A suggested technique for the immobilisation of large soft tissue grafts in oral surgery

Loss of tissue following surgical treatment of oral malignant lesions is usually very disabling. Conventional prosthetic restorations are usually difficult to make and are poorly tolerated by patients. Implants are a viable alternative and offer the possibility of an effective functional rehabilitation. However, if implants are to be used to eventually support a stable prosthesis, it is sometimes possible to use them during the other stages of treatment. For example, implants are often used the purposes of anchorage during orthodontic treatment. The aim of this article is to present the suggested use of implant-supported prostheses for the stabilisation of large soft tissue grafts.

The clinical situation presented is that of a 35 year old female patient having a left hemi-maxillectomy for a large tumour (^{fig. 1}). A removable prosthesis had been constructed in order to meet several objectives :

- to support an obturator ;

- to maintain the soft tissues ;

- to replace the missing teeth in as functional way as possible.

Despite all the precautions taken during the construction of this type of prosthesis, the obturator is often a poor fit. This leads to progressive loosening of the prosthesis. Its ability to function gradually deteriorates, but above all the stresses imposed on the clasped natural teeth become too great, leading inevitably to progressive extractions. Clinical situations such as these usually present a real challenge to both the dentist and oral surgeon. It is difficult to formulate a comprehensive treatment plan at the outset. First it is necessary to define the treatment objectives and to arrange a team meeting so that a logical sequence of treatments can be devised. ^{(Gary et al., 1992} ; ^{Brånemark et al., 1985} ; ^{Jortay et al., 1994} ; ^{Lorant et al., 1994} ; ^{Tideman et al., 1993} ; ^{Nakayama et al., 1994)}.

In the clinical situation presented, the removable prosthesis did not satisfactorily resolve difficulties of speech and other functional problems. In addition, each time the prosthesis was removed, the patient found herself confronted with her handicap. It was for these reasons that a definitive implant-supported restoration, seemed to be the best solution to meet these functional and aesthetic requirements. The treatment plan for this patient was as follows :

1. Reconstruction of the maxilla :

- closure of the oro-antral fistula - using a pedicle flap from the temporal muscle and initial bone graft ^{(Bradley et Brookbank, 1981} ; ^{Christie et al., 1994} ; ^{Falconer et Phillips, 1991} ; ^{Holmes et Marshall, 1979} ; ^{Krastinova, 1995} ; ^{Konno et al., 1981} ; ^{Martin et Brown, 1994} ; ^{Tessier et Krastinova, 1982)} ;

- bone graft - in order to ensure sufficient bone to accommodate the implants ^{(Boyne et James, 1980} ; ^{Brånemark et al., 1985} ; ^{Ellis et Sinn, 1993)}.

2. Placement of the implants (^{Brånemark et al., 1985}).

3. Construction of the implant-supported prosthesis. (^{Brånemark et al., 1985}).

However, two problems will be encountered (^{fig. 2}) :

1. When the surgeon undertakes the reconstruction of the alveolar ridge using a bone graft, he has no landmarks to indicate the future position of the implants. There are no remaining anatomical structures to assist the surgeon to visualise the ideal position of the ridge. There is a major risk that the bone graft will be placed in a position which is incompatible with a satisfactory implant-supported restoration. In these difficult clinical situations, it is necessary to provide a landmark for the surgeon. The use of a surgical guide can help to resolve this problem, providing that it is sufficiently stable during the surgery and does not interfere with the surgeon's work. In a case such as this, the first step is to establish a secure attachment for the guide using two roots which are retained for the purpose. At the same time as the placement of the bone graft, implants were inserted on the contralateral side. They will retain the surgical guide whilst the implants are placed in the graft.

2. Closure of the oro-antral communication necessitates a large flap of vestibular mucosal tissue which inevitably leads to almost complete loss of the vestibule in the area. The left side of the upper lip, being attached directly to the crest of the alveolar ridge, loses all its mobility. In order to resolve this problem, it is necessary to deepen the vestibule again by using a soft tissue graft. The difficulty with this type of intervention is how to avoid the progressive contraction of the flap during the healing period. It is necessary to use some method for effectively retaining the graft in the position in which it was placed. The device used must be removable to allow appropriate hygiene methods to be undertaken and must remain in place for at least eight weeks. The use of an implant-supported temporary bridge to retain such a stent is a possible solution. This principle is described in the presentation of this clinical case.

Once the therapeutic objectives have been properly defined, it is possible to formulate a treatment plan, bringing together all the specialties involved :

1. Preparation of a model of the proposed definitive prosthesis. Onto this a surgical guide is pulled down.

2. Two attachments are placed on the roots of teeth 12 and 13, to retain both the temporary bridge and also the surgical guide whilst undertaking the bone graft.

3. Bone is grafted to reconstruct the left half of the maxilla, using the surgical guide. At the same time two fixtures are placed in positions 14 and 16 (^{fig. 3}).

4. After 6 months healing, the roots of 12 and 13 are extracted and the implants connected with a flexible bar. This serves to retain the temporary bridge and also the surgical guide whilst placing the remaining implants (^{fig. 4} and ⁵).

