic treatment with autotransplantationof a third molar

Sung-Hwan Choia and Chung-Ju Hwangb

Seoul, Korea

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Autotransplantation is an option for tooth replacement when a suitable tooth is available and anatomic circum-stances are favorable. This case report describes successful orthognathic treatment that was combined withautotransplantation of a maxillary third molar. A 20-year-old woman had mandibular protrusion and facial asym-metry. Five years previously, her mandibular right first molar had been extracted because of dental caries. Afterpreoperative orthodontic treatment, we performed a LeFort I procedure and a bilateral intraoral vertical ramusosteotomy to correct the patient's mandibular protrusion and facial asymmetry. During the postoperative ortho-dontic treatment, the maxillary left third molar was autotransplanted into the mandibular right first molar site. Thetotal treatment period was 24months. As a result of these therapeutic treatments, the patient's facial appearancewas improved, and an implant was unnecessary. The autotransplanted tooth effectively supported the adjacentteeth and maintained her chewing ability. (Am J Orthod Dentofacial Orthop 2013;144:737-47)

Teeth can be lost from periodontal disease, severecaries, agenesis, trauma, or endodontic failure.This problem can be treated in various ways,

including orthodontic space closure, fixed or removablepartial dentures, dental implants, or tooth autotrans-plantation. Among various treatment options, auto-transplantation can lead to shorter treatment timesand improved treatment results when a suitable toothis available and anatomic circumstances permit.

In 1950, Apfel1 and Miller2 first described the trans-plantation of immature third molars to first molar posi-tions. Since then, autotransplantation of immature thirdmolars has become a common procedure for replacingmissing teeth.3-5 Recently, several studies havereported that third molars with complete rootformation can also be used as donor teeth. Watanabeet al6 reported a survival rate of 86.8% over a meanobservation time of 9.2 years. Sugai et al7 reported an

the Department of Orthodontics, College of Dentistry, Yonsei University,, Korea.raduate student.ssor, Institute of Craniofacial Deformity Center.thors have completed and submitted the ICMJE Form for Disclosure oftial Conflicts of Interest, and none were reported.rted by the Institute of Craniofacial Deformity Center, College of Dentistry,i University, Seoul, Korea.ss correspondence to: Chung-JuHwang, Department of Orthodontics, Insti-f Craniofacial Deformity Center, College of Dentistry, Yonsei University, 134hon-dong, Seodaemun-gu, Seoul 120-752, Korea; e-mail, hwang@yuhs.ac.itted, September 2012; revised and accepted, December 2012.5406/$36.00ight � 2013 by the American Association of Orthodontists./dx.doi.org/10.1016/j.ajodo.2012.12.013

overall 5-year survival rate of 84%. Although the currentsuccess rates are lower than the rates with dental im-plants, autotransplanted teeth result in good utilizationand maintenance of alveolar bone and attached gingiva.Furthermore, they provide superior esthetic results, areless expense, and have the potential for orthodonticmovement.

This case report demonstrates a successful orthog-nathic treatment that included autotransplantation ofa maxillary left third molar in a patient with a missingmandibular right first molar, mandibular protrusion,and facial asymmetry.

DIAGONSIS AND ETIOLOGY

A 20-year-old woman visited the orthodontic depart-ment at Yonsei University Dental Hospital in Seoul,Korea. Her chief complaint was mandibular prognathismand facial asymmetry. On the pretreatment question-naire, the patient reported a strong desire to improveher facial appearance. She had received orthodonticcamouflage treatment because of an anterior crossbite3 years previously, and she had used a temporary dentureafter the extraction of her mandibular right first molarfrom dental caries 5 years previously. She had no seriousmedical history, and no habits were reported.

Pretreatment facial photographs showed a mandib-ular deviation toward the right, and the patient's eye-brows were at noticeably different levels. Her lips wereincompetent, and the incisor-stomion distance was 6.0mm (Figs 1-3). Intraorally, she exhibited an AngleClass III malocclusion on the left side and an unknown

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Fig 1. Pretreatment facial and intraoral photographs.

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molar relationship on the right side, caused by themissing mandibular first molar. The maxillary dentalmidline had a 1.0-mm deviation toward the left, andthe mandibular dental midline had a 1.0-mm deviationtoward the right. A lateral cephalometric analysisshowed an SNA of 86.9�, an SNB of 86.2�, and anANB of 0.7�. The mandibular plane angle was 35.3�,the ramus height was 58.3 mm, and the gonial anglewas large, at 134.3�.

