Computer-aided Design Research Articles

Rational strategies for improving the efficiency of design and discovery of nanomedicines

AbstractThe rise of rational strategies in nanomedicine development, such as high-throughput methods and computer-aided techniques, has led to a shift in the design and discovery patterns of nanomedicines from a trial-and-error mode to a rational mode. This transition facilitates the enhancement of efficiency in the preclinical discovery pipeline of nanomaterials, particularly in improving the hit rate of nanomaterials and the optimization efficiency of promising candidates. Herein, we describe a directed evolution mode of nanomedicines driven by data to accelerate the discovery of nanomaterials with high delivery efficiency. Computer-aided design strategies are introduced in detail as one of the cutting-edge directions for the development of nanomedicines. Ultimately, we look forward to expanding the tools for the rational design and discovery of nanomaterials using multidisciplinary approaches. Rational design strategies may potentially boost the delivery efficiency of next-generation nanomedicines.

Upscaling of Copper Slag-Based Geopolymer to 3D Printing Technology

Additive manufacturing using cement has evolved rapidly in recent decades, revolutionizing the construction industry. This technology automates building structures through computer-aided design, offering benefits such as reduced material waste, optimized material distribution, and the ability to use composite materials. This paper aims to examine the potential of using copper-slag-based geopolymers in 3D printing. Geopolymers have gained popularity as an alternative and more energy-efficient material to traditional building materials, while copper slag allows for reducing and managing mining industry waste. Moreover, samples formed in molds based on the same material were produced to evaluate the method of manufacturing on the mechanical properties of geopolymers. This paper presents an evaluation of the mechanical properties including the compressive, flexural, and shear strength of the layered material. It reveals promising results, with strength development mainly observed within the first 14 days. The results show that the compressive strength after 28 days of curing is 46.4 MP and 42.1 MPa for formed and printed samples, respectively. Furthermore, the average bending strength value ranges between 7.4 MPa and 7.8 MPa, regardless of the bending direction and forming method. The obtained results show that printed geopolymers demonstrate adequate layer bonding, confirming the profitability of the 3D printing technology. This research confirms that 3D printing technology enables the use of geopolymer binder materials based on copper slag, which opens the door to sustainable alternatives in construction practices.

A comparative evaluation of the displacement and stress distribution of Kilroy spring, ballista spring and temporary anchorage devices during traction of palatally impacted canine using a 3 dimensional finite element analysis

The above study comprises a comparative evaluation of the displacement and stress distribution of Kilroy spring, Ballista spring and Temporary anchorage devices during traction of palatally impacted canine using a 3 dimensional finite element analysis. Palatally impacted canine is a common phenomenon occuring in around 8% of individuals. The Finite Element Analysis/Finite Element method (FEA/FEM) is the most intricate and dependable study that significantly revolutionized the world of dentistry and biomechanical research. Stresses and displacements can be precisely located using this type of numerical analysis. The orthodontist can better comprehend the physiological reactions that take place within the dentoalveolar complex because of the quantitative information it gives them. A Cone Beam Computed Tomography (CBCT)scan of the maxilla was obtained from a patient who reported to the Department of Orthodontics and Dentofacial Orthopaedics after he satisfied the inclusion and exclusion criterion. Finite element 3-D models of Kilroy spring, Ballista spring, Cantilever spring, miniscrew, lingual button, 0.022-inch-slot brackets, 0.019x0.025-inch SS archwire, stainless steel bands with molar tubes were constructed using a three-dimensional computer-aided design program (SolidWorks 2017; Solid Works K.K., Tokyo, Japan). All these components were imported and individually assembled in the ANSYS Software (Version 2021 R2, ANSYS, Canonsburg, Pa) and stress analysis was carried out. On the basis of this study following conclusion were drawn: The maximum amount of impacted canine displacement, with initial simulation, wasobserved with Kilroy spring followed by Ballista spring and miniscrew assisted Cantilever spring and the maximum amount of displacement of adjacent teeth i.e. lateral incisor and 1st premolar is observed with Ballista spring followed by kilroy spring and miniscrew assisted Cantilever spring. Furthurmore stress concentration on the canine is highest in case of ballista spring followed by Kilroy spring and miniscrew assisted Cantilever spring. Over all, miniscrew assisted Cantilever spring can be an efficient treatment option for traction of a palatally impacted canine.

