Anterior maxillary osteoplasty to broaden the narrow maxillary ridge
D. Richardson, J. I. C a w o o d Department of Oral & Maxillofacial Surgery, Chester Royal Infirmary, UK
D. Richardson and J. I. Cawood: Anterior maxillary osteoplasty to broaden the narrow maxillary ridge. Int. J. Oral Maxillofac. Surg. 1991; 20: 342-348. Abstract. The application of endosseous implants has extended the range of options and effectiveness of reconstructive preprosthetic surgery. Placement of endosseous implants in the edentulous maxilla is often restricted due to lack of available bone. Exposure of the underlying anterior maxillary bone frequently reveals a ridge form which is adequate in height but too narrow to accommodate endosseous implants. A horseshoe type osteotomy extending from the ridge crest into the floor of nose has been developed which allows advancement of the outer cortex to restore lost facial form and placement of an interpositional bone graft and endosseous implants to restore lost function.
Successful application of endosseous implants has extended the scope and effectiveness of reconstructive preprosthetic surgery. Of the many variables that govern the use of such implants, the availability of sufficient bulk of bone is most important. Studies have shown that patterns of resorption of the residual alveolar ridges are predictable7. In the anterior maxilla, the direction of bone loss is horizontal, with progressive loss of bone on the labial aspect of the ridge. This converts the broad Class III ridge, with adequate height and width of bone, into a knife edge Class IV ridge, with adequate height, but inadequate width of bone. Associated with the Class IV maxillary ridge, a collapse of the circumoral soft tissues is often seen, resulting in a decrease in the width of the oral commissure, and an increase in the nasolabial angle. Conventional prosthetic treatment is frequently unsatisfactory in this situation. The inadequate alveolar ridge usually provides poor retention and stability of the upper denture. In addition to this t h e resorption pattern in the maxilla tends towards a Class III jaw relationship with crossbite contributing to further denture instability. Adequate support of the collapsed circumoral soft tissues is often impossible. Various surgical techniques have been used in an attempt to overcome these problems. However, all of the techniques so far described address the
problem of the severely atrophic maxilla, corresponding to CAWOOB and HOWELL'S Class V or VI. The technique of anterior maxillary osteoplasty is specifically designed to correct both the s o f t and hard tissue deficiencies found in the Class IV anterior maxillary ridge. Material and methods Patient assessment
This procedure is indicated in patients with a Class IV maxillary anterior ridge where it is considered that endosseous implants would be indicated if sufficient width of supporting bone were present. In assessing the width of the ridge, clinical examination may be misleading, as the knife edge nature of the ridge may be masked by relativelythick submucosa on the palatal aspect. A lateral radiograph of the maxilla will show the outline of the bone
Fig. 1. Flap design (shaded area). Labial incision, submucosal dissection deepened to full thickness over crest of ridge.
Key words: atrophic maxilla; bone graft; endosseous implants; preprosthetic surgery. Accepted for publication 15 July 1991
in the midline. Ridge mappingz4 may be advisable in order to obtain a detailed picture of ridge morphology, and to assess whether there is sufficient bone already present to accommodate implants without the need forsurgery. If ridge width is inadequate, this method is helpful to assess whether an osteoplasty is applicable. As will be discussedlater, there must be sufficient cancellous bone between the cortical plates to make the crestal osteotomy cut. This necessitates a small reduction in the vertical height of the ridge to expose cancellous bone at operation. If this vertical reduction is excessive, it may result in insufficient vertical height to accommodate the implants. Operative technique
The operation is carried out under general anaesthesia with nasal endotracheal intu-
Fig. 2. Flap raised (shaded). Partial and full thickness as shown.
Anterior maxillary osteoplasty to broaden the narrow maxillary ridge
343
repositioned to cover the graft and repositioned segment, and sutured without tension, leaving a mucosal defect on the inside of the upper lip which heals by secondary intention. Prophylactic antibiotics are given peri-operatively. Intravenous Ampicillin and Metronidazole are given on induction of anaesthesia, and continued orally post operatively for 5 days. Endosseous implants are placed at a second operation 6 weeks later, following healing and incorporation of the bone graft (Fig. 9).
Fig. Z Advancement of anterior segment lab-
T Fig. 3. Contouring o f crestal irregularities (shaded). Vertical osteotomy cut extending into the nasal floor. bation. Local anaesthetic with vasoconstrictor is infiltrated submucosally in the upper lip and sulcus. A horseshoe-shaped incision is made in the mucosa well out on the upper lip and a mucosal flap dissected to a point a few millimetres below the crest of the ridge. Periosteum is then incised and the dissection continued subperiosteally onto the palatal aspect of the ridge in order to expose the crest (Figs. 1 & 2). Crestal irregularities are eliminated and cancellous bone is exposed between the cortical plates, sufficient to allow the crestal osteotomy cut to be made, This cut extends obliquely from the crest of the ridge to the floor of the nose (Fig. 3). It is extended laterally in the premolar region through the buccal plate. The anterior nasal spine is removed, and the anterior part of the nasal septum is detached from the segment to be mobilised (Figs. 4 & 5). The labial segment is then mobilised (Figs. 6 & 7) to allow placement of an interpositional bone graft (Fig. 8). The mucosal - mucoperiosteal flap is then
Cases
1. R.O., a 58-year-old man, had a left hemimandibulectomy for carcinoma arising in a mandibular cyst in 1980. The defect was reconstructed with a pectoralis major myocutaneous flap and surgery was followed by a course of radiotherapy. Five years later he declined further reconstruction with a deep circumflex iliac osteocutaneous flap, and as a compromise a free latissimus dorsi myocutaneous flap was transferred to improve skin cover. A year later he was noted to have a fracture o f the right mandibular condyle of unknown aetiology with shortening of the ramus height and interocclusal space. The condyle was excised and reconstructed with a costochondral graft. He had never been able to wear upper or lower dentures satisfactorily. In 1987 he was assessed for reconstructive preprosthetic surgery and found to have a Class IV mandibular ridge with inadequate width o f attached gingiva as well as a Class IV upper ridge with inadequate width of bone to accommodate implants. In July 1988 he underwent mandibular ridge contouring and vestibuloplasty and anterior maxillary osteoplasty using particulate hydroxyapatite as an allograft (Fig. 10). Four months later following uneventful healing, three 3.3 x 13 mm IMZ ® implants were placed into the grafted area, as well as three IMZ implants into the mandible (Fig. 11). These were uncovered after a further 6 months when all implants had integrated. Implant stabilised upper
ially.
