articles+ search results

Humans, Workflow, Imaging, Three-Dimensional methods, and Palate

Background: The introduction in the orthodontic field of the digital workflow for guided insertion of palatal TADs and the development of the 1-visit protocol led to the reduction of chair time and the possibility of complete customization of designs and materials. Conversely, the reduction of operative steps implicates a lower tolerance of deviations between the planned and the actual position of the miniscrews, particularly when the orthodontic device is fixed on 4 palatal TADs or has a rigid structure. This study aims to analyze the influence of each step of the digital workflow on the deviation of the miniscrews' axis of insertion in a bicortical sample. The null hypothesis is that there are no significant differences in the deviations among the operative steps.
Methods: 33 subjects were selected for insertion of bicortical palatal miniscrews with a 1-visit protocol. Digital files were collected at the three stages of the workflow (i.e., digital planning, laboratory prototype, post-insertion impression). A 3D software analysis was performed on a total of 64 miniscrews. After automatic shape recognition of the guiding holes of the digital plan and the scanbodies of the laboratory prototype and post-insertion impression as geometric cylinders, their three-dimensional longitudinal axis was traced and the deviation among them was calculated. Friedman test with Bonferroni correction was performed to assess the significance of the deviations among the three steps, with significance set at p < 0.05.
Results: The laboratory step has a significantly lower degree of deviations (2.12° ± 1.62) than both the clinical step (6.23° ± 3.75) and the total deviations (5.70° ± 3.42). No significant differences were found between miniscrews inserted on the left or the right side.
Conclusions: This study suggests that laboratory procedures such as surgical guide production or rapid prototyping don't play a significant role in the degree of deviations between the planned and the positioned palatal TADs. Conversely, the clinical steps have a bigger influence and need to be carefully evaluated. Despite this difference, there is a cumulative effect of deviations that can lead to the failure of the 1-visit protocol.
(© 2022. The Author(s).)

Magnetic Phenomena, Microscopy, Electron, Scanning, Imaging, Three-Dimensional methods, and Spectrometry, Mass, Secondary Ion

The structural, morphological, and chemical characterization of samples is of utmost importance for a large number of scientific fields. Furthermore, this characterization very often needs to be performed in three dimensions and at length scales down to the nanometer. Therefore, there is a stringent necessity to develop appropriate instrumentational solutions to fulfill these needs. Here we report on the deployment of magnetic sector secondary ion mass spectrometry (SIMS) on a type of instrument widely used for such nanoscale investigations, namely, focused ion beam (FIB)-scanning electron microscopy (SEM) instruments. First, we present the layout of the FIB-SEM-SIMS instrument and address its performance by using specific test samples. The achieved performance can be summarized as follows: an overall secondary ion beam transmission above 40%, a mass resolving power ( M /Δ M ) of more than 400, a detectable mass range from 1 to 400 amu, a lateral resolution in two-dimensional (2D) chemical imaging mode of 15 nm, and a depth resolution of ∼4 nm at 3.0 keV of beam landing energy. Second, we show results (depth profiling, 2D imaging, three-dimensional imaging) obtained in a wide range of areas, such as battery research, photovoltaics, multilayered samples, and life science applications. We hereby highlight the system's versatile capability of conducting high-performance correlative studies in the fields of materials science and life sciences.

Algorithms, Humans, Magnetic Resonance Imaging, Motion, Tomography, X-Ray Computed, Fluoroscopy methods, Imaging, Three-Dimensional methods, and Software

Purpose: With the growing availability and variety of imaging modalities, new methods of intraoperative support have become available for all kinds of interventions. The basic principles of image fusion and image guidance have been widely adopted and are commercialized through a number of platforms. Although multimodal systems have been found to be useful for guiding interventional procedures, they all have their limitations. The integration of more advanced guidance techniques into the product functionality is, however, not easy due to the proprietary solutions of the vendors. Therefore, the purpose of this work is to introduce a software system for image fusion, real-time navigation, and working points documentation during transcatheter interventions performed under X-ray (XR) guidance.
Methods: An interactive software system for cross-modal registration and image fusion of XR fluoroscopy with CT or MRI-derived anatomic 3D models is implemented using Qt application framework and VTK visualization pipeline. DICOM data can be imported in retrospective mode. Live XR data input is realized by a video capture card application interface.
Results: The actual software release offers a graphical user interface with basic functionality including data import and handling, calculation of projection geometry and transformations between related coordinate systems, rigid 3D-3D registration, and template matching-based tracking and motion compensation algorithms in 2D and 3D. The link to the actual software release on GitHub including source code and executable is provided to support independent research and development in the field of intervention guidance.
Conclusion: The introduced system provides a common foundation for the rapid prototyping of new approaches in the field of XR fluoroscopic guidance. As a pure software solution, the developed system is potentially vendor-independent and can be easily extended to be used with the XR systems of different manufacturers.

Cost-Benefit Analysis, Humans, Imaging, Three-Dimensional methods, Brain Neoplasms pathology, Imaging, Three-Dimensional economics, Models, Neurological, and Printing, Three-Dimensional economics

Background: Three-dimensional (3D) printing is a powerful tool for replicating patient-specific anatomic features for education and surgical planning. The advent of "desktop" 3D printing has created a cost-effective and widely available means for institutions with limited resources to implement a 3D-printing workflow into their clinical applications. The ability to physically manipulate the desired components of a "dynamic" 3D-printed model provides an additional dimension of anatomic understanding. There is currently a gap in the literature describing a cost-effective and time-efficient means of creating dynamic brain tumor 3D-printed models.
Methods: Using free, open-access software (3D Slicer) for patient imaging to Standard Tessellation Language file conversion, as well as open access Standard Tessellation Language editing software (Meshmixer), both intraaxial and extraaxial brain tumor models of patient-specific pathology are created.
Results: A step-by-step methodology and demonstration of the software manipulation techniques required for creating cost-effective, multidimensional brain tumor models for patient education and surgical planning are exhibited using a detailed written guide, images, and a video display.
Conclusions: In this technical note, we describe in detail the specific functions of free, open-access software and desktop 3D printing techniques to create dynamic and patient-specific brain tumor models for education and surgical planning.
(Copyright © 2020 Elsevier Inc. All rights reserved.)

Adult, Cadaver, Cervical Vertebrae surgery, Female, Humans, Male, Spinal Fusion methods, Imaging, Three-Dimensional methods, Patient-Specific Modeling, Pedicle Screws, Printing, Three-Dimensional, and Stereotaxic Techniques instrumentation

The conventional surgical method of percutaneous pedicle screw fixation (PPSF) mainly uses X-ray fluoroscopy guidance to target the vertebral pedicle for screw placement. This study aimed to explore the feasibility of establishing a personalized drill guide template for PPSF based on a three-dimensional (3D) printing technique and to evaluate the accuracy and safety of the method for assisting screw insertion in cadaveric specimens. The T3-L3 trunk cadaveric specimens from six adults were subject to a computed tomography (CT) scan in the prone position. A three-dimensional model containing the back skin contour was reconstructed. A bilateral ideal pedicle screw in the T6-L1 segment was designed. Then, the reverse templates were designed. The two templates were fused and printed into an individualized guide template. PPSF was performed under the assistance of the guide template, and the CT scan was taken postoperatively to access the screw position. Ninety-six pedicle screws were successfully placed on the bilateral vertebral body of the T6-L1 segment with the assistance of a guide template. The guide plate was not loosened or displaced when operated by a single hand, and the operation time was 24.6 ± 7.9 s. The axial CT images after puncture indicated that in 96 puncture needles, 90 needles were grade I and 6 were grade II, with a puncture accuracy rate of 98.6%. In conclusion, an individualized PPSF navigation template was developed using Mimics software and 3D printing prototyping, which improved the accuracy of PPSF in cadaveric specimens.
Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2020 Elsevier Ltd. All rights reserved.)