Discovery of α-amylase and α-glucosidase dual inhibitors from NPASS database for management of Type 2 Diabetes Mellitus: A chemoinformatic approach.

Postprandial hyperglycemia, typical manifestation of Type 2 Diabetes Mellitus (T2DM), is associated with notable global morbidity and mortality. Preventing the advancement of this condition by delaying the rate of glucose absorption through inhibition of α-amylase and α-glucosidase enzymatic activities is of utmost importance. Finding a safe antidiabetic drug is essential since those that are currently on the market have drawbacks like unpleasant side effects. The current study utilized computer-aided drug design (CADD), as a quick and affordable method to find a substitute drug template that can be used to control postprandial hyperglycemia by modulating the activity of α-amylase and α-glucosidase enzymes. The Natural Products Activity and Species database (NPASS) (30,926 compounds) was screened in silico, with a focus on evaluating drug-likeness, toxicity profiles and ability to bind on a target protein. Two molecules NPC204580 (Chrotacumine C) and NPC137813 (1-O-(2-Methoxy-4-Acetylphenyl)-6-O-(E-Cinnamoyl)-Beta-D-Glucopyranoside) were identified as potential dual inhibitors for α-amylase and α-glucosidase with free binding energies of -14.46 kcal/mol and -12.58 kcal/mol for α-amylase, and -8.42 kcal/mol and -8.76 kcal/mol for α-glucosidase, respectively. The molecules showed ionic, H-bonding and hydrophobic interactions with critical amino acid residues of both enzymes. Moreover, 100 ns molecular dynamic simulations showed that both molecules are stable on the receptors' active sites based on root mean square deviation (RMSD), root mean square fluctuation (RMSF), and the Generalized Born surface area (GBSA) energy calculated. The two compounds are thus promising therapeutic agents for T2DM that merit further investigation due to their excellent binding energies, encouraging pharmacokinetics, toxicity profiles, and stability as demonstrated in simulated studies.

SiRNAEfficacyDB: An experimentally supported small interfering RNA efficacy database.

Small interfering RNA (siRNA) has revolutionised biomedical research and drug development through precise post-transcriptional gene silencing technology. Despite its immense potential, siRNA therapy still faces technical challenges, such as delivery efficiency, targeting specificity, and molecular stability. To address these challenges and facilitate siRNA drug development, we have developed siRNAEfficacyDB, a comprehensive database that integrates experimentally validated siRNA efficacy data. This database contains 3544 siRNA records, covering 42 target genes and 5 cell lines. It provides detailed information on siRNA sequences, target genes, inhibition efficiencies, experimental techniques, cell lines, siRNA concentrations, and incubation times. siRNAEfficacyDB offers a user-friendly web interface that makes it easy to query, browse and analyse data, enabling efficient access to siRNA-related information. In summary, siRNAEfficacyDB provides a useful data foundation for siRNA drug design and optimisation, serving as a valuable resource for advancing computer-aided siRNA design research and nucleic acid drug development. siRNAEfficacyDB is freely available at https://cellknowledge.com.cn/siRNAEfficacy for non-commercial use.

Host-Guest Binding Free Energies à la Carte: An Automated OneOPES Protocol.

Estimating absolute binding free energies from molecular simulations is a key step in computer-aided drug design pipelines, but the agreement between computational results and experiments is still very inconsistent. Both the accuracy of the computational model and the quality of the statistical sampling contribute to this discrepancy, yet disentangling the two remains a challenge. In this study, we present an automated protocol based on OneOPES, an enhanced sampling method that exploits replica exchange and can accelerate several collective variables to address the sampling problem. We apply this protocol to 37 host-guest systems. The simplicity of setting up the simulations and producing well-converged binding free energy estimates without the need to optimize simulation parameters provides a reliable solution to the sampling problem. This, in turn, allows for a systematic force field comparison and ranking according to the correlation between simulations and experiments, which can inform the selection of an appropriate model. The protocol can be readily adapted to test more force field combinations and study more complex protein-ligand systems, where the choice of an appropriate physical model is often based on heuristic considerations rather than systematic optimization.

