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Reconstruction of an atrophic maxilla: comparison of two methods
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British Journal of Oral and Maxillofacial Surgery 49 (2011) 198–202
Reconstruction of an atrophic maxilla: comparison of two methods Ewoud L. van der Mark a,b,∗ , Frank Bierenbroodspot a,1 , Erik M. Baas a,1 , Jan de Lange a,b,2 a b
Department of Oral and Maxillofacial Surgery, Isala Clinics, Postbus 10400, 8000 GK Zwolle, The Netherlands Department of Oral and Maxillofacial Surgery, Academic Medical Center, University of Amsterdam, 1100 DD Amsterdam, The Netherlands
Accepted 4 March 2010 Available online 18 April 2010
Abstract We have evaluated the survival of dental implants in extremely atrophic edentulous maxillas after autogenous bone grafting. We compared two techniques: the Le Fort I down-grafting procedure and conventional raising of the sinus floor with onlay bone grafting. Twenty-seven consecutive patients had their atrophic maxillas reconstructed, 10 of whom were treated with a Le Fort I osteotomy with down-grafting and interpositioning of bone, and 17 by raising the sinus floor and onlay grafts. All implants were placed 5–6 months after grafting. There was no difference in the survival of implants between the two groups. The choice of grafting technique will therefore be based primarily on the interarch relations and the need for soft tissue support. © 2010 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved. Keywords: Edentulous maxilla; Le Fort I osteotomy; Sinus floor grafting; Onlay bone grafting; Iliac crest; Dental implants
Introduction Adequate reconstruction of an extremely atrophic edentulous maxilla has always been a challenge. There are two different conditions, or patterns of resorption, the first of which presents with a thin alveolar process but, however, considerable height (Cawood IV–V).1 The lack of bony volume in these patients is often treated by a sinus lift combined with onlay bone grafting which, for many surgeons, is a reliable and predictable technique. In other patients, particularly those with remaining teeth in the front of the mandible, the resorption occurs primarily in the front of the maxilla (Cawood VI and Kelly syndrome).1 These patients are often diagnosed as having ∗ Corresponding author at: Department of Oral and Maxillofacial Surgery, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands. Tel.: +31 20 5664098. E-mail addresses: [email protected] (E.L. van der Mark), [email protected] (F. Bierenbroodspot), [email protected] (E.M. Baas), [email protected] (J. de Lange). 1 Tel.: +31 38 4245217. 2 Tel.: +31 20 5664098.
a reversed maxillary–mandibular relation, an increased vertical intermaxillary distance, and a collapsed facial appearance.2 The effect of these alterations, combined with ageing, results in a change in facial morphology. In this group correction of bone volume alone is not enough to create a favourable site for implant and, therefore, the alveolar bone should be augmented at the same time as the maxillary–mandibular relation and the vertical dimension is restored to provide support for the collapsed facial muscles. Interpositional bone grafting and Le Fort I osteotomy may achieve these goals.3 In this paper we describe the results of the insertion of dental implants into severely atrophic maxillas that were reconstructed either by Le Fort I osteotomy with interpositional bone grafting or by a sinus lift combined with onlay bone grafting.
Patients and methods Between 2004 and 2007, 27 healthy patients had their severely or extremely atrophic maxillas reconstructed. The maxillas had been edentulous for a mean of 17.5 years (12–22
0266-4356/$ – see front matter © 2010 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
doi:10.1016/j.bjoms.2010.03.001
E.L. van der Mark et al. / British Journal of Oral and Maxillofacial Surgery 49 (2011) 198–202
Fig. 1. Rigid fixation with two L-shaped miniplates (1.5 system Synthes) in the frontal region to stabilise the maxilla in the desired position.
years). Two different techniques of bone grafting were used, depending on the resorption pattern. In the first group, 10 patients were treated by Le Fort I osteotomy, and interpositioning and repositioning of the maxilla forwards and downwards. There were 5 men and 5 women (mean (SD) age 53 (8) years). In the second group 2 men and 15 women (mean (SD) age 53 (7) years) were treated by raising the sinus floor and onlay bone grafting. There was one tobacco smoker in each group. All patients were operated on under general anaesthesia with nasal endotracheal intubation. Autogenous corticocancellous block grafts and autogenous particulate bone grafts were harvested from the posterior iliac crest for the Le Fort I group because of the larger volume of cancellous bone that was available, while for the onlay group the anterior iliac crest was used. The autogenous particulate bone grafts were mixed in a 4:1 ratio with Bio-oss® . In the first group a standard Le Fort I approach was used. If possible the sinus membrane was preserved, but some tears were inevitable. After the nasal mucosa had been raised and the septum released, the maxilla was down-fractured using Sailer’s technique.3 The maxillary sinus was closed with a cortical piece of bone shaped to fit the sinus as an inlay
Fig. 2. The interpositional bone grafts in place.
