Customized titanium reconstruction of post-traumatic orbital wall defects: a review of 22 cases

Clinical application of biomaterials in orbital implants: a systematic review

PURPOSE

Various materials have been proposed for reconstructing orbital fractures. The materials used must meet certain criteria to ensure their suitability for restoring the structure and function of the organ. These criteria include biocompatibility, ease of application, non-toxicity, hypo-allergenicity, and non-carcinogenicity. In this study, we systematically reviewed the studies regarding the biomaterials in orbital implants and their clinical application.

METHODS

A comprehensive search across various databases, including PubMed, Scopus, EMBASE, Cochrane Library, and Web of Science, was conducted until April 10th, 2023. After retrieving the search results and eliminating duplicates, final studies were included after screening through defined criteria. Human and animal studies assessing the clinical application of biomaterials in orbital implants were included. The quality of the case series and controlled intervention studies were evaluated using the NIH tool, and for animal studies, the risk of bias was assessed using SYRCLE's tool.

RESULTS

Seventeen studies were included according to defined criteria. These studies aimed to explore the clinical application of biomaterials and examine the associated complications in orbital implants.

CONCLUSION

We found that using biomaterials did not result in elevated intraocular pressure (IOP). However, we did observe certain complications, with infection, residual diplopia, and enophthalmos being the most frequently reported issues.

Utilizing 3D Printing for the Surgical Management of Orbital Floor Fractures

We present a technique for treating orbital floor fractures using three-dimensional (3D) printing technology and a preoperative template based on the mirror image of the unaffected orbit. Our patient, a 56-year-old man, experienced persistent diplopia in the upward direction and left enophthalmos after previous open reduction internal fixation surgery. To address these complications, we used a simulation of the ideal orbital floor from computed tomography images and used a 3D printer to create a template. Subsequently, an absorbable plate was molded intraoperatively based on this template. Notably, the plate fit seamlessly into the fracture site without requiring any adjustment, reducing the operation time. Postoperative computed tomography scans confirmed successful reduction, improved visual function, and the absence of complications. Our method offers a precise and efficient approach to reconstructing fractured orbital floors. By leveraging 3D printing technology and preoperative templates, surgeons can enhance postoperative outcomes and minimize patient burden. Further investigations are warranted to assess the long-term effectiveness and cost-effectiveness of this technique. Our findings highlight the potential of this approach to improve treatment strategies for patients with orbital floor fractures.

Is the Pre-Shaping of an Orbital Implant on a Patient-Specific 3D-Printed Model Advantageous Compared to Conventional Free-Hand Shaping? A Systematic Review and Meta-Analysis

This study aimed to perform a systematic review and meta-analysis to compare pre-shaped implants on a patient-specific 3D-printed (3DP) model to manual free-hand shaping (MFS) for orbital wall reconstruction. The PRISMA protocol was followed in this study, and the review was registered in the PROSPERO database (CRD42021261594). A search was conducted in MEDLINE (PubMed), Embase, Cochrane Library, Clinicaltrials.gov, Google Scholar, and the grey literature. Ten articles were included, and six outcomes were analyzed. In total, 281 patients were in the 3DP group and 283 were in the MFS group. The studies had an overall high risk of bias. 3DP models resulted in a better accuracy of fit, anatomical angle reproduction, and defect area coverage. The correction of orbital volume was also superior with statistical significance. There was a higher percentage of the correction of enophthalmos and diplopia in the 3DP group. Intraoperative bleeding and hospital stay were reduced in the 3DP group. The meta-analysis of operative time showed a reduction in the average operative time by 23.58 min (95% CI: -43.98 to -3.19), which was statistically significant (t(6) = -2.8299, p = 0.0300). The 3DP models appear advantageous for an accurate orbital wall reconstruction, with fewer complications than those for conventional free-hand-shaped implants.

Late patient-fitted total orbital reconstruction for facial gunshot wound sequelae

Late reconstructions of gunshot wounds (GSWs) in the orbital area are a true challenge to the oral and maxillofacial surgeon. Usually, the wall defects are large in size and commonly present loss of orbital volume, which can cause ocular dystopia. The only exceptions are when there is an explosion of the orbital walls-that is, blow-out fractures. We encountered a patient with a two-year sequelae after GSW in the face that caused the destructed orbit to have a 2.5 bigger size than the contralateral orbit, requiring meticulous planning of a patient-specific implant (PSI) to correctly reconstruct the orbit volume and bone projection. The PSI was developed using titanium and it had three pieces that could reconstruct all four walls of the orbit. After surgery, the patient regained orbital volume and malar projection, allowing him to benefit from facial symmetry. The PSI can be used to reconstruct all the orbital walls in cases of complex bone defects.

Patient-specific Implants for Orbital Fractures: A Systematic Review

PURPOSE

Orbital fractures are common facial fractures that can be challenging to repair and require careful attention to avoid unacceptable ophthalmic complications. Customized implants that are unique to an individual patient, or patient-specific implants (PSIs), have been increasingly used to repair orbital wall fractures. This systematic review summarizes the current evidence regarding custom-made orbital wall implants.

METHODS

A keyword search of published literature from January 2010 to September 2021 was performed using Ovid MEDLINE, PubMed, and the Cochrane Library databases. Original articles that included more than 3 human subjects with an orbital fracture repaired with a PSI were included. The search results were reviewed, duplicates were removed and relevant articles were included for analysis.

RESULTS

Fifteen articles meeting the inclusion criteria. The articles were categorized into 3 separate groups based on the method of PSI fabrication: manual molding of a PSI on a 3D-printed orbital model (53%), directly from a 3D printer (27%), or via a template fabricated from a 3D printer (20%). Three primary postoperative outcomes were assessed: rates of diplopia, enophthalmos, and orbital volume. Postoperative rates of diplopia and enophthalmos improved regardless of the PSI technique, and postoperative orbital volumes were reduced compared with their preoperative state. When PSIs were compared to conventional implants, patient outcomes were comparable.