Bone Screws, Cadaver, Humans, Minimally Invasive Surgical Procedures methods, Sampling Studies, Sensitivity and Specificity, Spinal Fusion methods, Zygapophyseal Joint diagnostic imaging, Imaging, Three-Dimensional, Lumbar Vertebrae surgery, Surgery, Computer-Assisted methods, Tomography, X-Ray Computed methods, and Zygapophyseal Joint surgery

It is technically demanding and requires rich experience to insert the translaminar facet screw(TFS) via the paramedian mini-incision approach. It seems that it is easy to place the TFS using computer-assisted design and rapid prototyping(RP) techniques. However, the accuracy and safety of these techniques is still unknown. The aim of this study is to assess the accuracy and safety of translaminar facet screw placement in multilevel unilateral transforaminal lumbar interbody fusion using a rapid prototyping drill guide template system. A patient-matched rapid prototyping translaminar facet screw guide was examined in fourteen cadaveric lumbar spine specimens. A three-dimensional (3D) preoperative screw trajectory was constructed using spinal computed tomography scans, from which individualized guides were developed for the placement of translaminar facet screws. Following bone tunnel establishment, the 3D positioning of the entry point and trajectory of the screws was compared to the preoperative plan as found in the Mimics software.Among 60 trajectories eligible for assessment, no cases of clinically significant laminar perforation were found. The mean deviation between the planned and the actual starting points on spinous process was 1.22 mm. The mean tail and submergence angle deviation was found to be 0.68°and 1.46°, respectively. Among all the deviations, none were found to have any statistical significance. These results indicate that translaminar facet screw placement using the guide system is both accurate and safe.

Acetabulum diagnostic imaging, Acetabulum surgery, Adolescent, Adult, Female, Follow-Up Studies, Humans, Male, Young Adult, Hip Dislocation, Congenital diagnostic imaging, Hip Dislocation, Congenital surgery, Imaging, Three-Dimensional methods, Osteotomy methods, and Prosthesis Design methods

Background: Bernese periacetabular osteotomy (PAO) has been shown to be applicable as a hip-preserving technique for the treatment of developmental dysplasia of the hip (DDH). The approach could be designed preoperatively using various types of reverse-engineering software and finite element analysis, but how to implement it in the actual PAO remains a challenge. This study examines and evaluates a solution to achieve higher accuracy when performing a PAO.
Methods: A patient-specific cutting and rotating template was predesigned through computer-aided design (CAD) with three-dimensional (3D) modeling programs. The templates were then reproduced with rapid prototyping (RP) technology and used in the actual PAO. Finally, the clinical and radiographic effects were assessed and compared between the newly developed PAO and conventional PAO groups.
Results: The customized cutting template fit well with the bone surface and served as a guide for surgeons as they slid the osteotome to the precise location that had been determined prior to surgery. A very similar acetabular fragment was reproduced, and no major complications occurred when performing the osteotomy along the edge of the cutting template. The acetabular fragment was then corrected to the predetermined position through one-off manipulation with the customized rotating template. The final position of the acetabular fragment in the new developed PAO group was highly consistent with the planned position, and the postoperative morphological parameters were consistent with the preoperative planned data compared to the conventional PAO group. The duration of the operation and the number of irradiation decreased significantly. The Harris hip score (HHS) and visual analogue scale (VAS) score improved significantly with the use of the new developed PAO.
Conclusions: We demonstrate that our system, which was based on CAD-RP technology, is feasible and could realize the predicted results accurately during the actual PAO.

Animals, Dogs, Limb Deformities, Congenital diagnostic imaging, Limb Deformities, Congenital surgery, Male, Surgery, Computer-Assisted veterinary, Treatment Outcome, Dog Diseases congenital, Dog Diseases diagnostic imaging, Dog Diseases surgery, Imaging, Three-Dimensional veterinary, Limb Deformities, Congenital veterinary, Osteotomy veterinary, and Tomography, X-Ray Computed veterinary

Introduction: We describe patient-specific surgical guide prototyping and surgical treatment of a complex antebrachial deformity in two skeletally mature dogs presented with chronic lameness. Computer-assisted surgery was elected to increase accuracy in the correction of the complex deformity. Radiographs and computed tomography (CT) scans revealed a biplane deformity with valgus, procurvatum and external torsion of the right radius in both cases. The pre-surgical planning started from the quantification of the angular deformity, followed by computer simulated correction and to end up with a rehearsal surgery on 3D printed bone models. During the surgery, the custom-made osteotomy guides closely fitted the bone, allowing for a precise corrective osteotomy, that was stabilized with two locking plates. Postoperative radiographs showed the successful correction of the deformity. Eight and 12 weeks postoperative follow up examinations showed improved lameness, weight-bearing and progression of bone healing in both dogs. Patient-specific surgical guides allowed for a satisfactory correction of the antebrachial deformity. Additional benefits of using customized surgical devices include standardization and reduced surgical time.

Animals, Art, Humans, Smart Glasses, Computer Graphics, Dinosaurs physiology, Imaging, Three-Dimensional methods, Locomotion physiology, and Virtual Reality

We present the results of a two-year design study to developing virtual reality (VR) flow visualization tools for the analysis of dinosaur track creation in a malleable substrate. Using Scientific Sketching methodology, we combined input from illustration artists, visualization experts, and domain scientists to create novel visualization methods. By iteratively improving visualization concepts at multiple levels of abstraction we helped domain scientists to gain insights into the relationship between dinosaur foot movements and substrate deformations. We involved over 20 art and computer science students from a VR design course in a rapid visualization sketching cycle, guided by our paleontologist collaborators through multiple critique sessions. This allowed us to explore a wide range of potential visualization methods and select the most promising methods for actual implementation. Our resulting visualization methods provide paleontologists with effective tools to analyze their data through particle, pathline and time surface visualizations. We also introduce a set of visual metaphors to compare foot motion in relation to substrate deformation by using pathsurfaces. This is one of the first large-scale projects using Scientific Sketching as a development methodology. We discuss how the research questions of our collaborators have evolved during the sketching and prototyping phases. Finally, we provide lessons learned and usage considerations for Scientific Sketching based on the experiences gathered during this project.

Algorithms, Computer Graphics, Humans, Image Interpretation, Computer-Assisted methods, Magnetic Resonance Imaging methods, Software, Diagnostic Imaging methods, Image Processing, Computer-Assisted methods, and Imaging, Three-Dimensional

Background and Objective: Segmentation is a ubiquitous operation in medical image computing. Various data representations can describe segmentation results, such as labelmap volumes or surface models. Conversions between them are often required, which typically include complex data processing steps. We identified four challenges related to managing multiple representations: conversion method selection, data provenance, data consistency, and coherence of in-memory objects.
Methods: A complex data container preserves identity and provenance of the contained representations and ensures data coherence. Conversions are executed automatically on-demand. A graph containing the implemented conversion algorithms determines each execution, ensuring consistency between various representations. The design and implementation of a software library are proposed, in order to provide a readily usable software tool to manage segmentation data in multiple data representations. A low-level core library called PolySeg implemented in the Visualization Toolkit (VTK) manages the data objects and conversions. It is used by a high-level application layer, which has been implemented in the medical image visualization and analysis platform 3D Slicer. The application layer provides advanced visualization, transformation, interoperability, and other functions.
Results: The core conversion algorithms comprising the graph were validated. Several applications were implemented based on the library, demonstrating advantages in terms of usability and ease of software development in each case. The Segment Editor application provides fast, comprehensive, and easy-to-use manual and semi-automatic segmentation workflows. Clinical applications for gel dosimetry, external beam planning, and MRI-ultrasound image fusion in brachytherapy were rapidly prototyped resulting robust applications that are already in use in clinical research. The conversion algorithms were found to be accurate and reliable using these applications.
Conclusions: A generic software library has been designed and developed for automatic management of multiple data formats in segmentation tasks. It enhances both user and developer experience, enabling fast and convenient manual workflows and quicker and more robust software prototyping. The software's BSD-style open-source license allows complete freedom of use of the library.
(Copyright © 2019 Elsevier B.V. All rights reserved.)

Animals, Dogs, Algorithms, Imaging, Three-Dimensional, Skull diagnostic imaging, and Tomography, X-Ray Computed

This study's objective was to determine the accuracy of using current computed tomography (CT) scan and software techniques for rapid prototyping by quantifying the margin of error between CT models and laser scans of canine skull specimens. Twenty canine skulls of varying morphology were selected from an anatomy collection at a veterinary school. CT scans (bone and standard algorithms) were performed for each skull, and data segmented (testing two lower threshold settings of 226HU and -650HU) into 3-D CT models. Laser scans were then performed on each skull. The CT models were compared to the corresponding laser scan to determine the error generated from the different types of CT model parameters. This error was then compared between the different types of CT models to determine the most accurate parameters. The mean errors for the 226HU CT models, both bone and standard algorithms, were not significant from zero error (p = 0.1076 and p = 0.0580, respectively). The mean errors for both -650HU CT models were significant from zero error (p < 0.001). Significant differences were detected between CT models for 3 CT model comparisons: Bone (p < 0.0001); Standard (p < 0.0001); and -650HU (p < 0.0001). For 226HU CT models, a significant difference was not detected between CT models (p = 0.2268). Independent of the parameters tested, the 3-D models derived from CT imaging accurately represent the real skull dimensions, with CT models differing less than 0.42 mm from the real skull dimensions. The 226HU threshold was more accurate than the -650HU threshold. For the 226HU CT models, accuracy was not dependent on the CT algorithm. For the -650 CT models, bone was more accurate than standard algorithms. Knowing the inherent error of this procedure is important for use in 3-D printing for surgical planning and medical education.
Competing Interests: The authors have declared that no competing interests exist.