199
Fig. 3. The lateral antrostomy to raise the maxillary sinus floor.
graft. The graft was fixed with three polyglactin 910 (Vicryl) sutures to the lateral sinus wall. This differs from fixation with two microplates as described by Cawood et al.4 and Stoelinga et al.5 The maxilla was positioned downwards and forwards, the mean forward movement being 5 mm (vary from 2 to 8 mm, SD 1.9). Rigid fixation with two L-shaped miniplates (1.5 system Synthes) in the frontal region stabilised the maxilla and the interpositional bone graft in the desired position (Figs. 1 and 2). The maxillary sinus floor was raised as in the classic lateral antrostomy pioneered by Tatum combined with onlay bone grafting.6 The space created after the sinus membrane had been raised by the intruded trapdoor was filled with a mixture of autogenous bone and Bio-oss® (Fig. 3). The onlay grafts were shaped so that they closely adapted to the recipient bed and were fixed with two screws (Fig. 4). Care was taken to achieve a tension-free closure of the soft tissue. In both groups antibiotic prophylaxis was continued orally for 7 days postoperatively with amoxycillin 500 mg three times daily. Non-steroidal analgesics were given postoperatively. Patients were requested not to wear their dentures for 2 weeks. After 2–3 weeks a new pair of dentures was made for use during the healing period until the suprastructures were completed and a
Fig. 4. The fixed onlay bone grafts.
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Table 1 Details of implants. Case no.
No of implants inserted
Type of implant
Interval between first operation and insertion (months)
Follow-up after insertion of implant (months)
No lost
1. Le Fort I 2. Le Fort I 3. Le Fort I 4. Le Fort I 5. Le Fort I 6. Le Fort I 7. Le Fort I 8. Le Fort I 9. Le Fort I 10. Le Fort I 11. Onlay 12. Onlay 13. Onlay 14. Onlay 15. Onlay 16. Onlay 17. Onlay 18. Onlay 19. Onlay 20. Onlay 21. Onlay 22. Onlay 23. Onlay 24. Onlay 25. Onlay 26. Onlay 27. Onlay
4 6 6 6 4 5 7 4 6 6 4 6 6 6 6 6 4 6 6 4 4 6 6 4 4 4 4
Straumann Straumann Nobel Nobel Straumann Straumann Straumann Straumann Straumann Straumann Straumann Straumann Nobel Nobel Nobel Straumann Straumann Straumann Straumann Straumann Straumann Straumann Astra Straumann Nobel Nobel Straumann
6 6 4 5 5 5 5 5 5 5 5 5 5 5 6 5 4 4 4 5 4 5 5 5 6 7 5
24 36 24 9 10 11 12 7 12 18 12 24 24 24 12 24 36 36 12 24 12 12 24 12 12 12 12
1 0 0 0 0 0 2 0 0 0 0 1 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0
final pair of dentures was made. Further instructions included soft diet for 3 months and the use of 0.12% chlorhexidine mouth rinse. Endosseous implants were placed 5–6 months postoperatively. A guidance template was used to ensure the correct position and alignment of the implants. Details of the implants are shown in Table 1. After a 6month healing period the implants were uncovered and the suprastructure was introduced. The Statistical Package for the Social Sciences (SPSS version16, SPSS, Chicago) was used to aid analysis. Pearson’s chi2 test was used to assess the significance of differences between the number of failures of implants in the both groups. Probabilities of less than 0.05 were accepted as significant.