CONCLUSIONS

This review of existing PSI orbital implant literature highlights that while PSI can accurately and safely repair orbital fractures, patient outcomes are largely comparable to orbital fractures repaired by conventional methods, and PSI do not offer a definitive benefit over conventional implants.

Prospective Evaluation of Intraorbital Soft Tissue Atrophy after Posttraumatic Bone Reconstruction: A Risk Factor for Enophthalmos

Orbital fractures are a common finding in facial trauma, and serious complications may arise when orbital reconstruction is not performed properly. The virtual planning can be used to print stereolithographic models or to manufacture patient-specific titanium orbital implants (PSIs) through the process of selective laser melting. This method is currently considered the most accurate technique for orbital reconstruction. Even with the most accurate techniques of bone reconstruction, there are still situations where enophthalmos is present postoperatively, and it may be produced by intraorbital soft tissue atrophy. The aim of this paper was to evaluate the orbital soft tissue after posttraumatic reconstruction of the orbital walls’ fractures. Ten patients diagnosed and treated for unilateral orbital fractures were included in this prospective study. A postoperative CT scan of the head region with thin slices (0.6 mm) and soft and bone tissue windows was performed after at least 6 months. After data processing, the STL files were exported, and the bony volume, intraorbital fat tissue volume, and the muscular tissue volume were measured. The volumes of the reconstructed orbit tissues were compared with the volumes of the healthy orbit tissues for each patient. Our findings conclude that a higher or a lower grade of fat and muscular tissue loss is present in all cases of reconstructed orbital fractures. This can stand as a guide for primary or secondary soft tissue augmentation in orbital reconstruction.

Advances in Regenerative Sports Medicine Research

Regenerative sports medicine aims to address sports and aging-related conditions in the locomotor system using techniques that induce tissue regeneration. It also involves the treatment of meniscus and ligament injuries in the knee, Achilles’ tendon ruptures, rotator cuff tears, and cartilage and bone defects in various joints, as well as the regeneration of tendon–bone and cartilage–bone interfaces. There has been considerable progress in this field in recent years, resulting in promising steps toward the development of improved treatments as well as the identification of conundrums that require further targeted research. In this review the regeneration techniques currently considered optimal for each area of regenerative sports medicine have been reviewed and the time required for feasible clinical translation has been assessed. This review also provides insights into the direction of future efforts to minimize the gap between basic research and clinical applications.

Effect of Surface Tooling Techniques of Medical Titanium Implants on Bacterial Biofilm Formation In Vitro

The aim of this study was to assess the biofilm formation of Streptococcus mutans, Staphylococcus aureus, Enterococcus faecalis, and Escherichia coli on titanium implants with CAD-CAM tooling techniques. Twenty specimens of titanium were studied: Titanium grade 2 tooled with a Planmeca CAD-CAM milling device (TiGrade 2), Ti6Al4V grade 5 as it comes from CAD-DMLS device (computer aided design-direct metal laser sintering device) (TiGrade 5), Ti6Al4V grade 23 as it comes from a CAD-CAM milling device (TiGrade 23), and CAD-DMLS TiGrade 5 polished with an abrasive disc (TiGrade 5 polished). Bacterial adhesion on the implants was completed with and without saliva treatment to mimic both extraoral and intraoral surgical methods of implant placement. Five specimens/implant types were used in the bacterial adhesion experiments. Autoclaved implant specimens were placed in petri plates and immersed in saliva solution for 30 min at room temperature and then washed 3×with 1 ×PBS. Bacterial suspensions of each strain were made and added to the specimens after saliva treatment. Biofilm was allowed to form for 24 h at 37 °C and the adhered bacteria was calculated. Tooling techniques had an insignificant effect on the bacterial adhesion by all the bacterial strains studied. However, there was a significant difference in biofilm formation between the saliva-treated and non-saliva-treated implants. Saliva contamination enhanced S. mutans, S. aureus, and E. faecalis adhesion in all material types studied. S. aureus was found to be the most adherent strain in the saliva-treated group, whereas E. coli was the most adherent strain in the non-saliva-treated group. In conclusion, CAD-CAM tooling techniques have little effect on bacterial adhesion. Saliva coating enhances the biofilm formation; therefore, saliva contamination of the implant must be minimized during implant placement. Further extensive studies are needed to evaluate the effects of surface treatments of the titanium implant on soft tissue response and to prevent the factors causing implant infection and failure.

A Stepwise Guide to Freehand Bending of Orbital Floor Mesh

Orbital fractures can often result in enophthalmos or diplopia. Orbital reconstruction with titanium meshes is the current treatment modality. Adapting the titanium orbital floor mesh is often challenging due to the complex anatomy of the orbital floor. Here, a stepwise free hand bending technique of a titanium orbital floor mesh is described. The bending can be done preoperatively, and mesh fit can be checked against a dry anatomical skull before sterilization. The methodical approach to free hand bending of titanium orbital floor mesh minimizes the intraoperative adjustments and permits quick orbital reconstruction. Trainees and less-experienced surgeons can benefit from the methodical approach to free hand bending of titanium orbital floor mesh.

The Management of Orbital Roof Fractures and Defects: A Review

PURPOSE

To explore the anatomy, etiopathogenesis, diagnosis and classification, current evidence on intervention and the surgical management of orbital roof fractures and defects (ORFD) for oculoplastic surgeons presented with such cases.