and lower dentures were subsequently constructed and the implants remain functional to date, 3 years after osteoplasty (Fig. 12). 2. S.E., a female born in 1972 was involved in a road traffic accident at the age of 13 years. Her maxillofacial injuries included a dento-alveolar fractrue of 1 I 123 region with avulsion of these teeth. After initial healing a partial denture was constructed. In October 1988 she requested a fixed bridge to replace the partial denture. At this time she was noted to have a Class IV residual maxillary ridge, as well as unfavourable vertical relationship due to over eruption of the lower labial segment (Figs. 13 & 14). She was considered unsuitable for a conventional fixed bridge because the length of the span and curvature of the dental arch would have resulted in unacceptable leverage on the abutment teeth. In September 1989 she underwent anterior maxillary osteoplasty utilizing autogenous cortico cancellous bone harvested from the iliac crest. Six weeks later following uneventful healing three 4 x 13 mm IMZ implants were placed and a lower subapical segmental osteotomy was carried out to reposition the anterior teeth to a lower level to improve the vertical relationship (Figs. 15 & 16). The implants were uncovered 3 months later (Fig. 17) and a fixed bridge subsequently constructed. This has been functioning well for 1 year. 3. J.H., a female born in 1974 had partial
Fig. 4. Transverse outline of osteotomy cuts (dotted line) and removal of anterior nasal spine (shaded area).
Fig. 5. Frontal outline of osteotomy cuts
Fig. 6. Mobilisation of anterior segment labi-
Fig. 8. Placement of interpositional bone
(shaded area).
ally.
graft (shaded).
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Fig. 9. Placement of endosseous implants following incorporation of bone graft.
anodontia. Mucosal depth analysis revealed a Class IV anterior maxillary ridge. Since conventional fixed bridge work was not possible and removable dentures were considered undesirable, she underwent anterior maxillary osteoplasty with a bone graft harvested from the mandibular symphysis. Implants were placed after 8 weeks and a fixed bridge subsequently constructed which has been functioning well for 14
months. 4. O.G., a female born in 1925 had lost all maxillary teeth except the central incisors. Conventional removable dentures had been unsatisfactory and assessment revealed a Class IV maxillary ridge (Fig. 18). In October 1988 she underwent a partial maxillary osteoplasty of the canine - bicuspid regions with autogenous cortico cancellous bone graft taken from the iliac crest (Figs. 19-22). Eight weeks later after uneventful healing three 4 x 13 mm IMZ implants were placed each side (Figs. 23 & 24). These were uncovered 7 months later (Fig. 25). An upper fixed bridge was constructed using the implants and central incisors as abutments and has been functioning well for 19 months (Figs. 26 & 27). 5. A 45-year-old woman presented with loss of all teeth posterior to the lateral incisor in the upper right quadrant. She was unable to tolerate a removable prosthesis and clinical and radiological examinations showed a Class IV anterior maxillary ridge. Posteriorly, there was only 2 to 3 mm between the crest of the ridge and the floor of the maxillary sinus. She underwent simultaneous anterior maxillary osteo-
plasty and sinus floor grafting, using autogenous iliac crest bone and hydroxyapatite. She is currently awaiting placement of implants. Discussion The a t r o p h i c maxilla often has a n inadequate a m o u n t o f b o n e to s u p p o r t or retain a c o n v e n t i o n a l prosthesis. It is also associated with a collapse of the circum-oral soft tissues, resulting in decreased w i d t h of the oral c o m m i s s u r e a n d increased nasolabial angle. Endosseous implants can i m p r o v e denture retention a n d stability, b u t do n o t improve facial form. In a d d i t i o n to this there is often i n a d q u a t e b o n e present to a c c o m m o d a t e implants. T h e a i m o f reconstructive preprosthetic surgery is to restore b o t h facial f o r m a n d oral f u n c t i o n 6. T h e a n t e r i o r maxillary osteoplasty utilizes a n osteo t o m y with interpositional b o n e grafting to restore lost ridge form, provide a d e q u a t e b o n e for p l a c e m e n t o f endos-
Fig. 10. Case 1 hydroxyapatite graft in situ.
Fig. 11. Case 1 endosseous implants in situ.
Fig. 12. Case 1 implants and superstructure in situ.
Fig. 13. Case 2 showing narrow maxillary ridge.
Anterior maxillary osteoplasty to broaden the narrow maxillary ridge
345
Fig. 14. Case 2 showing unfavourable vertical relationship.
Fig. 15. Case 2 showing insertion of implants after healing of bone graft.
Fig. 16. Case 2 radiograph showing implants in situ.
Fig. 17. Case 2 showing uncovered implants and corrected vertical relationship.
Fig. 18. Case 4 showing pre-operative ridge form and outline of mucosal flaps.
