Abstract

We report here a case of vertical alveolar distraction osteogenesis with many complications that required further surgical interventions. A 54-year-old man underwent mandibular resection followed by iliac bone grafting as the result of large mandibular odontogenic keratocyst. Eleven months later, alveolar vertical distraction osteogenesis was applied to the patient for prosthetic rehabilitation. Fracture of the basal bone occurred in the consolidation period, and the fracture was fixed by the titanium miniplate system. Radiographic examination after completion of distraction osteogenesis confirmed a radiolucent area in half of the distracted area between the basal bone and the transport segment, and when the distractor was removed the radiolucent area was filled with fibrous granulation tissue. The granulation tissue was removed and endosteal implants were inserted together with a bone graft. Ultimately, all implants were osseointegrated, and adequate esthetics and function of the implant-supported prosthesis were achieved.

CLINICALVERTICAL ALVEOLAR DISTRACTIONOSTEOGENESIS WITH COMPLICATIONS IN ARECONSTRUCTED MANDIBLEMasayuki Fukuda, DDS, PhDMitsuyoshi Iino, DDS, PhDTakayoshi Ohnuki, DDSHirokazu Nagai, DDS, PhDTetsu Takahashi, DDS, PhDKEY WORDSVertical distraction osteogenesisComplicationFractureInfectionEndosteal implantsMasayuki Fukuda, DDS, PhD, MitsuyoshiIino, DDS, PhD, Takayoshi Ohnuki, DDS,and Hirokazu Nagai, DDS, PhD, are withthe Division of Dentistry and Oral Surgery,Akita University School of Medicine, 1-1-1Hondo, Akita 010-8543, Japan. Addresscorrespondence to Dr Fukuda.Tetsu Takahashi, DDS, PhD, is with theSecond Department of Oral and MaxillofacialSurgery, Kyusyu Dental College, Kitakyusyu,Japan.We report here a case of vertical alveolar distraction osteogenesis with manycomplications that required further surgical interventions. A 54-year-old manunderwent mandibular resection followed by iliac bone grafting as the result oflarge mandibular odontogenic keratocyst. Eleven months later, alveolar verticaldistraction osteogenesis was applied to the patient for prosthetic rehabilitation.Fracture of the basal bone occurred in the consolidation period, and the fracturewas fixed by the titanium miniplate system. Radiographic examination aftercompletion of distraction osteogenesis confirmed a radiolucent area in half of thedistracted area between the basal bone and the transport segment, and when thedistractor was removed the radiolucent area was filled with fibrous granulationtissue. The granulation tissue was removed and endosteal implants were insertedtogether with a bone graft. Ultimately, all implants were osseointegrated, andadequate esthetics and function of the implant-supported prosthesis wereachieved.INTRODUCTIONistraction osteogenesishas been applied to themaxillofacial region.1-6Recently, vertical distractionosteogenesis hasbeen used in cases ofatrophic loss of bone volume in orderto improve alveolar bone height fordental implant placement.1,3-5 Althoughdistraction osteogenesis is a promisingmethod, it can have complications.7This report presents a case of intraoralvertical distraction osteogenesiswith complications for implant placementafter mandibular reconstruction.CASE REPORTA 54-year-old man was referred to ourdivision for swelling of the right mandible.A panoramic radiograph andcomputed tomography scan showed acystic radiolucency from the left canineto the right second molar region of themandible (Figure 1). Microscopic examinationof the biopsy specimenshowed odontogenic keratocyst of themandible. Under general anesthesia,mandibular segmental osteotomy wasperformed extraorally. Immediate reconstructionwith a titanium recon-Journal of Oral Implantology 185ALVEOLAR OSSEODISTRACTION WITH COMPLICATIONSFIGURES 1-5. FIGURE 1. Preoperative panoramic X-ray. FIGURE 2. Panoramic radiograph 11 months after reconstruction with titanium meshplate and particulate cancellous bone and marrow taken from the ilium. FIGURE 3. Panoramic radiograph immediately after the distractiondevice was fixed. FIGURE 