Search

Virtual surgical planning of an open cranial vault reconstruction enables a faster, safer and better surgical procedure for craniosynostosis patients. However, transfer a virtual surgical plan to the patient remains challenging. Although 3D-printed surgical guides can be used, their production is rather time-consuming and expensive. Since augmented reality (AR), allows the user to directly visualize a virtual planning onto the patient, it can be used as an alternative.By using AR-glasses (HoloLens), a new AR-based workflow was developed and compared with surgical guides to transfer the surgical plans on 3D-prints of 10 patients suffering from different types of craniosynostosis.An accuracy of 2.1 mm and a mean transfer time of 8.24 min were reported with the AR workflow as compared to an accuracy of 0.9 mm and a mean transfer time of 50 s for surgical guides.Surgical guides were the most fitting method to transfer virtual surgical plans. The relatively large outliers in the AR workflow meant that the mean accuracy was just outside the clinically acceptable margin. However, the low cost and simplicity make the AR workflow a promising alternative.

The rapid prototyping technology helped to convert the virtual surgical plans into action by the help of fusion deposition techniques. Starch based polymers like PLA (Poly lactic acid) are commonly used in the field of tissue engineering for making scaffolds. In dentistry its use is limited because of lack of precision. We tried to make a 3D printed locator guide for surgical removal of impacted maxillary premolar by using a starch based polymer.

Pedicle screws are used in spinal fusion for the stabilisation of the spine through a posterior approach. In spinal deformities, such as scoliosis, pedicle screw placement is especially challenging due to vertebral rotation and landmark distortion. Conventional surgical procedures such as Free-hand screw insertion mainly rely on surgeon experience and anatomical landmarks. Image- and robot-guided pedicle screw insertion can improve placement accuracy but require exposure to ionising radiation. Studies of 3D-printed patient-specific surgical guides (PSSG) have shown similar accuracy rates and reduced intra-operative radiation. Nevertheless, the guide design and workflow of these devices present significant challenges.This manuscript presents a narrative review of the literature regarding the analysis of designs, manufacturing, and technical considerations for patient-specific screw guides (PSSG). We focus on the analysis of imaging criteria, design variables (including spinal levels, anatomical landmarks and guiding tools), manufacturing technology, 3D-printing technology and validation studies (ex vivo and in vivo). We also discuss the clinical and economic benefits of PSSGs and provide further dialogue on the limitations and requirements for better adoption of this technology in future.Compared to Free-hand pedicle screw placement, we find that PSSGs show consistently superior placement accuracies and when compared to image and robot-guided technologies, their use requires less radiation exposure, shorter operative times and economic benefits. The guides are of additional use in cases of complex spinal deformities, especially if guided technologies are not available.