Fig. 19. Case 4 showing exposed narrow ridge.
seous implants, and to support the circum-oral musculature and soft tissues, thereby improving facial form as well as function of the prosthesis.
Various techniques have been described to augment the maxilla utilizing bone grafts 14'15'21.Bone grafts have been used in conjunction with endosseous ira-
plants as onlay grafts 1,5,16'18, inlay grafts 4'17'19, or interpositional grafts 18'22. The use of interpositional bone grafts is associated with less resorption than
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Richardson a n d C a w o o d
Fig. 20. Case 4 showing osteotomy cuts.
Fig. 21. Case 4 showing mobilised labial segment.
Figs. 22. Case 4 showing bone graft in situ.
Fig. 23. Case 4 showing post-operative broadened maxillary ridge.
Fig. 24. Case 4 showing implant insertion.
Fig. 25. Case 4 showing implants in the broadened ridge.
onlay grafts 2,~6,and their use in the maxilla in combination with endosseous implants has been reported by KELLERTM and SAILER22. They used interpositional bone grafts following Le Fort I down fracture with simultaneous 22 or delayed 18implant placement. However, all of the augmentation techniques described are applicable to the severely
atrophic maxilla, corresponding to CAWOOD and HOWELL'S Class V and VI, and are not suitable for the Class IV maxillary ridge. The Class IV maxillary ridge has adequate height but inadequate width of bone. To apply the above techniques to the Class IV situation would involve a surgical reduction in ridge height con-
verting the Class IV ridge into a Class V ridge, involving significant destruction of alveolar bone. The maxillary osteoplasty is specifically designed to correct the loss of bone in the Class IV ridge, without the need for significant reduction in height of the existing ridge. It results in adequate bulk of bone to place endosseous implants, as well as
Anterior maxillary osteoplasty to broaden the narrow maxillary ridge
Fig. 26. Case 4 radiograph showing implants in situ.
restoration of nasolabial support and oral commissure width due to advancement of the labial corticM plate, with its associated musculature and soft tissues. The only limitation of this technique in the Class IV ridge is where there is insufficient cancellous bone between the labial and palatal cortices to allow the crestal osteotomy cut to be made. This is assessed by clinical examination, radiographs, and ridge mapping. The alternative to osteoplasty in this situation is onlay grafting on the labial aspect of the alveolar ridge. Prophylatic antibiotics are administered intravenously on induction of anaesthesia, and maintained orally for 5 days post operatively. It is considered important that the blood clot surrounding and permeating the graft should contain therapeutic levels of antibiotics active against potential oral pathogens, in order to reduce the risk of graft loss due to infection. The use of the mucosal mucoperiosteal flap gives good access whilst preserving the blood supply to the mobilised segment from the labial and nasal aspects. It permits closure without tension, and simultaneous vestibuloplasty if necessary. The osteotomy cut allows placement of an interpositional bone graft, associated with a lower rate of resorption compared with onlay grafts, and no fixation is necessary. The best graft material currently available is a mixture of particulate hydroxyapatite with autogenous bone, using at least 50% bone. This mixture results in the highest percentage of hydroxyapatite particle integration 9, normal bone structure on histological examination TM, increased fracture strength 13, and a reduced rate of re-
347
Fig. 27. Case 4 fixed prosthesis in situ.
sorption 3,1°, when compared with autogenous bone alone or with mixtures containing higher proportions of hydroxyapatite. Our case grafted with hydroxyapatite alone showed successful implant integration. In this case, the implants were used to retain a mucosal borne denture. It is possible that this structurally weaker graft with less hydroxyapatite particle integration may not be suitable to support a fixed bridge. Various donor sites may be used to provide autogenous bone. LISTROM & SYMINGTON 20 reported disappointing results with particulate marrow and split rib when used with endosseous implants, but other donor sites were satisfactory. Iliac crest and mandibular symphysis have proved satisfactory in our cases. The implants are placed after primary bone healing has occurred (approximately 6 weeks after grafting). This differs from the technique reported by SAILER23. He described a similar osteotomy, but placed implants into the iliac crest bone graft extra-orally,~prior to insertion of the graft into the maxilla. It was then fixed by compression screws passing from labial to palatal cortices in between the implants. In the technique described in this paper, delaying implant placement has several advantages: 1. The initial operation is simple, and therefore potential complications are minimised. Healing of bone grafts and integration of endosseous implants are both complex processes which may fail individually for a variety of reasons. When implants and grafts are placed simultaneously, graft or implant failure may be expected to occur more frequently. For instance the presence of implants and
internal fixation at the stage of initial bone grafting may increase the incidence of infection. Should a mucosal dehiscence occur the particulate nature of the cancellous bone and hydroxyapatite graft will allow resolution with minimal graft loss. It is considered that the use of this graft material without fixation does not provide adequate stability for immediate implant placement. The presence of implants or fixation in a solid block graft will not only delay resolution of dehiscence or infection, but may result in total loss of the implants and bone graft. 2. At the stage of implant placement, a detailed assessment of the augmented ridge form is possible. This allows placement of the implants into the most favourable areas of the graft in the knowledge that primary bone healing has already taken place, and no supporting bone will be lost as a result of failure of this process. Accurate positioning and axial inclination with regard to the subsequent prosthesis is also facilitated. Implant placement at a second operation is a minor procedure which may be carried out under local anaesthesia as an outpatient causing minimal inconvenience to the patient. Osteoplasty is a versatile procedure which may be combined with other reconstructive preprosthetic surgical procedures. Vestibuloplasty may be combined with osteoplasty, and the posterior maxillary ridge may be augmented by alveolplasty with hydroxyapatite to improve ridge form and denture-bearing area for an implant retained and stabilised but mucosal borne denture. If implants are indicated in the
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Richardson and Cawood
posterior maxillary ridge, sinus floor grafting m a y be carried out at the same time as osteoplasty, as illustrated in our case.