Results All patients were discharged from hospital within 2 days, and the initial healing in all 27 patients was uneventful. During the Le Fort I osteotomy there was one unexpected fracture of the palate, but the maxilla could still be advanced. In the Le Fort I group there were no dehiscences of the soft tissue and no loss of bone grafts. In this group 54 implants were inserted (42 Straumann standard and12 Nobel replace select; Institut Straumann AG, Basel, Switzerland, and Nobel Biocare AB, Göteborg, Sweden). In one patient, one of the four implants did not integrate, which was discovered when the implant
was exposed. This implant was removed. In another patient in whom seven implants were inserted, two failed after 7 months. In total, 3 of the 54 implants were lost in this group, resulting in 6% failure. In the onlay group 86 implants were inserted (54 Straumann standard, 26 Nobel replace select, and 6 Astra) (Astra Tech AB, Mölndal, Sweden). In two patients the soft tissue dehisced, and the corticocancellous bone blocks partly sequestrated. A mixture of autogenous bone, Bio-oss® ,and Bio-gide was used during the second stage operation. Two other patients had a partial loss of bone around an implant, but the implants osseointegrated and functioned normally. In one patient, one of the six implants failed after 5 months, and was subsequently removed when the abutments were inserted. A new implant in the same position was also lost because of lack of bone. In another patient, one of the six implants was lost after 10 months. Overall, in the onlay group, 2 implants of a total of 86 were lost, resulting in 2% failure. There was no difference in failure of implants between the groups (p = 0.3) (Table 2). Some patients experienced disturbances of gait postoperatively, but were free of complaints from the donor site after 3 weeks. Two had temporary sensory disturbances, and two complained of mild pain over the wound after harvesting. Both disturbances and pain resolved after 3 months. One patient had residual pain that lasted longer than 6 months after an anterior harvest, but no patient had temporary or residual pain after a posterior procedure.
E.L. van der Mark et al. / British Journal of Oral and Maxillofacial Surgery 49 (2011) 198–202 Table 2 Number of implants. Survival of implants Success Operation Le Fort Onlay Total
Total Failure
51 84
3 2
54 86
135
5
140
In neither group were further implants lost during the 17 (range 7–36) months’ follow-up.
Discussion Clementschisch is thought to be the first clinician to have used free rib grafts to augment the resorbed mandible by an intraoral route.7 The method was popularised by Davis et al.,8 and also used for the maxilla by Terry et al.9 These grafts were fixed with wire osteosynthesis, but new techniques considerably improved the results of bony augmentation.10 Bell et al. were the first to describe Le Fort I osteotomy with interpositional bone grafts in edentulous patients to improve the position of the maxilla and restore the intermaxillary relation.11 In patients with a class III relation, creating an implant site merely by enlarging the bony volume will lead to unfavourable loading of the dentures and impaired aesthetic and functional results.12 In these cases a Le Fort I osteotomy with interpositioning of bone is indicated. This procedure was first described by Sailer as a one-stage operation,3 and later modified by Cawood et al. as a two-stage one.4 The insertion of the endosseous implants was delayed until the bone grafts had been revascularised. The delayed placement of implants resulted in less risk of their loss and made the use of a template possible.4 In the present study, the technique was slightly modified in that we used fewer osteosynthesis plates, which made it easier to plan and place the implants as only two miniplates were being used to stabilise the maxilla instead of four. The microplates that had been used to fix the cortical bone that formed the new floor of the sinus were not used because they cannot be removed later. By then they are completely covered by bone and can compromise the positioning of the implants. The cortical bone was fixed with 4/0 polyglactin 910 sutures (Vicryl) instead. The stability of the procedure was not compromised by using fewer plates. A Le Fort I osteotomy with interpositional grafts provides an increase in bony volume and a correction in the relation of the jaw to ensure optimal support and functional loading of the implants. It also makes it possible to place the implants through keratinised mucosa. Some authors have claimed that keratinised mucosa surrounding the abutments is a prerequisite for peri-implant health.13,14
201
