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Horizontal and vertical ridge augmentation for implant placement in the aesthetic zone
Int. J. Oral Maxillofac. Surg. 2007; 36: 944–948 doi:10.1016/j.ijom.2007.05.006, available online at http://www.sciencedirect.com
Technical Note Pre-implant Surgery
Horizontal and vertical ridge augmentation for implant placement in the aesthetic zone
S. Pelo, R. Boniello, G. Gasparini, G. Longobardi, P. F. Amoroso Maxillofacial Department, ‘‘Universita` Cattolica del Sacro Cuore’’, Policlinico ‘‘A. Gemelli’’, Rome, Italy
S. Pelo, R. Boniello, G. Gasparini, G. Longobardi, P. F. Amoroso: Horizontal and vertical ridge augmentation for implant placement in the aesthetic zone. Int. J. Oral Maxillofac. Surg. 2007; 36: 944–948. # 2007 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved. Abstract. Lack of sufficient bone to place an implant at the functionally and aesthetically most appropriate position is a common problem, especially in the upper anterior jaw. A surgical technique is proposed to augment the alveolar ridge for vertical and horizontal defects through a localized alveolar osteotomy and interpositional bone graft. Three bone cuts (two vertical and one horizontal) are made in the alveolar bone. This portion of bone is carefully down-fractured. The gap between this bone box and the alveolar bone is filled with an interpositional bone graft. An on-lay bone graft is placed in the buccal side of the defect and fixed with titanium osteosynthesis screws. The aim of this surgical technique is to achieve bone graft healing in a short period of time. The broad vascular pedicle on the palatal side is maintained to ensure a nutritional supply for the down-fractured bone and interposed bone graft. The on-lay bone graft augments the palatal-buccal dimension and the interposed graft guarantees vertical augmentation.
Extensive resorption of the maxillary anterior region can be a drawback in dental implant placement. Resorption increases the interarch space and necessitates the use of short fixtures but long crowns. There is then a risk of fixture overloading and aesthetic failure of the prosthodontic rehabilitation. Numerous surgical techniques have been described to correct the vertical defect and decreased overall bone volume; the autogenous corticocancellous on-lay bone graft, proposed by BREINE & BRA˚NE1 MARK , was the first. There is now ample documentation in terms of number of 0901-5027/100944 + 05 $30.00/0
Accepted for publication 9 May 2007 Available online 12 July 2007
Fig. 1. Frontal preoperative view: vertical defect.
# 2007 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
Horizontal and vertical ridge augmentation for implant placement
945
Fig. 2. Preoperative CT: horizontal and vertical defects.
cases treated and follow up of implants placed in the reconstructed area3,13. There is agreement in the literature that on-lay bone grafts placed to gain vertical height undergo extensive bone resorption compared to those used to reconstruct the alveolar bone in the palatal-buccal dimension. VERMEEREN et al.12 report very unfavourable results of mandibular on-lay grafts, attributable to severe bone
resorption that occurred after bone grafting and peri-implant bone resorption after implant placement and prosthetic loading. Consequently, clinical research has been oriented towards other alternatives to restore the anatomical morphology of the alveolar ridge. The authors propose a surgical technique to augment the alveolar ridge for vertical and horizontal defects
Fig. 3. (A–C) Preparation of alveolar bone box and down-fracture.
through a localized alveolar osteotomy and interpositional bone graft. Surgical technique
Preoperative case materials consisted of a conventional panoramic radiograph, plaster models and photographs. Since the panoramic radiograph could provide little or no information about ridge thickness,
946
Pelo et al.
Fig. 4. (A–C) The bone graft interposed between the alveolar ridge and the bone down-fractured.
Fig. 5. (A–C) Transversal defect correct with an on-lay graft fixed with titanium osteosynthesis screws.