METHODS

A review of the current literature through the MEDLINE database using the following search terms: "orbital roof fracture (+treatment/management)," "orbital roof defect (+treatment/management)," "orbital roof erosion (+treatment/management)," "orbital roof repair," "orbital roof," "orbital fracture," "pediatric orbital roof (defect/fracture/erosion)," "orbital anatomy," and "orbital roof anatomy" was conducted. As relatively little has been published on this topic, inclusion criteria were broad and peer-reviewed articles judged to be of clinical importance, relevant to the aims of this review, were included. Non-English abstracts were also included if relevant. Year of publication was not a strict exclusion criterion, and older articles were judged for their suitability based on clinical importance and relevance to current practice. Additional references were obtained from citations in key articles and recommendations from the coauthors based on their areas of expertise.

RESULTS

The etiopathogenesis of ORFD varies. Classification systems have been formulated to guide management decisions and can range from conservative management to complex neurosurgery. Eyelid approaches have also been described. This review provides a summary of the evidence for each and a management framework oculoplastic surgeons can use when presented with ORFD.

CONCLUSION

Oculoplastic surgeons can be involved, either alone or as part of a multidisciplinary team, in the management of ORFD, and for some, conduct orbital approach reconstructive surgery.

Prebending of Prefabricated Orbital Implants: Towards Improved Orbital Angle Symmetry Post Craniofacial Trauma Surgery

PURPOSE

Reconstructive surgery after craniofacial trauma aim to restore orbital anatomy for function and aesthetic reasons. The purpose of this study is to improve postoperative orbital symmetry with the use of prebent prefabricated titanium implants.

METHODS

In this retrospective study, patients with combined unilateral medial wall and floor fractures who underwent orbital reconstruction surgery were selected. The angle of inferomedial orbital strut (AIOS) was measured at 3 standard locations on preoperative facial computed tomography guided scans of the nonfractured orbit in the coronal view and used as a guide to bend the prefabricated titanium implants intraoperatively. The corresponding values were measured on the postoperative computed tomography and compared for symmetry.

RESULTS

Out of 83 patients recruited for the study, 54 were in the prebent group while 29 were in the control group. All other demographics were similar among the 2 groups. Anterior AIOS has a difference of 4.9° between 2 orbits in the prebent group whereas a difference of 15.5° was noted in the nonprebent group. For middle AIOS, a difference of 4.7° was noted in the prebent group whereas nonprebent group had a difference of 14.1°. For posterior AIOS, the prebent group had a difference of 3.8° versus 14.1° in the nonprebent group. The difference in AIOS at all 3 points between the prebent and nonprebent group were significant.

CONCLUSIONS

Anatomical prefabricated titanium plates are versatile implants that facilitate orbital reconstruction. Prebending of these implants according to the fellow orbit can achieve better surgical outcomes in a cost-effective manner.

Functional and Cosmetic Outcome after Reconstruction of Isolated, Unilateral Orbital Floor Fractures (Blow-Out Fractures) with and without the Support of 3D-Printed Orbital Anatomical Models

The present study aimed to analyze if a preformed "hybrid" patient-specific orbital mesh provides a more accurate reconstruction of the orbital floor and a better functional outcome than a standardized, intraoperatively adapted titanium implant. Thirty patients who had undergone surgical reconstruction for isolated, unilateral orbital floor fractures between May 2016 and November 2018 were included in this study. Of these patients, 13 were treated conventionally by intraoperative adjustment of a standardized titanium mesh based on assessing the fracture's shape and extent. For the other 17 patients, an individual three-dimensional (3D) anatomical model of the orbit was fabricated with an in-house 3D-printer. This model was used as a template to create a so-called "hybrid" patient-specific titanium implant by preforming the titanium mesh before surgery. The functional and cosmetic outcome in terms of diplopia, enophthalmos, ocular motility, and sensory disturbance trended better when "hybrid" patient-specific titanium meshes were used but with statistically non-significant differences. The 3D-printed anatomical models mirroring the unaffected orbit did not delay the surgery's timepoint. Nonetheless, it significantly reduced the surgery duration compared to the traditional method (58.9 (SD: 20.1) min versus 94.8 (SD: 33.0) min, p-value = 0.003). This study shows that using 3D-printed anatomical models as a supporting tool allows precise and less time-consuming orbital reconstructions with clinical benefits.

Going beyond the limitations of the non-patient-specific implant in titanium reconstruction of the orbit

Reconstruction of post traumatic orbital defects has undergone a stepwise evolution following developments in reconstructive materials and surgical techniques. Advances in communication between surgical teams and design technicians have allowed provision of bespoke surgical plates with a high degree of accuracy and surgical relevance in an appropriate timeframe. We present a case series of 41 consecutive patients treated in London and BernBern Switzer between March 2019 and September 2020 with extensive defects reconstructed with patient specific orbital plates. Complexity of fracture was risk adjusted using the Jaquiery scale with one patient (J3), 14 patients (J4), and 26 Patients (J5). Outcome was assessed by accuracy of fit at the surgical margins and was 94.5%. The study group was statistically tested against a previous series by the same group and was statistically different with respect to the case complexity (p<0.001) and accuracy of fit (p<0.001) (Fisher's exact test). Complications included the removal on one plate due to patient choice, with perfect surgical position and resolving diplopia. Only one plate articulation was poor, this mitigated by the size of the defect and the orbital soft tissue swelling which prohibited seating the implant. The patient remains well with acceptable function and satisfactory aesthetics. We present design considerations including the use two part plates, and surgical pearls to achieve predictable placement. We believe that the use of custom plates for reconstruction of Jaquiery 4 and 5 should be considered. We regard this technology as a game changer in surgical management of the complex high risk orbit.

Patient-Specific Implants in Oculofacial Plastic Surgery

PURPOSE

To investigate how patient-specific implants (PSIs) are being utilized for periocular facial skeletal reconstruction. Specifically, to characterize indications for custom implants, areas of reconstruction, intraoperative variables impacting implant placement, as well as to report on postoperative outcomes.