The maxillary incisors were labially inclined at anangle of 128.0� toward the SN plane, and the mandib-ular incisors were lingually inclined at an angle of82.0� toward the mandibular plane. The lower lip wasprotrusive with respect to the E-line, and an acute naso-labial angle was noted. A posteroanterior cephalometricanalysis indicated that the maxillary molars hadextruded on the left side by 3.0 mm more than on theright side, and the chin was deviated by 5.0 mm towardthe right. A panoramic radiograph showed that all 4 thirdmolars had complete root formation and were fully

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erupted, and the periodontal tissues were healthy (Figs1 and 3, Table).

TREATMENT OBJECTIVES

Based on the cephalometric findings, this patient wasdiagnosed with mandibular protrusion and facialasymmetry. The following treatment objectives wereplanned.

1. Maxilla. A total impaction of the maxilla wasplanned to correct the canted occlusal plane andthe excessive display of gingivae and to createsagittal coordination with the mandible.

2. Mandible. We planned to set back the mandible tocorrect the prognathism and the midline deviation.In addition, rotation of the maxillomandibular com-plex would reshape the bilateral gonial anglebecause of the bony ledge.

3. Maxillary dentition. We planned to coordinate thefacial and maxillary dental midlines, relieve the

Journal of Orthodontics and Dentofacial Orthopedics

Fig 2. Pretreatment cast models.

Fig 3. Pretreatment cephalometric and panoramic radiographs.

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Table. Cephalometric analysis before and after treat-ment

Measurement NormPretreatment(19 y 8 mo)

Posttreatment(21 y 8 mo)

SkeletalSNA (�) 81.6 6 3.2 86.9 86.4SNB (�) 79.2 6 3.0 86.2 81.0ANB (�) 2.5 6 1.8 0.7 5.4SN-GoGn (�) 33.4 6 5.0 35.3 38.5Gonial angle (�) 118.6 6 5.8 134.3 146.7Ramus height (mm) 51.6 6 4.2 58.3 58.7Go-Me (mm) 76.0 6 4.0 85.3 66.5

Dental factorsU1-SN (�) 106.0 6 5.0 128 112.5U1-NA (�/mm) 24.0/6.0 35.4/12.1 25.5/4.6L1-NB (�/mm) 27.0/6.0 25.3/8.3 29.6/10.4L1-GoGn (�) 94.0 6 5.0 82 90.2

Soft tissuesNasolabial angle (�) 92.9 6 7.4 80 96E-line (mm) �1.0 6 2.0 �1.5 �2.8Upper lip/lower lip 1.0 6 2.0 3.2 �2.5

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proclined incisor position, and achieve an idealoverbite and overjet relationship.

4. Mandibular dentition. We planned to relieve thedental compensation by straightening the mandib-ular incisors to an upright position over basalbone; in addition, restoring the missing mandibularright first molar was expected to establish a stableocclusion.

TREATMENT ALTERNATIVES

One treatment option for correcting the skeletalproblems was single-jaw surgery, with only amandibularsetback. However, this would have compromised thefacial esthetics. The patient had maxillary occlusalcanting and excessive maxillary incisor exposure.A single-jaw surgery would not have fulfilled herexpectations.

Various treatment options for the missing mandib-ular right first molar were considered, including ortho-dontic space closure, a fixed or a removable partialdenture, a dental implant, and autotransplantation. Aremovable partial denture was not ideal because of thepatient's age; also, adjacent abutment tooth reductionwould have been necessary for placing a fixed partialdenture.

An orthodontic treatment approach, such as closingthe edentulous space left by the missing tooth, wouldhave been difficult and would have involved a longtreatment time because it would have required protract-ing the mandibular right second molar by approximately10 mm mesially. Furthermore, it was assumed that the

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antagonist tooth of the maxillary right second molarhad disappeared. In contrast, an implant or autotrans-plantation was considered advantageous because itcould improve the occlusion by prosthesis alone. Inthis patient, the maxillary left third molar had an appro-priate crown size, and we expected that root canal treat-ment would not be difficult because the root shape wasnot abnormal. The patient agreed to transplantation ofthe maxillary left third molar into the mandibular rightfirst molar space.