Horizontal and vertical ridge augmentation for implant placement computed tomography (CT) scans reformatted with Dentascan software were requested (Figs. 1 and 2). A crestal incision was made over the vertical defect and was continued into the gingival sulcus of the teeth adjacent to the edentulous space. Medial and distal releasing incisions were performed when needed to achieve easy movement of the buccal flap. Subperiosteal exposure on the buccal side was initiated. Great care was taken not to expose the palatal side of the area of the vertical defect. A broad vascular pedicle was maintained to ensure nutrition from the palatal side. Two vertical bone cuts (not less than 5 mm) and one horizontal bone cut were then made with an oscillating bur. The length of the horizontal cut depended on the area where alveolar reconstruction was planned, and a box of alveolar bone was created. Using a small chisel, the osteotomy was completed. The last part of the osteotomy was made with chisel and hammer in order to preserve the integrity of the vascular pedicle on the palatal side. The box was then fractured, raised and placed directly above. The mucoperiosteum of the palatal side was only stretched (Fig. 3A–C). The donor site was the mandibular angle. Bone was harvested by splitting the outer cortical plate. The corticocancellous bone graft was then shaped to be interposed between the alveolar ridge and the box of bone (Fig. 4A–C). The mucoperiosteum on the palatal side is quite difficult to stretch. Consequently, the box of bone rotated to the palate when it was down-fractured, as also described by JENSEN et al.4. This problem was solved with an on-lay graft giving the correct shape in the transversal dimension. The vertical alveolar ridge augmentation was ensured by the down-fracture and interposed bone. The palatal-buccal defect was corrected by an on-lay graft fixed with titanium osteosynthesis screws (Fig. 5A– C). The mucoperiosteal flap was repositioned and carefully closed with 3.0 Vicryl mattress sutures. Intravenous antibiotic therapy was given 1 h before the operation (2 g piperacillin and 0.25 g tazobactam) and continued intramuscularly twice a day for 5 days. A CT scan was requested 4 months later to evaluate the gain of bone in the horizontal and vertical dimensions (Fig. 6A–C). A partial thickness, slightly paracrestal incision on the palatal aspect was made 5 months after the interpositional bone graft operation in order to place implants and remove the osteosynthesis screws. The flap was then sutured on the buccal side
947
Fig. 6. (A–C) CT scan 4 months after the surgical operation.
in order to shift back the mucoperiosteal junction (Figs 7A, B and 8). Discussion
The correction of vertical alveolar ridge defects to place dental implants can be achieved through several techniques, such as on-lay grafts, vertical guided bone regeneration and vertical distraction osteogenesis. The international literature appears to agree that on-lay grafts placed to gain more than 3 mm of vertical height are unpredictable, as often the extent of resorption of the graft reduces the possibility of implant placement2. The clinical experience of vertical guided bone regeneration is limited, and this technique has
the limitation that the vertical defect must be restricted to a small area5,8,9,10. Alveolar distraction osteogenesis is a predictable surgical technique that can be used to correct vertically deficient alveolar ridges, but still the size of the device does not allow bone gain in the vertical dimension in front edentulous segments. This surgical technique augments the alveolar ridge in the vertical direction up to 10 mm with an interposed bone graft and in the horizontal direction with an on-lay bone graft7,11. The palatal rotation of the down-fractured segment was an inconvenience already mentioned by JENSEN et al.4. The on-lay bone graft placed on the buccal side had the great advantage of overcoming this problem.
948
Pelo et al.
Fig. 7. (A and B) Two implants placed 5 months after the surgical operation.
stretching of the palatal mucosa must be avoided, as this can provoke vascular embarrassment by detaching the periosteal blood supply6. The height of the alveolar process obtained did not undergo large modifications between the time of interpositional bone graft with osteotomy and implant placement. The anatomical morphology of the alveolar ridge was restored and the implants were placed in the correct area, giving a satisfactory aesthetic result. The increase in alveolar bone volume obtained was stable and able to receive loaded implants. References Fig. 8. Radiograph of the implants.
The titanium osteosynthesis screws fixed all the bone segments. This technique has the advantage of restoring both transversal and vertical defects. The maintained broad vascular pedicle on the palatal side ensures a nutritional supply for the down-fractured bone, interposed graft and on-lay graft. Excessive
1. Breine U, Bra˚nemark PI. Reconstruction of alveolar jaw bone. An experimental and clinical study of immediate and preformed autologous bone grafts in combination with osseointegrated implants. Scand J Plast Reconstr Surg 1980: 14: 23–48. 2. Chiapasco M, Romeo E, Casentini P, Rimondini L. Alveolar distraction osteogenesis vs. vertical guided bone regeneration for the correction of vertical deficient edentulous ridges: a 1–3-year prospective study on humans. Clin Oral Implants Res 2004: 15: 82–95.
