Technical concept of patient-specific, ultrahigh molecular weight polyethylene orbital wall implant

Ultra-High Molecular Weight Polyethylene (marPOR) is a Suitable Material for the Reconstruction of Orbital Floor Fracture Defects in Human Cadavers

Purpose

Despite there being different materials for orbital floor reconstruction available today, outcomes are still not satisfying. In recent years, ultra-high molecular weight polyethylene (UHMWPE) has gained popularity in the field of orthopedic surgery due to its good biocompatibility and low infection rate. With its three-dimensional compound structure, it combines high stability and ductility, making it a potential material to be used for orbital floor reconstruction.

Methods

In a cadaver study, an overall of eighteen orbits were included. Fractures of the inferior wall were induced and then reconstructed using Polyglactin 910/PDS composite (Ethisorb) and UHMWPE (marPOR). Orbits were scanned by cone-beam CT in each condition: Intact, fractured and reconstructed with Ethisorb, marPOR 0.85 mm and marPOR 1.5 mm. Segmented orbital volumes were calculated by specialized software (Disior bonelogic CMF).

Results

All materials led to sufficient reconstruction of the initial orbital volumes (Ethisorb: p < 0.001; marPOR 0.85 mm: p = 0.003; marPOR 1.5 mm: p < 0.001). Orbits that were reconstructed with marPOR 0.85 mm showed the least mean volume difference from intact orbital volumes.

Conclusion

UHMWPE (marPOR) offers reliable reconstruction of orbital floor fractures combined with good stability, ductility and biocompatibility.

Preparation and In Vitro Analysis of Craniofacial Titanium Implants Surfaces Produced by Additive 3D Printing and Conventional Manufacturing

Study Design

Surface finish of titanium patient-specific craniofacial implants is known to affect their acceptability and durability and relevant literature still inconclusive on the best surface finishing protocol.

Objectives

This study investigated surface topography of three-dimensionally (3D) printed and conventionally manufactured craniofacial titanium implants following non-contact 3D laser profile-meter analysis.

Methods

Seven groups of titanium specimens (n = 10) were prepared and their surfaces were treated differently and included sole or combined treatment of mechanical polishing, gritting with 50 micron AL₂O₃, cold acid treatment using nitric acid for 20 hours (70% w/w), etching using acidic solution (69% nitric and 48% hydrofluoric acids) for 10 minutes and then electro-chemically anodized in another acidic solution (85% orthophosphoric and 98%sulphuric acid). Eighth group included specimens that were 3D printed. 3D micro-roughness parameters Sa, Sp, Sv, and Sz were determined (μm) for each specimen. Data was analyzed using one way ANOVA and Dunett T3 post-hoc tests (p < 0.05).

Results

There were statistically significant effects of surface finishing protocols (p < 0.05). Sa values were 2.72-13.75 and specimens which were electroplated or mechanically polished and acid treated were the smoothest (p < 0.05). Sp was in the range 9.07-43.56 as sandblasting significantly roughened surfaces (p < 0.05). The same inferior effect was evident for the Sv (p < 0.05). The Sz values were 19.46-107.05 and was the highest for sandblasted surfaces (p < 0.05) and the lowest for surfaces of electro-chemical treatment (p < 0.05).

Conclusion

Titanium surfaces are affected by the finishing procedure and electro-chemical treatment or mechanical polishing combined with acid treatment produced clinically-favorable smooth surfaces.

Custom-Made Zirconium Dioxide Implants for Craniofacial Bone Reconstruction

Reconstruction of the facial skeleton is challenging for surgeons because of difficulties in proper shape restoration and maintenance of the proper long-term effect. ZrO₂ implant application can be a solution with many advantages (e.g., osseointegration, stability, and radio-opaqueness) and lacks the disadvantages of other biomaterials (e.g., metalosis, radiotransparency, and no osseointegration) or autologous bone (e.g., morbidity, resorption, and low accuracy). We aimed to evaluate the possibility of using ZrO₂ implants as a new application of this material for craniofacial bone defect reconstruction. First, osteoblast (skeleton-related cell) cytotoxicity and genotoxicity were determined in vitro by comparing ZrO₂ implants and alumina particle air-abraded ZrO₂ implants to the following: 1. a titanium alloy (standard material); 2. ultrahigh-molecular-weight polyethylene (a modern material used in orbital surgery); 3. a negative control (minimally cytotoxic or genotoxic agent action); 4. a positive control (maximally cytotoxic or genotoxic agent action). Next, 14 custom in vivo clinical ZrO₂ implants were manufactured for post-traumatologic periorbital region reconstruction. The soft tissue position improvement in photogrammetry was recorded, and clinical follow-up was conducted at least 6 years postoperatively. All the investigated materials revealed no cytotoxicity. Alumina particle air-abraded ZrO2 implants showed genotoxicity compared to those without subjection to air abrasion ZrO₂, which were not genotoxic. The 6-month and 6- to 8-year clinical results were aesthetic and stable. Skeleton reconstructions using osseointegrated, radio-opaque, personalized implants comprising ZrO₂ material are the next option for craniofacial surgery.

