• Journal of Korea Multimedia Society
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• v.23 no.8
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• pp.903-914
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• 2020

In this paper, we present a novel algorithm to generate a 3D model of patient-specific orbital implant, which is finally produced by the 3D printer. Given CT (computed tomography) scan data of the defective orbital wall or floor, we compose the depth image of the defect site by using the depth buffering, which is a computer graphics technology. From the depth image, we compute the 3D surface which fills the broken part by interpolating the points around the broken part. By thickening the 3D surface, we get the 3D volume mesh of the orbital implant. Our algorithm generates the patient-specific orbital implant whose shape is accurately coincident to the broken part of the orbit. It provides the significant time efficiency for manufacturing the implant with supporting high user convenience.

• Archives of Craniofacial Surgery
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• v.20 no.6
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• pp.347-353
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• 2019

Most orbital surgeons believe that it's difficult to restore the primary orbital wall to its previous position and that the orbital wall is so thin that cannot be firmly its primary position. Therefore, orbital wall fractures generally have been reconstructed by replacing the bony defect with a synthetic implant. Although synthetic implants have sufficient strength to maintain their shape and position in the orbital cavity, replacement surgery has some drawbacks due to the residual permanent implants. In previous studies, the author has reported an orbital wall restoring technique in which the primary orbital wall fragment was restored to its prior position through a combination of the transorbital and transantral approaches. Simple straight and curved elevators were introduced transnasally to restore the orbital wall and to maintain temporary extraorbital support in the maxillary and ethmoid sinus. A transconjunctival approach provided sufficient space for implant insertion, while the transnasal approach enabled restoration of the herniated soft tissue back into the orbit. Fracture defect was reduced by restoring the primary orbital wall fragment to its primary position, making it possible to use relatively small size implant, furthermore, extraorbital support from both sinuses decreased the incidence of implant displacement. The author could recreate a natural shape of the orbit with the patient's own orbital bone fragments with this dual approach and effectively restored the orbital volume and shape. This procedure has the advantages for retrieving the orbital contents and restoring the primary orbital wall to its prior position.

• Archives of Craniofacial Surgery
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• v.20 no.3
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• pp.164-169
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• 2019

Background: The conventional surgical method for reconstructing orbital floor fractures involves restoration of orbital continuity by covering an onlay with a thin material under the periorbital region. However, in large orbital floor fractures, the implant after inserting is often dislocated, leading to malposition. This study aimed to propose a novel implanting method and compare it with existing methods. Methods: Among patients who underwent surgery for large orbital floor fractures, 24 who underwent the conventional onlay implanting method were compared with 21 who underwent the novel ${\gamma}$ implanting method that two implant sheets were stacked and bent to resemble the shape of the Greek alphabet ${\gamma}$. When inserting a ${\gamma}$-shaped implant, the posterior ledge of the orbital floor was placed between the two sheets and the bottom sheet was impacted onto the posterior wall of the maxilla to play a fixative role while the top sheet was placed above the residual orbital floor to support orbital contents. Wilcoxon signed-rank test and Mann-Whitney U test were used for data analyses. Results: Compared to the conventional onlay method, the gamma method resulted in better restoration of orbital contents, better improvement of enophthalmos, and fewer revision surgeries. Conclusion: Achieving good surgical outcomes for extended orbital floor fractures is known to be difficult. However, better surgical outcomes could be obtained by using the novel implantation method of impacting a ${\gamma}$-shaped porous polyethylene posteriorly.

• Archives of Craniofacial Surgery
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• v.18 no.2
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• pp.137-140
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• 2017

Alloplastic materials used for orbital fracture reconstruction can induce complications, such as infection, migration, extrusion, intraorbital hemorrhage, and residual diplopia. Silicone is one of the alloplastic materials that has been widely used for decades. The author reports a rare case of spontaneous extrusion of a silicone implant that was used for orbital fracture reconstruction 30 years earlier. A 50-year-old man was admitted to the emergency room for an exposed substance in the lower eyelid area of the left eye, which began as a palpable hard nodule a week earlier. The exposed material was considered to be implant used for previous surgery. Under general anesthesia, the implant and parts of the fibrous capsule tissue were removed. Several factors hinder the diagnosis of implant extrusions that occur a long period after the surgery. So, surgeons must be aware that complications with implants can still arise several decades following orbital fracture reconstruction, even without specific causes.

• Archives of Plastic Surgery
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• v.41 no.5
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• pp.480-485
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• 2014

Background The objective of this article is to evaluate clinical outcomes of combined orbital floor and medial wall fracture repair using a three-dimensional pre-bent titanium implant in an East Asian population. Methods Clinical and radiologic data were analyzed for 11 patients with concomitant orbital floor and medial wall fractures. A combined transcaruncular and inferior fornix approach with lateral canthotomy was used for the exposure of fractures. An appropriate three-dimensional preformed titanium implant was selected and inserted according to the characteristics of a given defect. Results Follow-up time ranged from 2 to 6 months (median, 4.07 months). All patients had a successful treatment outcome without any complications. Clinically significant enophthalmos was not observed after treatment. Conclusions Three-dimensional pre-bent titanium implants are appropriate for use in the East Asian population, with a high success rate of anatomic restoration of the orbital volume and prevention of enophthalmos in combined orbital floor and medial wall fracture cases.