Three-dimensional automated measurements of femoral angles for the preoperative planning in dogs with patellar luxation

ObjectivesTo report the surgical outcomes of treating patellar luxation (PL) in dogs with surgical planning based on three-dimensional (3D) automated measurement of femoral angles.Study designMulticenter retrospective study.MethodsForty-one dogs with PL underwent preoperative computed tomography (CT). Three-dimensional femur models were exported as stereolithographic files, and imported into computer-aided design (CAD) software where 3D measurements were performed. The anatomical laterodistal femoral (aLDFA), femoral neck (FNA), and femoral torsion (FTA) angles were recorded. Surgical records, complications, radiographic femoral postoperative alignment, preoperative and postoperative lameness evaluation, and patellar position were reviewed. The success of the surgical outcome was based on the presence of normal patellar tracking at the last clinical recheck.ResultsForty-seven limbs were included; 46% of the cases (22/47) were affected by grade 3 PL. Mean (±SD) 3D aLDFA, FNA, and FTA measurements were 101.4° (±3.6), 132.5° (±2.6), and 17.6° (±4.3) in dogs with medial patellar luxation (MPL) and 89.3° (±7.6), 134.8° (±2.9), 36.9° (±5.3) with lateral patellar luxation (LPL), respectively. Based on the 3D preoperative planning, corrective osteotomies were performed in 34 of 47 cases. The mean radiographic follow-up was 4.7 months. At the final follow-up, PL was successfully treated in 45 of 47 cases. Patella reluxated in five cases. In three of five cases, the 3D automated plan was not followed by the surgeon.DiscussionSurgical treatment of PL based on 3D femoral measurements successfully corrected PL in 45 of 47 cases (96%). This is the first study reporting the use of 3D automated femoral angle measurement in clinical cases affected by PL.

Effect of different corrective force directions applied by spinal orthoses on the patients with adolescent idiopathic scoliosis.

Spinal orthoses are commonly prescribed for adolescent idiopathic scoliosis (AIS), yet their three-dimensional correction was not fully understood. The amount of deformity control largely depends on the corrective forces applied, which remain empirically based due to a lack of consensus on optimal force application. This study investigated the effects of different corrective force directions exerted by spinal orthoses on patients with AIS. A retrospective analysis was conducted on 78 subjects. The trunk was segmented into four quadrants using coronal and sagittal planes from a top-down perspective. Each left or right posterolateral quadrant (with 90°) was further subdivided into zones 1-4, from the sagittal to coronal planes. Based on the zone where the resultant corrective force direction fell, the subjects were categorized into Group 1 (zone 1), Group 2 (zone 2), Group 3 (zone 3), or Group 4 (zone 4). The direction of the corrective force was estimated using modified models of the subjects' bodies, designed through a computer-aided design and manufacturing system integral to the orthosis fabrication process. The effects of corrective forces in different zones on scoliotic spine were assessed. Among the subjects, 3 were in Group 1, 17 in Group 2, 52 in Group 3, and 6 in Group 4. Due to the limited number of subjects, data from Groups 1 and 4 were not analysed. Groups 2 and 3 showed significant reductions in Cobb angle in the coronal plane and plane of maximum curvature (PMC) following orthosis fitting (p < 0.05). Group 2 displayed a significant decrease > 5º in thoracic kyphosis (p < 0.05). Both Groups 2 and 3 exhibited significant reductions in lumbar lordosis. PMC orientation remained unchanged over time (p > 0.05) but was notably higher in Group 2 after orthosis fitting (p < 0.05). Corrective forces applied by spinal orthoses in zones 2 and 3 effectively controlled lateral curve progression. Notably, only forces in zone 3 neither significantly reduced thoracic kyphosis nor exacerbated the deviation of scoliotic spine from the sagittal plane. Further research is needed to validate and expand upon these results.

