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

The Use and Outcomes of 3D Printing in Pediatric Craniofacial Surgery: A Systematic Review

Three-dimensional (3D) printing has demonstrated efficacy in multiple surgical specialties. As accessibility improves, its use in specific fields deserves further attention. We conducted a systematic review of the implementation and outcomes of 3D printing in pediatric craniofacial surgery, as none has been performed. A systematic review was conducted according to Cochrane and PRISMA guidelines. PubMed, Embase, Cochrane library, and Clinicaltrials.gov were queried with combinations of the terms: "3D printing," "craniofacial," "surgery," and "pediatric." Original human studies containing patients <18 years old implementing 3D printing to aid in craniofacial surgery were included. Study selection, grading, and data extraction were performed independently by multiple authors. After screening 120 articles, 7 (3 case series and 4 case reports) were included, published from 2017 to 2022. All studies addressed patients with different disease processes including craniosynostosis, cleft lip/palate, and mandibular hypoplasia. 3D printing was used to create mock surgical models in 2 studies, intraoperative cutting guides/molds (CGs) in 6 studies, and cranioplasty implants in 2 studies. Two case series determined the accuracy of the CGs was acceptable within historical comparison, while 4 articles included subjective statements on improved accuracy. Five studies noted reduced operating time, 2 noted reduced intraoperative blood loss, and 1 felt the use of 3D printed materials was responsible for shorter hospitalization duration. No adverse events were reported. Despite the limitations of the current literature, all studies concluded that the use of 3D printing in pediatric craniofacial surgery was beneficial. Definitive conclusions cannot be made until further controlled research is performed.

Advances and Prospects in Materials for Craniofacial Bone Reconstruction

The craniofacial region is composed of 23 bones, which provide crucial function in keeping the normal position of brain and eyeballs, aesthetics of the craniofacial complex, facial movements, and visual function. Given the complex geometry and architecture, craniofacial bone defects not only affect the normal craniofacial structure but also may result in severe craniofacial dysfunction. Therefore, the exploration of rapid, precise, and effective reconstruction of craniofacial bone defects is urgent. Recently, developments in advanced bone tissue engineering bring new hope for the ideal reconstruction of the craniofacial bone defects. This report, presenting a first-time comprehensive review of recent advances of biomaterials in craniofacial bone tissue engineering, overviews the modification of traditional biomaterials and development of advanced biomaterials applying to craniofacial reconstruction. Challenges and perspectives of biomaterial development in craniofacial fields are discussed in the end.

Controversies and Contemporary Management of Orbital Floor Fractures

Substantial controversy exists regarding the timing of intervention and management of patients with orbital floor fractures. Recent advances in computer-aided technology, including the use of 3-dimensional printing, intraoperative navigational imaging, and the use of novel implants, have allowed for improvement in prospective management modalities. As such, this article aims to review the indications and timing of repair, surgical approaches, materials used for repair, and contemporary adjuncts to repair. Indications for orbital floor fracture repair remain controversial as many of these fractures heal without intervention or adverse sequelae. Intraoperative navigation and imaging, as well as endoscopic guidance, can improve visualization of defects mitigating implant positioning errors, thereby reducing the need for secondary corrective procedures. Patient-specific implants may be constructed to fit the individual patient's anatomy using the preoperative CT dataset and mirroring the contralateral unaffected side and have been shown to improve pre-operative efficiency and minimize postoperative complications. With increased data, we can hope to form evidence-based indications for using particular biomaterials and the criteria for orbital defect characteristics, which may be best addressed by a specific surgical approach.

Primary Orbital Reconstruction with Selective Laser Melting (SLM) of Patient-Specific Implants (PSIs): An Overview of 96 Surgically Treated Patients

Contemporary advances in technology have allowed the transfer of knowledge from industrial laser melting systems to surgery; such an approach could increase the degree of accuracy in orbital restoration. The aim of this study was to examine the accuracy of selective laser melted PSIs (patient-specific implants) and navigation in primary orbital reconstruction. Ninety-six patients with orbital fractures were included in this study. Planned vs. achieved orbital volumes (a) and angles (b) were compared to the unaffected side (n = 96). The analysis included the overlay of post-treatment on planned images (iPlan 3.0.5, Brainlab®, Feldkirchen, Germany). The mean difference in orbital volume between the digitally planned orbit and the postoperative orbit was 29.16 cm3 (SD 3.54, presurgical) to 28.33 cm3 (SD 3.64, postsurgical, t = 5.00, df = 95.00; p < 0.001), resulting in a mean volume difference (planned vs. postop) of less than 1 cm3. A 3D analysis of the color mapping showed minor deviations compared to the mirrored unaffected side. The results suggested that primary reconstruction in complex orbital wall fractures can be routinely achieved with a high degree of accuracy by using selective laser melted orbital PSIs.