4. Panoramic radiograph 3 weeks after distraction. A fracture was seen in the basal bone. FIGURE 5. Panoramicradiograph 9 months after distraction showing a radiolucent area between the transport segment and the basal bone.struction plate and a cortico-cancellousbone block from the ilium was alsoperformed simultaneously. Eightmonths later, radiographic examinationconfirmed severe resorption andpathologic fracture of the grafted bone.Therefore, a second reconstructionwith a titanium mesh plate and particulatecancellous bone and marrowfrom the ilium was performed to restorethe resorptive mandible. Elevenmonths later, the radiographic examinationrevealed the correct take of thegraft (Figure 2). The patient wished toundergo implant therapy. However,from a prosthetic point of view, a significantincrease in vertical intermaxillarydistance and the defect present on186 Vol. XXIX/No. Four/2003the alveolar ridge in the grafted areamade implant treatment difficult. Forthese reasons, correction of the alveolarbony defect was planned using distractionosteogenesis with an intraoral alveolarvertical distractor (MOD; GebruderMartin GmbH Co, Tuttlingen,Germany).The patient was put under generalanesthesia and, through both the extraoraland intraoral incision, careful subperiostealdissection was performed topreserve the lingual mucoperiosteum.The grafted bone was exposed, and thetitanium mesh plate and screws previouslyused for reconstruction wereremoved. The distraction device wasadjusted and preplated before osteotomy.A vertical osteotomy in the defi-cient part of the grafted bone was thenperformed with a reciprocating saw tocompletely separate the transport segmentfrom the basal bone. The distractiondevice was fixed to both the transportsegment and the basal bone (Figure3). The function of the distractorwas then checked for any bony interferences.The surgical incision wasclosed, leaving part of the distractorpassing through the intraoral incision.One week after surgery, distractionwas performed at a rate of 1.0 mm perday (0.5 mm in the morning and 0.5mm in the evening). The gain obtainedin 13 days was 13 mm in the verticaldirection with optimal correction of theFIGURES 6-10. FIGURE 6. Granulation tissue was seen in half of the distracted area. FIGURE 7. Histologic specimen (hematoxylin-eosin stain)obtained from the ossification area in half of the distracted area. Mature bone consisting of lamellae was observed. FIGURE 8. Histologicspecimen (hematoxylin-eosin stain) obtained from the granulation (radiolucent) area in half of the distracted area. Fibrous tissue wasobserved. FIGURE 9. Panoramic radiograph 1 year after final prosthetic rehabilitation. FIGURE 10. Intraoral view after final prostheticrehabilitation.deficient area. Three weeks after distraction,a panoramic radiographshowed a fracture in the basal bone,and the fracture was fixed by the titaniumminiplate system (Figure 4). Radiographicexamination at 9 monthsconfirmed a radiolucent area in half ofthe distracted area between the 2 segments(Figure 5).The distractor was removed, andMasayuki Fukuda et algood ossification was recognized inhalf of the distracted area, but the radiolucentarea was filled with granulationtissue (Figures 6-8). The granulationtissue was removed, and 5Journal of Oral Implantology 187ALVEOLAR OSSEODISTRACTION WITH COMPLICATIONSscrew-type 17 mm long dental implants(Astra Tech AB, Goteborg, Sweden)were inserted, 4 in the distractedarea and the other in the existing bone.Cancellous bone chips obtained fromthe mandibular ramus were grafted tothe bone defect that was filled withgranulation tissue. Primary stability ofall implants was achieved. Fourmonths later, the implants were uncoveredand abutments installed for finalprosthesis. All implants were osseointegrated,and adequate aesthetics andfunction of the implant-supportedprosthesis was completed (Figures 9and 10). Two years after implant insertion,the implant-supported prosthesiswas stable, and there are no clinical orradiographic signs of recurrence andbone loss around the implants.DISCUSSIONA vertically