ASSESSMENT OF PHOTOGRAMMETRY TECHNIQUES FOR 3D MODEL ACQUISITION: A COMPARATIVE STUDY ON THE ACCURACY AND SUITABILITY OF SCANNED MODELS COMPARED TO CAD REFERENCES

This paper presents a comprehensive evaluation of the accuracy of 3D scanning methods using various devices and software to generate 3D models. The resulting models were compared to their corresponding Computer-Aided Design (CAD) models to quantify discrepancies. The primary objective was to assess potential errors, benefits, and limitations of each scanning method, providing insights for future research and development. A switch, chosen as the test object for its moderate complexity and size, enabled a thorough assessment under realistic conditions. The analysis reveals the strengths and limitations of each scanning method, guiding researchers and developers in selecting the most suitable techniques for specific applications. Additionally, the study underscores the importance of device and software parameters on the accuracy of 3D models, offering a comprehensive evaluation of effective techniques for 3D model.

Evaluation of Flexural Strength and Vickers Micro Hardness of Three Different Denture Base Resin Materials

ABSTRACT Objectives: To evaluate the Vickers hardness and flexural strength of computer-aided design/computer-aided manufacture (CAD/CAM) milled, 3D-printed, and traditional heat-polymerized denture base resins used in computer-aided design and manufacture. Materials and Methods: A total of 60 samples were fabricated from CAD/CAM milled resin (PMMA dental material-Ruthinium disc, Badia Polesine (Rovigo) Italy), CAD/CAM 3D-printed resin (NextDent Denture 3D+, Soesterberg, The Netherlands) and conventional heat-polymerized (HP) denture base resin (DBR) (Triplex hot Ivoclar-Vivadent, Liechtenstein). Based on the three different denture base resin materials (n = 10/material) (30/flexural strength and 30/microhardness), the samples were split into six groups. The 3-point bending test was used to assess flexural strength, while Vickers microhardness test was used to assess surface hardness. The acquired data was statistically assessed. Results: CAD/CAM milled resins showed appreciably greater values for both the flexural strength and surface hardness, followed by conventional HP denture base resin and CAD/CAM 3D-printed resin. Pairwise comparison for Flexural Strength and Vickers microhardness revealed significant differences between groups. Conclusion: CAD/CAM milled resins had the highest surface hardness and flexural strength compared to Conventional HP denture base resin and CAD/CAM 3D-printed resin.

Orthogonal Agent Comprising a Nitrile N-Oxide and a Phenylcarbamate for Facile Molecular Integration on Styrne-Butadiene Resin.

The covalent attachment of poly(ethylene glycol) (PEGylation) to materials minimizes non-specific fouling of the material surface with biocomponents. While the PEGylation reaction on polar surfaces is widely used and regarded as a common technique, the PEGylation on less polar polymers and elastomers is extremely difficult due to the absence of reactive points with PEG terminus. Herein, the design and synthesis of an orthogonal agent with a nitrile N-oxide and a phenyl carbamate that can mediate between an alkene and an amine are reported. The ligation capacity of the orthogonal agent is demonstrated through the model reaction to connect between 1-hexene and 4-methoxybenzylamine and the grafting reaction of PEG onto poly(styrene-co-butadiene) (SB) resin. The surface characteristics of PEGylated SB film are evaluated by X-ray photoelectron spectroscopy (XPS) and contact angle measurements. Because SB resin is frequently used as a 3D-printing polymer, the present study indicates that the orthogonal agent can be applicable to the surface modification of 3D-printed objects precisely manufactured by using a computer-aided design (CAD) file in the future.

Development of 3D-printed braces protocol for juvenile idiopathic scoliosis: From the torso measurement and mechanical properties to preliminary experience on fitting

Background: There has been no standard for a rapid prototyping process in manufacturing of the 3D-printed brace with respect to its design, biomechanical properties, procedures, and brace adjustment and fitting. Objective: Objective of this study was to develop the 3D-printed brace protocol for juvenile idiopathic scoliosis. Methods: With the help of the Torso Measurement Frame, the child stands still and is positioned with 1 of 2 manipulation techniques by the physician. Although the patient is in the corrected position, a hand-held scanner registers the three-dimentional (3D) torso, and then the brace is designed using computer aided design (CAD) model. Finite element analysis is used to determine the minimum required thickness of the brace. Acrylonitrile Butadiene Styrene (ABS) material (thermoplastic polymers) and DuraForm PA plastic (Nylon) material were printed by 2 different systems, respectively, and were tested using standard tensile test procedures. Results: The minimum thickness of the brace should be 2 mm to maintain a standard structural factor of safety twice that of the material failure strength. The strain in elongation was less for the ABS compared to the 3D-printed Nylon (6% vs. 14%), and the tensile strength was reduced more for ABS as compared to Nylon (42% vs. 14%). The ABS brace could not withstand changes in tension and cracked when drilled into, heat flared, or donned tightly. However, the Nylon brace improved strength and eliminated the vulnerable aspects. Conclusions: The Nylon material for the 3D-printed brace improved ease of adjustments in trimming, drilling, and heat modifications for better fit and function.

