Cortical Tenting Grafting Technique in theSeverely Atrophic Alveolar Ridge for

Implant Site Preparation

Bach Le, DDS, MD,* Jeffrey Burstein, DDS, MD,† and P. Parish Sedghizadeh, DDS, MS‡

Alveolar ridge augmentation us-ing autogenous block grafts isa predictable method to aug-

ment localized alveolar ridge defectsfor implant placement. Large atrophicedentulous segments present a morechallenging scenario in reconstruction,because there is a limited supply ofintraoral donor bone. Extraoral donorsites are an option, but present an ob-stacle to patient treatment acceptabil-ity because of increased costs andmorbidity. The purpose of this casestudy was to evaluate the effectivenessof using particulate human mineral-ized allograft in combination with anintraoral cortical block graft, in a“tenting” fashion, to augment large in-traoral alveolar ridge defects for im-plant placement.

Many authors have reported onthe use of autogenous bone,1–11 allo-grafts,12,13 xenografts,14 –16 and allo-plastic17,18 onlay grafts to augment thewidth of the atrophic ridge for place-ment and successful integration of en-dosseous implants. Autogenous bone,considered to be the gold standard forgrafting hard-tissue defects, can beclassified by its embryologic origin.Membranous bones, including the cal-varium, ramus, and symphysis, areformed by intramembranous ossifica-tion. This process involves embryonic

mesenchymal cells differentiating intoosteoblasts, which can synthesize anosteoid matrix that mineralizes to form

hard bone. Bone is also formed byendochondral ossification of cartilageat the epiphyseal surface of long

*Assistant Clinical Professor, Department of Oral andMaxillofacial Surgery, USC School of Dentistry, Los Angeles,CA.†Former Chief Resident, Department of Oral and MaxillofacialSurgery, USC School of Dentistry, Los Angeles, CA.‡Assistant Clinical Professor, Division of Diagnostic Sciences,Oral and Maxillofacial Pathology, USC School of Dentistry, LosAngeles, CA.

ISSN 1056-6163/08/01701-040Implant DentistryVolume 17 • Number 1Copyright © 2008 by Lippincott Williams & Wilkins

DOI: 10.1097/ID.0b013e318166d503

Objectives: Alveolar ridge aug-mentation using intraoral autogenousblock grafts to augment localized al-veolar ridge defects before implantplacement is a predictable method.However, large severely atrophicedentulous segments may require ex-traoral donor sites. The purpose ofthis study was to evaluate the effec-tiveness of using intraoral corticalblock grafts in combination with par-ticulate human mineralized allograft,in a “tenting” fashion, to augmentlarge atrophic alveolar ridge defectsfor implant placement.

Materials: This prospective casestudy evaluated augmentation in 10consecutive patients with severelyresorbed alveolar ridges missing aminimum of 4 adjacent teeth. Beforeaugmentation, all grafted sites weredeemed inadequate for placement of astandard 4-mm-diameter implant.Horizontal ridge augmentation wasperformed using autologous membra-nous cortical bone grafts from an oraldonor site to tent out the soft tissuematrix and periosteum for the adja-cent particulate allograft. The ridgeswere clinically evaluated 4 to 5months after augmentation, and 42implants were placed at that time.

Results: Implants were success-fully placed at all grafted sites 4 to 5months after the original graft date.Clinical evaluation of the grafted sites

upon re-entry revealed uniform ridgeanatomy. All edentulous segments hadat least 2 implants placed of at least4.0 mm diameter. In all, 42 implantswere placed into grafted sites in the 10patients. Implants were checked forosseointegration by using a countertorque of 35 N�cm. One implant failedto integrate. Mean follow-up was 22months after implant placement. Allaugmented ridges had retained theirfunctional and esthetic integrity at 1year after original augmentation.

Conclusion: Tenting of the peri-osteum and soft tissue matrix using acortical bone block maintains spaceand minimizes resorption of the par-ticulate allograft volume. In addition,bridging the cortical blocks with par-ticulate bone avoids unaesthetic ridgedefects between cortical block graftsin larger ridge defects. The result wasa more uniform and esthetic alveolarridge, capable of maintaining animplant-supported prosthesis. Thetechnique offers predictable functionaland esthetic reconstruction of large-volume defects without extensiveamounts of autogenous bone. This of-fers a superior functional and estheticresult than with either cortical or par-ticulate grafting alone. (Implant Dent2008;17:40–50)Key Words: bone graft, large-volumedefect, tent-pole

40 TENTING GRAFTING TECHNIQUE FOR IMPLANT SITE PREPARATION

bones. Two examples of endochondralbones used for intraoral grafting arethe iliac crest and tibial plateau.

