Orbital reconstruction:From simple materials to bioengineered solutions

Orbital fractures are a frequent and serious problem for practicing ophthalmologists. The complexity of the pathology is explained by the combined nature of the injuries(often associated with craniofacial injuries), multistage treatments, results that are often unsatisfactory, and a wide range of complaints about functional and cosmetic limitations. Over the years, significant progress has been made in the field of orbital reconstruction,allowing the transition from traditional methods using simple materials to innovative bioengineering solutions.This evolution has been driven by advances in surgical technologies, imaging techniques, and biomaterials aimed at optimizing the restoration of the shape and function of the orbital region. Traditional approaches are based on the use of autologous tissues such as bone grafts and muscle flaps, which provide biocompatibility and natural integration, but have limitations in terms of customization and accessibility. The advent of patient-specific implants and 3D printing technology has revolutionized the reconstruction of the orbit, allowing implants to be precisely adapted to a patient's anatomy. Biocompatible materials, such as porous polyethylene, titanium, and silicone, have become the basis for orbital reconstruction, ensuring durability and compatibility while minimizing long-term complications. Bioengineered solutions hold promise for further advancements in orbital reconstruction. We searched Pub Med, Cyberleninka, and other verified databases for published articles on orbital reconstruction reported in the literature between 1960 and January 2024. In this article, we consider the advantages and disadvantages of each category of reconstruction materials and provide up-to-date information on the methods for modifying their properties using modern processing technologies.

Charge transfer and orbital reconstruction of non‐noble transition metal single‐atoms anchored on Ti_(2)CT_(x)‐MXenes for highly selective CO_(2) electrochemical reduction

Inspired by MXene nanosheets and their regulation of surface functional groups,a series of Ti_(2)C‐based single‐atom electrocatalysts(TM@Ti_(2)CT_(x),TM=V,Cr,Mn,Fe,Co,and Ni)with two dif‐ferent functional groups(T=–O and–S)was designed.The CO_(2)RR catalytic performance was stud‐ied using well‐defined ab initio calculations.Our results show that the CO_(2) molecule can be more readily activated on TM@Ti_(2)CO_(2) than the TM@Ti_(2)CS_(2) surface.Bader charge analysis reveals that the Ti_(2)CO_(2) substrate is involved in the adsorption reaction,and enough electrons are injected into the 2π*u orbital of CO_(2),leading to a V‐shaped CO_(2) molecular configuration and partial negative charge distribution.The V‐shaped CO_(2) further reduces the difficulty of the first hydrogenation reac‐tion step.The calculatedΔG of the first hydrogenation reaction on TM@Ti_(2)CO_(2) was significantly lower than that of the TM@Ti_(2)CS_(2) counterpart.However,the subsequent CO_(2) reduction pathways show that the UL of the potential determining step on TM@Ti_(2)CS_(2) is smaller than that of TM@Ti_(2)CO_(2).Combining the advantages of both TM@Ti_(2)CS_(2) and TM@Ti_(2)CO_(2),we designed a mixed functional group surface with–O and–S to anchor TM atoms.The results show that Cr atoms an‐chored on the surface of mixed functional groups exhibit high catalytic activity for the selective production of CH4.This study opens an exciting new avenue for the rational design of highly selec‐tive MXene‐based single‐atom CO_(2)RR electrocatalysts.

Tuning zinc content in wollastonite bioceramic endowing outstanding angiogenic and antibacterial functions beneficial for orbital reconstruction

Prosthetic eye is indispensable as filler after enucleation in patients with anophthalmia,whereas there are still many complications including postoperative infection and eye socket depression or extrusion during the conventional artificial eye material applications.Some Ca-silicate biomaterials showed superior bioactivity but their biological stability in vivo limit the biomedical application as long-term or permanent implants.Herein we aimed to understand the physicochemical and potential biological responses of zinc doping in wollastonite bioceramic used for orbital implants.The wollastonite powders with different zinc dopant contents(CSi-Znx)could be fabricated as porous implants with strut or curve surface pore geometries(cubic,IWP)via ceramic stereolithography.The experimental results indicated that,by increasing zinc-substituting-Ca ratio(up to 9%),the sintering and mechanical properties could be significantly enhanced,and meanwhile the bio-dissolution in vitro and biodegradability in vivo were thoroughly inhibited.In particular,an appreciable angiogenic activity and expected antibacterial efficacy(over 90%)were synergistically achieved at 9 mol%Zn dopant.In the back-embedding and enucleation and implantation model experiments in rabbits,the superior continuous angiogenesis was corroborated from the 2D/3D fibrovascular reconstruction in the IWP-pore CSi-Zn9 and CSi-Zn13.5 groups within very short time stages.Totally,the present silicate-based bioceramic via selective Zn doping could produce outstanding structural stability and bifunctional biological responses which is especially valuable for developing the next-generation implants with vascular insertion and fixation in orbital reconstruction prothesis.

