At the patient’s first visit to discuss her orbital reconstruction, she communicated that she did not wish to receive any reconstructive surgery or general anesthesia and did not want to be admitted to the hospital. The patient expressed her desire for a natural-looking face (Fig. 1a–d). An orbital prosthesis was recommended instead of microvascular free-flap surgery to meet the patient’s request, and a dental implant that allowed removal of a silicone prosthesis was planned to avoid limitations in her routine MRI examination; any prosthesis that contained a metal frame would have interfered with follow-up scanning. Routine laboratory testing was carried out prior to the dental implant installation procedure, and all results were within the normal range except for mild anemia (hemoglobin, 11.8 g/dl; hematocrit, 34.6%) and an elevated erythrocyte sedimentation rate (34 mm/h).
The bony dimensions of the residual orbital wall were studied thoroughly on plain radiographs, which included frontal and lateral skull views (Fig. 2e, f), and computed tomography (CT) scans (Fig. 2g, h) with three-dimensional (3D) images. The treatment plan included placement of three implants in the lateral orbital rim of the zygoma due to the presence of titanium mesh on the superior orbital rim of the frontal bone. With the patient under local anesthesia induced with a lidocaine injection, we placed 4.0-mm-diameter and 7.0-mm-long Luna® implants (Shinhung Co., Seoul, Korea) (Fig. 2a–c). A tapered implant with a suitable length was selected to compensate for the bony wall density and to achieve good primary stability with a > 65 implant stability quotient value from each implant fixture. After inserting the cover screws, suturing was performed in three layers of periosteal membrane overlapping, the subcutaneous layer, and tension-free skin approximation. Six months after implant installation, re-entry surgery was performed under local anesthesia. Healing abutments with an appropriate height were chosen according to the surrounding soft tissue thickness and were applied and tightened with a torque of 25 Ncm, (Fig. 2d). One month later, when the soft tissue had achieved a satisfactory amount of healing and contour, the healing abutments were replaced with 1.0- or 2.0-mm gingival height magnetic keepers (MAGFIT IP system, Aichi Co., Japan) for the removable orbital prosthesis (Fig. 2e). Instead of taking traditional facial impressions to create a master facial stone model, 3D facial scanning using a Morpheus 3D Scanner® (Morpheus Co., Ltd, Seoul, Korea) was performed (Fig. 2f), and facial imaging reconstruction, which included the orbital texture and volume, was carried out (Fig. 2g) for modification of facial master cast fabrication. Formatted reconstruction data were used for 3D molding and printing (Fig. 2h) via image reconstruction ZBrush® software (Pixologic Inc., California, USA) to reconstruct the defect in the right orbital region (Fig. 2i) and finally be applied to the patient’s clinical facial image (Fig. 2j) of the design of the expected reconstruction.
The laboratory fabrication procedures were also updated and modified by creating a major mold for pouring the liquid silicone and allowing it to set safely. After making a molding orbital prosthesis on the major facial cast using modeling oil clay (NSP-soft®; Chavant, Inc., New Jersey, USA) (Fig. 3a, b), we created a block mold with celadon clay rim (Fig. 3c). After release agent application on the gypsum area of the blood mold, a plaster impression was performed (Fig. 3d). The inner surface of the major mold had a mirror outer appearance of the orbital skin area (Fig. 3e).
The artificial eye was created as a digital image first and then was polished after the determination of the detailed parameters, such as eye size, the correct position of the magnet, skin color, and silicone shade. This artificial eyeball was attached, and the molds of the magnets were made in a uniform shape using clay resin (Eyaco®, Goyang, Korea) and were adapted to the magnet part of the major facial cast (Fig. 3f). The main silicone elastomers (Smooth-Cast®; Smooth-On, Inc., Pennsylvania, USA), dimethyl siloxane polymers, and adhesive primers were used to create an effective bond between the silicone and the substructure [1, 2]. We added a liquid silicone color component (EcoflexTM 00-10®; Smooth-On, Inc., Pennsylvania, USA) to the main silicone elastomers to produce the basic skin shade based upon our many trial and error laboratory attempts (Fig. 3g). By pouring this liquid silicone base into the assemble combination of the major mold and the major facial cast through a small hole (Fig. 3h), we saved time that would have been used to set the silicone base by editing or handling a silicone surface. After solidification of the silicone base more than 6 h later, the initial raw appearance of the silicone orbital prosthesis on the major facial cast was observed after detaching the major mold (Fig. 3i). Additional trimming and placement of artificial hair in the eyebrow and eyelash areas as well as the outer appearance of the silicone orbital prosthesis was completed (Fig. 3j, k). The magnet molds were attached to the Magnet® (MAGFIT IP system, Aichi Co., Japan) using resin cement and fixed to the silicone base using Loctite® cyanoacrylate instant cement (Henkel Co., USA) in the finalization stage. The inner surface that contained the eyeball and the individual magnet was polished (Fig. 3l).
