A method for the bony and dental reconstruction of the maxilla in dentate patients

Copyright 9 Munksgaard 1997

Int. J. OralMaxillofac. Surg. 1997; 26:369-373 Printed in Denmark. All rights reserved

InternationalJournalof

Oral& MaxillofacialSurgery ISSN 0901-5027

A method for the bony and dental reconstruction of the maxilla in dentate patients

B. Hell, A. Tischer, E. Heissler, J. Bier Clinic for Maxillofacial Surgery, Charit~Virchow-Klinikum, Humboldt University Berlin, Berlin, Germany

B. Hell, A. Tischer, E. Heissler, J. Bier." A method for the bony and dental reconstruction o f the maxilla in dentate patients. Int. J. Oral Maxillofac. Surg. 1997," 26: 369-373. 9 Munksgaard, 1997 Abstract. Reconstruction was carried out on eleven patients using a vascularized full thickness calvarial bone flap following partial maxillectomy. The donor site was covered with a split calvarial bone graft. Intraorally a mucosal transposition flap was used to cover the graft. Six months later implants were inserted and were allowed to heal for three months before dental rehabilitation began. No serious complications were encounted. Zusammenfassung. Elf Patienten wurden nach Oberkieferteilresektion mit einem vaskularisierten bikortikalen Kalottentransplantat versorgt. Die Spenderregion wurde mit einem freien monokortikalen Transplantat gedeckt. Der WeichteilverschluB enoral erfolgte mit einem dorsal gestielten Mukosalappen. Nach sechs Monaten wurden enossale Implantate inseriert, die drei Monate unbelastet einheilten, ehe mit der prothetischen Weiterversorgung begonnen wurde. Da keine gravierenden Komplikationen auftraten, k r n n e n wir diesen Behandlungsplan zur Versorgung von Patienten nach partieller Maxillektomie empfehlen.

Following partial maxillectomy for radical treatment of maxillary tumours, patients face serious problems with mastication, swallowing, speech, and sometimes aesthetics. Radical tumour resection in this region often results in the removal of intraoral mucosa, the alveolar process, palatal bone, teeth and the mucosal lining of the maxillary sinus and the nose. Reconstruction is of paramount importance to these patients. Several techniques have been suggested using autogenous material or prosthetic devices. Free tissue transfers with or without microvascular reanastomosis have been reported ~~ as welt as locally pedicled transplants without the need for microvascular reanastomosis7. The purpose of this paper is to present a comprehensive

treatment strategy that includes bony reconstruction of the maxilla, restoration of the oral mucosa, and an implant-fixed prosthetic reconstruction. Our experience with 11 patients, who have been treated according to this concept since 1992, is reported.

Material and methods Since 1992 eleven patients with tumours of the maxilla have been treated (Table 1). Eight patients suffered from squamous cell carcinoma, one patient had a giant cell granuloma, one a fibromyxoma, and one had adenoid cystic carcinoma. The patient with adenoid cystic carcinoma died in another hospital seven months after the operation from pulmonary complications. Five patients were women and six were men. The average age was 46 years (age range 24-58 years).

Key words: maxilla; reconstruction; full thickness calvarial bone flap; dental implants.

Accepted for publication 1 April 1997

Removal of the draining lymphatic tissue was, if necessary, achieved by superficialparotidectomy and neck dissection.After radical removal of the turnout, which resulted in a perforating defect of the maxilla (Fig. 1), immediate reconstruction was performed. The largest defect was 3• cm, the smallest 2• cm. The temporal muscle, temporal bone and zygomatic arch were exposed through an extended hemicoronal incision, which can easily be extended downwards to perform the parotidectomy and neck dissection as needed. Care was taken to place the incision far enough behind the hairline particularly in men. The incision was carried down through the skin to the superficial fascia of the temporal muscle. The dissection followed the superficial fascia. Two cm above the zygomatic arch, the fascia was incised and further preparation was carried out directly on the surface of the muscle in order to prevent any

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Table 1. Patient data Patient no. 1 2 3 4 5 6 7 8 9 10 11

Age

Sex

Diagnosis

Tumour stage

Months postop.

