Mehmet Dalkiz, DDS, PhD, Bedri Beydemir, DDS, PhD, Yilmaz Gunaydin, DDS, PhD.
Department of Prosthetic Dentistry, Gulhane Military Medical Academy, Ankara, Turkey.
Department of Oral and Maxillofacial Surgery, Gulhane Military Medical Academy, Ankara, Turkey.

Osseointegrated implants have been used successfully in the prosthetic rehabilitation of edentulous, partially edentulous, and maxillofacial situations. Advances in bone grafting techniques have provided a superior environment for osseointegrated implants.
Implants help to support and retain prosthetic rehabilitation and maintain the newly grafted bone. A variety of techniques has been described for reconstructing the resected mandible with the placement of dental implants into the bone grafts to enhance the outcome of dental restoration. Solfanelli et al6 reported the reconstruction of the partially resected mandible with iliac crest. After four unsatisfactory dentures, a mandibular staple was placed into the grafted mandible, resulting in a stable prosthesis with gratifying speech, cosmetic appearance, and mastication for the patient. Lindstrom et al described two-stage grafting techniques. Initially, titanium implants were inserted into the donor iliac crest. Three to four months later, the graft was harvested and transferred to the deficient mandible. Additional implants were used to stabilize the graft to the host mandible and for later prosthetic attachment.
Keller et al harvested corticocancellous iliac crest to restore mandibular discontinuity defects that resulted from tumor and traumatic injuries. Six to twelve months later, implants were placed. Fixed implantsupported prostheses were fabricated 7 to 12 months later. Head et al used a microvascular free flap to reconstruct a mandible afflicted with osteomyelitis and then placed a transosteal implant into the grafted bone. The vascularized bone grafts placed by Sanger et al were reported to have beneficial masticatory and speech results in patients with mandibular transosseous staples and Nobelpharma (Nobelpharma USA, Chicago, IL) implant-retained restorations. Riedeger also showed reconstruction of the mandible. Aluminum oxide ceramic implants were placed into the graft six months later to enhance prosthetic rehabilitation. Schmelzeisen et al presented a technique that combined revascularized jejunum and iliac crest grafts as recipient sites for Branemark implants (Nobelpharma USA). Stoler and Hill described a multi-stage mandibular reconstruction that used free cranial grafts with free vascularized iliac crest. Core-Vent implants (Dentsply, Encino, CA) were subsequently placed into the grafted bone and restored with an overdenture. Huryn et al reported that vascularized fibula free grafts were suitable for implant placement and support for the dental prosthesis.
The dental use of vascularized free bone grafts for the reconstruction mandibular discontinuity defects to provide a suitable foundation for osseointegrated implant placement has been well documented. A case is reported in which a mandibular metal porcelain bridge was used and supported by implant fixtures placed into a vascularized fibular bone graft.