Acknowledgment. The authors wish to thank Ms Audrey Richardson for her invaluable secretarial assistance with the preparation of the manuscript.
References l. ADELL R, LEKHOLM U. GRONDAHL K, BRANEMARK PI, LINDSTROMJ, JACOBSSON
M. Reconstruction of severely resorbed edentulous maxillae using osseointegrated fixtures in immediate autogenous bone grafts. Int J Oral Maxillofac Implants. 1990: 5: 233-46. 2. BELLNH, BUCKLESRL. Correction of the atrophic alveolar ridge by interpositional bone grafting: A progress report. J Oral Surg 1978: 36: 693. 3. BOYNEP J, CHANG. Comparison of porous bone mineral and hydroxyapatite in maintenance of alveolar ridges in man. Abstract No. 70, Fourth International Congress on Preprosthetic Surgery, Palm Springs, California, 1991. 4. BOYNE, SJ, JAMES RA. Grafting the maxillary sinus floor with antogenous marrow bone. J Oral Surg 1980: 38: 613-16. 5. BREINE U, BRANEMARK PI. Reconstruction of the alveolar jaw bone. Scand J Plast Reconstr Surg 1980: 14: 2348. 6. CAWOOD JI. Arnhem consensus on preprosthetic surgery, May 1989. Int J Oral Maxillofac Surg 1990: 19:10 11. 7. CAWOOD JI, HOWELL RA. A classification of the edentulous jaws. Int J Oral Maxillofac Surg 1988: 17: 232-6. 8. CAWOODJI, HOWELLRA. Reconstructive preprosthetic surgery. 1. Anatomical con-
siderations. Int J Oral Maxiltofac Surg 1991: 20: 75-82. 9. COBB CM, EICK JD, BARBERBF, MOSBY EL, HIATTWR. Restoration of mandibular continuity defects using combinations of hydroxyapatite and autogenous bone; microscopic observations. J Oral Maxillofac Surg 1990: 48:268 75. 10. DE KOOMEN HA, STOELINGA PJW, BLIJDORP PA, HUYBERS TJM. Reconstruction of the mandible with interposed bone grafts and hydroxyapatite; a 4 to 7 year follow up. Abstract No. 72, Fourth International Congress on Preprosthetic Surgery, Palm Springs, California, 1991. 11. DE LANGE, GL, BLIJDORPPA, STOELINGA PJW, ORYEG. Histology of the maxillary sinus floor grafting with hydroxyapatite and bone. Abstract No. 63, Fourth International Congress on Preprosthetic Surgery, Palm Springs, California, 1991. 12. DE LANGE GL, VAN HEMEL V~ STOELINGA PJW, BLIJDORPP. Histology of mandibular augmentation with and without autogenous iliac bone. Abstract No. 73, Fourth International Congress on Preprosthetic Surgery, Palm Springs, California, 1991. 13. LICK JD, BEARL, COBBCM, MOSBYEL, HIATT WR. Mechanical behaviour of mandibular continuity defects using combinations of hydroxyapatite and autogenous bone. J Oral Maxillofac Surg 1990: 48:823 30. 14. FARMANDM. Horse shoe sandwich osteotomy of the edentulous maxilla as a preprosthetic procedure. J Maxillofac Surg 1986: 14: 238-44. 15. FARRELLCD, KENTJN, GUERRALR. One stage interpositional bone grafting and vestibuloplasty of the atrophic maxilla. J Oral Surg 1976: 34:901 6. 16. FRIEDMANKW. Simultaneous autogenous iliac onlay bone graft to the edentulous maxilla with Swedish osseointegrated
bone screws. Abstracts of the 9th Congress of E.A.C.M.ES. Athens, 1988. 17. JENSON J, K.RANTZ SIMONSENE, SINDETPEDERSEN S. Reconstruction of the severely resorbed maxilla with bone grafting and osseointegrated implants. J Oral Maxillofac Surg 1990: 48: 27-32. 18. KELLER EL, VAN ROCKELNB, DESJARDINS RP, fOEMAN DE. Prosthetic-surgical reconstruction of the severely resorbed maxilla with iliac bone grafting and tissue integrated prostheses. Int J Oral Maxillofac Implants. 1987: 2:155 65. 19. KENT JN, BLOCK MS. Simultaneous maxillary sinus floor bone grafting and placement of hydroxylapatite coated implants. J Oral Maxillofac Surg 1989: 47: 238 42. 20. LISTROMRD, SYMINGTONJM. Osseointegrated dental implants in conjunction with bone grafts. Int J Oral Maxillofac Surg 1988: 17: 116-8. 21. PIECUCH Jf, aLGAL D, GRASSOJE. Augmentation of the atrophic maxilla with interpositional autogenous bone grafts. J Maxillofac Surg 1984: 12: 133-8. 22. SAILER HF. A new method of inserting endosseous implants in a totally atrophic maxillae. J Cranio-Maxillofac Surg 1989: 17: 29%305. 23. SAILERHE Two new methods of combining osteotomies and endosseous titantium screw implants for the narrow maxillary ridge and atrophic lateral mandible. Book of Abstracts. Third International Congress on preprosthetic surgery, "The edentulous jaw". Arnhem, The Netherlands i989: No. 73: 62-63. 24. WILSON DJ. Ridge mapping for determination of alveolar ridge width. Int J Oral Maxillofac Implants 1989: 4: 41-3. Address: Mr J. L Cawood Maxillofacial Unit Royal Infirmary Chester CH1 2AZ UK
D. Richardson, J. I. C a w o o d Department of Oral & Maxillofacial Surgery, Chester Royal Infirmary, UK
D. Richardson and J. I. Cawood: Anterior maxillary osteoplasty to broaden the narrow maxillary ridge. Int. J. Oral Maxillofac. Surg. 1991; 20: 342-348. Abstract. The application of endosseous implants has extended the range of options and effectiveness of reconstructive preprosthetic surgery. Placement of endosseous implants in the edentulous maxilla is often restricted due to lack of available bone. Exposure of the underlying anterior maxillary bone frequently reveals a ridge form which is adequate in height but too narrow to accommodate endosseous implants. A horseshoe type osteotomy extending from the ridge crest into the floor of nose has been developed which allows advancement of the outer cortex to restore lost facial form and placement of an interpositional bone graft and endosseous implants to restore lost function.