Implants (y/n)

Prosthetics (y/n)

52 45 24 38 44 56 43 54 47 58 45

F F F M F M F M M M M

Giant cell granuloma SCC Fibromyxoma SCC Adenoid cystic carcinoma SCC SCC SCC SCC SCC SCC

pT4,pN0 pT4, pN1 pT4,pN0 pT3, pN0 pT3,pN1 pT4, pN1 pT1, pN0 pT1, pN0 pT2, pN0 pT4, pN0 pT2, pN1

29 17 16 15 died 12 11 8 6 3 2

y y y y y y y n n n

y y n y y y n n n n

F=female; M=male. SCC=squamous cell carcinoma. Implants (y/n): y=implants placed; n = n o t placed; Prosthetics (y/n): y=dental prosthetic treatment completed; n = n o t completed.

Fig. 1. Intraoral defect after partial maxillectomy.

Fig. 2. Diagram of the planned calvarial bone flap and its blood supply.

damage to the frontal branch o f the facial nerve. Blood supply to the temporal muscle and the adjacent bone mainly depends on the deep temporal vessels1,s,~s,17. While raising the muscle pedicle, care was taken not to damage these vessels which originate from the internal maxillary artery (Fig. 2) 12 14,16. The temporal bone was harvested in cooperation with the neurosurgeons by trepanation at the four corners of the planned bone flap and osteotomy with a Gigli saw at the superior and lateral borders of the flap. The base of the bone flap was cut with an osteotome after creating a tunnel under the temporal muscle (Fig. 3). In the region of the temporal lines and the contiguous parietal bone, the absolute thickness of the bone graft may vary from 4 to 7 mm. While the anterior part of the muscle serves as a pedicle for the flap, the posterior part is rotated anteriorly to achieve a better aesthetic result in the visible donor region. To avoid separation of the temporal muscle from the bone, the muscle was attached to the bone with sutures. To cover the resulting calvarial defect, a second full-thickness bone graft was harvested next to the primary defect (Fig. 4). This free graft was split into its inner and outer table. The inner table served to cover the bone defect in the donor region, while the outer table was put back from where it was harvested. The grafts were fixed using microplates (Fig. 5). I n order to transfer the pedicled graft intraorally, the zygomatic arch had to be removed temporarily. The dorsal and lateral walls of the maxillary sinus were removed to allow the intraoral positioning o f the bone graft. The bone graft was also shaped to accommodate the defect and then fixed to the remaining bone with microplates, miniplates or wires (Fig. 6). The temporal muscle, which served as a pedicle, also formed the lining structure towards the maxillary sinus and the nasal cavity. The attachment o f the temporal muscle at the coronoid process was left intact. Intraorally the bone was completely covered with a transpositional mucosal flap taken from the cheek 2~ The flap was based

Reconstruction o f the maxilla in dentate patients Fig. 3. Full thickness calvarial bone flap is raised.

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our patients and all but one graft were well incorporated. In one patient no bony union occurred which resulted in a mobile transplant. In this case the graft was extended too far posteriorly leading to interference with the coronoid process of the mandible during mastication. The graft was, therefore, shortened during the first-stage implantation operation, which resulted in stable bony tmion.

Discussion

Fig. 4. Flap covers maxillary defect. Donor site is reconstructed by inner table of split full-thickness bone graft harvested craniodorsal to donor defect.

craniodistally in the molar region of the buccal cavity. If necessary, the tip of the flap may reach the vestibular mucnsa of the lower lip. The largest defect in our patients measured 3• cm (patient no. 10), and the smallest 2• cm. All patients received intraoperative and postoperative antimicrobial treatment with cefotiam 3• g/d i.v. for seven days. The bone was allowed to heal for six months before implants were inserted with the help of a template (Fig. 7). Altogether 15 implants were inserted in seven patients. In all patients 10 mm Brfinemark standard fixtures were used. A screw tap was used because the calvarial bone is brittle and might otherwise fracture. In two patients a bone specimen was removed for histologic examin-

ation during this procedure. Both specimens showed healthy normal bone (Fig. 8). The implants were allowed to integrate for three months before abutments were placed. During this operation a vestibuloplasty was carried out in five patients using a free mucosal graft, because there was not enough fixed mucosa on the vestibular side of the bone graft due to the muscular pedicle. After healing, the patients received a fixed partial denture supported by implants (Fig. 9).