Humans, Anatomy instrumentation, Anatomy methods, Imaging, Three-Dimensional methods, Models, Anatomic, and Virtual Reality

This report provides a concise overview of the rendering and utilization of three-dimensional models in the field of anatomy. Anatomical three-dimensional virtual models are widely used for educational purposes, preoperative planning, and surgical simulations because they simply allow for interactive three-dimensional navigation across the human organs or entire body. Virtual three-dimensional models have been recently fabricated as accurate replicas of the anatomical structures thanks to advances in rapid prototyping technology.

Humans, Colon diagnostic imaging, Imaging, Three-Dimensional methods, Models, Anatomic, and Printing, Three-Dimensional

In this paper, we aim at providing results concerning the application of desktop systems for rapid prototyping of medical replicas that involve complex shapes, as, for example, folds of a colon. Medical replicas may assist preoperative planning or tutoring in surgery to better understand the interaction among pathology and organs. Major goals of the paper concern with guiding the digital design workflow of the replicas and understanding their final performance, according to the requirements asked by the medics (shape accuracy, capability of seeing both inner and outer details, and support and possible interfacing with other organs). In particular, after the analysis of these requirements, we apply digital design for colon replicas, adopting two desktop systems. The experimental results confirm that the proposed preprocessing strategy is able to conduct to the manufacturing of colon replicas divided in self-supporting segments, minimizing the supports during printing. This allows also to reach an acceptable level of final quality, according to the request of having a 3D presurgery overview of the problems. These replicas are compared through reverse engineering acquisitions made by a structured-light system, to assess the achieved shape and dimensional accuracy. Final results demonstrate that low-cost desktop systems, coupled with proper strategy of preprocessing, may have shape deviation in the range of ±1 mm, good for physical manipulations during medical diagnosis and explanation.

Humans, Mandible surgery, Mouth, Edentulous surgery, Phantoms, Imaging, Printing, Three-Dimensional, Stereotaxic Techniques instrumentation, Tomography, X-Ray Computed methods, User-Computer Interface, Dental Implants, Imaging, Three-Dimensional methods, and Surgery, Computer-Assisted methods

Purpose: This research aimed to propose a three-dimensional (3D) augmented reality navigation method with point cloud-based image-patient registration that could merge virtual images in the real environment for dental implants using a 3D image overlay and to evaluate its feasibility.
Materials and Methods: A total of 12 rapid prototyping mandibular models were fabricated using a 3D printing method and were divided into two groups: 3D augmented reality-guided group and traditional two-dimensional (2D) image-guided group. A point cloud-based preoperative image-to-patient registration method was introduced to replace the traditional point-to-point registration. After the registration, dental implant surgery was performed in the two model groups using an augmented reality-guided navigation method and a traditional two-dimensional image-guided navigation method. The planned and actual postoperative implant positions were compared for measuring positional implantation errors. The surgery time was also recorded and compared between the two groups.
Results: In the model experiment, the root-mean-square deviation of registration was 0.54 mm, and the implant surgery results showed < 1.5-mm mean linear deviation and < 5.5-degree angular deviation. The augmented reality-guided implantation showed smaller horizontal, vertical, and angular errors in the apical areas of the central incisor and the canine region. The surgery time using the augmented reality-guided navigation method was significantly shorter than that using the two-dimensional (2D) image-guided navigation method (P < .05). Moreover, the volunteer experiment demonstrated that the preoperative 3D models in situ accurately overlaid onto the surgical site.
Conclusion: The proposed point cloud-based registration method can achieve excellent registration accuracy. Dental implant placement guided by the proposed 3D augmented reality navigation method showed better accuracy and applicability, as well as higher efficiency, than the traditional 2D image navigation method.

Blood Loss, Surgical, Child, Humans, Male, Operative Time, Pedicle Screws, Imaging, Three-Dimensional methods, Kyphosis diagnostic imaging, Kyphosis surgery, Scoliosis diagnostic imaging, and Scoliosis surgery

Rationale: This study describes the technique of combined Orbic 3D navigation (O3DN) and 3D rapid prototyping (3DRP) to assist surgical correction of congenital scoliosis.
Patient Concerns: A 12-year-old boy with congenital scoliosis. His father brought him to our hospital upon noticing the boy's asymmetry of the trunk.
Diagnoses: Congenital scoliosis.
Interventions: O3DN and 3DRP were used to assist correction surgery in this patient.
Outcomes: The Cobb angle of segmental scoliosis (T8-L2) was 46.9° preoperatively and 2.3° at the last postoperative follow-up; correction was 95.1%. The average segmental kyphosis (T5-T12) was 45.2° preoperatively and 18.6° at the postoperative follow-up; correction was 58.9%. The preoperative sagittal imbalance of 56.2 mm was improved to 9.7 mm. The mean distance between the center sacral vertical line and the C7 plumb line was reduced from 5.7 to 4.1 mm. Operative time and bleeding volume was impressively little, with no misplacement of pedicle screws or other surgical complications.
Lessons: Combined 3DRP and O3DN helped achieve satisfactory correction for this case of congenital scoliosis. The application of 3DRP aided by O3DN in surgical treatment of congenital scoliosis can reduce operative time, lessen blood loss, reduce screw misplacement, and avoid neurovascular damage. However, patients' hospital costs were greater. Our lessons learnt are that the relative position between the tracker and the pedicle must be static to ensure the accuracy of the whole system during the entire operation.

Biomechanical Phenomena, Humans, Lower Extremity, Range of Motion, Articular, Femur diagnostic imaging, Gait, Imaging, Three-Dimensional methods, and Ultrasonography

Tracking joint motion of the lower extremity is important for human motion analysis. In this study, we present a novel ultrasound-based motion tracking system for measuring three-dimensional (3D) position and orientation of the femur and tibia in 3D space and quantifying tibiofemoral kinematics under dynamic conditions. As ultrasound is capable of detecting underlying bone surface noninvasively through multiple layers of soft tissues, an integration of multiple A-mode ultrasound transducers with a conventional motion tracking system provides a new approach to track the motion of bone segments during dynamic conditions. To demonstrate the technical and clinical feasibilities of this concept, an in vivo experiment was conducted. For this purpose the kinematics of healthy individuals were determined in treadmill walking conditions and stair descending tasks. The results clearly demonstrated the potential of tracking skeletal motion of the lower extremity and measuring six-degrees-of-freedom (6-DOF) tibiofemoral kinematics and related kinematic alterations caused by a variety of gait parameters. It was concluded that this prototyping system has great potential to measure human kinematics in an ambulant, non-radiative, and noninvasive manner.

Feasibility Studies, Humans, Computed Tomography Angiography, Imaging, Three-Dimensional, Internship and Residency, Intracranial Arteriovenous Malformations diagnostic imaging, Intracranial Arteriovenous Malformations pathology, Models, Anatomic, Neurosurgery education, and Printing, Three-Dimensional

Background: To fabricate three-dimensional (3D) models of brain arteriovenous malformation (bAVM) and report our experience with customized 3D printed models of patients with bAVM as an educational and clinical tool for patients, doctors, and surgical residents.
Methods: Using computerized tomography angiography (CTA) or digital subtraction angiography (DSA) images, the rapid prototyping process was completed with specialized software and "in-house" 3D printing service. Intraoperative validation of model fidelity was performed by comparing to DSA images of the same patient during the endovascular treatment process. 3D bAVM models were used for preoperative patient education and consultation, surgical planning, and resident training.
Results: 3D printed bAVM models were successful made. By neurosurgeons' evaluation, the printed models precisely replicated the actual bAVM structure of the same patients (n = 7, 97% concordance, range 95%-99% with average of < 2 mm variation). The use of 3D models was associated shorter time for preoperative patient education and consultation, higher acceptable of the procedure for patients and relatives, shorter time between obtaining intraoperative DSA data and the start of endovascular treatment. Thirty surgical residents from residency programs tested the bAVM models and provided feedback on their resemblance to real bAVM structures and the usefulness of printed solid model as an educational tool.
Conclusions: Patient-specific 3D printed models of bAVM can be constructed with high fidelity. 3D printed bAVM models were proven to be helpful in preoperative patient consultation, surgical planning, and resident training.
(Copyright © 2017 The Authors. Published by Wolters Kluwer Health, Inc. All rights reserved.)