3. Chiapasco M, Romeo E, Vogel G. Tridimensional reconstruction of knife-edge edentulous maxillae by sinus elevation, onlay grafts, and sagittal osteotomy of the anterior maxilla: preliminary surgical and prosthetic results. Int J Oral Maxillofac Implants 1998: 13: 394–399. 4. Jensen OT, Kuhlke L, Bedard JF, White D. Alveolar segmental sandwich osteotomy for anterior maxillary vertical augmentation prior to implant placement. J Oral Maxillofac Surg 2006: 64: 290–296. 5. Jovanovic SA, Nevins M. Bone formation utilizing titanium-reinforced barrier membranes. Int J Periodontics Restorative Dent 1995: 15: 56–69. 6. Politi M, Robiony M. Localized alveolar sandwich osteotomy for vertical augmentation of the anterior maxilla. J Oral Maxillofac Surg 1999: 57: 1380–1382. 7. Satow S, Slagter AP, Stoelinga PJW, Habets LLMH. Interposed bone grafts to accommodate endosteal implants for retaining mandibular overdentures. A 1–7 year follow-up study. Int J Oral Maxillofac Surg 1997: 26: 358–364. 8. Simion M, Jovanovic SA, Tinti C, Benfenati SP. Long-term evaluation of osseointegrated implants inserted at the time or after vertical ridge augmentation. A retrospective study on 123 implants with 1–5 year follow-up. Clin Oral Implants Res 2001: 12: 35–45. 9. Simion M, Jovanovic SA, Trisi P, Scarano A, Piattelli A. Vertical ridge augmentation around dental implants using a membrane technique and autogenous bone or allografts in humans. Int J Periodontics Restorative Dent 1998: 18: 8–23. 10. Simion M, Trisi P, Piattelli A. Vertical ridge augmentation using a membrane technique associated with osseointegrated implants. Int J Periodontics Restorative Dent 1994: 14: 496–511. 11. Stoelinga PJ, Blijdorp PA, Ross RR, De Koomen HA, Huybers TJ. Augmentation of the atrophic mandible with interposed bone grafts and particulate hydroxylapatite. J Oral Maxillofac Surg 1986: 44: 353–360. 12. Vermeeren JI, Wismeijer D, van Waas MA. One-step reconstruction of the severely resorbed mandible with onlay bone grafts and endosteal implants. A 5-year follow-up. Int J Oral Maxillofac Surg 1996: 25: 112–115. 13. Waite PD, Sastravaha P, Lemons JE. Biologic mechanical advantages of 3 different cranial bone grafting techniques for implant reconstruction of the atrophic maxilla. J Oral Maxillofac Surg 2005: 63: 63–67. Address: Pier Francesco Amoroso Via G. Moscati 31/33 00168 Rome Italy Tel: +39 3393797310 E-mail: [email protected]
Technical Note Pre-implant Surgery
Horizontal and vertical ridge augmentation for implant placement in the aesthetic zone
S. Pelo, R. Boniello, G. Gasparini, G. Longobardi, P. F. Amoroso Maxillofacial Department, ‘‘Universita` Cattolica del Sacro Cuore’’, Policlinico ‘‘A. Gemelli’’, Rome, Italy
S. Pelo, R. Boniello, G. Gasparini, G. Longobardi, P. F. Amoroso: Horizontal and vertical ridge augmentation for implant placement in the aesthetic zone. Int. J. Oral Maxillofac. Surg. 2007; 36: 944–948. # 2007 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved. Abstract. Lack of sufficient bone to place an implant at the functionally and aesthetically most appropriate position is a common problem, especially in the upper anterior jaw. A surgical technique is proposed to augment the alveolar ridge for vertical and horizontal defects through a localized alveolar osteotomy and interpositional bone graft. Three bone cuts (two vertical and one horizontal) are made in the alveolar bone. This portion of bone is carefully down-fractured. The gap between this bone box and the alveolar bone is filled with an interpositional bone graft. An on-lay bone graft is placed in the buccal side of the defect and fixed with titanium osteosynthesis screws. The aim of this surgical technique is to achieve bone graft healing in a short period of time. The broad vascular pedicle on the palatal side is maintained to ensure a nutritional supply for the down-fractured bone and interposed bone graft. The on-lay bone graft augments the palatal-buccal dimension and the interposed graft guarantees vertical augmentation.
Extensive resorption of the maxillary anterior region can be a drawback in dental implant placement. Resorption increases the interarch space and necessitates the use of short fixtures but long crowns. There is then a risk of fixture overloading and aesthetic failure of the prosthodontic rehabilitation. Numerous surgical techniques have been described to correct the vertical defect and decreased overall bone volume; the autogenous corticocancellous on-lay bone graft, proposed by BREINE & BRA˚NE1 MARK , was the first. There is now ample documentation in terms of number of 0901-5027/100944 + 05 $30.00/0
Accepted for publication 9 May 2007 Available online 12 July 2007
Fig. 1. Frontal preoperative view: vertical defect.