Customised products for orbital wall reconstruction: a systematic review

The purpose of this systematic review was to critically analyse the recent literature and present the state of the art in customised reconstruction of orbital fractures. Three electronic databases and manual search approaches were used to identify relevant articles. Only controlled clinical studies were included. Primary outcome was defined as the status of recovery (complete/partial functional, and aesthetic disturbances). The benefit of intrasurgical navigation should be described. The secondary outcome was defined as the time of surgery, post-surgical events, and hospitalisation. Of the 552 records identified, eight met the inclusion criteria. Post-surgical results regarding recovery were superior in the customised group, and were comparable to the control group in five studies. The time of surgery was shorter in the customised groups, and liquid infusion and time of hospitalisation were reduced. Four studies documented more accurate reconstruction with the use of navigation. All the studies presented at least one bias, and considerable heterogeneity was evaluated. This review found that the use of customised meshes in combination with surgical navigation resulted in more accurate reconstruction. A significant reduction in surgical time was revealed.

Tissue Engineering Through 3D Bioprinting to Recreate and Study Bone Disease

The applications of 3D bioprinting are becoming more commonplace. Since the advent of tissue engineering, bone has received much attention for the ability to engineer normal bone for tissue engraftment or replacement. While there are still debates on what materials comprise the most durable and natural replacement of normal tissue, little attention is given to recreating diseased states within the bone. With a better understanding of the cellular pathophysiology associated with the more common bone diseases, these diseases can be scaled down to a more throughput way to test therapies that can reverse the cellular pathophysiology. In this review, we will discuss the potential of 3D bioprinting of bone tissue in the following disease states: osteoporosis, Paget's disease, heterotopic ossification, osteosarcoma, osteogenesis imperfecta, and rickets disease. The development of these 3D bioprinted models will allow for the advancement of novel therapy testing resulting in possible relief to these chronic diseases.

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.

Plastic Surgery Innovation with 3D Printing for Craniomaxillofacial Operations

Plastic Surgery restores unique human qualities such as appearance, speech (palate), hands, to improve interaction with others and quality of life. Three-dimensional printing technology can be applied to Plastic Surgery craniomaxillofacial operations to change the bony skeleton of the skull, face, and jaws. Three-dimensional printing for patient-specific applications have four types: Type I contour models, Type II guides, Type III splints, Type IV implants. Plastic Surgery innovation in 3D printing clinical applications are described here and https://www.slucare.edu/newsroom/kmov-science-of-healing-faces-of-childhood.php.

Application of Three-Dimensional Printing Technology in the Orbital Blowout Fracture Reconstruction

The aim of this study was to investigate the clinical outcomes of orbital blowout fracture repair by using the three-dimensional (3D) printing-assisted fabrication of individual titanium mesh. Clinical and radiologic data were analyzed for 12 patients with orbital floor and/or medial wall fractures. Lower eyelid incision was used to expose the fractures. Preoperative computed tomographic data were input into an imaging software to rebuild a 3D orbit and mirror the unaffected side into the affected side to replace the demolished orbit. A resin model of the reshaped orbit was generated and used to develop an individual titanium mesh for repairing the fractured orbital. The surgical results were assessed by value of enophthalmos and a comparison of preoperative and postoperative orbital volume difference. All patients had a successful treatment outcome without any complications. Clinical significant enophthalmos were not observed after treatment, and diplopia were solved within 2 weeks postoperative. No extraocular muscle limitation was observed. Postoperative computed tomography scans demonstrated appropriate positioning of titanium mesh and there was no implant displacement. The postoperative orbital volume and enophthalmos difference between the 2 eyes decreased significantly than preoperative (P < 0.001). Three-dimensional printing-assisted fabrication of individual titanium mesh is appropriate for use in orbital blowout fracture.