Complications Postoperatively one patient developed a sinus tract of uncertain origin at the former suture line in the donor region. After excision it did not recur. Infections were not observed in

Maxillary defects resulting from radical t u m o u r surgery can be treated by a variety o f methods. Removable prosthetic devices particularly in the edentulous maxilla may be sufficient in some patients. The site of possible t u m o u r recurrence is easily accessible with the advantage of early detection of recurrent disease. However, at present many patients prefer complete reconstruction, which also allows the insertion of endosteal implants. TIDEMAN et al. is propose the use o f a split temporalis flap combined with free autogenous corticocancellous iliac bone that is held in place by a titanium mesh tray. A t the present time reliable data regarding the quality o f the new bone do not exist and resorption after placing implants might be a serious problem. With the m e t h o d presented in our study, two layers of cortical bone are available, which makes the secure placement of endosteal implants possible. The calvarial bone is also of membranous origin and is, therefore, probably more resistant to resorption than bone of endochondral origin 3'4'9'12'15. Several authors I~ suggest microvascular transfer of tissue. This seems to be a valuable alternative. Problems, however, might arise from donor site morbidity and excess tissue bulk, which is usually inherent in these methods. With the technique presented, problems with bulk were not seen because the muscular pedicle formed the lining structure towards the maxillary sinus. The operation time for microvascular tissue transfer can also be expected to be longer than for the proposed procedure. CONLE7 3 and CHOUNG et al. 2 describe reconstruction with monocortical calvarial transplants. Harvesting these pieces of bone, which requires the use of a chisel, however, is more traumatic than harvesting bicortical transplants. Intracerebral bleeding, cerebrospinal fluid leak and sagittal sinus perforation

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Fig. 5. Calvarium is

reconstructed by free bone graft.

Fig. 8. Vital bone in histological specimen harvested during insertion of implants (HE•

Fig. 6. Intraoral fix-

ation of flap by miniplate and wire osteosynthesis.

Fig. 7. Orthopantom-

ogram showing two implants into pedicled bone graft.

have been reported as complications of this operation 6,19. The stable placement of implants is also more difficult in monocortical than in bicortical bone. A similar reconstruction method is described by EWERSs, who performed a double musculoperiosteal flap in connection with a composite calvarial bone

graft. The disadvantage of this technique is a thick intraoral soft tissue layer, which may result in problems with the prosthetic rehabilitation. Although this technique was only performed following hemimaxillectomy, it should be possible to reconstruct the complete maxilla. In this case it would

be necessary to use a temporalis muscle flap from the opposite side as well. Oral coverage should be achieved by mucosal cheek flaps from both sides. In patients with large defects or in dentate patients, incomplete coverage by cheek flaps resulted in healing by secondary intention with rather adequate results. No problems in intraoral healing of the mucosal cheek flaps were seen in the treated patients. The vascularized bone seems to be an excellent receptor region for this transposition flap. The method is also suitable for the reconstruction of the anterior region of the maxilla, provided that the defect extends distally to the canine region. Harvesting the bone from below the anterior portion of the temporalis muscle is to be preferred, because the calvarial bone in this region is of consistent and sufficient thickness. The calvarial bone in the region of the sphenoidal wing is rather thin and the pedicle relatively short, so this is not a feasible donor site for the method presented. In most cases the graft was fixed at a steep angle of 1 0 2 0 ~ to mimic the shape of the palatal roof. Although the thickness of the calvarial bone ranged from 4 to 7 mm, it was possible to insert implants of 10-mm length without perforation of the outer table of the bone transplant. This was due to the slightly angulated direction of the implants in relation to the bony surface. In conclusion, the vascularized bicortical calvarial bone flap has the following advantages: 1. Immediate bony and soft tissue reconstruction with autogenous material. 2. Transfer of vital vascularized bone of membranous origin, which is re-

Reconstruction o f the maxilla in dentate patients Fig. 9. Intraoral situation after complete prosthetic rehabilitation showing implant-supported bridge extending from 13 to 16.

sistant to possible infection and resorption. 3. Stability of implants is enhanced by the two cortical layers. 4. Complete rehabilitation of masticatory function after placement of implants and fixation of a prosthetic bridge. 5. Little blood loss 6. 6. A l m o s t invisible scar in the donor region. 7. Complete coverage of the d o n o r defect with autogenous material. Possible disadvantages include: 1. Extensive surgery and, therefore, long operating time. 2. Possible injury to, and infections of, the central nervous system; 3. Recurrence of tumour might be difficult to diagnose, which implies frequent use of imaging methods (CT, MRI). 4. C o n t o u r deformity of the cranium. In light of the existing alternatives and considering the advantages and possible disadvantages of this treatment concept, we are of the opinion that the technique presented offers a valuable and reliable way to reconstruct the lost part of the maxilla and adjacent structures. Studies on a larger group of patients will be presented to attest to the relative safety of the method.