5. Placement of five additional implants (^{fig. 6}).

6. After 6 months healing, connectors are placed on the five new implants and the temporary bridge constructed (^{fig. 7} and ⁸).

7. Soft tissue graft to deepen the vestibule in the upper left quadrant (^{fig. 9}, ¹⁰, ¹¹, ¹², ¹³, ¹⁴, ¹⁵ and ¹⁶). The graft is applied to the recipient site, first moulded into position with silicone and later with autopolymerising resin.

8. After the graft has been allowed to heal for 3 months, the permanent implant-supported bridge is constructed (^{fig. 17} and ¹⁸).

9. Follow up and maintenance.

Conclusion

This complex clinical case was approached in a sequential manner. Each practitioner involved with the treatment had only to deal with the clinical situation with which he was familiar. However, it must be noted that in order to succeed with these complex cases, full patient cooperation is paramount. Before these lengthy treatments begin, it is essential that the patient is fully informed of the duration of treatment and the risks of complications involved. It is just as essential that all the members of the therapeutic team are aware of the problems and the objectives of the other specialties in order to reduce the number of surgical episodes to a minimum and also the total length of treatment.

In the case presented, Dr. Darina Krastinova undertook the maxillo-facial surgery, Dr. Franck Renouard the implant surgery and Mrs. Phillippe Poussin and Xavier Daniel (Laboratoire AL/ZR) the laboratory work.

BIBLIOGRAPHY

• ARTZI Z, Tal H, MOSES O, KOZLOVSKY A. Mucosal consideration for osseointegrated implants. J Prosthet Dent 1993;70:427-432.
• BOYNE PJ, JAMES RA. Grafting of the maxillary sinus floor with autogenous marrow and bone. J Oral Surgery 1980;38:613-616.
• BRADLEY P, BROOKBANK J. The temporalis muscle flap in oral reconstruction. J Maxillofac Surg 1981;9:139-145.
• BRANEMARK PI, ZARB G, ALBREKSTON T. Tissue integrated prosthesis : osseointegrated in clinical dentistery. Chicago, Ed Quintessence, 1985.
• CHRISTIE DR, DUNCAN GM, GLASSON DW. The ulnar artery free flap : the first 7 years. Plast Reconstr Surg 1994;93:547-551.
• ECKERDAL O, KVINT S. Presurgical planning for osseointegrated implant in the maxilla. Int J Maxillofac Surg 1986;15:722-726.
• ELLIS E, SINN DP. Use of homologeous bone in maxillofacial surgery. J Oral Maxillofac Surg 1993;51:1181-1193.
• FALCONER TD, PHILLIPS JC. Reconstruction of the defect at the donor site of the temporalis muscle flap. Br J Oral Maxillofac Surg 1991;29:10-18.
• GARY JJ, DONOVAN M, GARNER FT, FAULK JE. Rehabilitation with calvarial bone grafts and osseointegrated implants after partial maxillary resection : a clinical report. J Prosthetic Dent 1992;67:743-746.
• GONZALEZ JM, GIRAUD L. L'évaluation pré-implantaire en implantologie. Réalités Cliniques 1992;3:283-291.
• HOLMES AD, MARSHALL KA. Use of the temporalis muscle flap in blanking out orbis. Plast Reconstr Surg 1979;63:336-343.
• JORTAY A, COESSENS B, GREANT P, BISSHOP P. Use of osteomuscular free flaps after extended maxillectomy and craniofacial resection. About two cases. Acta Chir Belg 1994;94:236-239.
• KRASTINOVA D. Mask lift and facial aesthetic sculpturing. Plast Reconstr Surg 1995;95:21-36.
• KONNO A, TOGAWA K, LIZUKA K. Primary reconstruction after total or extended total maxillectomy for maxillary cancer. Plast Reconstr Surg 1981;67:440-448.
• LORANT JA, ROUMANAS E, NISHIMURA R, BEUMER J, WAGMAN LD. Restoration of oral function after maxillectomy with osseous integrated implant retained maxillary obturators. Am J Surg 1994;168:412-414.
• MARTIN LC, BROWN AE. Free vascularized fascial flap in oral cavity reconstruction. Head-Head 1994;16:45-50.
• MISIEEK DJ. Oral and maxillofacial reconstruction. J Oral Maxillofac Surg 1993;51(Suppl 1):56-61.
• NAKAYAMA B et al. New reconstruction for total maxillectomy defect with a fibula osteocutaneous free flap. Br J Plast Surg 1994;47:247-249.
• PERROT DH, SMITH RA, KABAN LB. The use of fresh frozen allogenic bone for maxillary and mandibular reconstruction. Int J Oral Maxillofac Surg 1992;24:260-265.
• TESSIER P, KRASTINOVA D. La transposition du muscle temporal dans l'orbite anophtalme. Ann Chir Plast 1982;27:213-220.
• TIDEMAN H, SAMMAN N, CHEUNG LK. Immediate reconstruction following maxillectomy : a new method. Int J Oral Maxillofac Surg 1993;22:221-225.