Results from earlier studies and from the present study show good success rates for implants in both groups.15–18 The implants used in this study were from different companies and manufacturers and 12–13 mm long, randomly used in both groups, so the source does not seem to influence the survival between the groups. Maxillary reconstruction with a Le Fort I osteotomy, bony interposition, and insertion of implants in a second stage seems a predictable way to ensure good functional and aesthetic outcomes for a group of patients with a reversed maxillomandibular relation. There were no dehiscences of soft tissue in the Le Fort I group, and vertical relapse of the down-grafted maxilla and bony resorption were of no clinical relevance at the time the implants were placed 5–6 months later. We did the buccal osteotomy in the Le Fort I group with a round burr instead of a reciprocal saw, after which we raised the sinus membrane carefully. In doing so we were unable to prevent little tears, but in no patient did we see entrapment cysts of the sinus epithelium as have been described by others.5 Complications such as sinusitis tend to occur in previously unhealthy sinuses.19 Major complications have been documented, however.20–23 Massive haemorrhage is possible during interpositional grafting and Le Fort I osteotomy. These relatively invasive operations can also give rise to haemorrhage as a result of accidental laceration of the major palatine artery or other branches of the maxillary artery.24 Occasionally a difficult osteotomy or down-fracture, or both, may be encountered. This is likely to be related to atypical maxillary morphology. Comprehensive preoperative cone beam imaging is probably helpful in dealing with this and therefore reduces the likelihood of complications. The possibilities of three-dimensional imaging also encourage the use of alternatives to bone grafting. In patients with no appreciable interarch discrepancy, the use of a zygomatic fixture is an alternative that can be considered if the maxilla is extremely atrophic.25 In conclusion, the results of this study together with published evidence show that patients with atrophic maxillas can be predictably and successfully rehabilitated with bone grafts and a two-stage implant procedure. The use of fewer osteosynthesis plates in the Le Fort I group made it easier to plan and place the implants and did not seem to compromise the stability of the procedure. The choice between a Le Fort I osteotomy or a sinus lifting procedure with onlay grafting should depend on the interarch relations and the need for soft tissue support. Only a considerable interarch discrepancy outweighs the potential risks of a more invasive Le Fort I osteotomy.
References 1. Cawood JI, Howell RA. A classification of the edentulous jaw. Int J Oral Maxillofac Surg 1988;17:232–6.
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2. Sutton DN, Lewis BR, Patel M, Cawood JI. Changes in facial form relative to progressive atrophy of the edentulous jaws. Int J Oral Maxillofac Surg 2004;33:676–82. 3. Sailer HF. A new method of inserting endosseus implants in totally atrophic maxillae. J Craniomaxillofac Surg 1989;17:299–305. 4. Cawood JI, Stoelinga PJW, Brouns JJA. Reconstruction of the severely resorbed (Class VI) maxilla. A two-step procedure. Int J Oral Maxillofac Surg 1994;23:219–25. 5. Stoelinga PJ, Slagter AP, Brouns JJA. Rehabilitation of patients with severe (Class VI) maxillary resorption using Le Fort I osteotomy, interposed bone grafts and endosteal implants: 1–8 years follow-up on a two-stage procedure. Int J Oral Maxillofac Surg 2000;29:188–93. 6. Tatum O. Maxillary and sinus implant reconstruction. Dent Clin North Am 1986;30:207–29. 7. Clementschisch F. In: Pichler H, Trauner R, editors. Mund- und Kieferchirurgie. Vienna: Urban & Schwarzenberg; 1948. p. 524. 8. Davis WH, Delo RI, Weiner JR, Terry B. Transoral bone graft for atrophy of the mandible. J Oral Surg 1970;28:760–5. 9. Terry BC, Albright JE, Baker RD. Alveolar ridge augmentation in the edentulous maxilla with use of autogenous ribs. J Oral Surg 1974;32:429–34. 10. Fazili M, von Overvest-Eerdmans GR, Vernooy AM, Visser WJ, van Waas MA. Follow-up investigation of reconstruction of the alveolar process in the atrophic mandible. Int J Oral Surg 1978;7:400–4. 11. Bell WH, Buche WA, Kennedy III JW, Ampil JP. Surgical correction of the atrophic alveolar ridge. A preliminary report on a new concept of treatment. Oral Surg Oral Med Oral Pathol 1977;43:485–98. 12. Cawood JI, Howell RA. Reconstructive preprosthetic surgery. 1. Anatomical considerations. Int J Oral Maxillofac Surg 1991;20:75–82. 13. Buser D, Weber HP, Bragger U. The treatment of partially edentulous patients with ITI hollow-screw implants: presurgical evaluation and surgical procedures. Int J Oral Maxillofac Implants 1990;5:165– 75. 14. Artzi Z, Tal H, Moses O, Koslovsky A. Mucosal considerations for osseointegrated implants. J Prosthet Dent 1993;70:427–32.