Acknowledgments. The authors kindly thank colleagues at the Clinic for Neurosurgery (University Clinic R u d o l f

Virchow) for their support during the operations.

References 1. CASANOVAR, CAVALCANTED, GROTTING JC, VASCONBZLO, PSILLAKISJM. Anatomic basis for vascularized outer-table calvarial bone flaps. Plast Reconstr Surg 1986: 78: 300-7. 2. CHOUNG PH, NAM IW, KIM KS. Vascularized cranial bone grafts for mandibular and maxillary reconstruction. J Cranio-Max-Fac Surg 1991: 19: 235-42. 3, CONLEY J. Use of composite flaps containing bone for major repairs in the head and neck. Plast Reconstr Surg 1972: 49: 522-6. 4. CUTTING CB, MCCARTHYJG. Comparison of residual osseous mass between vascularized and nonvascularized onlay bone grafts. Plast Reconstr Surg 1983: 72: 672-5. 5. CUTTING CB, MCCARTHY JG, BERENSTEIN A. Blood supply of the upper craniofacial skeleton: the search for composite calvarial bone flaps. Hast Reconstr Surg 1984: 74: 603-10. 6. DODSONTB, KABANLB. Donor site morbidity, diagnosis, treatment, and prevention. Oral and Maxi!lofacial Surgery Clinics of North America 1990: 2(3): 489-98. 7. EARLEY MJ. Primary maxillary reconstruction after cancer excision, Br J Plast Surg 1989: 42: 628-36. 8. EWERSR. Reconstruction of the maxilla with a double musculoperiosteal flap in connection with a composite calvarial bone graft. Plast Reconstr Surg 1988: 81: 431-6.

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9. FASANOD, MENONIV, RIBERTIC, BACCHINI P. The temporalis osteo-muscular flap versus the free calvarial bone graft. J Cranio-Max-Fac Surg 1987: 15: 332-41. 10, HELL B. Defektrekonstruktion in der Mund-Kiefer-Gesichtschirurgie mit mikrovaskulttr angeschlossenen Transplantaten. Chir Praxis 1993: 46: 127-38. 11. MANKTELOW RT. Mikrovaskul~ire Wiederherstellungschirurgie. Anatomie, Anwendung und chirurgische Technik. Berlin: Springer, 1988. 12. McCARTHYJG, ZIDE BM. The spectrum of calvarial bone grafting: introduction of the vascularized calvarial bone flap. Plast Reconstr Surg 1984: 74: 10-18. 13. McGREGOR E. The temporal flap in intraoral cancer: its use in repairing the postexcisional defect. Br J Plast Surg 1963: 16: 318-26. 14. MtrNoz FI, JU'NCOSAAM, CARILLOFO. Vascularized parietal bone flaps. J Cranio-Max-Fac Surg 1990: 18: 158-63. 15. MUSOLASA, COLOMBINIE, MICHELENAJ. Vascularized full-thickness parietal bone grafts in maxiUofacial reconstruction: the role of the galea and superficial..temporal vessels. Plast Reconstr Surg 1991: 87: 261-7. 16. PSILLAKISJM, GROTTINGJC, CASANOVA R, CAVALCANTED, VASCONEZLO. Vascularized outer-table calvarial bone flaps. Plast Reconstr Surg 1986: 78: 309-17. 17. SCHWIPPER V, SIEGERT R, PFEIFER G. Anwendung der Ultaschall-Doppler-Sonographie for gef~iBgestielte Lappenplastiken in der Mund-, Kiefer- und Gesichtschirurgie. Fortschr Kiefer Gesichtschir 1987: 32: 147-50. 18. TIDEMAN H, SAMMANN, CHEUNG LK. Reconstruction after maxillectomy: A new technique. Int J Oral Maxillofac Surg 1993: 22: 221-5. 19. YOUNGVL, SCHUSTERRH, HARRIS LW. Intracerebral hematoma complicating split calvarial bone graft harvesting. Plast Reconstr Surg 1990: 86: 763-5. 20. Z6LLER J, MAIER H. Intraoral cheek transposition flap for primary reconstruction of the soft palate. Int J Oral Maxillofac Surg 1992: 21: 156-9.

Address:

Arne Tischer Clinic for Maxillofacial Surgery CharitO-Virchow-Klinikum Humboldt University Berlin Augustenburger Platz 1 D-13344 Berlin Germany