TREATMENT PROGRESS

The preoperative orthodontic preparation was per-formed with preadjusted 0.018-in edgewise appliances.Before the leveling and alignment procedures, themaxillary first premolars were extracted to decompen-sate the maxillary incisor inclination and to reducethe acute nasolabial angle. The extraction spaceswere closed in the maxillary arch with a 0.016 30.022-in stainless steel archwire and miniscrewanchorage. The mandibular incisors were decompen-sated labially, and the mandibular right second molarwas straightened to an upright position. The preopera-tive orthodontic treatment was completed in 16months and required 2 stainless steel surgical archwires(0.017 3 0.025 in) for the maxillary and mandibulararches (Fig 4).

The orthognathic surgery involved a 1-piece LeFort Iprocedure with a horseshoe osteotomy, with 4.5 mm ofanterior and posterior impaction. The maxillary left mo-lars were further impacted by about 3.0 mm to correctthe occlusal canting. Both sides of the mandible wereset back with a bilateral intraoral vertical ramus osteot-omy. This was performed to improve the mandibularprotrusion and establish an Angle Class I canine positionwith ideal overbite and overjet. The chin was reduced inheight by 2.0 mm and advanced by 4.0 mm with a gen-ioplasty. Additionally, the right parasymphyseal area wasshaved to shape the bony edges. After 2 jaw surgeries,the patient was placed in intermaxillary fixation for 2weeks. The surgical splint was wired to the maxillaryarch for 4 weeks. Four weeks after surgery, finishingwas performed with a maxillary 0.016 3 0.022-intitanium-molybdenum alloy and mandibular 0.016-instainless steel archwires.

At 20 months after treatment, the maxillary left thirdmolar was transplanted to the site of the mandibularright first molar. We prepared a model of the maxillaryleft third molar based on 3-dimensional data that wereconverted to a DICOM format file (Fig 5, B). Then a resinmodel tooth was prepared with computer-aided rapidprototyping (Fig 5, C). The mandibular right first molarsocket was prepared with a surgical round bur and

Journal of Orthodontics and Dentofacial Orthopedics

Fig 4. Presurgical facial and intraoral photographs.

Fig 5. Images of the maxillary left third molar:A, periapical radiograph taken immediately before trans-plantation;B, 3-dimensional reconstruction image;C, photographs of a computer-aided rapid prototyp-ical model made of resin (left) and the molar extracted for transplantation (right).

Choi and Hwang 741

saline-solution irrigation. To minimize trauma, themaxillary left third molar was extracted carefully. Toreduce the injury to the periodontal ligament, the toothwas wrapped in wet gauze, and an apicoectomy was per-formed with a diamond point. A cavity was formed forretrograde filling and filled with super-ethoxybenzoic

American Journal of Orthodontics and Dentofacial Orthoped

acid under a microscope. The donor tooth was rotatedand cut down to a mesiodistal width of 10 mm to fitthe recipient site. The transplant surgery took a totalof 22 minutes. The transplanted tooth was fixed in placeand splinted with a wire for 2 weeks, and any occlusalinterference was removed (Fig 6).

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Fig 6. Periapical radiographs of the transplanted tooth: A, immediately before transplantation;B, immediately after transplantation;C, 4 weeks after transplantation;D, 3months after transplantation.

Fig 7. Posttreatment facial and intraoral photographs.

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Fig 8. Posttreatment cast models.

Fig 9. Posttreatment cephalometric and panoramic radiographs.

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Fig 10. Changes in mandibular geometry: pretreatment (blue line) and posttreatment (red line) ceph-alometric tracings are superimposed on A, the sella-nasion plane; B, the palatal plane; and C, themandibular plane.

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The appliances were removed after 24 months ofactive treatment (Figs 7 and 8). Fixed lingual retainerswere bonded to the lingual surfaces of the anteriorteeth in both arches, and the mandibular right firstmolar was restored with resin. Maxillary and mandib-ular circumferential retainers were delivered withinstructions to use them for 24 hours per day for thenext 6 months.