In reviewing the literature on graftsurvival,19,20 it can be found that mem-branous bone grafts had retainedgreater than 80% of their original vol-ume and had been replaced by newbone whereas iliac (endochondral)bone had undergone 65% to 88% re-sorption. In addition to the higher re-sorption rate of iliac crest grafts, otherdisadvantages include the high costsof hospitalization, risk of general an-esthesia, and morbidity of the proce-dure.4,7,21 Conversely, mandibularsymphysis and ramus bone seem toundergo less resorption because of thethick cortical layer and their rigidstructure.4,7,22 Other advantages of in-traoral donor sites include conven-tional access for surgeons familiarwith intraoral anatomy, reduced anes-thesia and operative time because ofclose proximity of donor and recipientsites, and no cutaneous scars.22–24 Itcan be done ideally as an outpatientsurgery, thereby decreasing the overallcosts of the procedure.

In addition to obtaining an optimalbone source for grafting, it is critical toadhere to surgical principles for predict-able success. These include primarytension-free wound closure, promotingangiogenesis by perforating the corticalgraft site, and rigidly fixating the blockgraft for stability. In addition, creatingadequate space for bone regeneration bysurgically expanding the soft tissue ma-trix can help prevent resorption of thegraft material.25

To reconstruct large edentulousdefects there is only a limited amountof intraoral bone available for graft-ing. Block and Degen13 have reportedon the use of particulate allograftalone to successfully augment par-tially edentulous segments for implantplacement through a minimally inva-sive tunneling technique. However,the high resorption rates associatedwith this technique are likely becauseof natural tissue contraction. Further-more, graft migration is a potentialproblem because retention of the par-ticulate graft is difficult, particularlyin the anterior maxilla, where there isno bony shelf to maintain the graftmaterial. In addition, direct visualiza-tion of the defect, especially in the

esthetic areas, can be challenging withthis tunneling technique. Using an openapproach in the severely resorbed max-illa makes it possible to place the boneexactly where it is needed with lesschance of migration.

A major limitation to reconstruct-ing large-volume bone defects is thecontraction of the “soft tissue matrix,”leading to resorption of the bone graft.Surgical control of the expanded softtissue volume prevents resorption ofgraft material9 by maintaining a spacebetween the periosteum and bone. Inour cases, the cortical block graftsserve as a tenting mechanism for sep-arating the periosteum and overlyinggingiva from the underlying nativebone. The slow resorption of the cor-tical membranous block is ideal formaintaining the ridge contour. Thisprovides space for human mineralizedparticulate allograft (Puros; ZimmerDental, Carlsbad, CA) to act as anosteoconductive scaffold for new boneformation between the cortical blocks.This concept makes it possible to graftlarge segments without the need toharvest bone from extraoral sites.

The hypothesis we evaluated waswhether minimal autogenous intraoralcortical block grafts interposed withhuman mineralized bone could beused to restore large-volume defectsresulting in sufficient bone quantityand quality after 4 months to allow forsubsequent osseointegration of endos-seous implants.

MATERIALS AND METHODS

Patients selected for this procedurehad less than 4 mm of bone width de-termined by preoperative examinationand imaging studies and were missing aminimum of 4 consecutive teeth in-volved in the grafted segments. Beforeridge augmentation, all ridges were toonarrow for placement of a 3.3-mm im-plant. All patients had adequate verticalheight for implant placement and wereconsidered healthy for outpatient gen-eral anesthesia. Smokers, patients withdiabetes, and any medically compro-mised patients were excluded from thisseries. After prosthodontic consultationfor implant restorations, patients werescheduled for bone grafting procedures.

Topical anesthesia was placedover the edentulous ridge and up to 9

mL of 2% lidocaine with 1:100,000epinephrine was given as blocks andinfiltrations in the maxilla and mandi-ble. To access the thin maxillary ridge,a crestal incision with vertical releaseswere used in the posterior as necessary(Figs. 1, A; 2, A; and 3, A). In theanterior maxilla, subperiosteal dissec-tion was carried up to the anterior na-sal spine to obtain adequate release forpassive primary closure.

