Oral Abstract Session 5

MAXILLOFACIAL RECONSTRUCTION/ORTHOGNATHIC SURGERYFriday, September 12, 2003, 1:00 pm–4:48 pm

Tetrafocal Intraoral Bone Transport forMandibular ReconstructionCesar A. Guerrero, DDS, Santa Rosa MaxillofacialSurgery Center, Centro Integral #105, Santa Rosa,Caracas, 1061 Venezuela

Purpose: This retrospective study was performed toevaluate a multiple bone transport system designed topredictably and securely perform major reconstructionof the mandible, including the mandibular symphysealcurvature, using intraoral distraction osteogenesis.

Materials and Methods: Four patients (3 females and 1male) ages 27 to 72 years old (average 47) underwenttetrafocal distraction osteogenesis after major mandibu-lar resection including the complete symphyseal area, 2ameloblastomas (pleomorphic and follicular), 1 giantcell granuloma, and 1 odontogenic myxoma. All patientsunderwent partial mandibulectomy and reconstructionplate placement through the intraoral route, using trans-cutaneous screws. The internal distraction devices were30 mm long and were cut, bent and fixed over thereconstruction plate; a 7-day latency period was awaitedand 1 mm a day activation period followed. Once thetransported disc or bullet reached the symphyseal area,the major disc was divided in 2, one half was fixed to thereconstruction plate with bicortical 2.7 screws and anew distraction device was placed transversally in thesecond half, to travel from canine to canine area. Oncethe bony segment met, a docking site surgery was per-formed to unite the 2 segments, with adequate rigidity tothe reconstruction plate. A year later, dental implantswere inserted and dental rehabilitation was completed.

Results: All mandibles were reconstructed by intraoralbone transport, creating 12.5 to 16.3 cm of new bone tofinally allow dental implants placement and dental reha-bilitation. No infections, fractures, or nonunions wereseen. The patients were seen on a weekly basis for 3months and then every 30 days until completion of thetreatment.

Conclusions: This multiple bone transport system per-mits mandibular reconstruction for the very difficult clin-ical situation, with excellent results. The surgical tech-nique is sensitive, complicated, and requires an impor-tant dedication from the patient. New devices wouldimprove the surgical technique and patient’s comfort.

References

Guerrero CA, Bell WH, Gonzalez M, et al: Intraoral distraction osteo-genesis, bone transport, in Fonseca (ed): Oral and Maxillofacial Sur-gery. Philadelphia, PA, Saunders, 2000, p 343

Guerrero CA, Bell WH, Gonzalez M, et al: Maxillo-mandibular recon-

struction by intraoral bone transport, in Diner A (ed): InternationalCongress on Facial Distraction Processes. Paris, France/Bologna, Italy,Monduzzi Editore, 2001, p 569

One-Stage Immediate Loading ImplantSystem: Novum and ZygomaticusMarianela Gonzalez, DDS, MS, Santa Rosa MaxillofacialSurgery Center, Centro Integral #105, Santa Rosa,Caracas, 1061 Venezuela (Guerrero C; Dominguez E)

Problem: Patients with full edentulism represent achallenge to the surgeon in terms of aesthetics, function,treatment time, and cost. These problems have beenmanaged by the use of bone grafts, soft tissue augmen-tation and/or distraction osteogenesis. The use of thesetechniques has accomplished excellent clinical resultswith the inconvenience of long-term treatment time.The purpose of this clinical study was to present theresults using 1 stage immediate loading implant systems,Novum and Zygomaticus, for maxillary and mandibularreconstruction.

Patients and Methods: Twenty-four patients ranging inage from 24 to 80 were treated by 1 stage implantplacement and immediate loading (7 days). All patientswere screened to be free of maxillary sinus disease, andno sinus grafts were used. We preserved the maxillarysinus membrane intact, while in 2 patients the mem-brane was accidentally perforated, but no attempt toreconstruct it was intended. The maxilla treatment con-sisted of 1 or 2 zygomaticus fixtures on either side(ranging from 42.5 mm to 52 mm length) accompaniedby 2 or 4 conventional fixtures at the premaxilla area tocomply with the biomechanical concepts to distributethe functional load and prevent rotation. Intraoperativeimpressions of the final maxillary fixtures were taken asthe first step for the prosthetic treatment. For the man-dible the Novum system was used (5 mm � 13 mm),based on prefabricated components and precision place-ment of 3 single-stage fixtures using minimal tolerancedrill guides for exact positioning by Brånemark’s proto-col. All patients were followed from 3 to 30 months withclinical photographs, panoramic, lateral cephalic, andposteroanterior radiographs after the surgical andprosthodontic treatment.