Humans, Patient Care Planning, Imaging, Three-Dimensional, Models, Dental, Printing, Three-Dimensional, and Software

3D imaging in dentistry plays an essential part in diagnostics and treatment planning. To transform digital images into a real object that can be experienced haptically may provide new opportunities to practitioners regarding patient communication, skills training, and treatment planning. Therefore, the aim of this article is to provide a practical guide from 3D imaging to 3D printing using low-cost printers and open source software; the authors used 3D Slicer software and a Meshmixer printer, including the printer's own software. The article presents step-by-step instructions on how to perform rapid prototyping via fused deposition modeling (FDM) and stereolithography (SLA). As an example, we printed the skull of a patient with Saethre-Chotzen syndrome who was undergoing maxillofacial surgery. The protocol explained here should enable the technically interested clinician to produce patient-specific 3D models in-house, prefabricate osteosynthesis plates, and take advantage of the benefits of 3D printing for dentist-patient communication.

Adult, Aged, Computer-Aided Design, Female, Humans, Male, Middle Aged, Pilot Projects, Prosthesis Design methods, Dental Impression Technique, Denture, Partial, Removable, Imaging, Three-Dimensional, Maxilla diagnostic imaging, Maxilla surgery, Maxillofacial Prosthesis, and Palatal Obturators

Statement of Problem: Digital techniques are not clinically applied for 1-piece maxillary prostheses containing an obturator and removable partial denture retained by the remaining teeth because of the difficulty in obtaining sufficiently accurate 3-dimensional (3D) images.
Purpose: The purpose of this pilot clinical study was to generate 3D digital casts of maxillary defects, including the defective region and the maxillary dentition, based on multisource data registration and to evaluate their effectiveness.
Material and Methods: Twelve participants with maxillary defects were selected. The maxillofacial region was scanned with spiral computer tomography (CT), and the maxillary arch and palate were scanned using an intraoral optical scanner. The 3D images from the CT and intraoral scanner were registered and merged to form a 3D digital cast of the maxillary defect containing the anatomic structures needed for the maxillary prosthesis. This included the defect cavity, maxillary dentition, and palate. Traditional silicone impressions were also made, and stone casts were poured. The accuracy of the digital cast in comparison with that of the stone cast was evaluated by measuring the distance between 4 anatomic landmarks. Differences and consistencies were assessed using paired Student t tests and the intraclass correlation coefficient (ICC). In 3 participants, physical resin casts were produced by rapid prototyping from digital casts. Based on the resin casts, maxillary prostheses were fabricated by using conventional methods and then evaluated in the participants to assess the clinical applicability of the digital casts.
Results: Digital casts of the maxillary defects were generated and contained all the anatomic details needed for the maxillary prosthesis. Comparing the digital and stone casts, a paired Student t test indicated that differences in the linear distances between landmarks were not statistically significant (P>.05). High ICC values (0.977 to 0.998) for the interlandmark distances further indicated the high degree of consistency between the digital and stone casts. The maxillary prostheses showed good clinical effectiveness, indicating that the corresponding digital casts met the requirements for clinical application.
Conclusions: Based on multisource data from spiral CT and the intraoral scanner, 3D digital casts of maxillary defects were generated using the registration technique. These casts were consistent with conventional stone casts in terms of accuracy and were suitable for clinical use.
(Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.)

Humans, Male, Mandibular Prosthesis Implantation instrumentation, Mandibular Reconstruction instrumentation, Printing, Three-Dimensional, Surgery, Computer-Assisted instrumentation, Young Adult, Computer-Aided Design, Imaging, Three-Dimensional, Mandibular Injuries surgery, Mandibular Prosthesis, Mandibular Prosthesis Implantation methods, Mandibular Reconstruction methods, and Surgery, Computer-Assisted methods

Purpose: The mandible is an essential esthetic and functional component of the lower third of the face and its reconstruction has always been a challenge, especially after severe post-traumatic injuries. The purpose of the present report was to introduce a new approach of mandibular reconstruction in a patient who had lost the entire mandible except for the rami after being severely injured in a blast.
Materials and Methods: A new approach using a titanium mandibular rami implant technique was applied using computer-aided 3-dimensional virtual planning and rapid prototyping technology. A prosthetic component was supported by the mandibular implant, which achieved occlusion and dedicated function for the patient.
Results: This method offered precise adaptation of the implant and prosthesis and an easier surgical procedure, providing a shortened operation time, no donor site morbidity, and more predictable outcomes.
Conclusion: This new technique allows reconstruction of large-scale mandibular defects that is not possible by conventional surgical methods.
(Copyright © 2017 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Computer-Aided Design, Diskectomy methods, Female, Humans, Lumbar Vertebrae diagnostic imaging, Lumbar Vertebrae surgery, Male, Multidetector Computed Tomography methods, Precision Medicine, Diskectomy instrumentation, Imaging, Three-Dimensional, Intervertebral Disc Degeneration diagnostic imaging, Intervertebral Disc Degeneration surgery, Intervertebral Disc Displacement diagnostic imaging, Intervertebral Disc Displacement surgery, Laser Therapy methods, and Printing, Three-Dimensional

Purpose: This paper aimed to explore the design and application of a customized navigation board for lumbar disc ablation.
Methods: Eight cases of lumbar disc herniation (diagnosed by spiral computerized tomography, CT) to be treated via intervertebral ablation using a path from the skin to the herniated intervertebral disc were included. The lumbar vertebrae, sacrum, and skin (adhered to a standard base, Figure 1) were reconstructed based on continuous spiral CT slices. The path was designed by the surgeon (Figure 2) to be line between the base and the puncture point, and was guided by the navigation board. The board was prototyped and used in ablation localization as a guide canal. The intra- and post-operative complications were recorded during the operation and 48-hours post operation, respectively.
Results: In all eight cases, target discs were punctured after a duration ranging from 6 to 13 minutes. No complications were observed either during the operation or at 48 hours post-operatively.
Conclusion: This customized navigation board could promote the accuracy and diminish the duration of intervertebral disc ablation. A stereolithography apparatus (SLA) and photosensitive resin could generate a customized reverse guide board with high fidelity for intervertebral disc ablation. Manually performed rigid registration can meet the accuracy requirements. The results presented in the present paper demonstrated that rapid prototyping via an SLA and photosensitive resin could maintain the accuracy and dynamic stability of a customized navigation board for lumbar disc ablation.

Humans, Tomography, X-Ray Computed, Bone and Bones diagnostic imaging, Imaging, Three-Dimensional methods, and Machine Learning

An effective method for reconstructing a 3D model of human bones from computed tomography (CT) image data based on dictionary learning is proposed. In this study, the dictionary comprises the vertices of triangular meshes, and the sparse coefficient matrix indicates the connectivity information. For better reconstruction performance, we proposed a balance coefficient between the approximation and regularisation terms and a method for optimisation. Moreover, we applied a local updating strategy and a mesh-optimisation method to update the dictionary and the sparse matrix, respectively. The two updating steps are iterated alternately until the objective function converges. Thus, a reconstructed mesh could be obtained with high accuracy and regularisation. The experimental results show that the proposed method has the potential to obtain high precision and high-quality triangular meshes for rapid prototyping, medical diagnosis, and tissue engineering.
(Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.)

Humans, Radiotherapy methods, Imaging, Three-Dimensional methods, Radiotherapy instrumentation, and Workflow

Humans, Infant, Male, Computer Simulation, Imaging, Three-Dimensional, Models, Anatomic, and Respiratory System Abnormalities surgery

Introduction: The incorporation of the clinic and the imaging allow a better understanding of anatomy. The aim of this work is to develop a rapid prototype in synthetic material that replicates anatomical details to be used in teaching and surgical training in Pediatrics.
Material and Method: Presentation of case-one year old female with respiratory distress syndrome. In the endoscopic examination was found a distal tracheal compression. The angiotomography confirmed the presence of a vascular malformation. In order to discuss appropriate conduct, the making of rapid prototyping in scale 1:1 was requested to simulate an identical condition of the thoracic topography of the patient, using virtual 3D images stored in th
Rapid Prototype Technique: Code "g" was generated, which was used to control the hardware of production and a three-dimensional digital grid was obtained. Digital simulation and production in plastic (ABS) with deposition and fusion technique (MDF) was performed. The prototype was validated by comparing measurements with witnesses of the virtual model in 3D.
Results and Discussion: The model replied exactly the defects found in the scan and endoscopy, confirming the presence of vascular malformation and its impact on the respiratory system. Rapid prototype shows the internal and external structures of the human body with maximum precision allowing a topographic view of "normal or pathological" situations that could facilitate the teaching and training of the surgical team to propose an appropriate treatment plan. There are many areas of medicine that could benefit from this model that could be built with different types of materials with different flexibility and consistency.
Conclusions: Rapid prototype gives form to virtual 3D images, allowing teaching and training of the surgical team.