To access the mandibular ramus,incisions along the oblique ridgehelped gain adequate exposure. Inlarge edentulous segments, multiplegrafts were taken sequentially fromonly one side of the mandibular ra-mus. The grafts were adapted to theridge (Figs. 1, B; 2, B; and 3, B) andseparated by 1 cm with particulate hu-man mineralized allograft material(Puros) with a 500-�m particle size.The particulate graft was compressedfirmly between the cortical grafts to

Fig. 1. (A) Preoperative Defect. (B) Particulateallograft adapted between cortical block graftwhich are place 1.5 cm apart. (C) Good in-corporation of particulate graft and corticalonlay grafts resulting in uniform alveolar ridge4 months postoperatively.

IMPLANT DENTISTRY / VOLUME 17, NUMBER 1 2008 41

form a compact and dense graft heldby a coagulum of the patient’s blood.The defect was overcorrected withparticulate material in anticipation offuture graft resorption. A resorbablemembrane (Ossix Plus; OraPharma,Warminster, PA) was carefully placedover all grafted sites. Primary closureover the entire graft was obtained withinterrupted resorbable sutures.

Postoperatively, all patients wereinstructed on a soft diet, and the pa-tient prosthesis was adjusted to avoidimpingement on the grafted site, and,when possible, to create positive tissuearchitecture. All patients were placedon postoperative antibiotics of penicil-

lin 500 mg for 7 days (for penicillinallergic, clindamycin 300 mg for 7days) and a chlorhexidine mouth rinsefor 1 week. After 4 to 6 months, thegrafted sites were uncovered (Figs. 1,C and 2, C) and screws removed. Atotal of 42 implants were placed inpatients with a mean age of 49.9 years(range, 32– 68 years) with a meanfollow-up of 14 months (range, 6–24months). Thirty-five implants wereplaced (Fig. 3, C) in cortical graftedareas and the remaining 7 were placedinto particulate grafted areas (Puros).A total of 31 implants were placed asa single-stage protocol and 11 wereplaced as a 2-stage protocol. Eight im-

plants were Biomet3i (Palm BeachGardens, FL) and 34 were Straumannimplants (Straumann, Basel, Switzer-land). All implants were allowed awaiting period of 4 months before therestorative phase began. Implant inte-gration was confirmed by successfulcounter torque test of 35 N�cm. Pre-and postoperative defects were evalu-ated at both the bony and soft tissuelevels (Fig. 2, D and E). Additionalallograft material was added to im-prove the final bone- and soft-tissuecontours as necessary to affect estheticoutcome.

RESULTS

Ten (4 men and 6 women) con-secutive patients with severe alveolarridge atrophy underwent surgery (Ta-ble 1). The mean age of patients was49.9 years (range, 32–68 years). Ninepatients had grafts placed to the max-illa and 1 patient had grafts to augmenta partially edentulous posterior man-dible. Of the 9 patients with grafts tothe maxilla, 5 were completely eden-tulous with severe resorption of themaxillary alveolar ridge. In all cases,adequate tension-free closure over thegraft was achieved, and the incisionshealed uneventfully. There were nopostoperative wound infections. At the2-month follow-up check all ridgeswere firm to palpation, and at 4 to 5months after ridge augmentation, afull-thickness periosteal reflection wasused to expose the reconstructed alve-

Fig. 2. (A) Large alveolar ridge defect with im-mediate implant placed at #7. (B) Particulateonlay graft placed around cortical block graftto “tent” periosteum to prevent resorption. (C)Implants placement surgery at 4 months. (D)Before. (E) After.

Fig. 3. (A) Severely resorbed knife-edge ridge. (B) Mineralize particulate bone used to bridgecortical bone grafts. (C) Implants placement at 4 months. (D) Implants 3 months after place-ment with thick uniform alveolar ridge.

42 TENTING GRAFTING TECHNIQUE FOR IMPLANT SITE PREPARATION

olar ridge. All screws were removed,and the ridge width was clinicallyevaluated to be larger than 6 mm at allsites of implant placement. A total of42 implants were placed into thegrafted ridges at locations determinedby the restoring dentists preopera-tively. Thirty-eight implants wereplaced in the maxilla and 4 wereplaced in the mandible. Thirty-sevenimplants were placed using a single-stage protocol. Only 5 implants re-quired uncovering. After 3 to 4months of integration, all implantswere tested for integration by success-ful resistance to a counter torque of 35N�cm. One implant placed in the par-ticulate grafted region failed to inte-grate and was successfully replaced inan adjacent site. Thirty-five implantshave been successfully restored in 8patients with a mean follow-up of 22months (range, 14–32 months) fromplacement. The remaining 2 patientsare currently undergoing restorativetreatment. Follow-up examinations

have indicated stable and healthy peri-implant tissue and bone levels.

