three-yearfollow-upofapatientwithhemifacial ... · meanwhile, temporary skeletal anchorage devices...

CASE REPORT

Three-year follow-up of a patient with hemifacialmicrosomia treated with distraction osteogenesis,temporary anchorage devices, and orthodontics

Elie William AmmBeirut, Lebanon

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The purpose of this case report is to describe the treatment, including 3-year follow-up records, for a patient withhemifacial microsmia. Treatment included the unusual use of temporary anchorage devices to correct the cant ofthe occlusal plane. The advantages of distraction osteogenesis are discussed. The successful outcome de-pended on the collaboration of the orthodontist and the craniofacial surgeon. (Am J Orthod DentofacialOrthop 2012;142:115-28)

Hemifacial microsomia is a common birth defectinvolving first and second branchial arch deriva-tives. In addition to craniofacial anomalies, there

can be cardiac, vertebral, and central nervous system de-fects. Although most cases are sporadic and a few fam-ilies consistent with autosomal recessive inheritancehave been reported, other families clearly show autoso-mal dominant inheritance.1

Branchial arch dysplasia is characterized by underde-velopment of the ear, mandible, and contiguous bonystructures of the cranium and the face. Involvement isusually limited to 1 side of the face. The heterogeneousnature of this malformation results in inconsistent phe-notypic expressions and requires a variety of treatmentapproaches.

Conventionally, for patients with severe deformities,early surgical intervention with autogenous costochon-dral grafting is indicated. After pubertal growth, milddeformities can be corrected with orthodontic treat-ment, genioplasty, and unilateral mandibular augmen-tation, but more severe problems might requirebimaxillary surgery.2

Distraction osteogenesis has become an acceptedtreatment method for patients requiring mandibular

al assistant, Department of Orthodontics, School of Dental Medicine, Sainth University, Beirut, Lebanon.uthor reports no commercial, proprietary, or financial interest in the prod-r companies described in this article.t requests to: Elie William Amm, Maria Center, 1st floor, N. D. des Secourstal Rd, Jbeil, 4503-3003, Lebanon; e-mail, [email protected], February 2010; revised and accepted, August 2010.5406/$36.00ight � 2012 by the American Association of Orthodontists..1016/j.ajodo.2010.08.020

lengthening because of congenital malformations. Ina Web-based survey in Europe, although there was dis-agreement on the essential steps in the distraction pro-cedures, more than 80% of the respondents consideredpatients with hemifacial microsomia, cleft lip and palate,and Crouzon syndrome suitable for distraction osteo-genesis.3

Distraction osteogenesis was used as early as 1905 byCodivilla and later popularized by Ilizarov.4 Synder et al5

in 1973 and Michieli and Miotti6 in 1977 reported man-dibular lengthening by gradual distraction in animalmodels. In 1992, mandibular lengthening by distractionosteogenesis was used in a human mandible by McCar-thy et al7 in a patient with hemifacial microsomia; sincethen, it has been applied to the various bones of thecraniofacial skeleton. Molina and Ortiz Monasterio8

reported mandibular elongation by distraction as a fare-well to major osteotomies.

Meanwhile, temporary skeletal anchorage deviceshave also revolutionized the world of orthodontics sincetheir introduction in the anchorage armamentarium.Miniscrews allow the management of wider discrep-ancies than those treatable by conventional biomechan-ics because force can be applied directly from thebone-borne anchor unit.9 Therefore, miniscrews notonly free orthodontists from anchorage-demandingcases, but they also enable clinicians to have good con-trol over tooth movement in 3 dimensions.

This article presents the records of a patient withhemifacial microsmia treated with distraction osteogen-esis and orthodontics. The use of temporary skeletal an-chorage devices to save the patient an additionalmaxillary surgery is emphasized.

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Fig 1. Pretreatment extraoral and intraoral photographs.

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DIAGNOSIS AND ETIOLOGY

The patient was a 17-year-old Lebanese girl whoseprimary complaint was her asymmetrical appearance(Fig 1). She had hemifacial microsomia as part of a widermultiple Tessier cleft with a notch in her left nostril andupper eyelid coloboma. These could correspond toa mild Tessier cleft.4-9 Her hemifacial microsomia wasa Tessier cleft in his classification.7 Her face was asym-metrical, with an underdeveloped left side, a chin devia-tion toward the affected side, and a retrusive chin in theprofile view, along with lip incompetence. There was nohistory of craniofacial deformities in her family.