deficient alveolar ridge ofthe mandible limits the placement ofendosteal dental implants. To resolvethis problem, 2 main solutions havebeen proposed: onlay grafts using autogenousbone, and guided bone regeneration(GBR) with semipermeablebarriers.3,4 However, autogenous bonegrafts increase patient morbidity, andGBR may result in unpredictable boneformation or infection from membraneexposure.Recently, distraction osteogenesishas been applied to alveolar ridge augmentation.1,3-5 This procedure has 2 advantages:no need for additional bonegraft or GBR, and simultaneous lengtheningof the surrounding soft tissues.The disadvantages, however, include along treatment period and danger ofinfection.8 On the other hand, somecomplications have also been reported:fracture of the transport segment, dif-ficulties in finishing the osteotomy onthe lingual side, excessive length of the188 Vol. XXIX/No. Four/2003threaded rod, incorrect direction ofdistraction, perforation of the mucosaby the transport segment, suture dehiscence,and bone formation defects.However, Garcia et al.7 reported thatmost of these complications could beconsidered minor and were readilyavoided or resolved by the use of appropriateprocedures.In this case, fracture of the basalbone occurred in the postdistractionperiod. This complication was consideredas an operative complication bythe surgeon or weakness of the boneproperty. In either case, this complicationmust be avoided by a precise procedure.A radiolucent image was stillseen at 9 months after distraction inhalf of the distracted area, and whenthe distractor was removed granulationtissue was recognized in that area. Thegranulation tissue may be caused byinfection through the portion of thedistractor, which was exposed to theoral cavity. This complication might beavoided by a slower distraction rateand/or additional membrane techniques.5,7 Fortunately, all implants wereosseointegrated and prosthetic rehabilitationwas achieved. However, manysurgical interventions imposed a severeburden on the patient.Distraction osteogenesis will likelybecome more useful in oral and maxillofacialsurgery. In our limited experience,however, vertical distraction osteogenesisfor implant placement appearedto have serious risks and notminor complications in a reconstructedbone. Ultimately, most complicationswere solved by continual efforts in thiscase. Therefore, further study might beneeded to determine the applicationsand limitations of vertical alveolar destructionosteogenesis for implantplacement in a reconstructed bone.REFERENCES1. Chin M, Toth BA. Distraction osteogenesisin maxillofacial surgery usinginternal devices: review of five cases.J Oral Maxillofac Surg. 1996;54:45-52.2. Block MS, Chang A, CrawfordC. Mandibular alveolar ridge augmentationin the dog using distraction osteogenesis.J Oral Maxillofac Surg. 1996;54:309-314.3. Chiapasco M, Brusati R, GaliotoS. Distraction osteogenesis of a fibularrevascularized flap for improvement oforal implant positioning in a tumor patient:a case report. J Oral MaxillofacSurg. 2000;58:1434-1440.4. Chiapasco M, Romeo E, VogelG. Vertical distraction osteogenesis ofedentulous ridges for improvement oforal implant positioning: a clinical reportof preliminary results. Int J OralMaxillofac Implants. 2001;16:43-51.5. Klug CN, Millesi-Schobel GA,Millesi W, Watzinger F, Ewers R. Preprostheticvertical distraction osteogenesisof the mandible using an Lshapedosteotomy and titanium membranesfor guided bone regeneration. JOral Maxillofac Surg. 2001;59:1302-1308.6. Takahashi T, Fukuda M, Aiba T,Funaki K, Ohnuki T, Kondoh T. Distractionosteogenesis for reconstructionafter mandibular segmental resection.Oral Surg Oral Med Oral Pathol Oral RadiolEndod. 2002;93:21-26.7. Garcia AG, Martin MS, Vila PG,Maceiras JL. Minor complications arisingin alveolar distraction osteogenesis.J Oral Maxillofac Surg. 2002;60:496-501.8. Oda T, Sawaki Y, Ueda M. Experimentalalveolar ridge augmentationby distraction osteogenesis usinga simple device that permits secondaryimplant placement. Int J Oral MaxillofacImplants. 2000;15:95-102.