Different printing technologies can be used for prosthetically oriented implant placement, however the influence of different printing orientations and steam sterilization remains unclear. In particular, no data is available for the novel technology Continuous Liquid Interface Production. The objective was to evaluate the dimensional accuracy of surgical guides manufactured with different printing techniques in vertical and horizontal printing orientation before and after steam sterilization. A total of 80 surgical guides were manufactured by means of continuous liquid interface production (CLIP; material: Keyguide, Keyprint), digital light processing (DLP; material: Luxaprint Ortho, DMG), stereolithography (SLA; Surgical guide, Formlabs), and fused filament fabrication (FFF; material: Clear Base Support, Arfona) in vertical and horizontal printing orientation (n = 10 per subgroup). Spheres were included in the design to determine the coordinates of 17 reference points. Each specimen was digitized with a laboratory scanner after additive manufacturing (AM) and after steam sterilization (134 °C). To determine the accuracy, root mean square values (RMS) were calculated and coordinates of the reference points were recorded. Based on the measured coordinates, deviations of the reference points and relevant distances were calculated. Paired t-tests and one-way ANOVA were applied for statistical analysis (significance p < 0.05). After AM, all printing technologies showed comparable high accuracy, with an increased deviation in z-axis when printed horizontally. After sterilization, FFF printed surgical guides showed distinct warpage. The other subgroups showed no significant differences regarding the RMS of the corpus after steam sterilization (p > 0.05). Regarding reference points and distances, CLIP showed larger deviations compared to SLA in both printing orientations after steam sterilization, while DLP manufactured guides were the most dimensionally stable. In conclusion, the different printing technologies and orientations had little effect on the manufacturing accuracy of the surgical guides before sterilization. However, after sterilization, FFF surgical guides exhibited significant deformation making their clinical use impossible. CLIP showed larger deformations due to steam sterilization than the other photopolymerizing techniques, however, discrepancies may be considered within the range of clinical acceptance. The influence on the implant position remains to be evaluated., 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 © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Objectives: The aim of this human cadaver study was to compare the accuracy of guided versus free-hand zygomatic implant placement. For the guided implant placement laser sintered titanium templates were used., Methods: Forty zygomatic implants were placed in ten cadavers heads. For each case two implants were inserted using the guided protocol (Ezgoma guide, Noris Medical, Israel) and the related surgical kit and the other two by using a free hand approach. Post-operative computed tomography (CT) scans were carried out to assess the deviations between planned and inserted implants. The accuracy was measured by overlaying the post-operative CT scan (with the final position of the achieved implants) with the pre-operative CT scan (with the planned implants)., Results: The difference of the mean between planned and placed zygomatic implants by using surgical guides or free hand were statistically significant for all the variables evaluated: angular deviation (1.19°±0.40° and 4.92°±1.71°, p<0.001), linear distance deviation at coronal point (0.88 mm±0.33 mm and 2.04 mm±0.56 mm, p<0.001), at apical point (0.79 mm±0.23 mm and 3.23 mm±1.43 mm, p<0.001) and at apical depth (0.35 mm±0.25 mm and 1.02 mm±0.61 mm, p<0.001)., Conclusions: The proposed guided surgery system exhibited a higher accuracy for all the investigated variables, when compared to the free hand technique., (Copyright © 2021 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Background: In patients with gingival exposure on smiling due to altered passive eruption, esthetic crown lengthening is often indicated. Meticulous planning and surgical precision are key for successful outcomes. Surgical guides are helpful tools that are seldomly reported on in the literature related to esthetic crown lengthening procedures., Types of Studies Reviewed: The authors searched the literature for articles that described the planning, tools, and execution related to esthetic crown lengthening procedures., Results: Several techniques have been reported to guide the esthetic crown lengthening procedure, ranging from direct bone level measurement to 3-dimensional printed surgical guides., Practical Implications: This review serves the clinician as an aid in the decision-making process for esthetic crown lengthening procedures and available surgical guide options, including computer-based guides., (Copyright © 2022 American Dental Association. Published by Elsevier Inc. All rights reserved.)

Additive manufacturing (AM) offers great design freedom that enables objects with desired unique and complex geometry and topology to be readily and cost-effectively fabricated. The overall benefits of AM are well known, such as increased material and resource efficiency, enhanced design and production flexibility, the ability to create porous structures and on-demand manufacturing. When AM is applied to medical devices, these benefits are naturally assumed. However, hard clinical evidence collected from clinical trials and studies seems to be lacking and, as a result, systematic assessment is yet difficult. In the present work, we have reviewed 23 studies on the clinical use of AM patient-specific surgical guides (PSGs) for the mandible surgeries (n = 17) and temporomandibular joint (TMJ) patient-specific implants (PSIs) (n = 6) with respect to expected clinical outcomes. It is concluded that the data published on these AM medical devices are often lacking in comprehensive evaluation of clinical outcomes. A complete set of clinical data, including those on time management, costs, clinical outcomes, range of motion, accuracy of the placement with respect to the pre-operative planning, and extra complications, as well as manufacturing data are needed to demonstrate the real benefits gained from applying AM to these medical devices and to satisfy regulatory requirements., (Copyright © 2021 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Introduction: Great precision is required for craniofacial surgery, and computer-aided design (CAD) methods may be used to plan surgery before it is performed. In this study, three-dimensional (3D)-printed cutting guides are used to match computer models with surgical procedures. We describe a novel method of computer-aided surgery for autologous cranioplasty that includes a new strategy for generating and using cutting guides. These guides may be used not only for osteotomies, but also for many other steps in the surgical procedure., Materials and Methods: Preoperatively, anatomical data were imported into a CAD package and used for virtual surgical planning (VSP). Cutting guides were designed after considering how to integrate all the surgical steps. Models of the microplates and micro-screws were also made. Surgical guides were exported and printed, and preoperative simulations using a replica of the patient's skull established the sequence of steps. The accuracy of the procedure was evaluated postoperatively using computed tomography (CT) scans., Results: In every patient examined, the all-in-one surgical-guide system was able to automate the many steps in the procedure and dramatically decreased the duration of surgery. The experimental guide enhanced every phase of surgery, including excising the lesion, and harvesting, positioning, and fixing the graft. In each step, precision was enhanced and the outcome corresponded with the VSP., Conclusions: The few previous reports on cutting guides used in cranioplasty generally describe the use of separate guides for dismantling and reconstruction. The ability to perform more surgical sequences using a single tool can improve surgical accuracy. Clearly there is no single perfect surgical guide; however, effective surgical-design strategies should be used to build the best approach to each procedure., (Copyright © 2018 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)