The intraoral examination showed frontal canting ofthe occlusal plane, mandibular midline deviation of 2mm to the right and a crossbite of the maxillary rightsecond premolar. There was extreme crown wear onthe mandibular right canine. The maxillary left first mo-lar was missing, and there were minor rotations in themaxillary and mandibular teeth. Moreover, she had anasymmetric sagittal occlusal relationship: complete ClassII malocclusion on the right and Class I on the left (Figs 1and 2).

The computed tomography scan confirmed the skel-etal components of this malformation and showed theanatomically different growth patterns between the

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left and right rami, along with deviation of menton(Fig 3).

The cephalometric analysis pointed to a skeletal ClassII relationship, with a hypodivergent pattern on the nor-mal side and a hyperdivergent pattern on the affectedside. The Z-angle indicated a convex profile with a retru-sive chin and a protrusive lower lip.

The posteroanterior cephalometric radiographshowed a deviated menton toward the affected side(midsagittal plane-Me, 16 mm to the left; midsagittalplane/Me, 8�) and canting of the occlusal plane(orbital plane/mandibular occlusal plane, 11�) (Figs 4and 5).

The panoramic radiograph illustrated the differencein ramus sizes between the left and right sides, as wellas a retained root fragment from the maxillary left firstmolar, and absence of the mandibular right third molar(Fig 6).

TREATMENT OBJECTIVES

1. Correct the facial asymmetry by lengthening theshorter ramus and moving the chin to the right side.

2. Correct the skeletal Class II relationship and improvethe profile.

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Fig 2. Pretreatment plaster models.

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3. Correct the canting of the occlusal plane and obtaina dental Class I relationship of the canines and mo-lars.

4. Close the space of the maxillary left first molar.

TREATMENT ALTERNATIVES

Based on the objectives, 3 treatment options wereproposed.

1. Combined orthodontic and surgical treatment withmaxillary clockwise frontal rotation and mandibularadvancement along with costochondral grafting toelongate the shorter ramus.

2. Combined orthodontic and surgical treatment withmaxillary clockwise frontal rotation and distractionosteogenesis to advance the mandible and elongatethe shorter ramus.

3. Combined orthodontic and distraction osteogenesistreatment without orthognathic surgery. The cantingof the maxillary occlusal plane after distraction os-teogenesis would be corrected with individual tootheruptions and temporary skeletal anchorage devices.

In all conditions, the patient was aware that somemi-nor refinements after her treatment could be needed forbetter results (ie, genioplasty and restorative buildup).

American Journal of Orthodontics and Dentofacial Orthoped

To decrease the number of surgeries and the require-ment for a large amount of mandibular and maxillarybone grafting, the third option was chosen.

TREATMENT PROGRESS

The active treatment was divided into 3 phases: pre-distraction, distraction and consolidation, and postdis-traction.

In the predistraction phase (Fig 7), standard edge-wise single brackets (0.022 in) were placed on the max-illary teeth first; bracketing of the mandibular teeth wasdelayed for 4 months to start the leveling with Class IIIelastics to maintain the mandibular incisor position af-ter leveling. The maxillary molars were bonded withbuccal tubes, and the mandibular second molars werebanded. The space of the maxillary left first molar wasclosed, and the mandibular and maxillary arches werealigned and leveled with a 0.020 3 0.025-in stainlesssteel ideal wire.

In the distraction and consolidation phase (Figs 8 and9), the patient was hospitalized, and surgery was per-formed under general anesthesia with nasal intubation.A horizontal ramus osteotomy was performed on theleft, at the level of the occlusal plane, and an angle os-teotomy was done on the right, both through intraoral

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Fig 3. Computed tomography scan showing the differences between the left and right sides.

Fig 4. Pretreatment lateral and anteroposterior x-rays.

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incisions. A Leibinger multi-guide, multi-vectorial exter-nal distractor (Stryker, Kalamazoo, Mich) was used toperform distraction osteogenesis along different vectors:


parallel to the posterior edge of the ramus on the left(“vertical vector” according to Grayson and Santiago10)and parallel to the occlusal plane (horizontal vector).


Fig 6. Pretreatment panoramic x-ray.

Fig 5. Pretreatment cephalometric analysis.

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The patient was advanced 18 mm along the ramus onthe left and 6 mm on the right.