# 2007 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
Horizontal and vertical ridge augmentation for implant placement
945
Fig. 2. Preoperative CT: horizontal and vertical defects.
cases treated and follow up of implants placed in the reconstructed area3,13. There is agreement in the literature that on-lay bone grafts placed to gain vertical height undergo extensive bone resorption compared to those used to reconstruct the alveolar bone in the palatal-buccal dimension. VERMEEREN et al.12 report very unfavourable results of mandibular on-lay grafts, attributable to severe bone
resorption that occurred after bone grafting and peri-implant bone resorption after implant placement and prosthetic loading. Consequently, clinical research has been oriented towards other alternatives to restore the anatomical morphology of the alveolar ridge. The authors propose a surgical technique to augment the alveolar ridge for vertical and horizontal defects
Fig. 3. (A–C) Preparation of alveolar bone box and down-fracture.
through a localized alveolar osteotomy and interpositional bone graft. Surgical technique
Preoperative case materials consisted of a conventional panoramic radiograph, plaster models and photographs. Since the panoramic radiograph could provide little or no information about ridge thickness,
946
Pelo et al.
Fig. 4. (A–C) The bone graft interposed between the alveolar ridge and the bone down-fractured.
Fig. 5. (A–C) Transversal defect correct with an on-lay graft fixed with titanium osteosynthesis screws.
Horizontal and vertical ridge augmentation for implant placement computed tomography (CT) scans reformatted with Dentascan software were requested (Figs. 1 and 2). A crestal incision was made over the vertical defect and was continued into the gingival sulcus of the teeth adjacent to the edentulous space. Medial and distal releasing incisions were performed when needed to achieve easy movement of the buccal flap. Subperiosteal exposure on the buccal side was initiated. Great care was taken not to expose the palatal side of the area of the vertical defect. A broad vascular pedicle was maintained to ensure nutrition from the palatal side. Two vertical bone cuts (not less than 5 mm) and one horizontal bone cut were then made with an oscillating bur. The length of the horizontal cut depended on the area where alveolar reconstruction was planned, and a box of alveolar bone was created. Using a small chisel, the osteotomy was completed. The last part of the osteotomy was made with chisel and hammer in order to preserve the integrity of the vascular pedicle on the palatal side. The box was then fractured, raised and placed directly above. The mucoperiosteum of the palatal side was only stretched (Fig. 3A–C). The donor site was the mandibular angle. Bone was harvested by splitting the outer cortical plate. The corticocancellous bone graft was then shaped to be interposed between the alveolar ridge and the box of bone (Fig. 4A–C). The mucoperiosteum on the palatal side is quite difficult to stretch. Consequently, the box of bone rotated to the palate when it was down-fractured, as also described by JENSEN et al.4. This problem was solved with an on-lay graft giving the correct shape in the transversal dimension. The vertical alveolar ridge augmentation was ensured by the down-fracture and interposed bone. The palatal-buccal defect was corrected by an on-lay graft fixed with titanium osteosynthesis screws (Fig. 5A– C). The mucoperiosteal flap was repositioned and carefully closed with 3.0 Vicryl mattress sutures. Intravenous antibiotic therapy was given 1 h before the operation (2 g piperacillin and 0.25 g tazobactam) and continued intramuscularly twice a day for 5 days. A CT scan was requested 4 months later to evaluate the gain of bone in the horizontal and vertical dimensions (Fig. 6A–C). A partial thickness, slightly paracrestal incision on the palatal aspect was made 5 months after the interpositional bone graft operation in order to place implants and remove the osteosynthesis screws. The flap was then sutured on the buccal side
947
Fig. 6. (A–C) CT scan 4 months after the surgical operation.
in order to shift back the mucoperiosteal junction (Figs 7A, B and 8). Discussion
The correction of vertical alveolar ridge defects to place dental implants can be achieved through several techniques, such as on-lay grafts, vertical guided bone regeneration and vertical distraction osteogenesis. The international literature appears to agree that on-lay grafts placed to gain more than 3 mm of vertical height are unpredictable, as often the extent of resorption of the graft reduces the possibility of implant placement2. The clinical experience of vertical guided bone regeneration is limited, and this technique has
the limitation that the vertical defect must be restricted to a small area5,8,9,10. Alveolar distraction osteogenesis is a predictable surgical technique that can be used to correct vertically deficient alveolar ridges, but still the size of the device does not allow bone gain in the vertical dimension in front edentulous segments. This surgical technique augments the alveolar ridge in the vertical direction up to 10 mm with an interposed bone graft and in the horizontal direction with an on-lay bone graft7,11. The palatal rotation of the down-fractured segment was an inconvenience already mentioned by JENSEN et al.4. The on-lay bone graft placed on the buccal side had the great advantage of overcoming this problem.