CASE REPORT.
A 26-year-old man presented with left posterior composite loss of the mandible. Five years earlier, he had been surgically treated for a gunshot wound of the mouth floor, tongue, and left mandible. The surgical team elected to reconstruct the mandible. A one-stage hemimandibulectomy with simultaneous free fibular graft reconstruction was planned. This one-stage procedure called for immediate reconstruction of the mouth floor and left mid-body arch after resection of the necrotic bone and tissue. The oral surgery team removed the mandible section while the plastic surgery team prepared the free vascularized graft from the right-leg fibula to reconstruct the mandible. The graft was secured to the remaining mandible with external fixation and an interosseous miniplate. Microvascular anastomoses were accomplished. Six months after the microvascular reconstruction, the patient presented for prosthodontic treatment. The graft was stable, and mandibular continuity was maintained.
Facial appearance was compromised because of the lack of one third of the lower face support and full projection of the grafted bone in the left mandibular area. Intraoral examination revealed a wide mandibular ridge with minimal height, labile soft tissue, and lack of vestibular depth in the grafted area. The residual ridge of the remaining mandible was at a higher level than the grafted bone. A removable partial denture was placed in the lower jaw. Prognosis for a successful mandibular denture was poor. Osseointegrated implants were recommended in the grafted bone to aid with the retention and support of a fixed partial denture.
Mandibular and maxillary impressions were made, and then jaw relation records were taken with the existing maxillary cast mounted on an articulator. A trial denture was made and processed in clear autopolymerizing acrylic for use as a surgical template to aid in implant positioning for a fixed-detachable tissue integrated fixed denture.
At the time of surgery, three 3.25-mm-wide, 10-13-mm-long spline implants (Calcitek, Carlsbad, CA) were placed into the grafted bone. Implant alignment and positioning was difficult because of the minimal arch curvature of the bone graft. Six months later at Stage II surgery, the left mesial-most implant was not integrated and was removed. Two 5.5-mm flared abutments were placed onto the remaining implant fixtures with healing caps. Definitive prosthodontic treatment began two weeks later. Impression copings were screwed onto the abutments. A polyether impression (Polyjel, Caulk Inc., Milford, DE) was made with a modified stock plastic impression tray. The impression was removed. Abutment replicas were inserted, and the master cast was poured in dental stone.
The two remaining implants were placed in a relatively straight line with minimal anterior-posterior spread and could not be placed more posteriorly because jaw movements were limited. This positioning precluded anterior cantilevering with a fixed partial denture (metal porcelain bridge) because the mesial most implant was removed. A cantilever bridge was obligatory because it was not planned previously. The patient refused further preprosthetic surgical revision or additional implant placement. The trial metal porcelain bridge was processed and finished to completion. An interocclusal registration was made.
The occlusion of the bridge was corrected, and the bridge was cemented on the implants On recall, the patient tolerated the denture well. However, he complained of difficulty in swallowing and speech caused by limitation in tongue mobility caused by the gunshot wounds.

DISCUSSION.
The major causes of mandibular discontinuity are tumor resection, trauma, gunshot wounds, and, to a lesser degree, osteoradionecrosis and osteomyelitis. The loss of a mandiburement and serious disabilities, including impairment of chewing, swallowing, speaking, and drooling. The degree of disability varies with the size and location of the defects. 1,11 Prosthetic rehabilitation in these patients poses a real problem. Often, the remaining mandibular segment is medially displaced and in an inconsistent occlusal position. A denture worn on the remaining mandibular segment is often unstable, making it difficult and painful to wear.
Therefore, the fabrication of a functional removable denture for patients who have undergone mandibular resection is often unsatisfactory without the incorporation of some type of tissue augmentation or reconstruction to restore mandibular continuity. 14 The following are some of the goals of mandibular reconstruction from the restorative dentist’s standpoint:

1. Restoration of jaw continuity. The greatest amount of mandibular form and function can be achieved only by restoration of the mandibular continuity. Restoration of mandibular form will also improve facial symmetry and denture esthetics.
2. Provision of a better prosthesis bearing area. Prosthetic rehabilitation is dependent an adequate bone height and width for proper support, retention, and stability of the prosthesis and for the restoration of a functional occlusal relationship.
3. The graft must be long lasting and able to withstand the functional demands placed on it.
4. Restoration of acceptable facial contours and esthetics. Restoring lower facial form and contour is valuable in returning the patient to a positive self-image and a productive life. The use of a prosthesis may be a positive factor in such physiological and psychological rehabilitation.

Various grafting techniques have been used for the reconstruction of mandibular defects. The vascularized graft is considered the standard of care in many institutions. The most commonly used donor sites for mandibular reconstruction are the fibula, iliac crest, scapula, and radius. Reconstructive efforts improve mandibular function, appearance, and mastication but often not to the levels expected by the patient. Combining these techniques with dental implants can enhance the prosthetic outcome of the patient after mandibular reconstruction. Therefore, if implant rehabilitation is to be anticipated, a suitable donor site must be selected for improved placement and osseointegration. Mososco et al and Frodel et al analyzed various donor sites for potential implant placement. They found the iliac crest to have consistently suitable dimensions for implantation. The scapula and then the fibula followed the iliac crest in available bone to accept dental implants in cadaver measurements. As alternatives to the iliac crest, Mososco et al1 and Frodel et al identified the fibula first and the scapula second. The radius was the least reliable donor site, particularly in females where no specimen met the criteria for implantation.
Immediate placement of dental implants during the transfer of bone has been recently popularized. The main disadvantages of immediate implant placement are improper alignment of implants caused by bone rotation and unpredictability of muscular coordination in the long term.

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