Use of 3-D printing technologies in craniomaxillofacial surgery: a review

Three-dimensional (3-D) printing is a method of manufacturing in which materials like plastic or metal are deposited onto one another in layers to produce a 3-D object. Because of the complex anatomy of craniomaxillofacial structures, full recovery of craniomaxillofacial tissues from trauma, surgeries, or congenital malformations is extremely challenging. 3-D printing of scaffolds, tissue analogs, and organs has been proposed as an exciting alternative to address some of these key challenges in craniomaxillofacial surgery. There are four broad types of 3-D printing surgical applications that can be used in craniomaxillofacial surgery: contour models (positive-space models to allow preapplication of hardware before surgery), guides (negative-space models of actual patient data to guide cutting and drilling), splints (negative-space models of virtual postoperative positions to guide final alignment), and implants (negative-space 3-D printed implantable materials or 3-D printed molds into which nonprintable materials are poured). 3-D printing technology is being successfully used for surgeries for head and neck malignancies, mandibular reconstruction, orthognathic surgeries, for mandibulectomies after osteoradionecrosis, orbital floor fracture surgeries, nasal reconstruction, and cranioplasties. The excitement behind 3-D printing continues to increase and hopefully will drive improvements in the technology and its surgical applications, especially in craniomaxillofacial region. This present review sets out to explore use of 3-D printing technologies in craniomaxillofacial surgery.

New and emerging patient-centered CT imaging and image-guided treatment paradigms for maxillofacial trauma

This article reviews the conceptual framework, available evidence, and practical considerations pertaining to nascent and emerging advances in patient-centered CT-imaging and CT-guided surgery for maxillofacial trauma. These include cinematic rendering-a novel method for advanced 3D visualization, incorporation of quantitative CT imaging into the assessment of orbital fractures, low-dose CT imaging protocols made possible with contemporary scanners and reconstruction techniques, the rapidly growing use of cone-beam CT, virtual fracture reduction with design software for surgical pre-planning, the use of 3D printing for fabricating models and implants, and new avenues in CT-guided computer-aided surgery.

Reconstruction of Orbital Floor With Auricular Concha

Orbital floor fractures of varying sizes commonly occur after orbital injuries and remain a serious challenge. Serious complications of such fractures include enopthalmos, restriction of extraocular movement, and diplopia. There is a dearth of literature that can be applied widely, easily, and successfully in all such situations, and therefore there is no consensus on the treatment protocol of this pathology yet. Autogenous grafts and alloplastic and allogenic materials with a wide variety of advantages and disadvantages have been discussed. The value of preoperative and postoperative ophthalmological examination should be standard of care in all orbital fracture patients. An ideal reconstructed orbital floor fracture should accelerate the restoration of orbital function with acceptable cosmetic results. Management parameters of orbital fractures such as timing of surgery, incision type, and implant materials, though widely discussed, remain controversial. In this study, 55 patients with orbital floor fractures surgically reconstructed with conchal cartilage grafts between 2008 and 2014 were retrospectively evaluated. Complications and long-time follow-up visit results have been reported with clinical and radiographic findings. The aim of this study was to present the authors' clinical experiences of reconstruction of blow-out fractures with auricular conchal graft and to evaluate the other materials available for use.

Recent advances in the reconstruction of cranio-maxillofacial defects using computer-aided design/computer-aided manufacturing

With the development of computer-aided design/computer-aided manufacturing (CAD/CAM) technology, it has been possible to reconstruct the cranio-maxillofacial defect with more accurate preoperative planning, precise patient-specific implants (PSIs), and shorter operation times. The manufacturing processes include subtractive manufacturing and additive manufacturing and should be selected in consideration of the material type, available technology, post-processing, accuracy, lead time, properties, and surface quality. Materials such as titanium, polyethylene, polyetheretherketone (PEEK), hydroxyapatite (HA), poly-DL-lactic acid (PDLLA), polylactide-co-glycolide acid (PLGA), and calcium phosphate are used. Design methods for the reconstruction of cranio-maxillofacial defects include the use of a pre-operative model printed with pre-operative data, printing a cutting guide or template after virtual surgery, a model after virtual surgery printed with reconstructed data using a mirror image, and manufacturing PSIs by directly obtaining PSI data after reconstruction using a mirror image. By selecting the appropriate design method, manufacturing process, and implant material according to the case, it is possible to obtain a more accurate surgical procedure, reduced operation time, the prevention of various complications that can occur using the traditional method, and predictive results compared to the traditional method.

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.