MATERIALS AND METHODS

A retrospective chart review was performed for patients who received a PSI for periocular skeletal reconstruction between 2015 and 2019. Three independent academic centers were included in this study, which encompassed 4 different primary surgeons. Medical records, radiographic imaging, and operative reports were reviewed.

RESULTS

Eleven patients, 8 females and 3 males, ages ranging from 15 to 63 years old received PSIs. The average duration of follow up was 16 months ± 6.6 months (range: 9-30 months). The most common underlying etiology for reconstruction was prior trauma (54.5%) followed by benign tumor resection (18.2%). The most frequent area of reconstruction involved the inferior orbital rim and adjacent maxilla (63.6%). Implant materials included porous polyethylene, polyetheretherketone, and titanium. Six implants required intraoperative modification, most commonly accommodate critical neurovascular structures (66.6%) or improve contour (33.3%). Two postoperative complications were noted, both in the form of infection with 1 implant requiring removal.

CONCLUSIONS

Reconstruction of complex facial skeletal defects can be achieved by utilizing computer-assisted design software and 3D printing techniques to create PSIs. These implants represent the most customizable option for symmetric restoration of the facial skeleton by not only addressing structural deficits but also volumetric loss. This was particularly apparent in reconstruction of the orbital rim and midface. PSIs were found to be of most benefit in patients with prior trauma or complex skeletal defects after tumor resection.

Clinical outcome of patients with orbital fractures treated with patient specific CAD/CAM ceramic implants - A retrospective study

The aim of this study was to determine whether patients benefit from a secondary reconstruction since it carries the risks of no improvement or worsening of their current situation. Patients treated with individual computer-aided-design/computer-aided-manufacturing (CAD/CAM) ceramic implants were reviewed. To ascertain changes throughout the secondary reconstruction, the study investigators reviewed ophthalmological examinations, took volumetric measurements of the orbits and asked the patients for evaluation of their situation before and after the reconstruction. Points addressed were double vision, visual acuity, field of vision, limitations in daily life and aesthetic considerations. A total of 14 patients were reviewed and 11 answered the questionnaire. Ophthalmological examinations showed that the physical integrity of the eye was maintained. Volumetric measurements preopeatively (33.94 ± 3.24 cm³) and postoperatively (30.67 ± 2.07 cm³) showed that a statistically significant overcorrection of orbital volume leads to good functional and aesthetic outcomes. Patients' subjective opinions were that they greatly benefitted, especially concerning limitations in daily life, which improved by 4.4 ± 2.8 points out of 10 possible points, and aesthetics, with an improvement of 5.9 ± 1.78 points. Based on these findings, we conclude that secondary reconstructions contribute to improvement of the patients' quality of life and therefore should be considered as an option to improve patients' condition.

Customized Orbit and Frontal Bone Implants

Orbitocranial reconstruction objectives include creation of a solid barrier between intracranial contents and the environment allowing restoration of physiologic homeostasis and restoration of aesthetic craniofacial contours. Historically, bone grafts have been used for reconstruction but were fraught with unpredictable resorption and imperfect contouring given the complex anatomy of the orbitofrontal bones. With advances in three-dimensional modeling technology, alloplastic custom implants in orbital and frontal bone reconstruction have allowed for rapid fixation reducing surgical times and improved cosmesis.

Aging of the Adult Bony Orbit

BACKGROUND

Accurate quantitative data of the adult bony orbital volume and dimension are needed for treatment optimization. In the present study, the authors aim to evaluate adult orbital volume and corresponding linear dimensions according to age, volume, and individual symmetry.

METHODS

Seventy computerized tomography facial scans of adults were randomly chosen from an institutional database and 3-dimensionally reconstructed. Studies were excluded for orbital pathology or incomplete radiographic data. Anatomic landmarks were marked. Interval linear distances and orbital volumes were calculated. Data were analyzed using paired T-tests, independent T-tests, linear regression analysis, and 1-way analysis of variance.

RESULTS

A total of 140 orbits from 70 patients were analyzed (female = 35, male = 35), ranging from 20 to 88 years of age. Orbital volume was similar between an individual's left and right side; however, a difference was observed in vertical orbital height, orbital width, inferior orbital rim position, orbital roof length, orbital width, and medial orbital wall length (0.45, 0.64, 0.4, 0.77, 0.97, and 5.1 mm, respectively; P < 0.05). In comparison to females, males averaged larger orbital volume by 3.07 cm (29.58 cm versus 26.51 cm, P = 0.0002), medial wall length by 2.66 mm (P < 0.05), and orbital width by 2.66 mm (P < 0.05). Orbital volume did not correlate with patient age, while lateral wall length was correlative.

CONCLUSION

This accurate normative data of the adult bony orbit impacts key aspects of patient diagnosis and treatment and also suggest clinical signs of periorbital aging are not due to bony orbital changes.

Treatment of orbital blowout fracture using a customized rigid carrier

PURPOSE

This study aimed to examine the usefulness of treating orbital blowout fracture using a customized rigid carrier.

MATERIAL AND METHODS

Patients who underwent surgery for orbital blowout fractures in our department from April 2016 to March 2019 were recruited in the study. We molded a rigid thermoplastic material into the same shape as the reconstruction material according to the 3D model and transplanted it into the orbital space along with the reconstruction material. We assessed Hertel exophthalmometry, awareness of diplopia, and the Hess area ratio (HAR%).

RESULTS

We performed this procedure in 15 patients with blowout fractures. Reconstruction materials used were iliac bone, absorbable plates, and titanium mesh in 12, 2, and 1 patient, respectively. None of the patients showed a difference of more than 2 mm on Hertel exophthalmometry. Only one patient had diplopia after surgery. The average preoperative and postoperative HAR% were 83.1 and 90.6, respectively. HAR% was more than 85% in 6 of 7 postoperative cases.