Bayesian mesh optimization for graph neural networks to enhance engineering performance prediction

Abstract In engineering design, surrogate models are widely employed to reduce the computational costs of simulations by approximating design variables and geometric parameters from computer-aided design (CAD) models. However, traditional surrogate models often lose critical information when simplified to lower dimensions, and face challenges in handling the complexity of 3D shapes, especially in industrial datasets. To address these limitations, we propose a Bayesian graph neural network (GNN) framework that directly learns geometric features from CAD mesh representations for accurate engineering performance prediction. Our framework leverages Bayesian optimization (BO) to dynamically determine the optimal mesh element size, significantly improving model accuracy while balancing computational efficiency. This approach addresses the challenge of mesh quality by optimizing mesh resolution, ensuring that critical geometric features are preserved in 3D deep-learning-based surrogate models. Unlike existing models that rely on static or predefined mesh resolutions, our method adapts mesh size based on the task, making it highly flexible for a wide range of engineering applications. Experimental results demonstrate that mesh quality directly impacts prediction accuracy, and the proposed BO-EI GNN model outperforms state-of-the-art models such as 3D CNN, SubdivNet, GCN, and GNN in predicting mass, rim stiffness, and disk stiffness. Our method also significantly reduces the computational costs compared to traditional optimization techniques. The proposed framework shows promising potential for application in finite element analysis (FEA) and other mesh-based simulations, enhancing the utility of surrogate models across various engineering fields.

Informatization model of Guqin based on grasshopper and CNC machining

ABSTRACT The integration of Computer-Aided Design (CAD) and Computer Numerical Control (CNC) machining has brought modern manufacturing techniques into the craft of Guqin crafting, introducing the concept of Industrialized Standardized Guqin Crafting (ISGC). This study proposes the concept of Guqin Information Modeling (GIM), on the basis of which, the parametric modeling method of Guqin is proposed to realize the parameter control of the key position of Guqin; combined with the CNC machining technology, it verifies the production of Guqin of different materials and shapes, summarizes the method of selecting the tools for CNC machining of Guqin and the machining parameters of each process, and puts forward the Industrialized Standard of Guqin Carving (ISGC). The proposal of GIM and ISGC provides information technology support for the research of the sound quality of Guqin and the protection of Guqin.

Marginal Discrepancy and Internal Fit of 3D-Printed Versus Milled Laminate Veneers: An In Vitro Study

The clinical success of laminate veneers depends upon their marginal discrepancy (MD) and internal gap (IG). This study aims to compare and evaluate the MD, overall discrepancy (OD), absolute marginal discrepancy (AMD), and IG of 3D-printed (Varseosmile TrinQ and Varseosmile Crown Plus) and computer-aided design and manufacturing (CAD/CAM)-milled (Brilliant Crios) laminate veneers using cone-beam computed tomography (CBCT). Thirty maxillary central incisors were prepared and divided randomly into three groups (n = 10). All teeth were scanned for veneer fabrication: Group PVT teeth with 3D-printed Varseosmile TrinQ, Group PVC teeth with 3D-printed Varseosmile Crown Plus, and Group BCM teeth with Brilliant Crios milled veneers. The specimens with respective veneers were scanned using CBCT, and the sectional images were measured for IG, MD, OD, and AMD. The mean values for MD recorded were 0.27, 0.31, and 0.40 for PVT, PVC, and BCM respectively). The mean values for IG recorded were as follows: PVT group—0.24, PVC group—0.28, and BCM group—0.39, and those for OD were as follows: PVT—0.22, PVC—0.32, and BCM—0.41. Intragroup significance was observed for IG and OD (p = 0.001). Findings revealed that milled veneers have a higher IG and MD than 3D-printed veneers, making them less clinically acceptable.