The specimen harvested from theparticulate graft consisted of dense vi-able bone, which could be classified astype 1 or type 2 bone (Figs. 1, C and 2,C). The osseous tissue has been depos-ited in a lamellar fashion and exhibitsosteocytes within lacunae. Thetrichrome stain (Fig. 4A) shows nicebone reversal lines indicating activeremodeling.

DISCUSSION

Many authors have reported onthe use of autogenous bone grafts1–11

to restore bony defects and allow forthe correct positioning of implants.However, when treating the severelyatrophic alveolar ridge, it is commonto encounter large-volume defects thatmust be fully reconstructed to createan esthetic and functional result. Withthese large-volume defects, it has beennecessary to obtain bone from ex-traoral sources. The authors prefer in-traoral membranous donor bone overendochondral extraoral sites becauseof the increased resorption, high cost,and increased morbidity of the lat-ter.4,19,20,21 In addition, we have foundthat by appropriately spacing autoge-nous cortical block grafts, interposedby particulate graft, it is possible toaugment a large, severely atrophicridge with less need for autogenousbone. This technique involves expand-ing the soft tissue volume and usingthe cortical bone grafts as “corticaltent poles” for the surrounding partic-ulate graft. This helps prevent the soft

tissues from contracting around theparticulate graft, and subsequently,displacing it or causing physiologicresorption.9 This soft tissue mainte-nance concept was confirmed by theclinical observation that the particulatebone graft material resorbed no furtherthan the level of the cortical bonegrafts (Figs. 1, C and 2, C). Althoughlonger follow-up is needed to evaluatewhether this is a permanent result, ourshort-term outcome demonstrates im-proved esthetic and functional results.

In addition to restoring the hardtissue defect, the particulate bone pre-serves and augments the soft tissuearchitecture that was lost to years ofresorption. This allows an option forimplant placement and creates a betteresthetic result. Soft-tissue contour typ-ically follows underlying bony archi-tecture. Any ridge augmentationthrough bone grafting must providethe foundation to reconstruct the hardtissue defects to affect the soft tissuearchitecture.

In this series of patients, 41 of 42implants (97.6%) placed integrated.The 1 implant that failed to integratewas placed in the posterior maxilla ina completely edentulous patient whoalso underwent a simultaneous maxil-lary sinus lift procedure. This implantwas eventually replaced successfullyin an adjacent site.

Postoperative wound infection ordehiscence was not observed in thispatient series. This can be attributed tothe meticulous reflection of tissueflaps and a tension-free closure. Thiswas achieved by releasing the perios-

Fig. 4. Trichrome stain shows nice bone re-versal lines.

Table 1. Patient Demographic Characteristics

Patient No.Patient Age

(y)*/Sex Diagnosis Sites of Implant Placement

Follow-up (TimeFrom Initial

Grafting) (mo)†

1 63/Female Complete edentulism 3, 5, 7, 10, 12, 14 322 52/Male Partial edentulism 18, 19, 20, 21 323 33/Male Partial edentulism 12, 13, 14, 15 264 53/Male Complete edentulism 3, 5, 7, 10, 12, 14 225 32/Female Partial edentulism 6, 7, 10 206 38/Female Partial edentulism 10, 12, 13, 14 207 62/Female Complete edentulism 5, 7, 10, 12 198 68/Female Complete edentulism 5, 7, 10, 12 199 34/Male Partial edentulism 6, 7, 10 16

10 64/Female Complete edentulism 5, 7, 10, 12 14Total no. implants was 42.

* Mean age 49.9 years (range, 32–68 years).

† Mean follow-up time 22 months (range, 14–32 months).

IMPLANT DENTISTRY / VOLUME 17, NUMBER 1 2008 43

teal flaps from the nasal spine in ad-dition to scoring the periosteum in allmaxillary cases. The author finds thisstep to be critical in avoiding wounddehiscence and subsequent graftresorption.

CONCLUSION

In our small patient series, this tech-nique has allowed us to restore large-tissue defects in a predictable manner.Long-term follow-up is needed to eval-uate the stability of graft retention, es-pecially in the particulate grafted area.Our preliminary report indicates that us-ing this technique allows for the suc-cessful reconstruction of large defects inthe patients selected.

Disclosure

The authors claim to have no fi-nancial interest, directly or indirectly,in any entity that is commercially re-lated to the products mentioned in thisarticle.