Humans, Cranial Nerves anatomy histology, Imaging, Three-Dimensional methods, Magnetic Resonance Imaging methods, Models, Anatomic, and Printing, Three-Dimensional

Steady-state free precession (SSFP) magnetic resonance imaging (MRI) can demonstrate details down to the cranial nerve (CN) level. High-resolution three-dimensional (3D) visualization can now quickly be performed at the workstation. However, we are still limited by visualization on flat screens. The emerging technologies in rapid prototyping or 3D printing overcome this limitation. It comprises a variety of automated manufacturing techniques, which use virtual 3D data sets to fabricate solid forms in a layer-by-layer technique. The complex neuroanatomy of the CNs may be better understood and depicted by the use of highly customizable advanced 3D printed models. In this technical note, after manually perfecting the segmentation of each CN and brain stem on each SSFP-MRI image, initial 3D reconstruction was performed. The bony skull base was also reconstructed from computed tomography (CT) data. Autodesk 3D Studio Max, available through freeware student/educator license, was used to three-dimensionally trace the 3D reconstructed CNs in order to create smooth graphically designed CNs and to assure proper fitting of the CNs into their respective neural foramina and fissures. This model was then 3D printed with polyamide through a commercial online service. Two different methods are discussed for the key segmentation and 3D reconstruction steps, by either using professional commercial software, i.e., Materialise Mimics, or utilizing a combination of the widely available software Adobe Photoshop, as well as a freeware software, OsiriX Lite.

Cerebral Revascularization methods, Cerebral Revascularization trends, Humans, Prospective Studies, Carotid Artery Diseases diagnostic imaging, Carotid Artery Diseases surgery, Imaging, Three-Dimensional methods, Intracranial Aneurysm diagnostic imaging, Intracranial Aneurysm surgery, Magnetic Resonance Imaging methods, and Printing, Three-Dimensional

Objective: Hemodynamics in cerebral aneurysms are currently investigated toward clinical efficacy using nonstandardized computational simulation techniques. At the same time, flow patterns and velocities are accessible by 4-dimensional phase contrast magnetic resonance imaging (4D pcMRI). Complexity of protocol design and imaging duration has limited the use of this technique in clinical imaging. A new approach is presented to overcome these limitations.
Methods: Three-dimensional (3D) replicas of 2 cerebral aneurysms were fabricated by fused deposition prototyping (3D printing) and imaged using 4D pcMRI while connected to a magnetic resonance imaging-compatible continuous flow loop. Acquisition parameters were optimized with imaging times not to exceed 10 minutes. Six patients harboring cerebral aneurysms with sizes ranging from 4.7 to 13.8 mm were imaged with the optimized 4D pcMRI protocol. After treatment with the pipeline embolization device (PED), 4D pcMRI examinations were repeated in 3 patients.
Results: In all cases, major flow patterns were visualized well; smaller aneurysms posed a challenge because of limited spatial resolution, whereas larger aneurysms contained regions of low velocity resulting in limited contrast in the flow-sensitive images. After PED placement, ordered aneurysmal flow was disrupted and intra-aneurysmal velocity was reduced on average by 24.5% (range, 12.9-31.5%). Exploratory statistical analysis yielded a positive significant correlation (P < 0.01) between changes in inflow velocity and posttreatment intra-aneurysmal flow velocity.
Conclusions: 4D pcMRI flow imaging in cerebral aneurysms within a time frame suitable for clinical imaging applications is feasible with optimized acquisition parameters, thereby enabling quantification of intra-aneurysmal flow changes after flow diverter device treatment.
(Copyright © 2017 Elsevier Inc. All rights reserved.)

Computer-Aided Design, Dimensional Measurement Accuracy, Humans, Image Processing, Computer-Assisted instrumentation, Imaging, Three-Dimensional instrumentation, Models, Dental, Orthodontics methods, Printing, Three-Dimensional, Reproducibility of Results, Software, Stereolithography, Dental Impression Technique instrumentation, Image Processing, Computer-Assisted methods, Imaging, Three-Dimensional methods, and Tooth diagnostic imaging

Objective: To determine the accuracy (trueness and precision) of two different rapid prototyping (RP) techniques for the physical reproduction of three-dimensional (3D) digital orthodontic study casts, a comparative assessment using two 3D STL files of two different maxillary dentitions (two cases) as a reference was accomplished.
Materials and Methods: Five RP replicas per case were fabricated using both stereolithography (SLA) and the PolyJet system. The 20 reproduced casts were digitized with a highly accurate reference scanner, and surface superimpositions were performed. Precision was measured by superimposing the digitized replicas within each case with themselves. Superimposing the digitized replicas with the corresponding STL reference files assessed trueness. Statistical significance between the two tested RP procedures was evaluated with independent-sample t-tests (P < .05).
Results: The SLA and PolyJet replicas showed statistically significant differences for trueness and precision. The precision of both tested RP systems was high, with mean deviations in stereolithographic models of 23 (±6) μm and in PolyJet replicas of 46 (±13) μm. The mean deviation for trueness in stereolithographic replicas was 109 (±4) μm, while in PolyJet replicas, it was 66 (±14) μm.
Conclusions: Comparing the STL reference files, the PolyJet replicas showed higher trueness than the SLA models. But the precision measurements favored the SLA technique. The dimensional errors observed in this study were a maximum of 127 μm. In the present study, both types of reproduced digital orthodontic models are suitable for diagnostics and treatment planning.

Humans, Image Processing, Computer-Assisted, Models, Anatomic, Skull, Surgery, Computer-Assisted, Workflow, Imaging, Three-Dimensional, Printing, Three-Dimensional, Prostheses and Implants, and Software

In this publication, the interactive planning and reconstruction of cranial 3D Implants under the medical prototyping platform MeVisLab as alternative to commercial planning software is introduced. In doing so, a MeVisLab prototype consisting of a customized data-flow network and an own C++ module was set up. As a result, the Computer-Aided Design (CAD) software prototype guides a user through the whole workflow to generate an implant. Therefore, the workflow begins with loading and mirroring the patients head for an initial curvature of the implant. Then, the user can perform an additional Laplacian smoothing, followed by a Delaunay triangulation. The result is an aesthetic looking and well-fitting 3D implant, which can be stored in a CAD file format, e.g. STereoLithography (STL), for 3D printing. The 3D printed implant can finally be used for an in-depth pre-surgical evaluation or even as a real implant for the patient. In a nutshell, our research and development shows that a customized MeVisLab software prototype can be used as an alternative to complex commercial planning software, which may also not be available in every clinic. Finally, not to conform ourselves directly to available commercial software and look for other options that might improve the workflow.

Aged, 80 and over, Atrial Appendage surgery, Atrial Fibrillation complications, Atrial Fibrillation diagnosis, Humans, Male, Preoperative Period, Printing, Three-Dimensional, Stroke etiology, Atrial Appendage diagnostic imaging, Atrial Fibrillation surgery, Cardiac Surgical Procedures methods, Echocardiography, Transesophageal methods, Imaging, Three-Dimensional, Multidetector Computed Tomography methods, and Stroke prevention control

Adult, Brain Neoplasms diagnostic imaging, Corpus Callosum diagnostic imaging, Female, Glioma diagnostic imaging, Humans, Magnetic Resonance Imaging, Neurosurgical Procedures, Tomography, X-Ray Computed, Brain Neoplasms surgery, Glioma surgery, Imaging, Three-Dimensional, Models, Anatomic, and Printing, Three-Dimensional

This paper illustrates the feasibility and utility of combining cranial anatomy and brain function on the same 3D-printed model, as evidenced by a neurosurgical planning case study of a 29-year-old female patient with a low-grade frontal-lobe glioma. We herein report the rapid prototyping methodology utilized in conjunction with surgical navigation to prepare and plan a complex neurosurgery. The method introduced here combines CT and MRI images with DTI tractography, while using various image segmentation protocols to 3D model the skull base, tumor, and five eloquent fiber tracts. This 3D model is rapid-prototyped and coregistered with patient images and a reported surgical navigation system, establishing a clear link between the printed model and surgical navigation. This methodology highlights the potential for advanced neurosurgical preparation, which can begin before the patient enters the operation theatre. Moreover, the work presented here demonstrates the workflow developed at the National University Hospital of Iceland, Landspitali, focusing on the processes of anatomy segmentation, fiber tract extrapolation, MRI/CT registration, and 3D printing. Furthermore, we present a qualitative and quantitative assessment for fiber tract generation in a case study where these processes are applied in the preparation of brain tumor resection surgery.