TREATMENT RESULTS

The posttreatment photographs showed that facialsymmetry was achieved, and ideal occlusion was estab-lished with proper overjet and overbite. The maxillarydental midline coincided with the facial and mandibularmidlines. The superimposition of the cephalometric trac-ings showed that the anterior and posterior maxillaryteeth were moved upward, and the mandible had rotatedclockwise and was set back (Fig 10). The cephalometricchanges included an increase in the ANB angle. Themandibular incisor to mandibular plane angle increasedfrom 82.0� to 90.2�. The maxillary incisors were up-righted from 128� to 112.5� with respect to the SNplane. A considerable increase in the nasolabial anglewas observed. Maxillary incisor exposure was decreased

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at rest. The occlusion was finished to an Angle Class Icanine relationship (Figs 9 and 10, Table).

Periapical radiographs taken immediately aftertransplantation showed that the tooth was in a wideextraction socket (Fig 6, B). One week after the trans-plantation, percussion was negative, but the toothmobility was grade 2. One month after transplantation,the morphology of the transplanted tooth and the sur-rounding gingiva was similar to that of the adjacentteeth. However, bone induction was not observedaround the transplanted tooth, and the probing depthwas 6.0 mm in the mesiobuccal sulcus (Fig 6, C). Threemonths after the transplantation, the mobility of thetransplanted tooth had stabilized to grade 1, and theperiodontal condition was good. No pain, discomfort,or other side effects were noted. No pathologic radio-lucency or root resorption (like that reported byAndreasen et al8) was observed (Fig 6, D). At 1 year af-ter transplantation, radiography showed a continuousperiodontal space and normal lamina dura aroundthe transplanted tooth. The results were stable at 8months after debonding (1 year after autotransplanta-tion) (Figs 11 and 12). A 2-year periapical radiographof the autotransplanted tooth shows a successful,healthy situation (Fig 13).

Journal of Orthodontics and Dentofacial Orthopedics

Fig 11. Facial and intraoral photographs show treatment results at 8 months after debonding (1 yearafter autotransplantation).

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DISCUSSION

The decision for surgical orthodontic treatment forthis patient was based on the fact that her primaryconcern was her facial profile, particularly the lower thirdof her face. Her chin was deviated 5.0 mm toward theright, and this deviation was related to the cant of themaxillary occlusal plane. The maxillary molars on theleft side were extruded 3 mm more than on the rightside. Therefore, 2-jaw surgery, including correction ofthe maxillary occlusal plane, was chosen to meet herexpectations.

Before 2-jaw surgery, preoperative orthodontic treat-ment, including decompensation of the malocclusion, isnecessary. The dental decompensation we performedwas intended to retract the proclined maxillary incisorswith miniscrews to avoid losing anchorage and to pro-cline the retroclined mandibular incisors to a normalaxial inclination. Lack of optimal dental decompensa-tion compromises the quality and quantity of an

American Journal of Orthodontics and Dentofacial Orthoped

orthognathic correction. This patient's teeth weredecompensated by closing the residual space in themaxillary arch and leveling the mandibular arch. Thiswas achieved after 16 months.

To increase the success rate of autogenous toothtransplantation, the tooth to be transplanted shouldhave a healthy, vital periodontal membrane attached,and the root morphology should be simple.9 In addition,the recipient site should be free of infection; duringsurgery, the extraoral period should be short, and traumashould be minimized.10,11 In this patient, 3-dimensionalcomputed tomography data indicated that the rootshape of the maxillary left third molar was normal. Thetooth was wrapped with gauze soaked in sterile salinesolution during the preparation of the recipient site tomaintain the vitality of the periodontal ligamentattached to the transplanted tooth.

The probability of pulp healing is increased when thetooth to be transplanted has an immature root.

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Fig 12. Posttreatment cephalometric and panoramic radiographs at 8 months after debonding (1 yearafter autotransplantation).

Fig 13. A 2-year periapical radiograph of the autotrans-planted tooth.

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Conversely, the pulp of a completely mature toothcannot regenerate.5,10,12 In this patient, the tooth hadcomplete root formation; therefore, an apicoectomy

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with extraoral endodontic treatment was performed onthe maxillary left third molar. In most cases, a longtime is required to create a bone socket at the recipientsite after extracting the tooth to be transplantedbecause the socket must conform to the shape of theextracted tooth. In addition, while fitting the extractedtooth to the bone socket, the root surface might beinjured. To prevent injury, we prepared a resin modelof the donor tooth by computer prototyping. The useof a resin model could shorten the bone preparationtime, and injury to the root surface was avoided.