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Reprint requests and correspondence to:Bach Le, DDS, MDOral and Maxillofacial SurgeryUSC School of Dentistry/LA CountyMedical Center2010 Zonal Ave.Los Angeles, CA 90089Phone: (323)-226-5013Fax: 323-226-5241E-mail: burstein@usc.edu orleb97201@yahoo.com

44 TENTING GRAFTING TECHNIQUE FOR IMPLANT SITE PREPARATION

Abstract Translations

GERMAN / DEUTSCHAUTOR(EN): Bach Le, DDS, MD, Jeffrey Burstein DDS,MD, P. Parish Sedghizadeh, DDS, MS. Schriftverkehr: BachLe, DDS, MD, Gesichts- und Kieferchirurgie (Oral &Maxillofacial Surgery), USC zahnmedizinische Fakultat/medizinisches Zentrum des Stadtbezirks LA (USC School ofDentistry/LA County Medical Center), 2010 Zonal Avenue,Los Angeles, CA 90089. Tel.: (323) 226-5013, Fax: 323-226-5241. eMail: burstein@usc.edu oder leb97201@yahoo.comKortikale Zeltstangen-Transplantierungstechnik bei Vorlie-gen eines schwer atrophischen alveolaren Kamms zur Vor-bereitung von Implantierungsstellen

ZUSAMMENFASSUNG: Zielsetzungen: Die Anreicherungdes alveolaren Kamms uber intraoral applizierte autogeneBlocktransplantate, die lokal zum Aufbau von Defiziten imalveolaren Kammbereich genutzt werden, stellt eine vorher-sagbar gute Methode im Vorfeld einer Implantierungsbehan-dlung dar. Es kann allerdings erforderlich werden, dass starkatrophische zahnlose Bereiche zusatzlich mittels extraoralerTransplantationsbereiche aufgefullt werden. Die vorliegendeStudie zielte darauf ab, die Effizienz bei Anwendung intrao-raler Kortikalblocktransplantate in Verbindung mit menschli-chem mineralisiertem Partikelallotransplantat zu ermittelnund zu bewerten. Hierbei wurde ein zeltartiger Aufbauvorgesehen, um die großen atrophischen Defekte im alveo-laren Kammbereich zur Implantierung vorzubereiten. Mate-rialien und Methoden: Diese retrospektive Fallstudie nahmeine Bewertung des Anreicherungsverhaltens bei 10 aufein-ander folgenden Patienten vor, die mit einem jeweils starkresorbierten alveolaren Kamm und einem Minimum vonmindestens 4 nebeneinander liegenden fehlenden Zahnen be-handelt wurden. Vor der Aufbaubehandlung wurden alle zurTransplantierung vorgesehenen Einsatzbereiche als unzu-reichend fur die Implantierung eines Standardimplantats von4 mm Durchmesser angesehen. Autologes, membranosesKortikalknochentransplantat mit Spendeursprungsstelle imMundraum wurde zur Anreicherung des horizontalen Kammsverwendet, um sowohl Weichgewebsmatrix als auchKnochenhaut fur das daneben angeordnete Partikelallotrans-plantat zeltformig auszuweiten. Die Kammbereiche wurden 4bis 5 Monate nach erfolgter Aufbaubehandlung klinisch un-tersucht und bewertet. Zu diesem Zeitpunkt wurden insge-samt 42 Implantate eingepflanzt. Ergebnisse: Bei allen mitTransplantat aufgebauten Stellen erwies sich die nach 4 bis 5Monaten nach dem ursprunglichen Transplantierungsdatumdurchgefuhrte Zahnimplantierung als erfolgreich. Die kli-nische Bewertung der transplantierten Bereiche bei Neuoff-nung ergab eine einheitliche Anatomie der betroffenenLeisten. Bei allen zahnlosen Segmenten konnten mindestens2 Implantate mit einem Minimum von 4,0 mm Durchmessereingepflanzt werden. Gesamt wurden bei 10 Versuchsper-sonen 42 Implantate in die transplantierten Bereiche eing-