CONCLUSIONS

This method can be applied for surgery using various reconstructive materials and can be a useful method, especially in patients with a wide range of orbital bone defects.

Analysis of Orbital Morphology and its Relationship With Eyelid Morphology

Correct anatomical reconstruction of the orbital wall for function and cosmesis is important; however, this is difficult because of the structure's complexity. The authors aimed to analyze and classify orbital morphology from computed tomography (CT) images and examine the relationship between orbital morphology and eyelid morphology in the Japanese population. CT images of 60 men (right side, 29; left side, 31) and 44 women (each side, 22) were included. The lengths of the orbital medial wall and floor in the coronal plane at the anterior, middle, and posterior planes of the orbit; angle between them; simotic index; and the thickness of upper eyelid were measured. Additionally, the presence or absence of double eyelids was evaluated. Non-paired Student's t test and Pearson correlation coefficient test were used for analysis. Orbital morphology was symmetrical on both sides, and men had a larger orbit than women. Orbital morphology was classified into 2 groups according to the posterior angle, and there was a difference between the groups in the simotic index. The difference between groups may represent a genetic difference between the Jomon and Yayoi people and not only provide a new classification for the orbit of the population but also be useful in orbital reconstruction.

Cost Analysis for In-house versus Industry-printed Skull Models for Acute Midfacial Fractures

Industry-printed (IP) 3-dimensional (3D) models are commonly used for secondary midfacial reconstructive cases but not for acute cases due to their high cost and long turnaround time. We have begun using in-house (IH) printed models for complex unilateral midface trauma. We hypothesized that IH models would decrease cost and turnaround time, compared with IP models.

Three-Dimensional Analysis of Isolated Orbital Floor Fractures Pre- and Post-Reconstruction with Standard Titanium Meshes and "Hybrid" Patient-Specific Implants

The aim of this study was to compare the efficacy of the intraoperative bending of titanium mesh with the efficacy of pre-contoured “hybrid” patient-specific titanium mesh for the surgical repair of isolated orbital floor fractures. In-house 3D-printed anatomical models were used as bending guides. The main outcome measures were preoperative and postoperative orbital volume and surgery time. We performed a retrospective cohort study including 22 patients who had undergone surgery between May 2016 and November 2018. The first twelve patients underwent conventional reconstruction with intraoperative free-hand bending of an orbital floor mesh plate. The subsequent ten patients received pre-contoured plates based on 3D-printed orbital models that were produced by mirroring the non-fractured orbit of the patient using a medical imaging software. We compared the preoperative and postoperative absolute volume difference (unfractured orbit, fractured orbit), the fracture area, the fracture collapse, and the effective surgery time between the two groups. In comparison to the intraoperative bending of titanium mesh, the application of preformed plates based on a 3D-printed orbital model resulted in a non-significant absolute volume difference in the intervention group (p = 0.276) and statistically significant volume difference in the conventional group (p = 0.002). Further, there was a significant reduction of the surgery time (57.3 ± 23.4 min versus 99.8 ± 28.9 min, p = 0.001). The results of this study suggest that the use of 3D-printed orbital models leads to a more accurate reconstruction and a time reduction during surgery.

Laser-Based Hybrid Manufacturing of Endosseous Implants: Optimized Titanium Surfaces for Enhancing Osteogenic Differentiation of Human Mesenchymal Stem Cells

Additive manufacturing (AM) is becoming increasingly important in the orthopedic and dental sectors thanks to two major advantages: the possibility of custom manufacturing and the integration of complex structures. However, at smaller scales, surface conditions of AM products are not mastered. Numerous non-fused powder particles give rise to roughness values (Sa) greater than 10 μm, thus limiting biomedical applications since the surface roughness of, e.g., metal implants plays a major role in the quality and rate of osseointegration. In this study, an innovative hybrid machine combining AM and a femtosecond laser (FS) was used to obtain Ti6Al4V parts with biofunctional surfaces. During the manufacturing process, the FS laser beam "neatly" ablates the surface, leaving in its path nanostructures created by the laser/matter interaction. This step decreases the Sa from 11 to 4 μm and increases the surface wettability. The behavior of human mesenchymal stem cells was evaluated on these new AM+FS surfaces and compared with that on AM surfaces and also on polished surfaces. The number of cells attached 24 h after plating is equivalent on all surfaces, but cell spreading is higher on AM+FS surfaces compared with their AM counterparts. In the longer term (days 7 and 14), fibronectin and collagen synthesis increase on AM+FS surfaces as opposed to AM alone. Alkaline phosphatase activity, osteocalcin production, and mineralization, markers of osteogenic differentiation, are significantly lower on raw AM surfaces, whereas on the AM+FS specimens they display a level equivalent to that on the polished surface. Overall, these results indicate that using an FS laser beam during the fabrication of AM parts optimizes surface morphology to favor osteoblastic differentiation. This new hybrid machine could make it possible to produce AM implants with functional surfaces directly at the end of AM, thereby limiting their post-treatments.

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.

Periorbital Reconstruction by "Periorbital Patch" Technique Using a Pericardium-Based Collagen Membrane and Titanium Mesh

OBJECTIVE

Titanium mesh is a commonly used material for the reconstruction of orbital floor fractures. However, in some instances, a subsequent inflammatory reaction can occur that causes the adhesion of orbital tissue to the titanium mesh. The adhesion of the orbital soft tissue to the mesh causes diplopia, lid rigidity and extraocular movements restriction. This study was performed to determine if the placement of a collagen membrane over a titanium mesh can prevent the adhesion of orbital soft tissue for an improved clinical outcome. Clinical considerations: A case study was performed investigating 106 patients undergoing a periorbital restoration. Seventy-two patients received a titanium mesh without a barrier membrane, 12 patients received a barrier membrane composed of autologous auricular cartilage to provide a barrier function and 22 patients received a pericardium collagen membrane and titanium mesh.