15. Nyström E, Ahlqvist J, Legrell PE, Kahnberg KE. Bone graft remodelling and implant success rate in the treatment of the severely resorbed maxilla: a 5-year longitudinal study. Int J Oral Maxillofac Surg 2002;31:158–64. 16. Nyström E, Ahlqvist J, Gunne J, Kahnberg KE. 10-Year follow-up of onlay bone grafts and implants in severely resorbed maxillae. Int J Oral Maxillofac Surg 2004;33:258–62. 17. Nyström E, Nilson H, Gunne J, Lundgren S. Reconstruction of the atrophic maxilla with interpositional bone grafting/Le Fort I osteotomy and endosteal implants: a 11–16 year follow-up. Int J Oral Maxillofac Surg 2009;38:1–6. 18. Nyström E, Nilson H, Gunne J, Lundgren S. A 9–14 year follow-up of onlay bone grafting in the atrophic maxilla. Int J Oral Maxillofac Surg 2009;38:111–6. 19. Timmenga NM, Raghoebar GM, Boering G, van Weissenbruch R. Maxillary sinus function after sinus lifts for the insertion of dental implants. J Oral Maxillofac Surg 1997;55:936–40. 20. Lanigan DT, Hey JH, West RA. Major vascular complications of orthognathic surgery: hemorrhage associated with Le Fort I osteotomies. J Oral Maxillofac Surg 1990;48:561–73. 21. Lanigan DT, Hey JH, West RA. Aseptic necrosis following maxillary osteotomies: report of 36 cases. J Oral Maxillofac Surg 1990;48:142–56. 22. Lanigan DT, Hey JH, West RA. Major vascular complications of orthognathic surgery: false aneurysms and arteriovenous fistulas following orthognathic surgery. J Oral Maxillofac Surg 1991;49:571–7. 23. Lanigan DT, Romanchuk K, Olson CK. Ophthalmic complications associated with orthognathic surgery. J Oral Maxillofac Surg 1993;51:480–94. 24. Turvey TA, Fonseca RJ. The anatomy of the internal maxillary artery in the pterygopalatine fossa: its relationship to maxillary surgery. J Oral Surg 1980;38:92–5. 25. Brånemark PI, Gröndahl K, Ohrnell LO, Nilsson P, Petruson B, Svensson B, et al. Zygoma fixture in the management of advanced atrophy of the maxilla: technique and long-term results. Scand J Plast Reconstr Surg Hand Surg 2004;38:70–85.
British Journal of Oral and Maxillofacial Surgery 49 (2011) 198–202
Reconstruction of an atrophic maxilla: comparison of two methods Ewoud L. van der Mark a,b,∗ , Frank Bierenbroodspot a,1 , Erik M. Baas a,1 , Jan de Lange a,b,2 a b
Department of Oral and Maxillofacial Surgery, Isala Clinics, Postbus 10400, 8000 GK Zwolle, The Netherlands Department of Oral and Maxillofacial Surgery, Academic Medical Center, University of Amsterdam, 1100 DD Amsterdam, The Netherlands
Accepted 4 March 2010 Available online 18 April 2010
Abstract We have evaluated the survival of dental implants in extremely atrophic edentulous maxillas after autogenous bone grafting. We compared two techniques: the Le Fort I down-grafting procedure and conventional raising of the sinus floor with onlay bone grafting. Twenty-seven consecutive patients had their atrophic maxillas reconstructed, 10 of whom were treated with a Le Fort I osteotomy with down-grafting and interpositioning of bone, and 17 by raising the sinus floor and onlay grafts. All implants were placed 5–6 months after grafting. There was no difference in the survival of implants between the two groups. The choice of grafting technique will therefore be based primarily on the interarch relations and the need for soft tissue support. © 2010 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved. Keywords: Edentulous maxilla; Le Fort I osteotomy; Sinus floor grafting; Onlay bone grafting; Iliac crest; Dental implants
Introduction Adequate reconstruction of an extremely atrophic edentulous maxilla has always been a challenge. There are two different conditions, or patterns of resorption, the first of which presents with a thin alveolar process but, however, considerable height (Cawood IV–V).1 The lack of bony volume in these patients is often treated by a sinus lift combined with onlay bone grafting which, for many surgeons, is a reliable and predictable technique. In other patients, particularly those with remaining teeth in the front of the mandible, the resorption occurs primarily in the front of the maxilla (Cawood VI and Kelly syndrome).1 These patients are often diagnosed as having ∗ Corresponding author at: Department of Oral and Maxillofacial Surgery, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands. Tel.: +31 20 5664098. E-mail addresses: [email protected] (E.L. van der Mark), [email protected] (F. Bierenbroodspot), [email protected] (E.M. Baas), [email protected] (J. de Lange). 1 Tel.: +31 38 4245217. 2 Tel.: +31 20 5664098.