Mechanical Effect of an Implant Under Denture Base in Implant-Supported Distal Free-End Removable Partial Dentures

Background: In recent years, implant-assisted removable partial dentures (IARPDs) have been used clinically. However, the extent to which additional implants reduce the burden of supporting tissues is unclear. The aim of this study was therefore to investigate the influence of implanted IARPDs on stress sharing among supporting tissues, using finite element (FE) analysis. Methods: FE models were constructed based on the computed tomography (CT) of a patient with a unilateral defect of the mandibular premolars and molars and the surface data of an RPD with cuspids as abutments, designed using computer-aided design software. A titanium implant was placed in the area equivalent to the first premolar, second premolar, or first molar (IARPD4, IARPD5, and IARPD6, respectively). FE analysis was performed for laterally symmetrical models, i.e., bilateral distal free-end IARPDs. A vertical load of 200 N was applied to the central fossa of the artificial premolars or molars (L4, L5, or L6). Results: Equivalent stress in the alveolar mucosa and vertical displacement of the denture was smaller, with IARPDs under L5 and L6 loads, compared to RPDs. However, abutment teeth were displaced upward under an L6 load in the IARPD5 model. Conclusions: Within the limitations of this study, the area corresponding to the first molar was recommended as the location for an implant under the denture base of bilateral distal free-end IARPDs. Implants located in the area corresponding to the second premolar may apply non-physiological extrusion force on abutment teeth under the load on the artificial second molar.

Development of a device for assessment of aortic root parameters and positioning of aortic valve cusps during aortic valve-sparing root replacement

Background. A promising method of surgical treatment of aneurysms of the root and ascending aorta (AA) with unchanged aortic valve (AV) cusps is aortic valve-sparing root replacement (VSRR) with AV reimplantation (David procedure). To date, there are no clear indications to make a choice in favor of valve-replacing or valve-sparing intervention. The result of visual evaluation and the choice of treatment method based on the surgeon’s experience remains the main criteria. Objective. In the experiment to develop a prototype and method of application of the device for positioning of AV cusps, which will simplify and standardize aortic valve-sparing root replacement, improve the results and increase the reproducibility of these operations. Design and methods. Three-dimensional (3D) modeling of the device components was performed in the parametric open-source computer-aided design environment FreeCAD 0.20.1. Two-dimensional sketches were converted into three-dimensional models and exported as stl files for 3D printing. Solid components of the model were made of polylactic acid (PLA-plastic), elastic components were made of rubber-like photopolymer (Dropstil F556 10 shore A) also by 3D printing using SLA technology. Results. The device consists of 2 similar ring-sizers of variable diameter connected by three struts of variable length. In the upper part of each of the struts fastenings to the distal ring represents T-shaped cutouts for temporary locking of the suture-holders passed through the commissures of the AV cusps. For proximal locking of the aortic graft and the proximal ring-sizer, 3 U-shaped sutures are used, passed from inside to outside through the AV ring, the proximal part of the graft and taken in the tourniquets. The diameters of the ring-sizers can be varied between 25–40 mm by rotating a worm drive. A graft is placed on the inner side of the device, the suture-holders attached to the tops of the commissures are locked in the T-shaped notches in the upper parts of the struts. The device will allow changing the position of the coaptation point, coaptation square and performing hydraulic tests in different positions of the cusps, as well as variable diameters at the level of the AV ring and sinotubular junction (25–40 mm). When the target position of the coaptation point, coaptation area and satisfactory hydraulic test result are achieved, the cusps with commissures are locked inside the graft and the device is removed. Conclusion. A new device has been developed to facilitate, reproduce, and standardize VSRR. The results obtained will facilitate and accelerate the performance of VSRR, increase the reproducibility of the technique, and reduce the risks of complications.