Interfacial engineering manipulation of magnetic anisotropy evolution via orbital reconstruction in low-dimensional manganite superlattices

Control of magnetic anisotropy in low-dimensional systems is of paramount importance in terms of their fundamental and technological perspectives.La_(0.7)Sr_(0.3)MnO_(3)(LSMO)is a ferromagnetic half-metal with a high Curie temperature and many efforts have been made to control its magnetic anisotropy.However,the relationship between the evolution of the magnetic anisotropy orientation and the electronic structure of low-dimensional LSMO still remains poorly understood.Here,the high-quality superlattices comprised of LSMO and SrMnO_(3)(SMO)layers are synthesized with a compatible structure at the atomic scale.Their magnetic anisotropy is gradually varied from planar to perpendicular by increasing the SMO thickness,and the special fourfold magnetic anisotropy is also observed at the intermediate superlattice thickness.The evolution of the magnetic anisotropy in these systems is confirmed by the electronic transport and magnetic measurements.Moreover,X-ray linear dichroism measurements and first-principles calculations reveal the interfacial orbital reconstruction with the in-plane to out-ofplane magnetic reorientation transition.Therefore,a new microscopic method for magnetic anisotropy manipulation is developed in the present study,enabling discovery of novel phenomena as well as control of the magnetic properties.

Materials to facilitate orbital reconstruction and soft tissue filling in posttraumatic orbital deformaties

Posttraumatic orbital reconstruction has been a challenging mission for decades in craniomaxillofacial surgery.Complications like enophthalmos,diplopia and gaze obstacles emerge when orbital trauma occurs,affecting people’s daily life as well as their appearance.Advances in technology and research gained through years of experience has provided us with a greater understanding of the changes following trauma,as well as providing us with a variety of filling materials that we can choose from to handle the deformities.However,the best type of material for repair of orbital deformities remains controversial.This paper reviewed approximately 60 articles discussing materials used in orbital reconstruction or soft tissue defect filling in the past years,with the aim of giving a comprehensive overview of the advantages and disadvantages of materials used in this field so as to help surgeons to make a better choice.

Does reconstruction affect outcomes following exclusively endoscopic endonasal resection of benign orbital tumors: A systematic review with meta-analysis

Objective:As exclusively endoscopic endonasal resection of benign orbital tumors has become more widespread,high-quality outcomes data are lacking regarding the decision of when and how to reconstruct the medial orbital wall following resection.The goal of this study was to systematically review pertinent literature to assess clinical outcomes relative to orbital reconstruction practices.Methods:Data Sources:PubMed,EMBASE,Web of Science.A systematic review of studies reporting exclusively endoscopic endonasal resections of benign orbital tumors was conducted.Articles not reporting orbital reconstruction details were excluded.Patient and tumor characteristics,operative details,and outcomes were recorded.Variables were compared usingχ^(2),Fisher’s exact,and independentt tests.Results:Of 60 patients included from 24 studies,34(56.7%)underwent orbital reconstruction following resection.The most common types of reconstruction were pedicled flaps(n=15,44.1%)and free mucosal grafts(n=11,32.4%).Rigid reconstruction was uncommon(n=3,8.8%).Performance of orbital reconstruction was associated with preoperative vision compromise(P<0.01).The tendency to forego orbital reconstruction was associated with preoperative proptosis(P<0.001),larger tumor size(P=0.001),and operative exposure of orbital fat(P<0.001)and extraocular muscle(P=0.035).There were no statistically significant differences between the reconstruction and nonreconstruction groups in terms of short-or long-term outcomes when considering all patients.In patients with intraconal tumors,however,there was a higher rate of short-term postoperative diplopia when reconstruction was foregone(P=0.041).This potential benefit of reconstruction did not persist:At an average of two years postoperatively,all patients for whom reconstruction was foregone either had improved or unchanged diplopia.Conclusion:Most outcomes assessed did not appear affected by orbital reconstruction status.This general equivalence may suggest that orbital reconstruction is not a necessity in these cases or that the decision to reconstruct was well-selected by surgeons in the reported cases included in this systematic review.