esetzt. Uber ein entgegengesetzt ausgerichtetes Drehmomentvon 35 N-CM wurden die betreffenden Implantate auf ihreKnochengewebsintegration hin uberpruft. Bei einem derImplantate schlug die Integration fehl (1/42). Nach Implan-tatsetzung betrug der durchschnittliche Nachverfolgungszei-traum 12 Monate. Ein Jahr nach der ursprunglichenAufbaubehandlung hatten alle angereicherten Leistenbe-reiche ihre funktionale sowie asthetische Integritat zuruckerlangt. Schlussfolgerung: Die zeltartige Ausdehnung vonKnochenhaut und Weichgewebsmatrix uber ein Kortikal-knochentransplantat erhalt den freien Raum und sorgt fur eineMinimierung der Volumenresorption des Partikelallotrans-plantats. Außerdem verhindert die Uberbruckung kortikalerBlocktransplantate mit Partikelknochengewebe unasthetischeKammdefekte zwischen den einzelnen Kortikalknochentrans-plantaten, wenn an großeren Kammdefekten gearbeitet wird. Esergibt sich ein einheitlicher aussehender und asthetischerer al-veolarer Kamm, der aufgrund seiner Struktur in der Lage ist,eine Implantatgestutzte Prothese zu tragen. Die vorgestellteTechnik ermoglicht eine vorhersagbar gute funktionale und as-thetische Wiederherstellung großvolumiger Defekte, ohne dassdabei ubermaßig große Mengen an zu transplantierendem auto-genem Knochengewebe erforderlich sind. Damit ergibt sichgegenuber der Einzelverwendung von entweder kortikalemTransplantat oder Partikeltransplantat ein eindeutig besseresfunktionales und asthetisches Ergebnis.

SCHLUSSELWORTER: Knochengewebstransplantat, großvolu-mige Defekte, Zeltstangen-Technik

SPANISH / ESPAÑOLAUTOR(ES): Bach Le, DDS, MD, Jeffrey Burstein, DDS,MD, P. Parish Sedghizadeh, DDS, MS. Correspondencia a:Bach Le, DDS, MD, Oral & Maxillofacial Surgery, USCSchool of Dentistry/LA County Medical Center, 2010 ZonalAvenue, Los Angeles, CA 90089. Telefono: (323) 226-5013,Fax: 323-226-5241. Correo electronico: burstein@usc.eduor leb97201@yahoo.comTecnica de injerto cortical “poste de la carpa” en la crestaalveolar severamente atrofiada para la preparacion del lu-gar del implante

ABSTRACTO: Objetivos: El aumento de la cresta alveolarusando injertos intraorales de bloques autogenos para aumen-tar lo defectos de la cresta alveolar antes de la colocacion delimplante es un metodo esperado. Sin embargo, grandes seg-mentos edentulosos severamente atroficos podrıan requerirlugares adicionales fuera de la boca como donantes. Elproposito de este estudio es evaluar la eficacia en el uso deinjertos de bloques corticales dentro de la boca en combina-cion con alografos con partıculas mineralizadas humanas alestilo de una “carpa”, para aumentar los grandes defectosalveolares atroficos para la colocacion del implante. Mate-

IMPLANT DENTISTRY / VOLUME 17, NUMBER 1 2008 45

riales y Metodos: Este estudio retrospectivo evaluo el au-mento en 10 pacientes consecutivos con crestas alveolaresseveramente reabsorbidas con una la falta mınima de 4 dientesadyacentes. Antes del aumento, todos los lugares del injertofueron considerados inadecuados para la colocacion de un im-plante comun de 4 mm de diametro. Se realizo el aumentohorizontal de la cresta usando injertos de hueso cortical conmembrana autologa de un lugar de la boca como donante parausar sobre la matriz de tejido blando y el periostomo del alografoadyacente de partıculas. Las crestas fueron evaluadas clınica-mente 4 a 5 meses despues del aumento y se colocaron 42implantes en dicho momento. Resultados: Los implantes secolocaron exitosamente en todos los lugares del injerto 4 a 5meses despues de la fecha del injerto original. Las evaluacionesclınicas de los lugares del injerto luego de la reentrada revelaronuna anatomıa uniforme de la cresta. Todos los segmentos eden-tulosos tenıan por lo menos dos implantes colocados de por lomenos 4,00 mm de diametro. En total, se colocaron 42 implantesen los lugares injertados en los diez pacientes. Los implantesfueron evaluados para determinar su integracion osea usandouna contra torsion de 35 N-CM. Un implante no logro integrarse(1/42). El seguimiento medio fue de 12 meses despues de lacolocacion del implante. Todas las crestas aumentadas retuvi-eron su integridad funcional y estetica luego de 1 ano delaumento original. Conclusion: El recubrimiento estilo “carpa”del periostio y la matriz de tejido blando usando un bloque dehueso cortical mantiene el espacio y minimiza la reabsorcion delvolumen del alografo de partıculas. Ademas, conectar losbloques corticales con hueso de partıculas evita defectos pocoesteticos entre los injertos corticales de bloque en grandes de-fectos de la cresta. El resultado fue una cresta alveolar mas uni-forme y estetica, capaz de mantener una protesis soportada con unimplante. La tecnica ofrece una reconstruccion funcional y esteticade los defectos de gran volumen sin cantidades extensas de huesoautogeno. Esto ofrece un resultado funcional y estetico superior quecon solamente un injerto cortical o de partıculas.