Results: All patients received their prosthetic recon-struction recovering their function and aesthetics. With1 patient treated in the past with radiotherapy we hadthe necessity of bridging the 2 zygomas with a palatal bar

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for extra stabilization. This early report indicates a suc-cess rate of 100% of fixtures and fixed prostheses com-parable to that of the conventional bridge. Bone losspatterns seem to indicate the same kind of steady-statebone resolution occurs with the Novum that has beenthe benchmark of the original Brånemark fixed implantbridgework in the anterior mandible.

Conclusions: While this Novum and Zygomaticus fol-low-up period cannot be compared to the long-termdocumentation available for the conventional approach,these initial report of survival and sustained bone levelssupport the contention that the Novum and Zygomati-cus techniques should be and equally viable approach asa single-stage immediate loading systems. The fact thatthe fixture is anchored in both the maxilla and thezygoma further increases the strength of the anchorage.With immediate stabilization and prefabricated compo-nents, fewer implants are required. This, in turn, canlead to lower treatment cost and shorter treatment time.

References

Brånemark PI, Engstrand P, Ohrnell LO, et al: A new treatmentconcept for rehabilitation of the edentulous mandible: Preliminaryresults from a prospective clinical follow-up study. Clin Implant DentRel Res 2-16, 1999

Branemark P-I, Grondahl K, Worthington P: Osseointegration andAutogenous Onlay Bone Grafts: Recostruction of the Edentulous Atro-phic Maxilla. Illinois, Quintessence, 2001, pp 65-92

The Clinical Significance of SinusMembrane Perforation DuringAugmentation of the Maxillary SinusLeon Ardekian, DMD, Ben-Ami St. 21, AKKO, 21319Israel (Peled M; Tannyhill RJ)

Purpose: To assess the clinical significance of Shnide-rian membrane perforation during sinus augmentationand simultaneous placement of dental implants in theseverely atrophic posterior maxilla.

Materials and Methods: The study population con-sisted of patients who received sinus floor augmentationand simultaneous placement of dental implants. Thestudy group was divided into 2 subgroups: subgroup Iconsisted of patients in whom the sinus membrane wasperforated and obliterated with resorbable collagenmembrane during the procedure, and subgroup II,which consisted of patients whose Shniderian mem-brane was not perforated during the procedure. Thecumulative success rate of the implants and all compli-cations were analyzed.

Results: A total of 415 implants were placed in 110augmented maxillary sinuses. Patients were followedbetween 2 to 5 years after the placement of definitive

prosthesis. In 35 patients perforation of the sinus mem-brane was observed during the procedure (subgroup I).A total of 106 implants were placed in this group. Siximplants failed during the follow-up period. Only 1 com-plication was observed in this group. For the purpose ofthe study, 35 randomly chosen patients, sex and agematched, were analyzed (subgroup II). A total of 115implants were placed. Seven implants failed in thisgroup during the study period and no complicationswere observed. No statistically significant differenceswere found between the 2 groups.

Conclusion: Perforation of the sinus membrane duringsinus floor augmentation has no impact on the cumula-tive implant success rate and on the rate of complica-tions.

Funding Source: Institutional.

Implant Success in Radiated Mandiblesand Fibula FlapsValmont Desa, DDS, MD, 985180 Nebraska MedicalCenter, NE (Miloro M; Mehanna G)

Purpose: The success of osseointegrated implants inthe irradiated mandible with free flap reconstruction isvariable and there is little available data in the literature.The goal of this study is to evaluate implant success inmicrovascular fibula flaps and irradiated mandibles statuspost oral cancer resection.

Materials and Methods: The records of 30 patients thatunderwent resection and reconstruction of the mandiblefrom 1995 to 2002 were reviewed retrospectively. Theaverage time from fibula graft reconstruction to stage Iendosseous implant placement was 10.7 months (range:5 to 37 months). The number of implants placed was148 and was categorized into 4 groups: native mandiblenon-irradiated (MNI), native mandible irradiated (MI),fibula non-irradiated (FNI), and fibula irradiated (FI). Allexcept 7 patients received adjunctive tumorcidal dosesof radiation therapy (greater than 6,000 cGy). All radi-ated patients received 20 preoperative and 10 postoper-ative hyperbaric oxygen dives. The average time be-tween stage I and II implant procedures was 4 months.Approximately two-thirds of the patients underwent ves-tibuloplasty with split-thickness skin grafting or alloge-neic grafting at stage II. The follow-up ranged from 7 to82 months (mean 37.6 months).

Results: Implants were determined successful if therewas no radiographic evidence of peri-implant bone loss,and if the implants were clinically integrated at stage II.Sixteen of 148 implants failed, with an overall successrate of 89.19%. The success of implants in fibula graftswas 89.21% and the success in irradiated mandibles was87.18 % with the use of HBO therapy. Early failures were

Oral Abstract Session 5: Maxillofacial Reconstruction/Orthognathic Surgery

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