a reversed maxillary–mandibular relation, an increased vertical intermaxillary distance, and a collapsed facial appearance.2 The effect of these alterations, combined with ageing, results in a change in facial morphology. In this group correction of bone volume alone is not enough to create a favourable site for implant and, therefore, the alveolar bone should be augmented at the same time as the maxillary–mandibular relation and the vertical dimension is restored to provide support for the collapsed facial muscles. Interpositional bone grafting and Le Fort I osteotomy may achieve these goals.3 In this paper we describe the results of the insertion of dental implants into severely atrophic maxillas that were reconstructed either by Le Fort I osteotomy with interpositional bone grafting or by a sinus lift combined with onlay bone grafting.
Patients and methods Between 2004 and 2007, 27 healthy patients had their severely or extremely atrophic maxillas reconstructed. The maxillas had been edentulous for a mean of 17.5 years (12–22
0266-4356/$ – see front matter © 2010 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
doi:10.1016/j.bjoms.2010.03.001
E.L. van der Mark et al. / British Journal of Oral and Maxillofacial Surgery 49 (2011) 198–202
Fig. 1. Rigid fixation with two L-shaped miniplates (1.5 system Synthes) in the frontal region to stabilise the maxilla in the desired position.
years). Two different techniques of bone grafting were used, depending on the resorption pattern. In the first group, 10 patients were treated by Le Fort I osteotomy, and interpositioning and repositioning of the maxilla forwards and downwards. There were 5 men and 5 women (mean (SD) age 53 (8) years). In the second group 2 men and 15 women (mean (SD) age 53 (7) years) were treated by raising the sinus floor and onlay bone grafting. There was one tobacco smoker in each group. All patients were operated on under general anaesthesia with nasal endotracheal intubation. Autogenous corticocancellous block grafts and autogenous particulate bone grafts were harvested from the posterior iliac crest for the Le Fort I group because of the larger volume of cancellous bone that was available, while for the onlay group the anterior iliac crest was used. The autogenous particulate bone grafts were mixed in a 4:1 ratio with Bio-oss® . In the first group a standard Le Fort I approach was used. If possible the sinus membrane was preserved, but some tears were inevitable. After the nasal mucosa had been raised and the septum released, the maxilla was down-fractured using Sailer’s technique.3 The maxillary sinus was closed with a cortical piece of bone shaped to fit the sinus as an inlay
Fig. 2. The interpositional bone grafts in place.
199
Fig. 3. The lateral antrostomy to raise the maxillary sinus floor.
graft. The graft was fixed with three polyglactin 910 (Vicryl) sutures to the lateral sinus wall. This differs from fixation with two microplates as described by Cawood et al.4 and Stoelinga et al.5 The maxilla was positioned downwards and forwards, the mean forward movement being 5 mm (vary from 2 to 8 mm, SD 1.9). Rigid fixation with two L-shaped miniplates (1.5 system Synthes) in the frontal region stabilised the maxilla and the interpositional bone graft in the desired position (Figs. 1 and 2). The maxillary sinus floor was raised as in the classic lateral antrostomy pioneered by Tatum combined with onlay bone grafting.6 The space created after the sinus membrane had been raised by the intruded trapdoor was filled with a mixture of autogenous bone and Bio-oss® (Fig. 3). The onlay grafts were shaped so that they closely adapted to the recipient bed and were fixed with two screws (Fig. 4). Care was taken to achieve a tension-free closure of the soft tissue. In both groups antibiotic prophylaxis was continued orally for 7 days postoperatively with amoxycillin 500 mg three times daily. Non-steroidal analgesics were given postoperatively. Patients were requested not to wear their dentures for 2 weeks. After 2–3 weeks a new pair of dentures was made for use during the healing period until the suprastructures were completed and a
Fig. 4. The fixed onlay bone grafts.