Successful application of endosseous implants has extended the scope and effectiveness of reconstructive preprosthetic surgery. Of the many variables that govern the use of such implants, the availability of sufficient bulk of bone is most important. Studies have shown that patterns of resorption of the residual alveolar ridges are predictable7. In the anterior maxilla, the direction of bone loss is horizontal, with progressive loss of bone on the labial aspect of the ridge. This converts the broad Class III ridge, with adequate height and width of bone, into a knife edge Class IV ridge, with adequate height, but inadequate width of bone. Associated with the Class IV maxillary ridge, a collapse of the circumoral soft tissues is often seen, resulting in a decrease in the width of the oral commissure, and an increase in the nasolabial angle. Conventional prosthetic treatment is frequently unsatisfactory in this situation. The inadequate alveolar ridge usually provides poor retention and stability of the upper denture. In addition to this t h e resorption pattern in the maxilla tends towards a Class III jaw relationship with crossbite contributing to further denture instability. Adequate support of the collapsed circumoral soft tissues is often impossible. Various surgical techniques have been used in an attempt to overcome these problems. However, all of the techniques so far described address the
problem of the severely atrophic maxilla, corresponding to CAWOOB and HOWELL'S Class V or VI. The technique of anterior maxillary osteoplasty is specifically designed to correct both the s o f t and hard tissue deficiencies found in the Class IV anterior maxillary ridge. Material and methods Patient assessment
This procedure is indicated in patients with a Class IV maxillary anterior ridge where it is considered that endosseous implants would be indicated if sufficient width of supporting bone were present. In assessing the width of the ridge, clinical examination may be misleading, as the knife edge nature of the ridge may be masked by relativelythick submucosa on the palatal aspect. A lateral radiograph of the maxilla will show the outline of the bone
Fig. 1. Flap design (shaded area). Labial incision, submucosal dissection deepened to full thickness over crest of ridge.
Key words: atrophic maxilla; bone graft; endosseous implants; preprosthetic surgery. Accepted for publication 15 July 1991
in the midline. Ridge mappingz4 may be advisable in order to obtain a detailed picture of ridge morphology, and to assess whether there is sufficient bone already present to accommodate implants without the need forsurgery. If ridge width is inadequate, this method is helpful to assess whether an osteoplasty is applicable. As will be discussedlater, there must be sufficient cancellous bone between the cortical plates to make the crestal osteotomy cut. This necessitates a small reduction in the vertical height of the ridge to expose cancellous bone at operation. If this vertical reduction is excessive, it may result in insufficient vertical height to accommodate the implants. Operative technique
The operation is carried out under general anaesthesia with nasal endotracheal intu-
Fig. 2. Flap raised (shaded). Partial and full thickness as shown.
Anterior maxillary osteoplasty to broaden the narrow maxillary ridge
343
repositioned to cover the graft and repositioned segment, and sutured without tension, leaving a mucosal defect on the inside of the upper lip which heals by secondary intention. Prophylactic antibiotics are given peri-operatively. Intravenous Ampicillin and Metronidazole are given on induction of anaesthesia, and continued orally post operatively for 5 days. Endosseous implants are placed at a second operation 6 weeks later, following healing and incorporation of the bone graft (Fig. 9).
Fig. Z Advancement of anterior segment lab-
T Fig. 3. Contouring o f crestal irregularities (shaded). Vertical osteotomy cut extending into the nasal floor. bation. Local anaesthetic with vasoconstrictor is infiltrated submucosally in the upper lip and sulcus. A horseshoe-shaped incision is made in the mucosa well out on the upper lip and a mucosal flap dissected to a point a few millimetres below the crest of the ridge. Periosteum is then incised and the dissection continued subperiosteally onto the palatal aspect of the ridge in order to expose the crest (Figs. 1 & 2). Crestal irregularities are eliminated and cancellous bone is exposed between the cortical plates, sufficient to allow the crestal osteotomy cut to be made, This cut extends obliquely from the crest of the ridge to the floor of the nose (Fig. 3). It is extended laterally in the premolar region through the buccal plate. The anterior nasal spine is removed, and the anterior part of the nasal septum is detached from the segment to be mobilised (Figs. 4 & 5). The labial segment is then mobilised (Figs. 6 & 7) to allow placement of an interpositional bone graft (Fig. 8). The mucosal - mucoperiosteal flap is then
Cases
1. R.O., a 58-year-old man, had a left hemimandibulectomy for carcinoma arising in a mandibular cyst in 1980. The defect was reconstructed with a pectoralis major myocutaneous flap and surgery was followed by a course of radiotherapy. Five years later he declined further reconstruction with a deep circumflex iliac osteocutaneous flap, and as a compromise a free latissimus dorsi myocutaneous flap was transferred to improve skin cover. A year later he was noted to have a fracture o f the right mandibular condyle of unknown aetiology with shortening of the ramus height and interocclusal space. The condyle was excised and reconstructed with a costochondral graft. He had never been able to wear upper or lower dentures satisfactorily. In 1987 he was assessed for reconstructive preprosthetic surgery and found to have a Class IV mandibular ridge with inadequate width o f attached gingiva as well as a Class IV upper ridge with inadequate width of bone to accommodate implants. In July 1988 he underwent mandibular ridge contouring and vestibuloplasty and anterior maxillary osteoplasty using particulate hydroxyapatite as an allograft (Fig. 10). Four months later following uneventful healing, three 3.3 x 13 mm IMZ ® implants were placed into the grafted area, as well as three IMZ implants into the mandible (Fig. 11). These were uncovered after a further 6 months when all implants had integrated. Implant stabilised upper
ially.
