مقاله انگلیسی رایگان در مورد بازسازی دیوارهای اوربیتال توسط الگوی لیزری – IEEE 2017

The success of reconstructive orbital surgery depends on diverse aspects related to the preoperative evaluation of the trawnatic deformity, the design and manufacturing of the implant, and the surgical protocol. Patients who suffered disruption of the eyeball following direct or indirect ocular trauma often present an untreated fracture of one or more orbital walls. Usually the fracture involves the floor and/or the medial wall of the orbit, with consequent vertical dystopia and asymmetry of the ocular prosthesis compared to the controlateral side. Ocular and orbital volwne are critical in these cases. The primary goal for orbital reconstruction is repairing the fractured wall by restoring the skeletal cavity and the orbital volume [1, 2]. In this regard, image-guidance technology is useful for the design of anatomic orbital implants, particularly for two-walled defects involving the floor and medial wall [3]. Custom implants can also be utilized for DOl: 10.2316IP.20J7.852-045 260 reconstruction of irregular defects or when there is a significant bone loss [4, 5]. The problems connected with the previous cited approach are related to the high cost of the surgical procedure due both to the planning phase and, particularly, to the manufacturing of a preformed titanium orbital implant. The present paper reports on a case of secondary reconstruction of the orbital cavity due to a 35- year-old displaced fracture of the orbital floor. The paper consists of a computer-assisted approach, based on anatomical modelling and custom-made mould fabrication via selective laser sintering, for manufacturing a preformed orbital implant. Such in-office procedure offers precise and predictable results of orbital reconstruction. Moreover, it reduces at the same time the surgical time, morbidity, and it is a low-cost surgical procedure. Such an approach is suggested for achieving accurate results both in secondary and primary reconstruction of the orbital wall. To date, surgeons have three main choices for the reconstruction of orbital walls: (1) to shape the implant directly on the patient orbital wall during the surgery, (2) to implant a preformed titanium plate or a 3D printed, custom-made titanium mesh, and (3) to model the implant on the 3D printed mould of the pathological orbital wall (with the fracture virtually closed). The three diverse procedures show some disadvantages. In the first case, the repetitive trial fitting of the implant can be traumatic to the periorbital tissues and the geometry and placement of the implant could be not accurate. In the second case, the main problem is related to the costs connected with the manufacturing of the implant. In fact, to date 3D printed titanium orbital implants, manufactured via electron beam melting (EBM) 0 direct metal sintering (DMS), have costs between 3000€ and 5000€. The costs of prefabricated titanium orbital plates or meshes range between 250€ (KLS Martin) and 600€ to 800€ (Synthes, West Chester, PA) [5]. In the last case, the main issue is the time required to the surgeon to manually model the implant on the mould and then re-adjust the shape of the plate on the patient. An example of this methodology is reported in [5], where Vehmeijer et al.