Radio-opaque polyethylene for personalized craniomaxillofacial implants

OBJECTIVE

This study aimed to present a new possibility to create radio-opaque implant material for craniomaxillofacial reconstruction.

MATERIALS AND METHODS

The test disks made of the own compound of polyethylenes with addiction of 2, 4, and 6 % of weight TiO₂ was investigated for cytotoxicity [each group 15 disks respectively]. Next, computed tomography of the disks was performed in environment of muscle and fat. Hardness, tensile modulus and strength, and compressive modulus and strength were tested too.

RESULTS

Deterioration of mechanical properties of the composites containing titanium dioxide was observed [hardness, tensile modulus and strength, compressive modulus and strength, respectively: 56.7 ± 1.6 shore D, 354 ± 52, 22.5 ± 1.3, 21.8 ± 1.1, and 2995 ± 327 MPa as addiction of 2 % TiO₂; 52.0 ± 0.9 shore D, 347 ± 66, 18.0 ± 0.7, 14.2 ± 0.9, and 1396 ± 477 MPa as 4 % TiO₂; 51.3 ± 1.3 shore D, 316 ± 9, 17.4 ± 0.2, 13.6 ± 0.6, and 1100 ± 144 MPa as 6 % TiO₂ added]. The test disks revealed no cytotoxicity effect on human osteoblasts. The new material presents mild radio-opacity which was enough to observe the implant in relation to fat and muscle, but with no visible effect of beam hardening.

CONCLUSION

In view of the performed tests, the polyethylene enriched by titanium dioxide seems to be a proper material to consider manufacturing of craniomaxillofacial implants.

CLINICAL RELEVANCE

Maxilloafacial surgery is still looking for new implantologic materials. The proposed one is a new way to manufacture an implant visible in computed tomography which does not interfere with its shape in radiological examination and makes it possible to observe the surrounding soft tissues.

3D-printing techniques in a medical setting: a systematic literature review

BACKGROUND

Three-dimensional (3D) printing has numerous applications and has gained much interest in the medical world. The constantly improving quality of 3D-printing applications has contributed to their increased use on patients. This paper summarizes the literature on surgical 3D-printing applications used on patients, with a focus on reported clinical and economic outcomes.

METHODS

Three major literature databases were screened for case series (more than three cases described in the same study) and trials of surgical applications of 3D printing in humans.

RESULTS

227 surgical papers were analyzed and summarized using an evidence table. The papers described the use of 3D printing for surgical guides, anatomical models, and custom implants. 3D printing is used in multiple surgical domains, such as orthopedics, maxillofacial surgery, cranial surgery, and spinal surgery. In general, the advantages of 3D-printed parts are said to include reduced surgical time, improved medical outcome, and decreased radiation exposure. The costs of printing and additional scans generally increase the overall cost of the procedure.

CONCLUSION

3D printing is well integrated in surgical practice and research. Applications vary from anatomical models mainly intended for surgical planning to surgical guides and implants. Our research suggests that there are several advantages to 3D-printed applications, but that further research is needed to determine whether the increased intervention costs can be balanced with the observable advantages of this new technology. There is a need for a formal cost-effectiveness analysis.

Orbital reconstruction

PURPOSE OF REVIEW

Post-traumatic orbital reconstruction is a complex issue that involves both the soft tissue and bony injury. The current literature focuses primarily on bony reconstruction, with fewer investigators evaluating soft-tissue injuries. This article will review recent advances in orbital reconstruction, including presurgical planning software, intra-operative navigation, patient-specific implants, and intra-operative imaging.

RECENT FINDINGS

Traditional techniques for diagnosis and orbital injuries continue to be refined; however, advances in computer-aided surgery are allowing surgeons to significantly improve the anatomic accuracy of orbital reconstruction.

SUMMARY

While not all surgeons currently have access to computer-aided applications for orbital reconstruction, these techniques will continue to be refined, resulting in lower cost and greater access.

Digital import of orbital implants to enhance navigation in reconstruction of the deep orbit

Stereotactic navigation has become established in orbital surgery. It can assist in exploration and reconstruction by preventing plate positioning errors and ensuring adequate restoration of deep orbital anatomy. Pre-formed and custom-made implants have become increasingly popular with reliable outcomes in complex orbital reconstructions, but may require adjustment at the time of surgery. Planning for reconstruction can be improved by import of digital models of implants into the navigation system. This technique allows on-table confirmation of successful orbital reconstruction.