948
Pelo et al.
Fig. 7. (A and B) Two implants placed 5 months after the surgical operation.
stretching of the palatal mucosa must be avoided, as this can provoke vascular embarrassment by detaching the periosteal blood supply6. The height of the alveolar process obtained did not undergo large modifications between the time of interpositional bone graft with osteotomy and implant placement. The anatomical morphology of the alveolar ridge was restored and the implants were placed in the correct area, giving a satisfactory aesthetic result. The increase in alveolar bone volume obtained was stable and able to receive loaded implants. References Fig. 8. Radiograph of the implants.
The titanium osteosynthesis screws fixed all the bone segments. This technique has the advantage of restoring both transversal and vertical defects. The maintained broad vascular pedicle on the palatal side ensures a nutritional supply for the down-fractured bone, interposed graft and on-lay graft. Excessive
1. Breine U, Bra˚nemark PI. Reconstruction of alveolar jaw bone. An experimental and clinical study of immediate and preformed autologous bone grafts in combination with osseointegrated implants. Scand J Plast Reconstr Surg 1980: 14: 23–48. 2. Chiapasco M, Romeo E, Casentini P, Rimondini L. Alveolar distraction osteogenesis vs. vertical guided bone regeneration for the correction of vertical deficient edentulous ridges: a 1–3-year prospective study on humans. Clin Oral Implants Res 2004: 15: 82–95.
3. Chiapasco M, Romeo E, Vogel G. Tridimensional reconstruction of knife-edge edentulous maxillae by sinus elevation, onlay grafts, and sagittal osteotomy of the anterior maxilla: preliminary surgical and prosthetic results. Int J Oral Maxillofac Implants 1998: 13: 394–399. 4. Jensen OT, Kuhlke L, Bedard JF, White D. Alveolar segmental sandwich osteotomy for anterior maxillary vertical augmentation prior to implant placement. J Oral Maxillofac Surg 2006: 64: 290–296. 5. Jovanovic SA, Nevins M. Bone formation utilizing titanium-reinforced barrier membranes. Int J Periodontics Restorative Dent 1995: 15: 56–69. 6. Politi M, Robiony M. Localized alveolar sandwich osteotomy for vertical augmentation of the anterior maxilla. J Oral Maxillofac Surg 1999: 57: 1380–1382. 7. Satow S, Slagter AP, Stoelinga PJW, Habets LLMH. Interposed bone grafts to accommodate endosteal implants for retaining mandibular overdentures. A 1–7 year follow-up study. Int J Oral Maxillofac Surg 1997: 26: 358–364. 8. Simion M, Jovanovic SA, Tinti C, Benfenati SP. Long-term evaluation of osseointegrated implants inserted at the time or after vertical ridge augmentation. A retrospective study on 123 implants with 1–5 year follow-up. Clin Oral Implants Res 2001: 12: 35–45. 9. Simion M, Jovanovic SA, Trisi P, Scarano A, Piattelli A. Vertical ridge augmentation around dental implants using a membrane technique and autogenous bone or allografts in humans. Int J Periodontics Restorative Dent 1998: 18: 8–23. 10. Simion M, Trisi P, Piattelli A. Vertical ridge augmentation using a membrane technique associated with osseointegrated implants. Int J Periodontics Restorative Dent 1994: 14: 496–511. 11. Stoelinga PJ, Blijdorp PA, Ross RR, De Koomen HA, Huybers TJ. Augmentation of the atrophic mandible with interposed bone grafts and particulate hydroxylapatite. J Oral Maxillofac Surg 1986: 44: 353–360. 12. Vermeeren JI, Wismeijer D, van Waas MA. One-step reconstruction of the severely resorbed mandible with onlay bone grafts and endosteal implants. A 5-year follow-up. Int J Oral Maxillofac Surg 1996: 25: 112–115. 13. Waite PD, Sastravaha P, Lemons JE. Biologic mechanical advantages of 3 different cranial bone grafting techniques for implant reconstruction of the atrophic maxilla. J Oral Maxillofac Surg 2005: 63: 63–67. Address: Pier Francesco Amoroso Via G. Moscati 31/33 00168 Rome Italy Tel: +39 3393797310 E-mail: [email protected]