200
E.L. van der Mark et al. / British Journal of Oral and Maxillofacial Surgery 49 (2011) 198–202
Table 1 Details of implants. Case no.
No of implants inserted
Type of implant
Interval between first operation and insertion (months)
Follow-up after insertion of implant (months)
No lost
1. Le Fort I 2. Le Fort I 3. Le Fort I 4. Le Fort I 5. Le Fort I 6. Le Fort I 7. Le Fort I 8. Le Fort I 9. Le Fort I 10. Le Fort I 11. Onlay 12. Onlay 13. Onlay 14. Onlay 15. Onlay 16. Onlay 17. Onlay 18. Onlay 19. Onlay 20. Onlay 21. Onlay 22. Onlay 23. Onlay 24. Onlay 25. Onlay 26. Onlay 27. Onlay
4 6 6 6 4 5 7 4 6 6 4 6 6 6 6 6 4 6 6 4 4 6 6 4 4 4 4
Straumann Straumann Nobel Nobel Straumann Straumann Straumann Straumann Straumann Straumann Straumann Straumann Nobel Nobel Nobel Straumann Straumann Straumann Straumann Straumann Straumann Straumann Astra Straumann Nobel Nobel Straumann
6 6 4 5 5 5 5 5 5 5 5 5 5 5 6 5 4 4 4 5 4 5 5 5 6 7 5
24 36 24 9 10 11 12 7 12 18 12 24 24 24 12 24 36 36 12 24 12 12 24 12 12 12 12
1 0 0 0 0 0 2 0 0 0 0 1 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0
final pair of dentures was made. Further instructions included soft diet for 3 months and the use of 0.12% chlorhexidine mouth rinse. Endosseous implants were placed 5–6 months postoperatively. A guidance template was used to ensure the correct position and alignment of the implants. Details of the implants are shown in Table 1. After a 6month healing period the implants were uncovered and the suprastructure was introduced. The Statistical Package for the Social Sciences (SPSS version16, SPSS, Chicago) was used to aid analysis. Pearson’s chi2 test was used to assess the significance of differences between the number of failures of implants in the both groups. Probabilities of less than 0.05 were accepted as significant.
Results All patients were discharged from hospital within 2 days, and the initial healing in all 27 patients was uneventful. During the Le Fort I osteotomy there was one unexpected fracture of the palate, but the maxilla could still be advanced. In the Le Fort I group there were no dehiscences of the soft tissue and no loss of bone grafts. In this group 54 implants were inserted (42 Straumann standard and12 Nobel replace select; Institut Straumann AG, Basel, Switzerland, and Nobel Biocare AB, Göteborg, Sweden). In one patient, one of the four implants did not integrate, which was discovered when the implant
was exposed. This implant was removed. In another patient in whom seven implants were inserted, two failed after 7 months. In total, 3 of the 54 implants were lost in this group, resulting in 6% failure. In the onlay group 86 implants were inserted (54 Straumann standard, 26 Nobel replace select, and 6 Astra) (Astra Tech AB, Mölndal, Sweden). In two patients the soft tissue dehisced, and the corticocancellous bone blocks partly sequestrated. A mixture of autogenous bone, Bio-oss® ,and Bio-gide was used during the second stage operation. Two other patients had a partial loss of bone around an implant, but the implants osseointegrated and functioned normally. In one patient, one of the six implants failed after 5 months, and was subsequently removed when the abutments were inserted. A new implant in the same position was also lost because of lack of bone. In another patient, one of the six implants was lost after 10 months. Overall, in the onlay group, 2 implants of a total of 86 were lost, resulting in 2% failure. There was no difference in failure of implants between the groups (p = 0.3) (Table 2). Some patients experienced disturbances of gait postoperatively, but were free of complaints from the donor site after 3 weeks. Two had temporary sensory disturbances, and two complained of mild pain over the wound after harvesting. Both disturbances and pain resolved after 3 months. One patient had residual pain that lasted longer than 6 months after an anterior harvest, but no patient had temporary or residual pain after a posterior procedure.