Tooth transplantation is judged to be successfulwhen the tooth is fixed in the socket without discomfort,chewing is satisfactory, the tooth is immobile, no path-ological conditions are detected radiographically, andthe sulcus depth, gingival contour, and gingival colorare normal.13 With autogenous tooth transplantation,long-term, firm fixation can have negative effects onhealing. In contrast, nonrigid fixation for 7 to 10 days

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stimulates the alveolar ligament cells and bone heal-ing.14,15 In our patient, fixation was removed after 2weeks, when all vertical mobility had disappeared.

This study showed that tooth autotransplantationwas an effective treatment option, combined with acomprehensive plan that included orthodontic and or-thognathic treatments. The alternative option wasplacement of dental implants, also a valid method. How-ever, this patient was 20 years old, and we expectedchanges in the jaws and teeth with aging and adultgrowth.16 In this patient, autotransplantation was theoptimal choice because autotransplanted teeth willerupt in concert with vertical changes in the alveolarbone because of the presence of a periodontal ligament.

CONCLUSIONS

This case report demonstrates that orthognathic sur-gery combined with autotransplantation of a third molarcan be an effective approach for patients with mandib-ular protrusion, facial asymmetry, and missing teeth.The therapeutic results showed improvement in thepatient's facial appearance, with no need for a dentalimplant. In addition, the autotransplanted tooth effec-tively supported the adjacent teeth and maintainedchewing ability. We recommend autotransplantationwhen a suitable tooth is available and anatomic circum-stances permit.

REFERENCES

1. Apfel H. Transplantation of the unerupted third molar tooth. OralSurg Oral Med Oral Pathol 1956;9:96-8.

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2. Miller HM. Transplantation and reimplantation of teeth. Oral SurgOral Med Oral Pathol 1956;9:84-95.

3. Galanter DR, Minami RT. The periodontal status of autograftedteeth. A pilot study of thirty-one cases. Oral Surg Oral Med OralPathol 1968;26:145-59.

4. Singh KK, Dudani IC. Autogenous transplantation of developingmandibular third molars. J Indian Dent Assoc 1970;42:199-212.

5. Lundberg T, Isaksson S. A clinical follow-up study of 278 auto-transplanted teeth. Br J Oral Maxillofac Surg 1996;34:181-5.

6. Watanabe Y, Mohri T, Takeyama M, Okiji T, Saito C, Saito I. Long-term observation of autotransplanted teeth with complete rootformation in orthodontic patients. Am J Orthod DentofacialOrthop 2010;138:720-6.

7. Sugai T, Yoshizawa M, Kobayashi T, Ono K, Takagi R, Kitamura N,et al. Clinical study on prognostic factors for autotransplantationof teeth with complete root formation. Int J Oral MaxillofacSurg 2010;39:1193-203.

8. Andreasen JO, Paulsen HU, Yu Z, Schwartz O. A long-term study of370 autotransplanted premolars. Part III. Periodontal healingsubsequent to transplantation. Eur J Orthod 1990;12:25-37.

9. Andreasen JO. Periodontal healing after replantation and auto-transplantation of incisors in monkeys. Int J Oral Surg 1981;10:54-61.

10. Schwartz O, Bergmann P, Klausen B. Autotransplantation ofhuman teeth. A life-table analysis of prognostic factors. Int JOral Surg 1985;14:245-58.

11. Smith JJ, Wayman BE. Successful autotransplantation. J Endod1987;13:77-80.

12. Tsukiboshi M. Autotransplantation of teeth: requirements for pre-dictable success. Dent Traumatol 2002;18:157-80.

13. Chamberlin JH, Goerig AC. Rationale for treatment and manage-ment of avulsed teeth. J Am Dent Assoc 1980;101:471-5.

14. Pogrel MA. Evaluation of over 400 autogenous tooth transplants.J Oral Maxillofac Surg 1987;45:205-11.

15. Sange S, Thilander B. Transalveolar transplantation of maxillarycanines. A follow-up study. Eur J Orthod 1990;12:140-7.

16. Behrents RG. The biological basis for understanding craniofacialgrowth during adulthood. Prog Clin Biol Res 1985;187:307-19.

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