and lower dentures were subsequently constructed and the implants remain functional to date, 3 years after osteoplasty (Fig. 12). 2. S.E., a female born in 1972 was involved in a road traffic accident at the age of 13 years. Her maxillofacial injuries included a dento-alveolar fractrue of 1 I 123 region with avulsion of these teeth. After initial healing a partial denture was constructed. In October 1988 she requested a fixed bridge to replace the partial denture. At this time she was noted to have a Class IV residual maxillary ridge, as well as unfavourable vertical relationship due to over eruption of the lower labial segment (Figs. 13 & 14). She was considered unsuitable for a conventional fixed bridge because the length of the span and curvature of the dental arch would have resulted in unacceptable leverage on the abutment teeth. In September 1989 she underwent anterior maxillary osteoplasty utilizing autogenous cortico cancellous bone harvested from the iliac crest. Six weeks later following uneventful healing three 4 x 13 mm IMZ implants were placed and a lower subapical segmental osteotomy was carried out to reposition the anterior teeth to a lower level to improve the vertical relationship (Figs. 15 & 16). The implants were uncovered 3 months later (Fig. 17) and a fixed bridge subsequently constructed. This has been functioning well for 1 year. 3. J.H., a female born in 1974 had partial
Fig. 4. Transverse outline of osteotomy cuts (dotted line) and removal of anterior nasal spine (shaded area).
Fig. 5. Frontal outline of osteotomy cuts
Fig. 6. Mobilisation of anterior segment labi-
Fig. 8. Placement of interpositional bone
(shaded area).
ally.
graft (shaded).
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Richardson and Cawood
Fig. 9. Placement of endosseous implants following incorporation of bone graft.
anodontia. Mucosal depth analysis revealed a Class IV anterior maxillary ridge. Since conventional fixed bridge work was not possible and removable dentures were considered undesirable, she underwent anterior maxillary osteoplasty with a bone graft harvested from the mandibular symphysis. Implants were placed after 8 weeks and a fixed bridge subsequently constructed which has been functioning well for 14
months. 4. O.G., a female born in 1925 had lost all maxillary teeth except the central incisors. Conventional removable dentures had been unsatisfactory and assessment revealed a Class IV maxillary ridge (Fig. 18). In October 1988 she underwent a partial maxillary osteoplasty of the canine - bicuspid regions with autogenous cortico cancellous bone graft taken from the iliac crest (Figs. 19-22). Eight weeks later after uneventful healing three 4 x 13 mm IMZ implants were placed each side (Figs. 23 & 24). These were uncovered 7 months later (Fig. 25). An upper fixed bridge was constructed using the implants and central incisors as abutments and has been functioning well for 19 months (Figs. 26 & 27). 5. A 45-year-old woman presented with loss of all teeth posterior to the lateral incisor in the upper right quadrant. She was unable to tolerate a removable prosthesis and clinical and radiological examinations showed a Class IV anterior maxillary ridge. Posteriorly, there was only 2 to 3 mm between the crest of the ridge and the floor of the maxillary sinus. She underwent simultaneous anterior maxillary osteo-
plasty and sinus floor grafting, using autogenous iliac crest bone and hydroxyapatite. She is currently awaiting placement of implants. Discussion The a t r o p h i c maxilla often has a n inadequate a m o u n t o f b o n e to s u p p o r t or retain a c o n v e n t i o n a l prosthesis. It is also associated with a collapse of the circum-oral soft tissues, resulting in decreased w i d t h of the oral c o m m i s s u r e a n d increased nasolabial angle. Endosseous implants can i m p r o v e denture retention a n d stability, b u t do n o t improve facial form. In a d d i t i o n to this there is often i n a d q u a t e b o n e present to a c c o m m o d a t e implants. T h e a i m o f reconstructive preprosthetic surgery is to restore b o t h facial f o r m a n d oral f u n c t i o n 6. T h e a n t e r i o r maxillary osteoplasty utilizes a n osteo t o m y with interpositional b o n e grafting to restore lost ridge form, provide a d e q u a t e b o n e for p l a c e m e n t o f endos-
Fig. 10. Case 1 hydroxyapatite graft in situ.
Fig. 11. Case 1 endosseous implants in situ.
Fig. 12. Case 1 implants and superstructure in situ.
Fig. 13. Case 2 showing narrow maxillary ridge.
Anterior maxillary osteoplasty to broaden the narrow maxillary ridge
345
Fig. 14. Case 2 showing unfavourable vertical relationship.
Fig. 15. Case 2 showing insertion of implants after healing of bone graft.
Fig. 16. Case 2 radiograph showing implants in situ.
Fig. 17. Case 2 showing uncovered implants and corrected vertical relationship.
Fig. 18. Case 4 showing pre-operative ridge form and outline of mucosal flaps.