A careful cleaning regimen was followed in which thepin tracks were cleansed with a dilute hydrogen peroxidesolution at least 4 times a day of any blood and serousdischarge. An antibiotic cream was also prescribed toprevent infection. After a latency period of 5 days, dis-traction commenced at a rate of 0.5 mm twice per day.This rate was continued for 18 days until the mandibularlength was overcorrected by several millimeters. At thattime, orthodontic intermaxillary elastics were used tomold the regenerating new bone and optimize theocclusion.

Dental impressions were taken, and a bite-blockwas placed in the surgically created posterior unilateralopen bite. The devices were left in place to serve asexternal fixators throughout the consolidation phasefor 12 weeks. The elastics and the bite-block contrib-uted also to this consolidation phase as internal fixa-tors while “molding the regenerate” as needed.11 Thedistraction devices were removed under minimal localanesthesia in the office. The pin track scars were al-lowed to heal secondarily, and they left minimal,point-like external scars. At the end of this phase,we were confronted with a posterior open bite onthe elongated side and a crossbite on the contralateralside.

In the postdistraction phase (Figs 10 and 11), levelingof the maxillary occlusal plane was initiated by allowingthe eruption of the ipsilateral maxillary teeth. The


biteplane was reduced first under the maxillary left sec-ond molar to allow its gradual eruption, and then thefirst and second premolars were erupted at 1 time. Afterposterior tooth eruption, sectional wires were hinged be-tween the right canine and lateral incisor, and verticaltraction was flanked by a mandibular miniscrew anda hook soldered between the left canine and lateral inci-sor. This system allowed quick en-masse correction ofthe canting of the maxillary occlusal plane. A continuousmaxillary wire was inserted, and seating the occlusionand finishing were the last stages.

Six months later, the facial and profile esthetics werereevaluated. A dermis-fat graft was performed to accentthe mandibular contour on the left; lipo filling was usedon the affected malar and submalar areas of her leftcheek, and a recentering genioplasty completed theactive treatment.


Fig 7. Predistraction lateral and panoramic x-rays and a mandibular superimposition showing the con-trolled mandibular incisor position.

Fig 8. Distraction and consolidation phase.

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After the removal of all appliances, a bonded 3-to-3mandibular lingual retainer was made as well as an invis-ible maxillary removable retainer. They would be usedconstantly for 3 months and then at night only.


TREATMENT RESULTS

The treatment objectives were obtained after 36months. The patient showed excellent compliance inwearing her intermaxillary elastics and maintaining


Fig 9. Distraction and consolidation phase on anteroposterior and panoramic x-rays.

Fig 10. Posterior leveling of the maxillary occlusal plane by tooth eruption.

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Fig 11. Anterior leveling of the maxillary occlusal plane by en-masse eruption with the help of a tempo-rary anchorage device.

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oral hygiene. She expressed satisfaction with her facialand profile appearances as well as her smile (Figs 12and 13).

The posttreatment extraoral photographs show a bal-anced and more symmetrical face. The profile is moreharmonious, with lip competence and a better chin-to-lip contour. The smile arc agrees with the lower lip andis horizontal with no more canting, and the left oralcommissure is leveled horizontally with the right one.

The intraoral photographs demonstrate good align-ment, but a midline discrepancy of 1 mm persists. Thereis an inclination difference between the left and rightmandibular canines and buccal segments; the rightside shows more lingual crown torque than the left side.

We achieved Class I canine and molar relationshipson the right side, but the left side is poorly seated


because of a dental Class III tendency after space closureof the maxillary left first molar.

The maxillary and mandibular arches were coordi-nated with correction of all rotations.

The patient was debonded prematurely, during thewar in June 2006; it was difficult to collect the final ra-diographs because she lived in a distant village. She re-turned 3 years later, just as we began working on thisreport, and new records were taken (Figs 14-17). Sheremained pleased with her appearance and smile.

Other than the mandibular right first premolars thathad moved buccally, her dentition was stable. The mid-line relapsed 1 mm. The cephalometric superimpositionshows the correction of the skeletal Class II relationshipand the improved mandibular angle on both sides. Theprofile was improved.


Fig 12. Posttreatment extraoral and intraoral photographs.

Fig 13. Posttreatment plaster models.

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Fig 14. Extraoral and intraoral 3-year follow-up photographs.

Fig 15. Plaster models at 3-year follow-up.

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Fig 16. Three-year follow-up lateral and anteroposterior x-rays.

Fig 17. Three-year follow-up cephalometric analysis.