PALABRAS CLAVES: injerto de hueso, defecto de granvolumen, poste de la carpa

PORTUGUESE / PORTUGUÊSAUTOR(ES): Bach Le, Cirurgiao-Dentista, Medico, JeffreyBurstein, Cirurgiao-Dentista, Medico, P. Parish Sedghizadeh,Cirurgiao-Dentista, Mestre em Ciencia. Correspondenciapara: Bach Le, DDS, MD, Oral & Maxillofacial Surgery,USC School of Dentistry/LA County Medical Center, 2010Zonal Avenue, Los Angeles, CA 90089. Telefone: (323) 226-5013, Fax: 323-226-5241, e-Mail: burstein@usc.edu ouleb97201@yahoo.comTecnica de Enxerto Cortical “Pau-de-Barraca” no RebordoAlveolar Gravemente Atrofico para Preparo do Local deImplante

RESUMO: Objetivos: O aumento do rebordo alveolar usandoenxertos de bloco autogeno intra-oral para aumentar defeitoslocalizados do rebordo alveolar antes da colocacao de im-

plante e um metodo previsıvel. Contudo, grandes segmentosdesdentados gravemente atroficos podem exigir areas doa-doras extra-orais. O proposito deste estudo e avaliar a eficaciado uso de enxerto de bloco cortical intra-oral em combinacaocom enxerto aloplastico mineralizado humano particulado, demodo “expandido”, para aumentar grandes defeitos do re-bordo alveolar atrofico para a colocacao de implante. Mate-riais e Metodos: Este estudo de caso retrospectivo avaliou oaumento em 10 pacientes consecutivos com rebordos alveo-lares gravemente reabsorvidos com falta de no mınimo 4dentes adjacentes. Antes do aumento, todos os locais enxer-tados foram considerados inadequados para a colocacao deum implante-padrao de 4 mm. O aumento do rebordo hori-zontal foi realizado usando-se enxertos de osso cortical mem-branoso autologo de uma area doadora oral para excluir amatriz de tecido mole e o periosteo para o enxerto aloplasticoparticulado adjacente. Os rebordos foram clinicamente avali-ados 4–5 meses apos o aumento e 42 implantes foram co-locados naquela ocasiao. Resultados: Os implantes foramcolocados com sucesso em todos os locais enxertados 4 a 5meses apos a data do enxerto original. A avaliacao clınica doslocais enxertados por ocasiao do novo acesso revelou anato-mia uniforme do rebordo. Todos os segmentos desdentadostiveram pelo menos dois implantes colocados de pelo menos4.0 mm de diametro. No total, 42 implantes foram colocadosem locais enxertados nos dez pacientes. Os implantes foramchecados quanto a osseointegracao usando-se um contra-torque de 35 N-CM. Um implante deixou de integrar (1/42).O acompanhamento medio foi de 12 meses apos a colocacaodo implante. Todos os rebordos aumentados tinham retidosua integridade funcional e estetica 1 ano apos o aumentooriginal. Conclusao: A expansao do periosteo e da matriz detecido mole usando-se um bloco do osso cortical mantemespaco e minimiza a reabsorcao do volume do enxerto alo-plastico particulado. Alem disso, ligar os blocos corticais comosso particulado evita defeitos nao-esteticos do rebordo entreos enxertos de bloco cortical em defeitos maiores do rebordo.O resultado foi um rebordo alveolar mais uniforme e estetico,capaz de manter uma protese suportada por implante. Atecnica oferece reconstrucao previsıvel e estetica de defeitosde grande volume sem quantidades extensas de osso autog-eno. Isso oferece um resultado funcional e estetico superioraquele com enxerto cortical ou particulado apenas.