Present and future for technologies to develop patient-specific medical devices: a systematic review approach

The main purpose of this investigation was to systematically review the literature regarding case studies on patient-specific implants and devices, with the goal of analyzing the process of developing custom-made medical devices. A content analysis was performed to identify design processes and methodologies implemented to develop devices such as implants adapted to bone geometries. Reverse engineering, computer-aided design, simulation of assets, and rapid prototyping technologies were selected according to their interoperability in a process framework for developing new products. Finally, results from the case studies and process stages identified in the consulted research were analyzed. These results showed a relationship between the scope and complexity of the process and the stage of technology integration of the patient-specific device development. The analyzed case studies were characterized by technical, scientific, and multidisciplinary components to achieve research goals. Likewise, integration of technologies using patient-specific technologies is needed for product development that converges into designing devices, such as implants, biomodels, and cutting drilling guides.

[Rational choice of revascularized autograft in midface reconstruction]

The article presents an analysis of the results of the use of revascularized autografts in the plastic elimination of combined defects in the middle zone of the face. Difficulties and negative moments of each of them were revealed and recommendations were given on the rationality of their clinical application with the development of the algorithm of surgical tactics.

Low-cost, self-made CAD/CAM-guiding system for mandibular reconstruction

Facial symmetry, as well as function, remains the big challenge for surgeons who attempt mandibular reconstruction. Nowadays several studies recommend the use of computer aided surgery (CAS) and CAD/CAM technology to guide mandibular segmental osteotomies and reconstruction using free fibula flap. Although these systems have radically changed the way of doing mandibular reconstructive surgery, they are expensive and require extended periods of time for prototypation. This may be an important limitation in case of malignant neoplasms which require short-term treatment. The aim of our study is to investigate the reliability and efficiency of a protocol to obtain cutting guides produced in a "homemade" way. This study includes four consecutive patients who underwent a segmental mandibulectomy and fibula osteo-cutaneous free flap reconstruction for oral squamous cell carcinoma between January and September 2016. The CAD/CAM system algorithm proposed was based on the use of free open source software for digital planning and 3D layer plastic deposition printer. A cost of about 3 Euro for each case was estimated. An average mean distance between 3D preoperative and postoperative mesh points of 1.631 mm and a standard deviation of 5.496 mm has been demonstrated by 3D volume overlay analysis. Overlapping results with much shorter prototyping time was required with the in-house procedure described as compared to the available commercial system. In conclusion, we expect that this technique will reduce operative time and cost however further study and large series are needed to confirm our results and better define the applicability in everyday surgical practice.

Custom-Made Titanium Miniplates Associated With Ultrahigh-Molecular-Weight Polyethylene Graft in Orthognathic Surgery: An Adjunct to Maxillary Advancement

Patients with considerable maxillomandibular anteroposterior discrepancies and maxillary hypoplasia require corrective treatment through orthognathic surgery. However, in the treatment of severe maxillary retrognathism, it is necessary to reconstruct areas of bone deficiency through grafting techniques in addition to maxillary advancement using only the Le Fort I osteotomy. Treatment in these patients is more challenging and requires high surgical predictability. Alloplastic materials often have been used for the reconstruction of poor bone contours. Ultrahigh-molecular-weight polyethylene (UHMWPE) is currently an excellent filler material for poor bone regions and is a good substitute for autografts and other alloplastic materials for its unique properties, including high biocompatibility. Insertion of this material in the fixation system customized for virtually planned orthognathic surgeries is an innovative technique. This report describes the insertion of UHMWPE into custom-made titanium miniplates manufactured by computer-aided design and computer-aided manufacturing technology for orthognathic surgery consisting of maxillary advancement and mandibular retrusion to treat a patient with Crouzon syndrome, Class III malocclusion, and severe maxillary retrognathism.