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The overall superimposition illustrates the profilechanges and the influence of the residual growth. Thepalatal superimposition shows a labial inclination ofthe maxillary incisors, a stable vertical right first molar,and eruption of the left second molar in place of theleft first molar (Fig 18).


The anteroposterior radiograph demonstrates thecorrection of the occlusal plane, and the superimpositionon the orbital plane and the intersection with the mid-sagittal plane shows the improvement of the cantingof the occlusal plane and its stability after 3 years. Therelapse from the consolidation phase to 3 years after


Fig 18. Overall superimposition on sella-nasion and palatal superimposition.

Fig 19. Three-year follow-up panoramic x-ray.

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the treatment was 1� (orbital plane/mandibular occlusalplane) (Fig 16).

The posttreatment panoramic radiograph shows thenecessity to extract the mandibular left third molar. Italso shows the enhancement in the length of the left ra-mus and its stability (Fig 19).

DISCUSSION

The horizontal vs vertical placement of the distrac-tion device, originally believed to be the crucial determi-nant of force vectors during distraction, is only one ofmany forces affecting change in mandibular morphol-ogy. Specific methods of planning that fail to includeneuromuscular influences and externally exerted forces(eg, occlusion, orthodontic and orthopedic forces, dis-traction device adjustment, and so on) might not givepredictable and consistent results.12 The posterioropen bite on the distracted side and the crossbite onthe contralateral side are not unusual after the distrac-tion phase in patients with hemifacial microsomia, andthis represents a viable example of the variation be-tween the clinically observed vector and the plannedvector.10

If the distraction goal is purely vertical elongation ofthe ramus, this is best accomplished when the vector ofdistraction is perpendicular or acute to the patient's oc-clusal plane. If the distraction goal is purely sagittal ad-vancement of the mandibular body, this is best achieved


when the vector of distraction is parallel to the patient'socclusal plane, as was done on the right side of our pa-tient, although this might predispose her to early poste-rior occlusal interference. In most cases, however, if thedistraction goal is to achieve both ramus and bodylengthening, an oblique vector is used, similar to whatwe did on the left side of our patient.

Autorotation of the mandible usually transformssome vertical lengthening into horizontal advancement.This was achieved by placing the device parallel to theposterior border of the left ramus. In patients with severeramus deficiency, it might be necessary to producea more “true” vertical vector (ie, perpendicular to theFrankfort horizontal plane). Risk of airway compromise


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and difficult segment control are often associated withthis true vertical vector.

During the closing of the posterior open bite, themandibular occlusal plane must be maintained in theposition that was achieved through mandibular distrac-tion. Failure to do so could result in less than completecorrection of the occlusal cant. This occurs as both themaxillary and mandibular posterior dental segments un-dergo supereruption. Development of a maxillary andmandibular occlusal cant at this time constitutes den-toalveolar compensation of the corrected mandibularskeletal anatomy. Bimaxillary osteotomies, which wouldbe required to correct the occlusal asymmetry, would al-ter the position of the inferior border, reintroducingmandibular asymmetry. Carefully controlled closure ofthe open bite contributes to the stability of the surgicallycorrected mandibular position and might reduce theneed for future treatment.

These changes in dental occlusion are minimal inchildren because of rapid growth of the maxilla andcan be corrected easily with minor orthodontic treat-ment. To avoid this problem in adults with hemifacialmicrosmia, Molina13 advocated an incomplete LeFortI osteotomy simultaneously with the mandibular corti-cotomy. Intermaxillary fixation is placed on the fifthpostoperative day, and distraction is initiated. Othersuse an acrylic wafer that is reduced by 1 tooth ata time to allow serial eruption of the maxillary posteriordentition, in addition to elastic traction. In our case, weused the acrylic wafer, elastic traction, and a temporaryskeletal anchorage device to obtain more anchorageand en-masse movement; therefore, our techniqueconsumed less time than the conventional methods.This is a much less invasive method compared with bi-maxillary distraction, and it maintains the integrity ofthe mandibular occlusal plane. Moreover, it is safer, be-cause LeFort I distraction is sometimes associated withnonunion in the anterior nasomaxillary buttress. Allosteotomies were done intraorally, and the only resul-tant scars were pinpoint scars that were cosmeticallyacceptable.

Marquez et al14 and Iseri et al15 evaluated long-term follow-ups of mandibular lengthening by distrac-tion osteogenesis and demonstrated that the resultswere not stable; relapses occurred especially on theelongated sides. In our 3-year follow-up, the resultsof the distraction osteogenesis were reasonably stable.Their patients were growing children, whereas our pa-tient experienced negligible growth during and afterthe treatment.