Surgical management of upgaze diplopia in patients after posttraumatic orbital floor reconstruction

OBJECTIVE

The most common complication of otherwise successful reconstructive surgery of a fractured orbital floor is persistent diplopia. For patients with troublesome double vision in upgaze, a reasonable solution is offered by strabismus surgery. The aim of our study is to examine the results of extraocular muscle surgery in cases of diplopia that persisted in upgaze after posttraumatic orbital floor reconstruction.

MATERIAL AND METHODS

In this study we present a retrospective series of 24 patients with troublesome vertical diplopia in upgaze. In all cases, the surgery consisted of a posterior fixation suture placement on the contralateral superior rectus muscle with or without its recession. Full orthoptic examination was conducted before and 3 months after the surgery.

RESULTS

Postoperatively 19 patients (79%) were diplopia free and 6 (21%) had vertical diplopia in extreme upgaze. The field of binocular single vision improved threefold. None of the patients reported diplopia in the primary position or in any position other than upgaze.

CONCLUSION

Vertical incomitant strabismus and diplopia in upgaze persisting after orbital reconstructive surgery may be corrected surgically. Contralateral posterior fixation of the superior rectus muscle, with or without its recession, appears to be an effective procedure for use in these patients.

Blood-aqueous barrier integrity in patients with Graves' ophthalmopathy (GO), before and after rehabilitative surgery

PURPOSE

The study was conducted to analyze aqueous flare and its correlations in patients with Graves' ophthalmopathy (GO) undergoing orbital decompression, extraocular muscle, and eyelid surgery. Prospective interventional case series.

PATIENTS AND METHODS

Forty-eight eyes of 27 patients (20 female and 7 male, aged 54.4 ± 5.7) undergoing surgical treatment for GO. Eighteen eyes of nine patients (aged 55.3 ± 3.6) undergoing orbital decompression. Nineteen eyes of 11 patients (aged 54.7 ± 5.6) undergoing extraocular muscle surgery and 13 eyes of 7 patients (aged 53.9 ± 4.9) undergoing eyelid surgery and control group (34 patients aged 53.9 ± 5.1). Laser flare analysis and clinical assessment were performed before surgery and at 1 day, 7 days, and 3 months following surgery.

RESULTS

Aqueous flare was significantly higher in patients with GO (14.03 ± 8.45) before intervention than in the control group (7.89 ± 3.56) (P<0.001), and correlated with Clinical Activity Score and intraocular pressure. In the patients undergoing orbital decompression, flare increased from 17.77 ± 10.63 pc/ms to 38.32 ± 13.56 pc/ms on the first day and 41.31 ± 17.19 pc/ms on the seventh day and returned to 16.01 ± 8.58 pc/ms in 3 months. In patients undergoing extraocular muscle surgery flare increased from 13.05 ± 6.50 to 23.04 ± 11.53 pc/ms (P<0.001) on the first day and returned to 18.02 ± 14.09 pc/ms on the seventh day. Eyelid surgery did not change flare values.

CONCLUSIONS

Orbital decompression disrupts blood-aqueous barrier (BAB). The integrity of BAB returns to preoperative status within 3 months. Extraocular muscle surgery mildly affects BAB integrity, and the effect subsides within 7 days. Eyelid surgery does not affect BAB.

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.

Patient specific implants (PSI) in reconstruction of orbital floor and wall fractures

Fractures of the orbital wall and floor can be challenging due to the demanding three-dimensional anatomy and limited intraoperative overview. Misfitting implants and inaccurate surgical technique may lead to visual disturbance and unaesthetic results. A new approach using individually manufactured titanium implants (KLS Martin, Group, Germany) for daily routine is presented in the current paper. Preoperative CT-scan data were processed in iPlan 3.0.5 (Brainlab, Feldkirchen, Germany) to generate a 3D-reconstruction of the affected orbit using the mirrored non-affected orbit as template and the extent of the patient specific implant (PSI) was outlined and three landmarks were positioned on the planned implant in order to allow easy control of the implant's position by intraoperative navigation. Superimposition allows the comparison of the postoperative result with the preoperative planning. Neither reoperation was indicated due to malposition of the implant and the ocular bulb nor visual impairments could be assessed. PSI allows precise reconstruction of orbital fractures by using a complete digital workflow and should be considered superior to manually bent titanium mesh implants.