Tuning magnetic anisotropy by interfacial engineering in La2/3Sr1/3Co1-xMnxO2.5+δ/La2/3Sr1/3MnO3/La2/3Sr1/3Co1-xMnxO2.5+δ trilayers

Grouping different oxide materials with coupled charge, spin, and orbital degrees of freedom together to form heterostructures provides a rich playground to explore the emergent interfacial phenomena. The perovskite/brownmillerite heterostructure is particularly interesting since symmetry mismatch may produce considerable interface reconstruction and unexpected physical effects. Here, we systemically study the magnetic anisotropy of tensely strained La2/3Sr1/3Co1-xMnxO2.5+δ/La2/3Sr1/3MnO3/La2/3Sr1/3Co1-xMnxO2.5+δ trilayers with interface structures changing from perovskite/brownmillerite type to perovskite/perovskite type. Without Mn doping, the initial La2/3Sr1/3CoO2.5+δ/La2/3Sr1/3MnO3/La2/3Sr1/3CoO2.5+δ trilayer with perovskite/brownmillerite interface type exhibits perpendicular magnetic anisotropy and the maximal anisotropy constant is 3.385×106 erg/cm3, which is more than one orders of magnitude larger than that of same strained LSMO film. By increasing the Mn doping concentration, the anisotropy constant displays monotonic reduction and even changes from perpendicular magnetic anisotropy to in-plane magnetic anisotropy, which is possible because of the reduced CoO4 tetrahedra concentration in the La2/3Sr1/3Co1-xMnxO2.5+δ layers near the interface. Based on the analysis of the x-ray linear dichroism, the orbital reconstruction of Mn ions occurs at the interface of the trilayers and thus results in the controllable magnetic anisotropy.

Recurrent basal cell carcinoma of lower lid invading the orbit and whole hemiface reconstructed by rectus abdominis free flap

Dear Sir, I am Dong Hyun Ji, from the Department of Ophthalmology of St. Vincent’s Hospital, Suwon, Korea. I write to present a very severely recurrent basal cell carcinoma (BCC) in lower lid invading left orbit and whole hemiface,

A retrospective study to compare the treatment outcomes with and without surgical navigation for fracture of the orbital wall

Purpose To evaluate the outcomes with and without aid of a computer-assisted surgical navigation system(CASNS)for treatment of unilateral orbital wall fracture(OWF).Methods Patients who came to our hospital for repairing unilateral traumatic OWF from 2014 to 2017 were included in this study.The patients were divided into the navigation group who accepted orbital wall reconstruction aided by CASNS and the conventional group.We evaluated the surgical precision in the navigation group by analyzing the difference between actual postoperative computed tomography data and preoperative virtual surgical plan through color order ratios.We also compared the duration of surgery,enophthalmos correction,restoration of orbital volumes,and improvement of clinical symptoms in both groups systemically.Quantitative data were presented as mean±SD.Significance was determined by the two-sample t-test using SPSS Version 19.0 A p<0.05 was considered statistically significant.Results Seventy patients with unilateral OWF were included in the study cohort.The mean difference between preoperative virtual planning and actual reconstruction outcome was(0.869±0.472)mm,which means the reconstruction result could match the navigation planning accurately.The mean duration of surgery in the navigation group was shorter than it is in the control group,but not significantly.Discrepancies between the reconstructed and unaffected orbital-cavity volume and eyeball projection in the navigation group were significantly less than that in the conventional group.One patient had remnant diplopia and two patients had enophthalmos after surgery in the navigation group;two patients had postoperative diplopia and four patients had postoperative enophthalmos in the conventional group.Conclusion Compare with the conventional treatment for OWF,the use of CASNS can provide a significantly better surgical precision,greater improvements in orbital-cavity volume and eyeball projection,and better clinical results,without increasing the duration of surgery.