The dental occlusion at the end of the treatmentshowed incongruent interdigitation of the posteriorteeth on the affected side. This could be due to the


tooth-size discrepancy created by the extraction of thefirst molar, the midline discrepancy, or the inherent in-stability of the newly erupted teeth and alveolar pro-cesses. An imperfect occlusion is not uncommon afterdistraction osteogenesis.

CONCLUSIONS

The orthodontist has a primary role in planning andexecuting treatment for patients undergoing distractionosteogenesis. Active orthodontic treatment is used be-fore, during, and after distraction. The type of orthodon-tic treatment used in conjunction with distraction canrange from standard orthodontic protocols to orthodon-tic and orthopedic manipulations that are designed toaddress the unique malocclusion resulting from distrac-tion osteogenesis. The use of temporary skeletal anchor-age devices to correct the cant of the maxillary occlusalplane saves time and preserves stability. Variations fromthe planned distraction path must be punctually notedand corrected so that the planned clinical outcome canbe achieved. Close follow-up and joint collaboration ofthe orthodontist and the craniofacial surgeon before,during, and after the distraction are required to givethe patient the best result.

Distraction osteogenesis achieves a superior skeleto-facial change compared with conventional orthognathicsurgery, because both bone and soft-tissue correctionsare accomplished simultaneously.

REFERENCES

1. McKusick VA. Hemifacial microsomia; HFM page [database on-line]. Available at: http://omim.org/entry/164210. Accessed onJune 21, 2009.

2. Yamashiro T, Takano-Yamamoto T, Takada K. Case report: dento-facial orthopedic and surgical orthodontic treatment in hemifacialmicrosomia. Angle Orthod 1997;67:463-6.

3. Nada RM, Sugar AW, Wijdeveld MG, Borstlap WA, Clauser L,Hoffmeister B, et al., Eurocran Distraction Osteogenesis Group.Current practice of distraction osteogenesis for craniofacial anom-alies in Europe: a web based survey. J Craniomaxillofac Surg 2009;38:83-9.

4. Ilizarov GA. The principles of the Ilizarov method. Bull Hosp Jt DisOrthop Inst 1988;48:1-11.

5. Snyder CC, Levine GA, Swanson HM, Browne EZ Jr. Mandibularlengthening by gradual distraction. Preliminary report. Plast Re-constr Surg 1973;51:506-8.

6. Michieli S, Miotti B. Lengthening of mandibular body by gradualsurgical-orthodontic distraction. J Oral Surg 1977;35:187-92.

7. McCarthy JG, Schreiber J, Karp N, Thorne CH, Grayson BH.Lengthening the humanmandible by gradual distraction. Plast Re-constr Surg 1992;89:1-8.

8. Molina F, Ortiz Monasterio F. Mandibular elongation and remod-eling by distraction: a farewell to major osteotomies. Plast Re-constr Surg 1995;96:825-40.

9. Leung MT, Lee TC, Rabie AB, Wong RW. Use of miniscrews andminiplates in orthodontics. J Oral Maxillofac Surg 2008;66:1461-6.


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10. Grayson BH, Santiago PE. Treatment planning and biomechanicsof distraction osteogenesis from an orthodontic perspective. SeminOrthod 1999;5:9-24.

11. Luchs JS, Stelnicki EJ, Rowe NM, Naijher NS, Grayson BH,McCarthy JG.Molding of the regenerate in mandibular distraction:part 1: laboratory study. J Craniofac Surg 2002;13:205-11.

12. Hanson PR, Melugin MB. Orthodontic management of the patientundergoing mandibular distraction osteogenesis. Semin Orthod1999;5:25-34.


13. Molina F. Combined maxillary and mandibular distraction osteo-genesis. Semin Orthod 1999;5:41-5.

14. Marquez IM, Fish LC, Stella JP. Two-year follow-up of distractionosteogenesis: its effect on mandibular ramus height in hemifacialmicrosomia. Am J Orthod Dentofacial Orthop 2000;117:130-9.

15. Iseri H, Kisnisci R, Altu�g-Atac AT. Ten-year follow-up of a patientwith hemifacial microsomia treated with distraction osteogenesisand orthodontics: an implant analysis. Am J Orthod DentofacialOrthop 2008;134:296-304.


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