Fig. 19. Case 4 showing exposed narrow ridge.
seous implants, and to support the circum-oral musculature and soft tissues, thereby improving facial form as well as function of the prosthesis.
Various techniques have been described to augment the maxilla utilizing bone grafts 14'15'21.Bone grafts have been used in conjunction with endosseous ira-
plants as onlay grafts 1,5,16'18, inlay grafts 4'17'19, or interpositional grafts 18'22. The use of interpositional bone grafts is associated with less resorption than
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Richardson a n d C a w o o d
Fig. 20. Case 4 showing osteotomy cuts.
Fig. 21. Case 4 showing mobilised labial segment.
Figs. 22. Case 4 showing bone graft in situ.
Fig. 23. Case 4 showing post-operative broadened maxillary ridge.
Fig. 24. Case 4 showing implant insertion.
Fig. 25. Case 4 showing implants in the broadened ridge.
onlay grafts 2,~6,and their use in the maxilla in combination with endosseous implants has been reported by KELLERTM and SAILER22. They used interpositional bone grafts following Le Fort I down fracture with simultaneous 22 or delayed 18implant placement. However, all of the augmentation techniques described are applicable to the severely
atrophic maxilla, corresponding to CAWOOD and HOWELL'S Class V and VI, and are not suitable for the Class IV maxillary ridge. The Class IV maxillary ridge has adequate height but inadequate width of bone. To apply the above techniques to the Class IV situation would involve a surgical reduction in ridge height con-
verting the Class IV ridge into a Class V ridge, involving significant destruction of alveolar bone. The maxillary osteoplasty is specifically designed to correct the loss of bone in the Class IV ridge, without the need for significant reduction in height of the existing ridge. It results in adequate bulk of bone to place endosseous implants, as well as
Anterior maxillary osteoplasty to broaden the narrow maxillary ridge
Fig. 26. Case 4 radiograph showing implants in situ.
restoration of nasolabial support and oral commissure width due to advancement of the labial corticM plate, with its associated musculature and soft tissues. The only limitation of this technique in the Class IV ridge is where there is insufficient cancellous bone between the labial and palatal cortices to allow the crestal osteotomy cut to be made. This is assessed by clinical examination, radiographs, and ridge mapping. The alternative to osteoplasty in this situation is onlay grafting on the labial aspect of the alveolar ridge. Prophylatic antibiotics are administered intravenously on induction of anaesthesia, and maintained orally for 5 days post operatively. It is considered important that the blood clot surrounding and permeating the graft should contain therapeutic levels of antibiotics active against potential oral pathogens, in order to reduce the risk of graft loss due to infection. The use of the mucosal mucoperiosteal flap gives good access whilst preserving the blood supply to the mobilised segment from the labial and nasal aspects. It permits closure without tension, and simultaneous vestibuloplasty if necessary. The osteotomy cut allows placement of an interpositional bone graft, associated with a lower rate of resorption compared with onlay grafts, and no fixation is necessary. The best graft material currently available is a mixture of particulate hydroxyapatite with autogenous bone, using at least 50% bone. This mixture results in the highest percentage of hydroxyapatite particle integration 9, normal bone structure on histological examination TM, increased fracture strength 13, and a reduced rate of re-
347
Fig. 27. Case 4 fixed prosthesis in situ.
sorption 3,1°, when compared with autogenous bone alone or with mixtures containing higher proportions of hydroxyapatite. Our case grafted with hydroxyapatite alone showed successful implant integration. In this case, the implants were used to retain a mucosal borne denture. It is possible that this structurally weaker graft with less hydroxyapatite particle integration may not be suitable to support a fixed bridge. Various donor sites may be used to provide autogenous bone. LISTROM & SYMINGTON 20 reported disappointing results with particulate marrow and split rib when used with endosseous implants, but other donor sites were satisfactory. Iliac crest and mandibular symphysis have proved satisfactory in our cases. The implants are placed after primary bone healing has occurred (approximately 6 weeks after grafting). This differs from the technique reported by SAILER23. He described a similar osteotomy, but placed implants into the iliac crest bone graft extra-orally,~prior to insertion of the graft into the maxilla. It was then fixed by compression screws passing from labial to palatal cortices in between the implants. In the technique described in this paper, delaying implant placement has several advantages: 1. The initial operation is simple, and therefore potential complications are minimised. Healing of bone grafts and integration of endosseous implants are both complex processes which may fail individually for a variety of reasons. When implants and grafts are placed simultaneously, graft or implant failure may be expected to occur more frequently. For instance the presence of implants and
internal fixation at the stage of initial bone grafting may increase the incidence of infection. Should a mucosal dehiscence occur the particulate nature of the cancellous bone and hydroxyapatite graft will allow resolution with minimal graft loss. It is considered that the use of this graft material without fixation does not provide adequate stability for immediate implant placement. The presence of implants or fixation in a solid block graft will not only delay resolution of dehiscence or infection, but may result in total loss of the implants and bone graft. 2. At the stage of implant placement, a detailed assessment of the augmented ridge form is possible. This allows placement of the implants into the most favourable areas of the graft in the knowledge that primary bone healing has already taken place, and no supporting bone will be lost as a result of failure of this process. Accurate positioning and axial inclination with regard to the subsequent prosthesis is also facilitated. Implant placement at a second operation is a minor procedure which may be carried out under local anaesthesia as an outpatient causing minimal inconvenience to the patient. Osteoplasty is a versatile procedure which may be combined with other reconstructive preprosthetic surgical procedures. Vestibuloplasty may be combined with osteoplasty, and the posterior maxillary ridge may be augmented by alveolplasty with hydroxyapatite to improve ridge form and denture-bearing area for an implant retained and stabilised but mucosal borne denture. If implants are indicated in the
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posterior maxillary ridge, sinus floor grafting m a y be carried out at the same time as osteoplasty, as illustrated in our case.