Simultaneous Computer-Aided Design/Computer-Aided Manufacture Bimaxillary Orthognathic Surgery and Mandibular Reconstruction Using Selective-Laser Sintered Titanium Implant

This patient report describes simultaneous bimaxillary orthognathic surgery and mandibular reconstruction by means of three-dimensional (3D) planning, 3D printed biocompatible surgical wafers, and 3D selective-laser sintered titanium implant. A 26-year-old male patient presented with a left mandibular defect secondary to trauma. The whole body of the mandible on the left hand side was deficient with a narrow connection with the remaining left condyle. He had undergone orthodontic treatment for 18 months and was ready to undergo bimaxillary orthognathic surgery. Advanced cranio-maxillofacial software was used in processing his cone beam computer tomography scan data, and e-casts of his upper and lower dental arches. Bimaxillary surgery was planned with Le Fort 1 maxillary impaction and mandibular advancement to achieve a class 1 incisor relationship. Intermediate and final surgical wafers were designed following the planned movements and printed using biocompatible resin. The deficient left side of the mandible was reconstructed by means of mirror imaging the contra-lateral right side into the deficient left side with the aim of restoring normal facial symmetry. Biomedical software was then used in designing a reconstruction plate that connected the condylar head and the mandible following the planned bimaxillary surgery and mandibular continuity symmetry reconstruction. The plate was printed in titanium following state-of the-art selective laser sintering technology. The bimaxillary surgery and mandibular reconstruction were done simultaneously as planned along with an iliac-crest bone graft. This patient confirms the advantages of 3D computer-aided design/computer-aided manufacture technologies in optimizing clinical outcomes for cranio-maxillofacial reconstruction, especially when conducting two simultaneous clinical procedures.

3D segmentation of intervertebral discs: from concept to the fabrication of patient-specific scaffolds

Aim: To develop a methodology for producing patient-specific scaffolds that mimic the annulus fibrosus (AF) of the human intervertebral disc by means of combining MRI and 3D bioprinting. Methods: In order to obtain the AF 3D model from patient's volumetric MRI dataset, the RheumaSCORE segmentation software was used. Polycaprolactone scaffolds with three different internal architectures were fabricated by 3D bioprinting, and characterized by microcomputed tomography. Results: The demonstrated methodology of a geometry reconstruction pipeline enabled us to successfully obtain an accurate AF model and 3D print patient-specific scaffolds with different internal architectures. Conclusion: The results guide us toward patient-specific intervertebral disc tissue engineering as demonstrated by a way of manufacturing personalized scaffolds using patient's MRI data.

Classical versus custom orbital wall reconstruction: Selected factors regarding surgery and hospitalization

PURPOSE

Nowadays, in orbital wall reconstruction, maxillofacial surgeons have the possibility to treat patients in modern ways such as with individual implants. Nevertheless, conventional treatment including standard titanium mesh shaped during the surgical procedure is also widely used. The aim of this study was to compare the above methods of orbital wall reconstructions.

MATERIALS AND METHODS

In the first group (39 cases), patients were treated by means of computer-aided design/computer-aided manufacturing (CAD/CAM) milled individual implants made of ultra-high-molecular-weight polyethylene, dioxide zirconium and rapid prototyping titanium mesh pre-bent on an ABS model made by a three-dimensional (3D) printer. In the second group (54 cases), intraoperative bending of titanium mesh was implemented.

RESULTS

Ophthalmologic outcomes were the same in both groups. In patients who had greater destruction of the orbit, surgical procedures were longer regardless of the material used for individual implants (p < 0.05). Time of surgery was shorter in patients in whom individual implants were used. Intraoperative bleeding was higher in patients who were treated using intraoperative bending titanium mesh (p < 0.01).

CONCLUSION

Application of CAD/CAM techniques do not give better ophthalmologic results in reference center but improve patient condition postoperatively. For this reason, CAD/CAM is a safer treatment method for patients.

Application of Computer-Aided Designing and Rapid Prototyping Technologies in Reconstruction of Blowout Fractures of the Orbital Floor

INTRODUCTION

Traumatology of the maxillofacial region represents a wide range of different types of facial skeletal injuries and encompasses numerous treatment methods. Application of computer-aided design (CAD) in combination with rapid prototyping (RP) technologies and three-dimensional computed tomography techniques facilitates surgical therapy planning for efficient treatment.