PALAVRAS-CHAVE: enxerto osseo, defeito de grande vol-ume, pau-de-barraca

RUSSIAN /������: Bach Le, ������ ����������, ���������� ���, Jeffrey Burstein, ������ ����������, ���-��� ���� ���, P Parish Sedghizadeh, ������ �����-�����, ������ ������������ ����. ����� ������������� : Bach Le, DDS, MD, Oral & Maxillofa-cial Surgery, USC School of Dentistry/LA County MedicalCenter, 2010 Zonal Avenue, Los Angeles, CA 90089.������: (323) 226-5013, ����: 323-226-5241, �����

46 TENT-POLE GRAFTING TECHNIQUE FOR IMPLANT SITE PREPARATION

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TURKISH / TURKCEYAZARLAR: Dis Hekimi, Dr. Bach Le, Dis Hekimi, Dr.Jeffrey Burstein, Dis Hekimi, Dr. P Parish Sedghizadeh.Yazyþma icin: Bach Le, DDS, MD, Oral & MaxillofacialSurgery, USC School of Dentistry/LA County Medical Cen-ter, 2010 Zonal Avenue, Los Angeles, CA 90089 ABD. Tele-fon: (323) 226-5013, Faks: 323-226-5241, E-posta:burstein@usc.edu veya leb97201@yahoo.comYmplant Yeri Hazyrlanmasynda Ciddi Atrofili AlveolerKrette Kortikal “Cadyr Direði” Greft Tekniði

OZET: Amaclar: Lokalize alveoler kret defektlerinin aug-mentasyonunda implant yerlestirme isleminden once intra-oral otojen blok greftleri uygulaması yoluyla alveoler kretaugmentasyonu yapılması, sonucları onceden tahmin edile-bilen bir yontemdir. Ancak, genis ve ciddi sekilde atrofiyeugramıs dissiz segmanlar, ekstra oral donor yerlerini zorunlukılabilir. Bu calısmanın amacı, genis ve atrofili alveoler kretdefektlerinin implant yerlesimi icin augmentasyonunda intra-oral kortikal blok greftlerinin partikul halinde insan mineral-ize allogrefti ile birlikte “cadır” seklinde kullanılmasınınetkinligini degerlendirmektir. Gerec ve Yontem: Bu retros-pektif calısma, ciddi sekilde rezorbe olmus alveoler kretesahip ve en az 4 adet yan yana dis eksikligi olan ardısık 10hastada augmentasyonu degerlendirdi. Augmentasyon onc-esinde tum greft yerleri, standart 4 mm capındaki implantla-rın yerlestirilmesi icin yetersiz bulunmustu. Bir oral donoryerinden alınan otolog membranlı kortikal kemik greftleri,yandaki partikullu allogreft icin yumusak doku matrisi veperiosteum cadır gibi uygulanarak yatay kret augmentasyonu

IMPLANT DENTISTRY / VOLUME 17, NUMBER 1 2008 47

yapıldı. Kretler, augmentasyondan 4–5 ay sonra klinik olarakdegerlendirildi ve o tarihte 42 implant yerlestirildi. Bulgular:Orijinal greft tarihinden 4–5 ay sonra tum greft yerlerindebasarıyla implantasyon yapıldı. Greft yerlerine tekrar giristeyapılan klinik degerlendirmede, es dagılımlı kret anatomisigozlendi. Tum dissiz segmanlara, en azından 4.00 mm cap-ında en az iki implant yerlestirilmisti. On hastadaki greftyerlerine toplam 42 implant yerlestirildi. Ters torklu 35N-CM kullanılarak implantlarda osseointegrasyon kontroledildi. Bir implantta entegrasyon basarısızlıgı goruldu (1/42).Ortalama takip, implantasyondan sonra 12 aydı. Augmenta-syon yapılan tum kretler, orijinal augmentasyondan sonraki 1yıl icinde islevsel ve estetik butunluklerini korudu. Sonuc:Kortikal kemik blogu kullanılarak periosteum ve yumusakdoku matrisinin cadırlanması, aralıgı muhafaza eder ve par-

tikullu allogreft hacminin rezorpsiyonunu minimuma indirir.Ayrıca, kortikal blokların partikullu kemik ile koprulenmesi,daha genis kret defektlerinde kortikal blok greftleri arasındaestetiksel olmayan kret defektlerini onler. Bunun sonucunda,implant tarafından desteklenen bir protezi muhafaza edebi-lecek nitelikte daha es dagılımlı ve estetik bir alveoler kretolusur. Bu teknik, buyuk miktarda otojen kemik kulla-nılmadan buyuk hacimli defektlerin islevsel ve estetik birsekilde yeniden yapılandırılmasını saglar. Boylece, tek basınakortikal veya partikullu greftleme yontemlerine karsın dahaustun islevsel ve estetik sonuclar elde edilir.

ANAHTAR KELYMELER: kemik grefti, buyuk hacimli de-fekt, cadır diregi

JAPANESE /

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CHINESE /

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KOREAN /

50 TENT-POLE GRAFTING TECHNIQUE FOR IMPLANT SITE PREPARATION