Rehabilitation implants after

with calvarial bone grafts and osseointegrated partial maxillary resection: A clinical report

J. J. Gary, DDS,* M. Donovan, J. E. Faulk, DDSd

DDS,b F. T. Garner,

MD,C and

William Beaumont Army Medical Center, Fort Bliss, Tex.

T

his article describes the rehabilitation of an edentulous patient with a partial maxillary resection (Fig. 1) and an edentulous atrophic mandible. Osseointegrated implants are used in both the defect and nondefect sides of the maxillae after augmentation with calvarial bone grafts. Location of an implant within the defect will limit movement of the prosthesis, encourage axial loading of the implants, and provide better support and retention for the prosthesis.

SIGNIFICANT

MEDICAL

HISTORY

In March 1988 the patient underwent a left partial maxillary resection for an inverted papilloma in the lateral nasal wall. The extent of surgery was necessary because of the size of the tumor, the local aggressiveness, high rate of reThe opinions and assertionscontained in this article are those of the authors and are not to be construed as official or as reflecting the views of the United States Army. BColonel, DC, U.S. Army; Chief, Maxillofacial Prosthetics. bColonel, DC, U.S. Army; Program Director, Oral and Maxillofacial Surgery Residency Program. CMajor, MC, U.S. Army; Assistant Chief, Otolaryngology. dMajor, DC, U.S. Army; Resident,, Oral and Maxillofacial Surgery. 10/1/35693

currence, and associated malignancy.’ The patient did not receive radiation therapy, which is ineffective in the management of this lesion and in the prevention of recurrence.2 The chief complaint was the inadequacy of the present prostheses, which used intermaxillary spring retention in the first molar regions bilaterally.

SURGICAL

TECHNIQUE

Interim prostheses were fabricated to deteimine placement of implants in the maxillae and mandible. Computed tomography scan aided in analyzing the spatial relationships and in assisting in placement of the bone grafts (Fig. 2). The right maxillary residual ridge was approximately 1.0 cm in height and 2.0 mm in width. The residual zygoma on the defect side was lateral to the defect, preventing placement of a usable implant. It was determined that a bone graft was needed to augment the atrophic maxillary residual ridge on the nondefect side and the medial surface of the zygoma and inferior surface of the orbital floor on the defect side. The objective was to position an implant that exits through the split-thickness skin graft medial to the zygoma on the floor of the orbit remote from the mobile tissue of the cheek. At the same time, the left infraorbital rim was to be augmented to restore the facial form.

Fig. 1. Pretreatment status.

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Fig. 2. Horizontal view of three-dimensional model showing planned nial bone grafts. Arrow denotes planned position of bone graft medial

Fig. :3. Single strip of calvarial grafted

to orbital

bone is cantilevered

placement of crato zygoma.

from zygoma. Deep to this strip is bone

floor.

Four strips of unicortical calvarial bone measuring 6 cm long, 1 cm wide, and 3 mm thick were harvested from the right parietal bone.3 The left infraorbital rim, the orbital floor, and the residual zygoma were exposed through a midpalpebral incision (Fig. 3) along a scar from previous surgery. Upon exposure of the inferior surface of the orbital floor and the medial surface of the zygoma, the calvarial bone strips were cut to size and stacked vertically against the medial surface of the zygoma and horizontally against the inferior surface of the orbital floor. The graft was 1.0 cm thick in all regions. The vertical strips were secured with a single 2 mm self-tapping screw. The horizontal strips were stacked and retained by pressure from the skin graft lining

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the defect on the inferior surface of the orbital floor. To augment the infraorbital rim, a single strip of calvarial bone was cantilevered from the zygoma with a single 2 mm selftapping screw (see Fig. 3). The maxillary residual ridge was exposed and an onlay graft was placed laterally to increase the width to more than 6 mm. The strips were secured with 2 mm self-tapping screws. The surgical sites were allowed to heal for 5 months before placement of titanium implants. Three implants were placed in the residual ridge. One 10 mm implant was placed in the tuberosity and two 13 mm implants were placed in the maxilla, which had been grafted with calvarial bone. JUNE

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REHABILITATION

AFTER

PARTIAL

MAXILLARY

RESECTION

Fig. 4. Tomogram medial plant.

shows thickness of calvarial bone gpft to zygoma on orbital floor before placement of im-

Fig. 5. Radiograph

Fig. 6. Metallic

framework

One 10 mm implant was placed in the grafted bone on the orbital floor on the defect side (Figs. 4 to 6). The implant placed in the tuberosity region failed.

PROSTHODONTIC

TECHNIQUE

An interim mandibular complete denture and maxillary obturator prosthesis were used before the cranial bone THE

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and magnet

keeper

shows position

of implants.

are in place.

graft. For the 5 months after the bone graft, an obturator was placed that was supported by a minimum of tissue remote from the grafted regions. Interim complete dentures were again made after implant placement. At the end of the 6-month integration period, the transmucosal abutments were connected. A tissue conditioner was used to reline the prostheses temporarily.

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Fig. 7. Intaglio surface of prosthesis.

Final impressions for new prostheses were made with a polyether material (Impregum, Premier Dental Products, Norristown, Pa.) in a custom tray. The impression did not include the implant on the defect side. The two implants in the residual maxilla were joined by a cast metallic framework (Ney Option., J. M. Ney Co., Bloomfield, Conn.) that incorporated two extracoronal hinge resilient attachments (Stern ERA, APM-Sterngold, Attleboro, Mass.) and one acrylic clip (Hader castable and clip system, Implant Support Systems, Irvine Calif.). A titanium minimagnet and keeper (Dyna Magnet, Parkell, Framingdale, N.Y.) were placed on the implant within the defect to provide minimal retention but significant support for the obturator prosthesis (see Fig. 6). After the retentive clip, magnet and resilient hinge attachments were attached to the prosthesis (Fig. 7), new jaw relation records were made, and the monoplane occlusion was refined on the articulator.

ficult because the axis of rotation for an obturator prosthesis is located along the palatal margin of the defect. Rotation of the prosthesis due to a class I lever will encourage stresses within the implants and the bone surrounding the implants on the nondefect side, and this may be detrimental.4 Placement of implants within the defect will prevent rotation of the prosthesis and encourage axial loading of the implants.

SUMMARY

Reprint

Osseointegrated implants can be positioned on the nondefect side of a midline maxillary resection if there is sufficient residual bone. Axial loading of the implants is dif-

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REFERENCES 1. Lawson W, LeBenger J, Som P, Bernard PJ, Biller HF. Inverted papilloma: an analysis of 87 cases. Laryngoscope 1989;99:1117-23. 2. Snyder RM, Persin KH. Papillomatosis of nasal cavity and paranasal sinuses (inverted papilloma, squamous papilloma): a clinicopathologic study. Cancer 1972;30:888-99. 3. Markowits NR, Allen PG. Cranial bone graft harvesting: a modified technique. J Oral Maxillofac Surg 1989;47:1113-5. 4. Rangert B, Jemt T, Jorneus L. Forces and moments on Branemark implants. Int J Oral Maxillofac Implants 1989;4:241-7. requests

to:

DR.JOHNJ.GARY U.S. &MY DENTAC FoRTBLIss,TX~~~~O

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1992

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67

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