OBJECTIVE

The purpose of this study is to determine the efficiency of individually designed implants of poly-DL-lactide (PDLLA) in the reconstruction of blowout fractures of the orbital floor.

METHODS

In the course of a surgical treatment, individually designed implants manufactured by CAD/RP technologies were used. Preoperative analysis and postoperative monitoring were conducted to evaluate the successfulness of orbital floor reconstruction using customized PDLLA implants, based on: presence of diplopia, paresthesia of infraorbital nerve, and presence of enophthalmos.

RESULTS

In 6 of the 10 patients, diplopia completely disappeared immediately after surgical procedure. Diplopia gradually disappeared after 1 month in 3 patients, whereas in 1, it remained even after 6 months. In 7 patients, paresthesia disappeared within a month after surgery and in 3 patients within 2 months. Postoperative average Orbital volume (OV) of the injured side (13.333 ± 3.177) was significantly reduced in comparison with preoperative OV (15.847 ± 3.361) after reconstruction of the orbital floor with customized PDLLA implant (P < 0.001). Thus, average OV of corrected orbit was not different compared with the OV of the uninjured orbit (P = 0.981).

CONCLUSIONS

Reconstruction of blowout fractures of the orbital floor by an individually designed PDLLA implant combined with virtual preoperative modeling allows easier preoperative preparation and yields satisfactory functional and esthetic outcomes.

Repair of the Orbital Wall Fractures in Rabbit Animal Model Using Nanostructured Hydroxyapatite-Based Implant

Cellular uptake and cytotoxicity of nanostructured hydroxyapatite (nanoHAp) are dependent on its physical parameters. Therefore, an understanding of both surface chemistry and morphology of nanoHAp is needed in order to be able to anticipate its in vivo behavior. The aim of this paper is to characterize an engineered nanoHAp in terms of physico-chemical properties, biocompatibility, and its capability to reconstitute the orbital wall fractures in rabbits. NanoHAp was synthesized using a high pressure hydrothermal method and characterized by physico-chemical, structural, morphological, and optical techniques. X-ray diffraction revealed HAp crystallites of 21 nm, while Scanning Electron Microscopy (SEM) images showed spherical shapes of HAp powder. Mean particle size of HAp measured by DLS technique was 146.3 nm. Biocompatibility was estimated by the effect of HAp powder on the adhesion and proliferation of mesenchymal stem cells (MSC) in culture. The results showed that cell proliferation on powder-coated slides was between 73.4% and 98.3% of control cells (cells grown in normal culture conditions). Computed tomography analysis of the preformed nanoHAp implanted in orbital wall fractures, performed at one and two months postoperative, demonstrated the integration of the implants in the bones. In conclusion, our engineered nanoHAp is stable, biocompatible, and may be safely considered for reconstruction of orbital wall fractures.

The use of anatomically drop-shaped bioactive glass S53P4 implants in the reconstruction of orbital floor fractures--A prospective long-term follow-up study

An isolated fracture of the orbital floor needs reconstruction if there is a clear herniation of adipose tissue or of the rectus inferior muscle into the maxillary sinus. A prospective study was carried out treating 20 patients with an isolated blow-out fracture of the orbital floor or with a combined zygomatico-orbito-maxillary complex fracture, using a newly designed anatomically drop-shaped implants made of bioactive glass (BAG) S53P4. Computed tomography (CT) was performed immediately postoperatively to confirm the correct position of the plate. The patients were followed up for an average of 32 months clinically and radiologically with magnetic resonance imaging (MRI) for an average of 31 months. None of the patients had any signs of complications related to the implant and the clinical outcome was very good. None of the patients had persisting diplopia. The level of the pupillas was normal in 15 of 20 patients. Minor hypo-ophthalmos ranging from 0.5 to 1.0 mm was observed in three patients, and moderate hypo-ophthalmos of 2.0 mm was seen in one patient. Hyperophthalmos of 1.0 mm was seen in one patient. Minor enophthalmos on the operated side ranging from 0.5 to 1.0 mm was seen in eight patients. Mild to moderate paraesthesia of the infraorbital nerve was observed in six patients. The immediate postoperative CT and the long term follow-up MRI revealed that the drop-shaped BAG implants retained their correct position in the orbital floor and did not show any evidence of losing their original shape or material resorption. No adverse tissue reaction was associated with the material. Due to the anatomical drop shape, the implants could successfully maintain the orbital volume and compensate for the retrobulbar adipose tissue atrophy.

