A 43-year-old male patient presented to our department with a severe left midfacial post-traumatic deformity due to road traffic accident that occurred 6 years prior (Figure 1). Clinical examination of the left midface revealed the loss of the antero-posterior and medio-lateral (transverse) projections of the left zygomatic bone. A slight enophthalmos was also present. The soft tissues of the area were hypotrophic in response to the initial injury (Figure 2). The clinical findings were confirmed on computerized tomogram (CT) images in axial and coronal plane (Figure 3).
The zygomatic-orbito-maxillary defect was reconstructed using a custom-made titanium implant for esthetic reasons. Fine-cut CT scanning of the region with 3-dimensional (3D) reconstruction was performed (Siemens Somatom Sensation, Erlangen, Germany). The CT data were imported into the MIMICS® software (Materialise, Leuven, Belgium), and a 3D virtual model of the implant was produced by “mirroring” the healthy side using Freeform Modeling Plus® (3D Systems, Sensable, Valencia, CA, USA) platform software. Because a full-density titanium SLM implant would have been too heavy for implantation, we decided to produce an implant in the form of a shell that was supported by the residual bone and fixation rods (Figure 4).
The virtual model was then printed into the 3D implant by SLM using commercially pure titanium Grade 2 (SLM-Solutions, Luebeck, Germany) and an SLM 250HL machine (SLM-Solutions). The physical model of the skull was printed in white acrylic resin using Multi-Jet-Printing (Objet Eden 250, Stratasys, Eden Prairie, MN,USA). The SLM implant was placed on the plastic model of the skull to verify proper matching and seating. No further mechanical processing was needed. Finally, the produced implant was post-processed by sand-blasting and drilling the screw holes and then cleaned and sterilized by autoclaving.
The implant was inserted into the planned position using a combination of mid-tarsal lower eyelid, hemicoronal and intraoral incisions. Proper seatings at the infraorbital rim, zygomatic body and zygomatico-alveolar buttress were confirmed. The fixation was performed with three 2.0-mm titanium screws (Stryker®, Michigan, MI, USA) using the lag-screw principle (Figure 5). The space between the shell-shaped implant and the residual zygomatic bone was filled with a cortico-cancellous iliac crest bone graft. The facial soft tissues were resuspended, and the left temporal hollowing was corrected with a titanium mesh. The wounds were sutured in layers and dressed appropriately.
The patient received 1 g of ceftriaxone, 80 mg of gentamycin, 0.5 g of metronidazole, and 100 mg of ketoprofen b.i.d. for 7 days. The postoperative course was uneventful, and the patient was discharged 8 days after the operation. The follow-ups at 1 month, 6 months and 1 year revealed no complications. At one year, the clinical examination revealed the persistence of a slight asymmetry in the zygomatic regions (Figure 6), and a CT scan supported the good projection of the reconstructed site and the symmetry between the two zygomas (Figure 7). We believe the residual asymmetry resulted from soft tissue atrophy. The CT scan also revealed good implant integration with ossification of the cortico-cancellous chips that were placed between the implant and the residual bone and no resorption of the residual zygoma.