Acknowledgment. The authors wish to thank Ms Audrey Richardson for her invaluable secretarial assistance with the preparation of the manuscript.
References l. ADELL R, LEKHOLM U. GRONDAHL K, BRANEMARK PI, LINDSTROMJ, JACOBSSON
M. Reconstruction of severely resorbed edentulous maxillae using osseointegrated fixtures in immediate autogenous bone grafts. Int J Oral Maxillofac Implants. 1990: 5: 233-46. 2. BELLNH, BUCKLESRL. Correction of the atrophic alveolar ridge by interpositional bone grafting: A progress report. J Oral Surg 1978: 36: 693. 3. BOYNEP J, CHANG. Comparison of porous bone mineral and hydroxyapatite in maintenance of alveolar ridges in man. Abstract No. 70, Fourth International Congress on Preprosthetic Surgery, Palm Springs, California, 1991. 4. BOYNE, SJ, JAMES RA. Grafting the maxillary sinus floor with antogenous marrow bone. J Oral Surg 1980: 38: 613-16. 5. BREINE U, BRANEMARK PI. Reconstruction of the alveolar jaw bone. Scand J Plast Reconstr Surg 1980: 14: 2348. 6. CAWOOD JI. Arnhem consensus on preprosthetic surgery, May 1989. Int J Oral Maxillofac Surg 1990: 19:10 11. 7. CAWOOD JI, HOWELL RA. A classification of the edentulous jaws. Int J Oral Maxillofac Surg 1988: 17: 232-6. 8. CAWOODJI, HOWELLRA. Reconstructive preprosthetic surgery. 1. Anatomical con-
siderations. Int J Oral Maxiltofac Surg 1991: 20: 75-82. 9. COBB CM, EICK JD, BARBERBF, MOSBY EL, HIATTWR. Restoration of mandibular continuity defects using combinations of hydroxyapatite and autogenous bone; microscopic observations. J Oral Maxillofac Surg 1990: 48:268 75. 10. DE KOOMEN HA, STOELINGA PJW, BLIJDORP PA, HUYBERS TJM. Reconstruction of the mandible with interposed bone grafts and hydroxyapatite; a 4 to 7 year follow up. Abstract No. 72, Fourth International Congress on Preprosthetic Surgery, Palm Springs, California, 1991. 11. DE LANGE, GL, BLIJDORPPA, STOELINGA PJW, ORYEG. Histology of the maxillary sinus floor grafting with hydroxyapatite and bone. Abstract No. 63, Fourth International Congress on Preprosthetic Surgery, Palm Springs, California, 1991. 12. DE LANGE GL, VAN HEMEL V~ STOELINGA PJW, BLIJDORPP. Histology of mandibular augmentation with and without autogenous iliac bone. Abstract No. 73, Fourth International Congress on Preprosthetic Surgery, Palm Springs, California, 1991. 13. LICK JD, BEARL, COBBCM, MOSBYEL, HIATT WR. Mechanical behaviour of mandibular continuity defects using combinations of hydroxyapatite and autogenous bone. J Oral Maxillofac Surg 1990: 48:823 30. 14. FARMANDM. Horse shoe sandwich osteotomy of the edentulous maxilla as a preprosthetic procedure. J Maxillofac Surg 1986: 14: 238-44. 15. FARRELLCD, KENTJN, GUERRALR. One stage interpositional bone grafting and vestibuloplasty of the atrophic maxilla. J Oral Surg 1976: 34:901 6. 16. FRIEDMANKW. Simultaneous autogenous iliac onlay bone graft to the edentulous maxilla with Swedish osseointegrated
bone screws. Abstracts of the 9th Congress of E.A.C.M.ES. Athens, 1988. 17. JENSON J, K.RANTZ SIMONSENE, SINDETPEDERSEN S. Reconstruction of the severely resorbed maxilla with bone grafting and osseointegrated implants. J Oral Maxillofac Surg 1990: 48: 27-32. 18. KELLER EL, VAN ROCKELNB, DESJARDINS RP, fOEMAN DE. Prosthetic-surgical reconstruction of the severely resorbed maxilla with iliac bone grafting and tissue integrated prostheses. Int J Oral Maxillofac Implants. 1987: 2:155 65. 19. KENT JN, BLOCK MS. Simultaneous maxillary sinus floor bone grafting and placement of hydroxylapatite coated implants. J Oral Maxillofac Surg 1989: 47: 238 42. 20. LISTROMRD, SYMINGTONJM. Osseointegrated dental implants in conjunction with bone grafts. Int J Oral Maxillofac Surg 1988: 17: 116-8. 21. PIECUCH Jf, aLGAL D, GRASSOJE. Augmentation of the atrophic maxilla with interpositional autogenous bone grafts. J Maxillofac Surg 1984: 12: 133-8. 22. SAILER HF. A new method of inserting endosseous implants in a totally atrophic maxillae. J Cranio-Maxillofac Surg 1989: 17: 29%305. 23. SAILERHE Two new methods of combining osteotomies and endosseous titantium screw implants for the narrow maxillary ridge and atrophic lateral mandible. Book of Abstracts. Third International Congress on preprosthetic surgery, "The edentulous jaw". Arnhem, The Netherlands i989: No. 73: 62-63. 24. WILSON DJ. Ridge mapping for determination of alveolar ridge width. Int J Oral Maxillofac Implants 1989: 4: 41-3. Address: Mr J. L Cawood Maxillofacial Unit Royal Infirmary Chester CH1 2AZ UK