CONCLUSIONS

Titanium has been shown to generate an intense inflammatory reaction in host tissues, which can cause fibrosis to adjacent structures. Fibrosis is an essential factor in the repair of fracture sites, however this can lead to adverse effects in the orbital socket. Fibrosis can cause cicatrization and lower eyelid retraction when induced along the lower orbital rim. An improved outcome can be achieved by using a barrier between the titanium mesh and the soft tissue, such as autogenous auricular cartilage, however, only patients treated with a resorbable collagen membrane to act as a soft tissue barricade during site regeneration, prevented the fibrosis reaction and related problems from occurring.

Repair of Orbital Post-Traumatic Wall Defects by Custom-Made TiNi Mesh Endografts

Repairs of orbital post-traumatic and extensive malignant defects remain a major surgical challenge, in view of follow-up outcomes. Incorrect surgical management of injured facial structures results in cosmetic, ophthalmic, and social aftereffects. A custom-made knitted TiNi-based mesh (KTNM) endograft was employed to overcome post-surgical complications and post-resected lesions of the orbital area. Preoperative high-resolution computed tomography (CT) imaging and CAD modelling were used to design the customized KTNM in each case. Twenty-five patients underwent surgery utilizing the suggested technique, from 2014 to 2019. In all documented cases, resolution of the ophthalmic malfunction was noted in the early period. Follow-up observation evidenced no relapsed enophthalmos, hypoglobus, or diplopia as late complications. The findings emanating from our clinical observations allow us to claim that the KTNM indicated a high level of biocompatibility. It is simply modified intraoperatively to attach any desired shape/size for implantation and can also be screw-fixed, providing a good supporting ability. The KTNM precisely renders orbitozygomatic outlines and orbital floor, thus recovering the anatomical structure, and is regarded as an attractive alternative to Ti-based meshes and plates. Additionally, we report one of the studied cases, where good functional and cosmetic outcomes have been achieved.

Intensity of artefacts in cone beam CT examinations caused by titanium and glass fibre-reinforced composite implants

OBJECTIVES:

The aim was to compare titanium and glass fibre-reinforced composite (FRC) orbital floor implants using cone beam CT (CBCT). FRC implants are nonmetallic and these implants have not been analysed in CBCT images before. The purpose of this study is to compare the artefact formation of the titanium and the FRC orbital floor implants in CBCT images.

METHODS:

One commercially pure titanium and one S-glass FRC with bioactive glass particles implant were imaged with CBCT using the same imaging values (80 kV, 1 mA, FOV 60 × 60 mm). CBCT images were analysed in axial slices from three areas to determine the magnitude of the artefacts in the vicinity of the implants. Quantified results based on the gray values of images were analysed using analysis-of-variance.

RESULTS:

Compared to the reference the gray values of the titanium implant are more negative in every region of interest in all slices (p < 0.05) whereas the gray values of the FRC implant differ statistically significantly in less than half of the examined areas.

CONCLUSIONS:

The titanium implant caused artefacts in all of the analysed CBCT slices. Compared to the reference the gray values of the FRC implant changed only slightly and this feature enables to use wider imaging options postoperatively.

Reconstruction of the orbital wall using superior orbital rim osteotomy in a patient with a superior orbital wall fracture

BACKGROUND

Fractures of the orbital wall are mainly caused by traffic accidents, assaults, and falls and generally occur in men aged between 20 and 40 years. Complications that may occur after an orbital fracture include diplopia and decreased visual acuity due to changes in orbital volume, ocular depression due to changes in orbital floor height, and exophthalmos. If surgery is delayed too long, tissue adhesion will occur, making it difficult to improve ophthalmologic symptoms. Thus, early diagnosis and treatment are important. Fractures of the superior orbital wall are often accompanied by skull fractures. Most of these patients are unable to perform an early ocular evaluation due to neurosurgery and treatment. These patients are more likely to show tissue adhesion, making it difficult to properly dissect the tissue for wall reconstruction during surgery.

CASE PRESENTATION

This report details a case of superior orbital wall reconstruction using superior orbital rim osteotomy in a patient with a superior orbital wall fracture involving severe tissue adhesion. Three months after reconstruction, there were no significant complications.

CONCLUSION

In a patient with a superior orbital wall fracture, our procedure is helpful in securing the visual field and in delamination of the surrounding tissue.

Bone regeneration strategies: Engineered scaffolds, bioactive molecules and stem cells current stage and future perspectives

Bone fractures are the most common traumatic injuries in humans. The repair of bone fractures is a regenerative process that recapitulates many of the biological events of embryonic skeletal development. Most of the time it leads to successful healing and the recovery of the damaged bone. Unfortunately, about 5-10% of fractures will lead to delayed healing or non-union, more so in the case of co-morbidities such as diabetes. In this article, we review the different strategies to heal bone defects using synthetic bone graft substitutes, biologically active substances and stem cells. The majority of currently available reviews focus on strategies that are still at the early stages of development and use mostly in vitro experiments with cell lines or stem cells. Here, we focus on what is already implemented in the clinics, what is currently in clinical trials, and what has been tested in animal models. Treatment approaches can be classified in three major categories: i) synthetic bone graft substitutes (BGS) whose architecture and surface can be optimized; ii) BGS combined with bioactive molecules such as growth factors, peptides or small molecules targeting bone precursor cells, bone formation and metabolism; iii) cell-based strategies with progenitor cells combined or not with active molecules that can be injected or seeded on BGS for improved delivery. We review the major types of adult stromal cells (bone marrow, adipose and periosteum derived) that have been used and compare their properties. Finally, we discuss the remaining challenges that need to be addressed to significantly improve the healing of bone defects.