Detailed Images of Deep Brain Stimulation Leads Using Micro-CT

Introduction: One of the challenges in directional deep brain stimulation (DBS) is to determine the orientation of implanted electrodes relative to targeted regions. Post-operative images must be aligned with a model of the implanted lead, usually a computer-based model provided by the manufacturer. This paper shows that models can alternatively be obtained by capturing images of individual leads using micro-CT, a high-resolution CT technique. Contrary to computer-aided design models, lead models generated this way provide realistic X-ray contrast and finer details. Methods: We scanned DBS leads from various vendors using a Bruker SkyScan 1276 micro-CT system. To reduce beam-hardening artefacts, samples were scanned at maximum X-ray tube voltage (100 kV) and with copper filtering. Images were made publicly available for download and 3D visualisation. Conclusion: Detailed images of single DBS leads can be generated using standard micro-CT systems. Their use as reference models could improve lead orientation algorithms, in particular those dedicated to X-ray modalities. Furthermore, the possibility to share models online could broaden access for clinical research.

FABRICATION AND CHARACTERIZATION OF DISSOLVING MICRONEEDLE PATCH USING 3D PRINTED MASTER

Objective: The purpose of this study was to fabricate a dissolving microneedle patch using a 3D-printed master and characterize it using various techniques. Methods: Dissolving microneedle patches were developed using Computer-Aided Design (CAD) software and 3D printing. Polydimethylsiloxane (PDMS) reverse molds were cast from the 3D-printed masters and filled with a solution of 20% Chitosan Oligosaccharide (COS) and 20% Polyvinyl Alcohol (PVA). The patches were dried at room temperature and characterized using Scanning Electron Microscopy (SEM), Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR), X-ray diffraction (XRD), Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), and in vitro skin penetration studies. Results: Optical microscopy and SEM images showed the formation of a uniform microneedle. The peak at 1248 cm⁻¹ in the ATR-FTIR spectrum indicates the formation of cross-links between certain PVA radical groups and COS. XRD revealed that both polymers blended well and showed partial crystallinity, with peaks at 2θ = 11.39°, 2θ = 20°, and 2θ = 41°. DSC and TGA analyses revealed that the blend could withstand high temperatures with good stability at temperatures up to 200 °C. In vitro skin penetration studies confirmed that microneedles could successfully penetrate the skin, indicating their potential for effective transdermal drug delivery. Conclusion: This study demonstrated that COS/PVA dissolving microneedles fabricated using 3D printing and micro-molding have significant potential for transdermal drug delivery.

A Novel Method of Correcting Lower Facial Asymmetry: Computer-Assisted Surgery with Contralateral Mandibular Outer Cortex Sandwich Grafting.

Lower facial asymmetry often results in an esthetically unpleasing appearance. The purpose of this study was to develop a novel method for correcting lower facial asymmetry using mandibular augmentation with sandwich bone grafts from the contralateral mandibular outer cortex (MOC), and to evaluate the efficacy of this method using computer-assisted techniques. The medical records of 16 patients with lower facial asymmetry who underwent mandibular augmentation with sandwich bone grafts from the contralateral MOC between January 2016 and December 2019 were retrospectively reviewed. Preoperative computer-aided design (CAD) was performed based on CBCT data, MOC grafts were harvested from the donor side using a 3D printed osteotomy guide template and grafted to the recipient side in sandwich manner to augment the contralateral mandible. Effectiveness was evaluated through pre- and postoperative CBCT data and FACE-Q questionnaire scores. Neurosensory recovery of the inferior alveolar nerve was assessed using the functional sensory recovery (FSR) scale. All procedure were successfully completed, and the asymmetry was effectively corrected three-dimensionally with no serious complications. The patients' FACE-Q scores for satisfaction with the lower facial area significantly increased from 52.19±7.51 to 86.69±7.50. No significant differences were observed in the pre- and postoperative lengths of mandibular ramus or body on either side. The donor site volume increased by 559.38±335.12 mm3 at 6 months postoperatively. The recipient site volume increased by 4415.94±1017.21 mm3 on the 7th day postoperatively and decreased by 202.63±300.85 mm3 at 6 months, reflecting a bone resorption rate of 5.67 ± 8.12%. The median FSR time for the chin and lower lip was 90 days. Mandibular augmentation with contralateral MOC sandwich grafts effectively increases mandibular width and volume witha low resorption rate. This method allows for three-dimensional restoration of facial symmetry in cases of mild to moderate lower facial asymmetry, achieving a harmonious and symmetric appearance. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266. www.springer.com/00266.