Adolescent, Adult, Aged, Female, Humans, Male, Middle Aged, Orbit diagnostic imaging, Orbital Fractures diagnosis, Retrospective Studies, Tomography, Spiral Computed, Tomography, X-Ray Computed methods, Young Adult, Bone Plates, Imaging, Three-Dimensional, Orbit surgery, Orbital Fractures surgery, Prostheses and Implants, Plastic Surgery Procedures methods, and Titanium

Objective: The aim of the study was to precisely assess the severity of traumatic orbital defects and techniques for personalized orbital reconstruction.
Methods: A retrospective study was conducted in 97 patients with traumatic orbital defects who were treated in our hospital between July 2003 and June 2012. Pre- and postoperative spiral computed tomography scans were performed in all patients. A spatial orientation technique was used to measure the three-dimensional position of the globe and calculate the changes in the orbital volume. Subsequently, a computer-assisted technique and a rapid prototyping technique were used to create a personalized orbital model to aid in the planning of surgery as well as the preforming of implants and bone plates. During surgery, the herniated orbital contents were returned; the preformed titanium mesh, Medpor, or other implants were placed; the orbital shape in the defect site was precisely restored; and normal proportions between the orbital walls and orbital contents were regained. The treatment outcomes were evaluated with respect to postoperative appearance, patients' satisfaction, ophthalmologic examination, and computed tomography scan. The complications were analyzed accordingly.
Results: Satisfactory results were achieved in all patients with the following exceptions: 1 patient with an unsatisfactory facial appearance; 2 patients with old trauma and an unfavorable correction of enophthalmos who experienced diplopia with no significant improvement within 6 months after surgery; and 2 patients of mild postoperative lower eyelid ectropion. All other patients achieved satisfactory treatment effects, that is, the orbital shape in the defect site was precisely restored, and normal proportions between the orbital walls and orbital contents were regained. There were no other severe complications reported.
Conclusions: In patients with traumatic orbital defects, accurate digital evaluations of the three-dimensional position of the globe and changes in the orbital volume aid in surgical planning with a personalized model and promote early surgery with minimal trauma. When the orbital volume was restored and the position of the globe was maintained or corrected, the precise reconstruction of the anatomic shape of the orbit was concurrently completed. Personalized orbital reconstruction can improve the efficacy of plastic surgery in patients with orbital deformities.

Humans, Patient Satisfaction, Congenital Microtia surgery, Imaging, Three-Dimensional, and Plastic Surgery Procedures

Conclusions: The use of the 3D template model in microtia surgery leads to satisfactory results, for its contribution to the engraving and localization of the microtia auricle in auricle reconstruction.
Objectives: The aim of the study was to create an anatomical correct 3D rapid prototyping model for patients with microtia, to assist with the accurate fabrication and localization of a coastal cartilage framework for auricular reconstruction, and patients, who had undergone rib-cartilage reconstruction to treat a congenital auricular defect, were evaluated for aesthetic outcomes following ear reconstruction with a different template model.
Methods: Forty patients with unilateral congenital microtia were enrolled in this study during the last 2 years, they were divided into two groups randomly before surgery; 20 patients who had a 3D digital template made for clinical application and the other 20 who underwent ear reconstruction with a 2D template.
Results: The patients who had undergone ear reconstruction with the 3D template model had a better result of the appearance and location of the constructed auricle, and a higher level of satisfaction with their clinical outcomes (p < .05).

Equipment Design, Phantoms, Imaging, Cardiac Catheterization instrumentation, Cardiac Catheters, Imaging, Three-Dimensional methods, Magnetic Resonance Imaging instrumentation, and Robotic Surgical Procedures instrumentation

This paper presents a novel MR-compatible 3-DOF cardiac catheter steering mechanism. The catheter's steerable structure is tendon driven and consists of miniature deflectable, helical segments created by a precise rapid prototyping technique. The created catheter prototype has an outer diameter of 9 Fr (3 mm) and a steerable distal end that can be deflected in a 3-D space via four braided high-tensile Spectra fiber tendons. Any longitudinal twist commonly observed in helical structures is compensated for by employing clockwise (CW) and counter clockwise (CCW) helical segments in an alternating fashion. A 280 μm flexible carbon fiber rod is used as a backbone in a central channel to improve the structure's steering and positioning repeatability. In addition to the backbone, a carbon fiber tube can be inserted into the structure to a varying amount capable of changing the structure's forcibility and, thus, providing a means to change the curvature and to modify the deflectable length of the catheter leading to an extension of reachable points in the catheter-tip workspace. A unique feature of this helical segment structure is that the stiffness can be further adjusted by appropriately tensioning tendons simultaneously. An experimental study has been conducted examining the catheter-tip trajectory in a 3-D space and its positioning repeatability using a 5-DOF magnetic coil tracking system. Furthermore, MRI experiments in a 1.5-T scanner confirmed the MR-compatibility of the catheter prototype. The study shows that the proposed concept for catheter steering has great potential to be employed for robotically steered and MR-guided cardiac catheterization.

Adult, Female, Humans, Male, Middle Aged, Orbit diagnostic imaging, Orbital Fractures diagnosis, Prostheses and Implants, Computer Simulation, Imaging, Three-Dimensional methods, Orbit surgery, Orbital Fractures surgery, Printing, Three-Dimensional, Plastic Surgery Procedures methods, and Tomography, X-Ray Computed methods

Background: It is difficult to restore original orbital contours because of their complex 3-dimensional structure. Moreover, slight implant malpositioning can result in enophthalmos or other complications. The authors describe our experience of using individualized prebent titanium-Medpor mesh implants and stereolithographic modeling in a series of patients who underwent orbital wall reconstruction.
Methods: A consecutive series of 104 patients with orbital fractures received computer simulation-designed prebent titanium-Medpor mesh implants insertion. Preoperative computed tomography (CT) data were processed for each patient, and a rapid prototyping (RP) model was produced. The uninjured side was concurrently mirrored and superimposed onto the traumatized side to create a mirror image of the RP model. The authors fabricated the titanium-Medpor implants to intraoperatively reconstruct the 3-dimensional orbital structure. The prefabricated titanium-Medpor implants were inserted into the defective orbital wall and fixed. Postoperative CT images were immediately taken to evaluate the reconstructed contours and compare the preoperative and postoperative intraorbital volumes.
Results: All reconstructions were successful without postoperative complications. The implants were correctly positioned in the sagittal, axial, and coronal planes relative to the original orbital contours. The mean preoperative intraorbital volumes of the uninjured and traumatized sides were 21.39 ± 1.93 and 23.17 ± 2.00 cm, respectively, and the postoperative mean intraorbital volume was 20.74 ± 2.07 cm.
Conclusions: Orbital reconstruction can be optimized using individually manufactured rapid prototype skull model and premolded synthetic scaffold by computer-aid of mirroring-reconstruction of 3-dimensional images and 3-dimensional printing techniques.

Adolescent, Adult, Databases, Factual, Female, Humans, Italy, Young Adult, Anthropometry methods, Beauty, Face anatomy histology, Imaging, Three-Dimensional methods, and White People

The aim of this paper is to develop a database to determine a new biomorphometric standard of attractiveness. Sampling was carried out using noninvasive three-dimensional relief methods to measure the soft tissues of the face. These anthropometric measurements were analyzed to verify the existence of any canons with respect to shape, size, and measurement proportions which proved to be significant with regard to the aesthetics of the face. Finally, the anthropometric parameters obtained were compared with findings described in the international literature.The study sample was made up competitors in the Miss Italy 2010 and 2009 beauty contest. The three-dimensional (3D) scanning of soft tissue surfaces allowed 3D digital models of the faces and the spatial 3D coordinates of 25 anthropometric landmarks to be obtained and used to calculate linear and angular measurements. A paired Student t test for the analysis of the means allowed 3 key questions in the study of biomorphometric parameters of the face to be addressed through comparison with the data available in the literature.The question of statistical evidence for the samples analyzed being members of the populations samples reported in literature was also addressed.The critical analysis of the data helped to identify the anthropometric measurements of the upper, middle, and lower thirds of the face, variations in which have a major influence on the attractiveness of the face. These changes involve facial width, height, and depth. Changes in measurements of length, angles, and proportions found in the sample considered were also analyzed.
Competing Interests: The authors report no conflicts of interest.