• Archives of Plastic Surgery
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• v.43 no.1
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• pp.84-87
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• 2016

Titanium micro-mesh implants are widely used in orbital wall reconstructions because they have several advantageous characteristics. However, the rough and irregular marginal spurs of the cut edges of the titanium mesh sheet impede the efficacious and minimally traumatic insertion of the implant, because these spurs may catch or hook the orbital soft tissue, skin, or conjunctiva during the insertion procedure. In order to prevent this problem, we developed an easy method of inserting a titanium micro-mesh, in which it is wrapped with the aseptic transparent plastic film that is used to pack surgical instruments or is attached to one side of the inner suture package. Fifty-four patients underwent orbital wall reconstruction using a transconjunctival or transcutaneous approach. The wrapped implant was easily inserted without catching or injuring the orbital soft tissue, skin, or conjunctiva. In most cases, the implant was inserted in one attempt. Postoperative computed tomographic scans showed excellent placement of the titanium micro-mesh and adequate anatomic reconstruction of the orbital walls. This wrapping insertion method may be useful for making the insertion of titanium micro-mesh implants in the reconstruction of orbital wall fractures easier and less traumatic.

• Archives of Craniofacial Surgery
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• v.19 no.4
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• pp.264-269
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• 2018

Background: Orbital resorbable mesh plates are adequate to use for isolated floor and medial wall fractures with an intact bony buttress, but are not recommended to use for large orbital wall fractures that need load bearing support. The author previously reported an orbital wall restoring surgery that restored the orbital floor to its prior position through the transnasal approach and maintained temporary extraorbital support with a balloon in the maxillary sinus. Extraorbital support could reduce the load applied on the orbital implants in orbital wall restoring surgery and the use of resorbable implants was considered appropriate for the author's orbital wall restoring technique. Methods: A retrospective review was conducted of 31 patients with pure unilateral orbital floor fractures between May 2014 and May 2018. The patients underwent transnasal restoration of the orbital floor through insertion of a resorbable mesh plate and maintenance of temporary balloon support. The surgical results were evaluated by the Hertel scale and a comparison of preoperative and postoperative orbital volume ratio (OVR) values. Results: The OVR decreased significantly, by an average of 6.01% (p<0.05) and the preoperative and postoperative Hertel scale measurements decreased by an average of 0.34 mm with statistical significance (p<0.05). No complications such as buckling or sagging of the implant occurred among the 31 patients. Conclusion: The use of resorbable mesh plate in orbital floor restoration surgery is an effective and safe technique that can reduce implant deformation or complications deriving from the residual permanent implant.

• Archives of Plastic Surgery
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• v.33 no.5
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• pp.659-662
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• 2006

Purpose: Alloplastic implants, such as methylmethacrylate, Teflon, silicone, Supramid are commonly used to cover the floor defect and to prevent reherniation of the displaced orbital tissue in orbital floor fracture. Silicone implant has been used for reconstruction of orbital wall defects because of pliability, advantage of carving and chemically inert nature. However, silicone implant also has complications including infection, extrusion, pain, dystopia and tissue reaction. Cyst formation around the silicone implant is a very rare complication. According to many reports, cysts around alloplastic implant in an orbital area are mostly hemorrhagic cysts consisted of blood breakdown product with fibrous capsule cell in histologic examination. Methods: The authors report atypical case and successful treatment of intraorbital hemorrhagic cyst around silicone implant of a 37-year-old male patient. Results: Preoperative symptoms of diplopia, exophthalmos, proptosis, vertical dystopia and ectropion of lower eyelid were resolved after surgical removal of implants with surrounding capsule. Conclusion: Clinical suspicion of plastic surgeon is important in diagnosis of intraorbital cyst of patients who have history of silicone implantation and computed tomography is the standard tool of diagnosis. During the operation, caution must be taken on delivering the whole capsule of intraorbital cyst along with silicone implant to prevent recurrence of the cyst.

• Archives of Craniofacial Surgery
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• v.10 no.1
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• pp.29-32
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• 2009

Purpose: Alloplastic implants, such as $Silastic^{(R)}$, $Supramid^{(R)}$, Porous polyethylene, $Teflon^{(R)}$ have been used to prevent reherniation of orbital tissue and are known to be inert for many years, though complications are infrequently reported many years after their insertion. Complications associated with implants are infrequent, but infection, orbital hemorrhage, implant extrusion, motility restriction, migration of implant causing dacryocystitis, cystic formation have been described. The latter was known as a rare late complication of blow-out fracture repair. Methods: We report the case of a discovery of a intraorbital hemorrhagic cyst which developed after silicon implant insertion. This patient developed diplopia, unilateral proptosis, exophthalmos, vertical dystopia, ectropion 10 years after repair of blow-out fracture. In this case, orbital CT scan revealed intraorbital cyst surrounding the orbital implant. At surgery, a fibrous capsule surrounded the silicon implant and was filled with mucin pools. Results: Proptosis, diplopia, exophthalmos, ectropion, vertical dystopia were resolved after surgical removal of the cyst and implant. Conclusion: This case illustrate that it is important for us to be aware of the complication of cyst formation around the silicon implants.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.46 no.5
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• pp.353-357
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• 2020

Fractures of the orbital floor and walls are among the most frequent maxillofacial fractures. Virtual three-dimensional (3D) planning and use of patient-specific implants (PSIs) could improve anatomic and functional outcomes in orbital reconstruction surgery. The presented case was a victim of a terrorist attack involving improvised explosive devices. This 58-year-old female suffered severe wounds caused by a single piece of metal from a bomb, shattering the left orbital floor and lateral orbital wall. Due to remaining hypotropia of the left eye compared to the right eye, late orbital floor reconstruction was carried out with a personalised 3D printed titanium implant. We concluded that this technique with PSI appears to be a viable method to correct complex orbital floor defects. Our research group noted good aesthetic and functional results one year after surgery. Due to the complexity of the surgery for a major bony defect of the orbital floor, it is important that the surgery be executed by experienced surgeons in the field of maxillofacial traumatology.