The management of naso-orbital-ethmoid (NOE) fractures

The bony naso-orbital-ethmoid (NOE) complex is a 3-dimensional delicate anatomic structure. Damages to this region may result in severe facial dysfunction and malformation. The management and optimal surgical treatment strategies of NOE fractures remain controversial. For a patient with NOE trauma, doctors should perform comprehensive clinical examination and radiographic analysis to assess the type and extent of fracture. The results of assessment will assist doctors to make a patientspecific program for the sake of reducing post-operation complications and restoring normal appearance and function as much as possible. This review focuses on the advancement of management of NOE fractures including symptoms, classifications, diagnosis, approaches, treatment and new techniques in this field.

Mechanical properties of collagen membranes: are they sufficient for orbital floor reconstructions?

INTRODUCTION

The most common reconstruction materials for orbital floor fractures are PDS (polydioxanone) foil and titanium meshes. These materials have advantages and disadvantages. Therefore, new materials are needed to improve surgical outcomes.

MATERIALS AND METHODS

Three resorbable collagen membranes (Smartbrane(®), BioGide(®), Creos(®)) were tested for their mechanical properties (puncture strength) in mint and artificially aged (3, 6, 8 weeks) conditions and were compared to PDS foil, titanium meshes (0.25 mm, 0.5 mm) and human orbital floors (n = 7).

RESULTS

The following puncture strengths were evaluated: human orbital floor, 0.81 ± 0.49 N/mm(2); 0.25 mm titanium mesh, 5.36 ± 0.25 N/mm(2); 0.5 mm titanium mesh, 16.08 ± 5.17 N/mm(2); Smartbrane, 0.74 ± 0.31 N/mm(2); BioGide, 1.65 ± 0.45 N/mm(2); and Creos, 2.81 ± 0.27 N/mm(2). After artificial aging, the puncture strengths were significantly reduced (p ≤ 0.05) at 3, 6 and 8 weeks as follows: Smartbrane, 0.05 ± 0.03 N/mm(2), 0.03 ± 0.02 N/mm(2), and 0.01 ± 0.01 N/mm(2), respectively; BioGide, 0.42 ± 0.06 N/mm(2), 0.41 ± 0.12 N/mm(2), and 0.32 ± 0.08 N/mm(2), respectively; and Creos, 2.02 ± 0.37 N/mm(2), 1.49 ± 0.42 N/mm(2), and 1.36 ± 0.42 N/mm(2), respectively.

CONCLUSION

The tested materials showed sufficient puncture strength for orbital floor reconstruction in mint condition. Moreover, after artificial aging, the Creos and BioGide membranes showed sufficient resistance, while Smartbrane showed equivocal data after eight weeks. Therefore, collagen membranes have adequate properties for further in vivo investigations for orbital floor reconstructions.

Reconstruction of orbital floor blow-out fractures with autogenous iliac crest bone: a retrospective study including maxillofacial and ophthalmology perspectives

This is a 10-year retrospective study of patients with an isolated unilateral orbital floor fracture reconstructed with an autogenous iliac crest bone graft. The following inclusion criteria applied: isolated orbital floor fracture without involvement of the orbital rim or other craniofacial injuries, pre-/post-operative ophthalmological/orthoptic follow-up, pre-operative CT. Variables recorded were patient age and gender, aetiology of injury, time to surgery, follow-up period, surgical morbidity, diplopia pre- and post-operatively (Hess test), eyelid position, visual acuity, and the presence of en-/or exophthalmos (Hertel exophthalmometer). Twenty patients met the inclusion criteria. The mean age was 29 years. The mean follow up period was 26 months. No patient experienced significant donor site morbidity. There were no episodes of post-operative infection or graft extrusion. Three patients had diplopia in extremes of vision post-operatively, but no interference with activities of daily living. One patient had post-operative enophthalmos. Isolated orbital blow-out fractures may be safely and predictably reconstructed using autogenous iliac crest bone. The rate of complications in the group of patients studied was low. The value of pre- and post-operative ophthalmology consultation cannot be underestimated, and should be considered the standard of care in all patients with orbitozygomatic fractures, in particular those with blow-out fractures.