Generation of customized orbital implant templates using 3-dimensional printing for orbital wall reconstruction

OBJECTIVES

To describe and evaluate a novel surgical approach to orbital wall reconstruction that uses three-dimensionally (3D) printed templates to mold a customized orbital implant.

METHODS

A review was conducted of 11 consecutive patients who underwent orbital wall reconstruction using 3D-printed customized orbital implant templates. In these procedures, the orbital implant was 3D pressed during surgery and inserted into the fracture site. The outcomes of this approach were analyzed quantitatively by measuring the orbital tissue volumes within the bony orbit using computed tomography.

RESULTS

All 11 orbital wall reconstructions (6 orbital floor and 5 medial wall fractures) were successful with no post operative ophthalmic complications. Statistically significant differences were found between the preoperative and post operative orbital tissue volumes for the affected orbit (24.00 ± 1.74 vs 22.31 ± 1.90 cm³; P = 0.003). There was no statistically significant difference found between the tissue volume of the contralateral unaffected orbit and the affected orbit after reconstruction (22.01 ± 1.60 cm³ vs 22.31 ± 1.90 cm³; P = 0.182).

CONCLUSION

3D-printed customized orbital implant templates can be used to press and trim conventional implantable materials with patient-specific contours and sizes for optimal orbital wall reconstruction. It is difficult to design an orbital implant that exactly matches the shape and surface of a blowout fracture site due to the unique 3D structure of the orbit. The traditional surgical method is to visually inspect the fracture site and use eye measurements to cut a two-dimensional orbital implant that corresponds to the anatomical structure of the fracture site. However, implants that do not fit the anatomical structure of a fracture site well can cause complications such as enophthalmos, diplopia and displacement of the implant.

3D printing for preoperative planning and surgical training: a review

Surgeons typically rely on their past training and experiences as well as visual aids from medical imaging techniques such as magnetic resonance imaging (MRI) or computed tomography (CT) for the planning of surgical processes. Often, due to the anatomical complexity of the surgery site, two dimensional or virtual images are not sufficient to successfully convey the structural details. For such scenarios, a 3D printed model of the patient's anatomy enables personalized preoperative planning. This paper reviews critical aspects of 3D printing for preoperative planning and surgical training, starting with an overview of the process-flow and 3D printing techniques, followed by their applications spanning across multiple organ systems in the human body. State of the art in these technologies are described along with a discussion of current limitations and future opportunities.

Effects of Build Orientation on Surface Morphology and Bone Cell Activity of Additively Manufactured Ti6Al4V Specimens

Additive manufacturing of lightweight or functional structures by selective laser beam (SLM) or electron beam melting (EBM) is widespread, especially in the field of medical applications. SLM and EBM processes were applied to prepare Ti6Al4V test specimens with different surface orientations (0°, 45° and 90°). Roughness measurements of the surfaces were conducted and cell behavior on these surfaces was analyzed. Hence, human osteoblasts were seeded on test specimens to determine cell viability (metabolic activity, live-dead staining) and gene expression of collagen type 1 (Col1A1), matrix metalloprotease (MMP) 1 and its natural inhibitor, TIMP1, after 3 and 7 days. The surface orientation of specimens during the manufacturing process significantly influenced the roughness. Surface roughness showed significant impact on cellular viability, whereas differences between the time points day 3 and 7 were not found. Collagen type 1 mRNA synthesis rates in human osteoblasts were enhanced with increasing roughness. Both manufacturing techniques further influenced the induction of bone formation process in the cell culture. Moreover, the relationship between osteoblastic collagen type 1 mRNA synthesis rates and specimen orientation during the building process could be characterized by functional formulas. These findings are useful in the designing of biomedical applications and medical devices.

Surgical Management of the Recent Orbital War Injury

Maxillofacial trauma affects sensitive and essential functions for the human being such as smell, breathing, talking, and the most importantly the sight. Trauma to the orbit may cause a vision loss especially if this trauma yields a high kinetic energy like that encountered during wars. The purpose of the study was to evaluate the surgical outcomes of the orbital war trauma, enriching the literature with the experience of the authors in this field. A total of 16 patients were injured, evacuated, and managed, between June 2014 and June 2017, from the fight between the Iraqi army and the Islamic State of Iraq and Syria (ISIS) in different areas of Iraq. Two-stage protocol was adopted, that is debridement and reconstruction. There were 14 military patients and 2 civilians. The cause of trauma was either bullet or shrapnel from an explosion. In the battlefield, delayed evacuation of the casualties led to increase the morbidity and mortality. Wearing a protective shield over the eye during the war along with fast evacuation highly improved the survival rates.

Application of computer-assisted navigation systems in oral and maxillofacial surgery

The oral and maxillofacial region has a complicated anatomy with critical contiguous organs, including the brain, eyes, vital teeth, and complex networks of nerves and blood vessels. Therefore, advances in basic scientific research within the field of intraoperative oral and maxillofacial surgery have enabled the introduction of the features of these techniques into routine clinical practice to ensure safe and reliable surgery. A navigation system provides a useful guide for safer and more accurate complex in oral and maxillofacial surgery. The effectiveness of a navigation system for oral and maxillofacial surgery has been indicated by clinical applications in maxillofacial trauma surgery including complex midfacial fractures and orbital trauma reconstruction, foreign body removal, complex dentoalveolar surgery, skull base surgery including surgery of the temporomandibular joint (TMJ), and orthognathic surgery. However, some fundamental issues remain involving the mobility of the mandible and difficulty in updating images intraoperatively. This report presents an overview and feasible applications of available navigation systems with a focus on the clinical feasibility of the application of navigation systems in the field of oral and maxillofacial surgery and solutions to current problems.