Bone Screws, Female, Fracture Fixation instrumentation, Fracture Fixation methods, Fracture Healing physiology, Fractures, Spontaneous diagnostic imaging, Humans, Male, Mandibular Fractures diagnostic imaging, Mandibular Neoplasms diagnostic imaging, Oral Surgical Procedures methods, Radiography, Panoramic methods, Plastic Surgery Procedures methods, Tomography, X-Ray Computed methods, Treatment Outcome, Wound Healing physiology, Bone Plates, Fractures, Spontaneous surgery, Imaging, Three-Dimensional, Mandibular Fractures surgery, Mandibular Neoplasms surgery, and Plastic Surgery Procedures instrumentation

Background: Locking reconstruction plates are used in the treatment of jaw trauma and diseases if there is a need for surgical resection and to prevent pathologic fracture after tumor excision. Fixation is typically performed using an extraoral approach.
Methods: This article describes a technique for the intraoral fixation of locking reconstruction plates that uses prototyping to model the plate before the procedure as well as an implant handpiece with adapted drills for bone drilling and the insertion of screws into relatively inaccessible areas.
Conclusion: Intraoral fixation not only prevents nerve damage and facial scarring but also minimizes the plate's risk of extraoral exposure and reduces surgical morbidity. © 2016 Wiley Periodicals, Inc. Head Neck 38: 1436-1439, 2016.
(© 2016 Wiley Periodicals, Inc.)

Humans, Cardiology methods, Computer Simulation, Heart anatomy histology, Imaging, Three-Dimensional methods, Models, Biological, and Tomography, X-Ray Computed

Biomodeling the human anatomy in exact structure and size is an exciting field of medical science. Utilizing medical data from various medical imaging topography, the data of an anatomical structure can be extracted and converted into a three-dimensional virtual biomodel; thereafter a physical biomodel can be generated utilizing rapid prototyping machines. Here, we have reviewed the utilization of this technology and have provided some guidelines to develop biomodels of cardiac structures. Cardiac biomodels provide insights for cardiothoracic surgeons, cardiologists, and patients alike. Additionally, the technology may have future usability for tissue engineering, robotic surgery, or routine hospital usage as a diagnostic and therapeutic tool for cardiovascular diseases (CVD). Given the broad areas of application of cardiac biomodels, attention should be given to further research and development of their potential.

Adult, Computer Simulation, Humans, Magnetic Resonance Imaging, Male, Middle Aged, Nose surgery, Paranasal Sinuses surgery, Skull Base diagnostic imaging, Skull Base surgery, Tomography, X-Ray Computed, Endoscopy methods, Imaging, Three-Dimensional methods, Nasal Surgical Procedures methods, Nose diagnostic imaging, and Paranasal Sinuses diagnostic imaging

There is often a need to more precisely identify the extent of pathology and the fine elements of intracranial anatomic features during the diagnostic process and during many operations in the nose, sinus, orbit, and skull base region. In two case reports, we describe the methods used in the diagnostic workup and surgical therapy in the nose and paranasal sinus region. Besides baseline x-ray, multislice computed tomography, and magnetic resonance imaging, operative field imaging was performed via a rapid prototyping model, virtual endoscopy, and 3-D imaging. Different head tissues were visualized in different colors, showing their anatomic interrelations and the extent of pathologic tissue within the operative field. This approach has not yet been used as a standard preoperative or intraoperative procedure in otorhinolaryngology. In this way, we tried to understand the new, visualized "world of anatomic relations within the patient's head" by creating an impression of perception (virtual perception) of the given position of all elements in a particular anatomic region of the head, which does not exist in the real world (virtual world). This approach was aimed at upgrading the diagnostic workup and surgical therapy by ensuring a faster, safer and, above all, simpler operative procedure. In conclusion, any ENT specialist can provide virtual reality support in implementing surgical procedures, with additional control of risks and within the limits of normal tissue, without additional trauma to the surrounding tissue in the anatomic region. At the same time, the virtual reality support provides an impression of the virtual world as the specialist navigates through it and manipulates virtual objects.

Computer-Aided Design, Humans, Lung surgery, Lung Diseases surgery, Prosthesis Implantation, Stents, Imaging, Three-Dimensional, Lung diagnostic imaging, Lung Diseases diagnostic imaging, Printing, Three-Dimensional, and Prosthesis Design

Recent advances in the three-dimensional (3D) printing industry have enabled clinicians to explore the use of 3D printing in preprocedural planning, biomedical tissue modeling, and direct implantable device manufacturing. Despite the increased adoption of rapid prototyping and additive manufacturing techniques in the health-care field, many physicians lack the technical skill set to use this exciting and useful technology. Additionally, the growth in the 3D printing sector brings an ever-increasing number of 3D printers and printable materials. Therefore, it is important for clinicians to keep abreast of this rapidly developing field in order to benefit. In this Ahead of the Curve, we review the history of 3D printing from its inception to the most recent biomedical applications. Additionally, we will address some of the major barriers to wider adoption of the technology in the medical field. Finally, we will provide an initial guide to 3D modeling and printing by demonstrating how to design a personalized airway prosthesis via 3D Slicer. We hope this information will reduce the barriers to use and increase clinician participation in the 3D printing health-care sector.
(Copyright © 2016 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.)

Cone-Beam Computed Tomography, Dental Materials, Fiducial Markers, Humans, Models, Anatomic, Dental Impression Technique, Face, Imaging, Three-Dimensional, and Printing, Three-Dimensional

Purpose: The purpose of this investigation was to compare the accuracy of facial models fabricated using facial moulage impression methods to the three-dimensional printed (3DP) fabrication methods using soft tissue images obtained from cone beam computed tomography (CBCT) and 3D stereophotogrammetry (3D-SPG) scans.
Materials and Methods: A reference phantom model was fabricated using a 3D-SPG image of a human control form with ten fiducial markers placed on common anthropometric landmarks. This image was converted into the investigation control phantom model (CPM) using 3DP methods. The CPM was attached to a camera tripod for ease of image capture. Three CBCT and three 3D-SPG images of the CPM were captured. The DICOM and STL files from the three 3dMD and three CBCT were imported to the 3DP, and six testing models were made. Reversible hydrocolloid and dental stone were used to make three facial moulages of the CPM, and the impressions/casts were poured in type IV gypsum dental stone. A coordinate measuring machine (CMM) was used to measure the distances between each of the ten fiducial markers. Each measurement was made using one point as a static reference to the other nine points. The same measuring procedures were accomplished on all specimens. All measurements were compared between specimens and the control. The data were analyzed using ANOVA and Tukey pairwise comparison of the raters, methods, and fiducial markers.
Results: The ANOVA multiple comparisons showed significant difference among the three methods (p < 0.05). Further, the interaction of methods versus fiducial markers also showed significant difference (p < 0.05). The CBCT and facial moulage method showed the greatest accuracy.
Conclusions: 3DP models fabricated using 3D-SPG showed statistical difference in comparison to the models fabricated using the traditional method of facial moulage and 3DP models fabricated from CBCT imaging. 3DP models fabricated using 3D-SPG were less accurate than the CPM and models fabricated using facial moulage and CBCT imaging techniques.
(© 2015 by the American College of Prosthodontists.)

Adult, Female, Humans, Magnetic Resonance Imaging, Male, Neoplasms, Students, Medical statistics numerical data, Tomography, X-Ray Computed, Young Adult, Imaging, Three-Dimensional methods, Models, Anatomic, and Printing, Three-Dimensional

Background: Three-dimensional (3D) printing has been used in the manufacturing industry for rapid prototyping and product testing. The aim of our study was to assess the feasibility of creating anatomical 3D models from a digital image using 3D printers. Furthermore, we sought face validity of models and explored potential opportunities for using 3D printing to enhance surgical education and clinical practice.
Methods: Computed tomography and magnetic resonance images were reviewed, converted to computer models, and printed by stereolithography to create near exact replicas of human organs. Medical students and surgeons provided feedback via survey at the 2014 Surgical Education Week conference.
Results: There were 51 respondents, and 95.8% wanted these models for their patients. Cost was a concern, but 82.6% found value in these models at a price less than $500. All respondents thought the models would be useful for integration into the medical school curriculum.
Conclusion: Three-dimensional printing is a potentially disruptive technology to improve both surgical education and clinical practice. As the technology matures and cost decreases, we envision 3D models being increasingly used in surgery.
(© The Author(s) 2015.)