E.L. van der Mark et al. / British Journal of Oral and Maxillofacial Surgery 49 (2011) 198–202 Table 2 Number of implants. Survival of implants Success Operation Le Fort Onlay Total
Total Failure
51 84
3 2
54 86
135
5
140
In neither group were further implants lost during the 17 (range 7–36) months’ follow-up.
Discussion Clementschisch is thought to be the first clinician to have used free rib grafts to augment the resorbed mandible by an intraoral route.7 The method was popularised by Davis et al.,8 and also used for the maxilla by Terry et al.9 These grafts were fixed with wire osteosynthesis, but new techniques considerably improved the results of bony augmentation.10 Bell et al. were the first to describe Le Fort I osteotomy with interpositional bone grafts in edentulous patients to improve the position of the maxilla and restore the intermaxillary relation.11 In patients with a class III relation, creating an implant site merely by enlarging the bony volume will lead to unfavourable loading of the dentures and impaired aesthetic and functional results.12 In these cases a Le Fort I osteotomy with interpositioning of bone is indicated. This procedure was first described by Sailer as a one-stage operation,3 and later modified by Cawood et al. as a two-stage one.4 The insertion of the endosseous implants was delayed until the bone grafts had been revascularised. The delayed placement of implants resulted in less risk of their loss and made the use of a template possible.4 In the present study, the technique was slightly modified in that we used fewer osteosynthesis plates, which made it easier to plan and place the implants as only two miniplates were being used to stabilise the maxilla instead of four. The microplates that had been used to fix the cortical bone that formed the new floor of the sinus were not used because they cannot be removed later. By then they are completely covered by bone and can compromise the positioning of the implants. The cortical bone was fixed with 4/0 polyglactin 910 sutures (Vicryl) instead. The stability of the procedure was not compromised by using fewer plates. A Le Fort I osteotomy with interpositional grafts provides an increase in bony volume and a correction in the relation of the jaw to ensure optimal support and functional loading of the implants. It also makes it possible to place the implants through keratinised mucosa. Some authors have claimed that keratinised mucosa surrounding the abutments is a prerequisite for peri-implant health.13,14
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Results from earlier studies and from the present study show good success rates for implants in both groups.15–18 The implants used in this study were from different companies and manufacturers and 12–13 mm long, randomly used in both groups, so the source does not seem to influence the survival between the groups. Maxillary reconstruction with a Le Fort I osteotomy, bony interposition, and insertion of implants in a second stage seems a predictable way to ensure good functional and aesthetic outcomes for a group of patients with a reversed maxillomandibular relation. There were no dehiscences of soft tissue in the Le Fort I group, and vertical relapse of the down-grafted maxilla and bony resorption were of no clinical relevance at the time the implants were placed 5–6 months later. We did the buccal osteotomy in the Le Fort I group with a round burr instead of a reciprocal saw, after which we raised the sinus membrane carefully. In doing so we were unable to prevent little tears, but in no patient did we see entrapment cysts of the sinus epithelium as have been described by others.5 Complications such as sinusitis tend to occur in previously unhealthy sinuses.19 Major complications have been documented, however.20–23 Massive haemorrhage is possible during interpositional grafting and Le Fort I osteotomy. These relatively invasive operations can also give rise to haemorrhage as a result of accidental laceration of the major palatine artery or other branches of the maxillary artery.24 Occasionally a difficult osteotomy or down-fracture, or both, may be encountered. This is likely to be related to atypical maxillary morphology. Comprehensive preoperative cone beam imaging is probably helpful in dealing with this and therefore reduces the likelihood of complications. The possibilities of three-dimensional imaging also encourage the use of alternatives to bone grafting. In patients with no appreciable interarch discrepancy, the use of a zygomatic fixture is an alternative that can be considered if the maxilla is extremely atrophic.25 In conclusion, the results of this study together with published evidence show that patients with atrophic maxillas can be predictably and successfully rehabilitated with bone grafts and a two-stage implant procedure. The use of fewer osteosynthesis plates in the Le Fort I group made it easier to plan and place the implants and did not seem to compromise the stability of the procedure. The choice between a Le Fort I osteotomy or a sinus lifting procedure with onlay grafting should depend on the interarch relations and the need for soft tissue support. Only a considerable interarch discrepancy outweighs the potential risks of a more invasive Le Fort I osteotomy.
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