Low-Cost 3D Printing Orbital Implant Templates in Secondary Orbital Reconstructions

PURPOSE

Despite its increasing use in craniofacial reconstructions, three-dimensional (3D) printing of customized orbital implants has not been widely adopted. Limitations include the cost of 3D printers able to print in a biocompatible material suitable for implantation in the orbit and the breadth of available implant materials. The authors report the technique of low-cost 3D printing of orbital implant templates used in complex, often secondary, orbital reconstructions.

METHODS

A retrospective case series of 5 orbital reconstructions utilizing a technique of 3D printed orbital implant templates is presented. Each patient's Digital Imaging and Communications in Medicine data were uploaded and processed to create 3D renderings upon which a customized implant was designed and sent electronically to printers open for student use at our affiliated institutions. The mock implants were sterilized and used intraoperatively as a stencil and mold. The final implant material was chosen by the surgeons based on the requirements of the case.

RESULTS

Five orbital reconstructions were performed with this technique: 3 tumor reconstructions and 2 orbital fractures. Four of the 5 cases were secondary reconstructions. Molded Medpor Titan (Stryker, Kalamazoo, MI) implants were used in 4 cases and titanium mesh in 1 case. The stenciled and molded implants were adjusted no more than 2 times before anchored in place (mean 1). No case underwent further revision.

CONCLUSIONS

The technique and cases presented demonstrate 1) the feasibility and accessibility of low-cost, independent use of 3D printing technology to fashion patient-specific implants in orbital reconstructions, 2) the ability to apply this technology to the surgeon's preference of any routinely implantable material, and 3) the utility of this technique in complex, secondary reconstructions.

Three dimensional reconstruction of late post traumatic orbital wall defects by customized implants using CAD-CAM, 3D stereolithographic models: A case report

Aim

Purpose of this case report is to highlight the precision and accuracy obtained with patient specific implants for orbital reconstruction designed on the basis of volumetric analysis of orbital computed tomographic scan (CT) scans using virtual planning, computerised designing and manufacturing and stereolithographic models to correct late post-traumatic orbital deformities such as enophthalmos and diplopia.

Material and methods

This case report describes a patient who visited our outpatient clinic for correction of enophthalmos and persistent diplopia in upward gaze, seven months post trauma. Three dimensional (3D) virtual treatment planning was carried out by using the 3D CT data. The unaffected orbit of the contralateral side was superimposed on the deformed orbit to highlight the defect and a customized implant was designed in the desired size and shape on the virtual model using computer aided designing and manufacturing (CAD-CAM) and milled in titanium mesh for precise anatomic orbital reconstruction.

Results

There was a marked improvement in both the diplopia in upward gaze and enophthalmos post surgery when the customized patient specific orbital implant was used.

Conclusion

The concept of using customized implant with the help of 3D virtual treatment planning, 3D stereolithographic models and CAD-CAM greatly improves the correction of extremely difficult late post-traumatic orbital deformities.

Prototyping for the treatment of late zygomatic-orbital fracture: A case report

INTRODUCTION

Zygomatic-orbital complex fractures are the most common facial traumas that can result in severe esthetic and functional sequelae. Surgical correction of these fractures is a delicate approach and prototyping is an excellent tool to facilitate this procedure.

PRESENTATION OF CASE

A 27-year-old man, a motorcycle accident victim, was hospitalized in the intensive care unit for 30days. After this period, facial fractures were treated surgically, leaving sequelae such as enophthalmos, dystopia and loss of projection of the zygomatic arch. A second intervention was planned after one year for reconstruction of the orbit with the help of prototyping. Better outcomes were achieved than in the first intervention.

DISCUSSION

This report permits to compare the result of conventional surgery and the use of a prototype in the same patient. Noticeably better outcomes were achieved with the second approach. Prototyping made the surgical procedure more predictable and reduced operative time because of the possibility of using preshaped titanium plates.

CONCLUSIONS

Prototyping was found to be an excellent option to overcome the deficiencies of the conventional technique, recovering the functional and esthetic characteristics of the patient's face and ensuring a markedly satisfactory outcome.

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.

Evolution of design considerations in complex craniofacial reconstruction using patient-specific implants

Previously published evidence has established major clinical benefits from using computer-aided design, computer-aided manufacturing, and additive manufacturing to produce patient-specific devices. These include cutting guides, drilling guides, positioning guides, and implants. However, custom devices produced using these methods are still not in routine use, particularly by the UK National Health Service. Oft-cited reasons for this slow uptake include the following: a higher up-front cost than conventionally fabricated devices, material-choice uncertainty, and a lack of long-term follow-up due to their relatively recent introduction. This article identifies a further gap in current knowledge – that of design rules, or key specification considerations for complex computer-aided design/computer-aided manufacturing/additive manufacturing devices. This research begins to address the gap by combining a detailed review of the literature with first-hand experience of interdisciplinary collaboration on five craniofacial patient case studies. In each patient case, bony lesions in the orbito-temporal region were segmented, excised, and reconstructed in the virtual environment. Three cases translated these digital plans into theatre via polymer surgical guides. Four cases utilised additive manufacturing to fabricate titanium implants. One implant was machined from polyether ether ketone. From the literature, articles with relevant abstracts were analysed to extract design considerations. In all, 19 frequently recurring design considerations were extracted from previous publications. Nine new design considerations were extracted from the case studies – on the basis of subjective clinical evaluation. These were synthesised to produce a design considerations framework to assist clinicians with prescribing and design engineers with modelling. Promising avenues for further research are proposed.

Patient-Specific Orbital Implants: Development and Implementation of Technology for More Accurate Orbital Reconstruction

Fracture of the orbital floor is commonly seen in facial trauma. Accurate anatomical reconstruction of the orbital floor contour is challenging. The authors demonstrate a novel method to more precisely reconstruct the orbital floor on a 50-year-old female who sustained an orbital floor fracture following a fall. Results of the reconstruction show excellent reapproximation of the native orbital floor contour and complete resolution of her enopthalmos and facial asymmetry.