Anatomy education, Humans, Pathology education, Imaging, Three-Dimensional instrumentation, Imaging, Three-Dimensional methods, Joints anatomy histology, Models, Anatomic, Musculoskeletal Diseases pathology, and Teaching

Three-dimensional (3D) printing has recently erupted into the medical arena due to decreased costs and increased availability of printers and software tools. Due to lack of detailed information in the medical literature on the methods for 3D printing, we have reviewed the medical and engineering literature on the various methods for 3D printing and compiled them into a practical "how to" format, thereby enabling the novice to start 3D printing with very limited funds. We describe (1) background knowledge, (2) imaging parameters, (3) software, (4) hardware, (5) post-processing, and (6) financial aspects required to cost-effectively reproduce a patient's disease ex vivo so that the patient, engineer and surgeon may hold the anatomy and associated pathology in their hands.

Adolescent, Adult, Aged, Cephalometry, Esthetics, Female, Humans, Male, Radiography, Panoramic, Young Adult, Computer-Aided Design, Facial Asymmetry diagnostic imaging, Facial Asymmetry surgery, Facial Bones diagnostic imaging, Facial Bones surgery, Fibrous Dysplasia, Polyostotic diagnostic imaging, Fibrous Dysplasia, Polyostotic surgery, Image Processing, Computer-Assisted methods, Imaging, Three-Dimensional methods, Models, Anatomic, Surgery, Computer-Assisted methods, and Tomography, X-Ray Computed methods

Facial asymmetry deformity is the most common symptom of patients with fibrous dysplasia. This study provides a novel method based on computed tomography scan data, mirror-imaged reverse engineering and rapid prototyping for design and manufacture of an individual template guiding accurately the extent and quantity of partial resection of hyperplastic tissues to reshape the affected bones during operation. Ten adult patients with unilateral facial fibrous dysplasia accepted these treatments, the postoperative appearances showed that the protrusions were effectively reduced; bilateral faces were basically symmetric with no serious complications. This method shorts operation time, decreases surgical risk, and guarantees the aesthetic symmetry. Apparent recurrence was not observed during the follow-up period, and the final outcomes were satisfactory for both surgeons and patients.

Computer-Aided Design, Cone-Beam Computed Tomography methods, Dental Pulp Cavity, Humans, Image Processing, Computer-Assisted instrumentation, Imaging, Three-Dimensional instrumentation, Models, Dental, Printing, Three-Dimensional, Software, Tooth Root, Endodontics methods, Image Processing, Computer-Assisted methods, Imaging, Three-Dimensional methods, Patient Care Planning, and Root Canal Therapy methods

Objectives: Obliteration of the root canal system due to accelerated dentinogenesis and dystrophic calcification can challenge the achievement of root canal treatment goals. This paper describes the application of 3D digital mapping technology for predictable navigation of obliterated canal systems during root canal treatment to avoid iatrogenic damage of the root.
Methods: Digital endodontic treatment planning for anterior teeth with severely obliterated root canal systems was accomplished with the aid of computer software, based on cone beam computer tomography (CBCT) scans and intra-oral scans of the dentition. On the basis of these scans, endodontic guides were created for the planned treatment through digital designing and rapid prototyping fabrication.
Results: The custom-made guides allowed for an uncomplicated and predictable canal location and management.
Conclusion: The method of digital designing and rapid prototyping of endodontic guides allows for reliable and predictable location of root canals of teeth with calcifically metamorphosed root canal systems.
Clinical Significance: The endodontic directional guide facilitates difficult endodontic treatments at little additional cost.
(Copyright © 2016. Published by Elsevier Ltd.)

Computer Simulation, Cranial Sutures anatomy histology, Cranial Sutures diagnostic imaging, Humans, Image Processing, Computer-Assisted methods, Radiographic Image Interpretation, Computer-Assisted, Imaging, Three-Dimensional methods, Models, Anatomic, Skull anatomy histology, and Skull diagnostic imaging

This paper presents the effects of building mesh models of the human skull and the cranial bones from a series of CT-scans. With the aid of computer so ware, 3D reconstructions of the whole skull and segmented cranial bones were performed and visualized by surface rendering techniques. The article briefly discusses clinical and educational applications of 3D cranial models created using stereolitographic reproduction.

Dental Prosthesis Design instrumentation, Humans, Imaging, Three-Dimensional instrumentation, Dental Implants, Dental Prosthesis Design methods, and Imaging, Three-Dimensional methods

Aim: This study proposes the replacement of all the physical devices used in the manufacturing of conventional prostheses through the use of digital tools, such as 3D scanners, CAD design software, 3D implants files, rapid prototyping machines or reverse engineering software, in order to develop laboratory work models from which to finish coatings for dental prostheses. Different types of dental prosthetic structures are used, which were adjusted by a non-rotatory threaded fixing system.
Method: From a digital process, the relative positions of dental implants, soft tissue and adjacent teeth of edentulous or partially edentulous patients has been captured, and a maser working model which accurately replicates data relating to the patients oral cavity has been through treatment of three-dimensional digital data.
Results: Compared with the conventional master cast, the results show a significant cost savings in attachments, as well as an increase in the quality of reproduction and accuracy of the master cast, with the consequent reduction in the number of patient consultation visits. The combination of software and hardware three-dimensional tools allows the optimization of the planning of dental implant-supported rehabilitations protocol, improving the predictability of clinical treatments and the production cost savings of master casts for restorations upon implants.

Anatomic Landmarks, Equipment Design, Humans, In Vitro Techniques, Maxilla abnormalities, Models, Dental, Printing, Three-Dimensional, Software, Computer-Aided Design, Dental Articulators, Imaging, Three-Dimensional, Maxilla surgery, Orthognathic Surgical Procedures instrumentation, and Tomography, X-Ray Computed

Objective: We examined the precision of a computer-aided design/computer-aided manufacturing-engineered, manufactured, facebow-based surgical guide template (facebow wafer) by comparing it with a bite splint-type orthognathic computer-aided design/computer-aided manufacturing-engineered surgical guide template (bite wafer).
Study Design: We used 24 rapid prototyping (RP) models of the craniofacial skeleton with maxillary deformities. Twelve RP models each were used for the facebow wafer group and the bite wafer group (experimental group). Experimental maxillary orthognathic surgery was performed on the RP models of both groups. Errors were evaluated through comparisons with surgical simulations. We measured the minimum distances from 3 planes of reference to determine the vertical, lateral, and anteroposterior errors at specific measurement points. The measured errors were compared between experimental groups using a t test.
Results: There were significant intergroup differences in the lateral error when we compared the absolute values of the 3-D linear distance, as well as vertical, lateral, and anteroposterior errors between experimental groups. The bite wafer method exhibited little lateral error overall and little error in the anterior tooth region. The facebow wafer method exhibited very little vertical error in the posterior molar region.
Conclusions: The clinical precision of the facebow wafer method did not significantly exceed that of the bite wafer method.
(Copyright © 2015 Elsevier Inc. All rights reserved.)

Humans, Osteoarthritis diagnostic imaging, Reproducibility of Results, Scapula surgery, Shoulder Joint surgery, Arthroplasty, Replacement methods, Bone Nails, Imaging, Three-Dimensional methods, Models, Biological, Osteoarthritis surgery, Shoulder Joint diagnostic imaging, and Tomography, X-Ray Computed methods

Background: A substantial challenge in total shoulder replacement is accurate positioning and alignment of the glenoid component. This challenge arises from limited intraoperative exposure and complex arthritic-driven deformity. We describe a novel pin array guide and method for patient-specific guiding of the glenoid central drill hole. We also experimentally tested the hypothesis that this method would reduce errors in version and inclination compared with 2 traditional methods.
Methods: Polymer models of glenoids were created from computed tomography scans from 9 arthritic patients. Each 3-dimensional (3D) printed scapula was shrouded to simulate the operative situation. Three different methods for central drill alignment were tested, all with the target orientation of 5° retroversion and 0° inclination: no assistance, assistance by preoperative 3D imaging, and assistance by the pin array guide. Version and inclination errors of the drill line were compared.
Results: Version errors using the pin array guide (3° ± 2°) were significantly lower than version errors associated with no assistance (9° ± 7°) and preoperative 3D imaging (8° ± 6°). Inclination errors were also significantly lower using the pin array guide compared with no assistance.
Discussion and Conclusion: The new pin array guide substantially reduced errors in orientation of the central drill line. The guide method is patient specific but does not require rapid prototyping and instead uses adjustments to an array of pins based on automated software calculations. This method may ultimately provide a cost-effective solution enabling surgeons to obtain accurate orientation of the glenoid.
(Copyright © 2015 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.)