Biomaterials for orbital implants and ocular prostheses: overview and future prospects

The removal of an eye is one of the most difficult and dramatic decisions that a surgeon must consider in case of severe trauma or life-threatening diseases to the patient. The philosophy behind the design of orbital implants has evolved significantly over the last 60 years, and the use of ever more appropriate biomaterials has successfully reduced the complication rate and improved the patient's clinical outcomes and satisfaction. This review provides a comprehensive picture of the main advances that have been made in the development of innovative biomaterials for orbital implants and ocular prostheses. Specifically, the advantages, limitations and performance of the existing devices are examined and critically compared, and the potential of new, smart and suitable biomaterials are described and discussed in detail to outline a forecast for future research directions.

Comparison of pre-bent titanium mesh versus polyethylene implants in patient specific orbital reconstructions

Introduction

Computerized tomography DICOM file can be relatively easily transformed to a virtual 3D model. With the help of additional software we are able to create the mirrored model of an undamaged orbit and on this basis produce an individual implant for the patient Authors decided to apply implants with any thickness, which are authors own invention to obtain volumetric support and more stable orbital wall reconstruction outcome. Material of choice was ultra-high molecular weight polyethylene (UHMWPE).

Objective

The aim of this study was to present and compare functional results of individual reconstructions of orbital wall using either titanium mesh or ultra-high molecular weight polyethylene.

Materials and methods

57 consecutive patients affected by orbital wall fracture (46 males, 11 females, mean age 34±14 year) were treated in Department of Maxillofacial Surgery from 2010 to 2012. In the first group we used patient specific treatment by titanium mesh shaped on a 3D printed model of a mirrored intact orbit (37 orbits) or by individually manufactured UHMW-PE implantby CAM milling in second group (20 orbits). All of these patients were subjected to preoperative helical computerized tomography and consultation of an ophthalmologist (including binocular single vision loss test - BSVL). Further on, patients were operated under general anaesthesia using transconjuctival approach. BSVL was again evaluated post-operationally in 1 month and 6 months later.

Results

Functional treatment results (BSVL) for both groups were similar in 1 month as well as 6 months post operational time. There was no statistically significant difference between these two groups.

Conclusions

This study of 6 months functional result assessment of pre-bent individual implants and CNC milled ultra-high molecular weight polyethylene of the orbital wall has shown it to be a predictable reconstruction method. Individually shaped UHMWPE seems to be as good as pre-bent titanium mesh.

Computer-aided orbital wall defects treatment by individual design ultrahigh molecular weight polyethylene implants

Despite of well-known advantages of high molecular weight polyethylene (Medpor, Synpore) in orbital reconstructions, the thickness of those implants significantly exceeds 0.5 mm and precise modification of thickness is limited. The aim of this study was to present the application of a self-developed method of treatment orbital wall fracture by custom implant made of ultrahigh molecular weight polyethylene (UHMW-PE).

MATERIAL AND METHOD

First, the test of influence of sterilization process upon implant deformation was performed (autoclaving, ethylene oxide, gas plasma, irradiation). Next, ten cases for delayed surgical treatment of orbital fracture were included into this study (7 males, 3 females). Based on CT scan and mirrored technique, a CAD model of virtual implant for repairing orbital wall was made. Then, an implant was manufactured with a computer numerical controlled milling machine from UHMW-PE block, sterilized and used during a surgical procedure. Clinically used implants had thickness from 0.2 to 4.0 mm.

RESULTS

The best method of sterilization is ethylene oxide process, and the worst is autoclaving. In this series of delayed surgical cases, functional results of orbital surgery are worse than in simpler, early treated cases, but long-term subsidence of diplopia is noticeable [10% poor results]. The results of the treatment depend on the initial level of diplopia where severe initial diplopia to be corrected requires thicker implants (p < 0.01). It also leads to longer surgical procedures (p < 0.01), but prolongation of the surgery had no negative influence upon results of any investigated follow-up examinations. Obviously, the orbital destruction intensity is related to injury-evoked initial diplopia but it also influences whole results of treatment up to 12 months post-op. Interesting result is presented by the relation of maximal implant thickness to 12-month diplopia evaluation. Thicker implants used result in lower residual diplopia (p < 0.05). This is important because of the correlation between the higher orbital destruction intensity with a thicker UHMW-PE implant (p < 0.05) applied in this series.

CONCLUSION

Patient-specific ultrahigh molecular weight polyethylene implants enable precise reconstructions of orbital wall. One should not be afraid of a significant eye globe reposition caused by these thickness modulated implants, as such repositioning is essential for an efficient correction of enophthalmos.