Position Of Implants Research Articles

Improving life quality via mandibular reconstruction: Innovations and techniques – A literature review

Mandibular abnormalities can arise from a range of causes, including illnesses, trauma to the face, and surgical excision of tumors. These conditions can significantly affect daily activities such as eating, speaking, and even grooming. These functions are impaired without appropriate repair, which has a major negative impact on an individual's quality of life. Mandibular reconstruction aims to preserve facial symmetry and allow patients to regain their normal ability to chew food by restoring both the structure and functionality of the jaw. A successful restoration also takes into account elements such as the positioning of implants to restore oral function and, in certain cases, the reconnecting of the inferior alveolar nerve to enhance feeling.Mandibular reconstruction has undergone a revolutionary change in technique over the years. These developments are still ongoing, with the goal of improving patient recovery and outcomes. This article highlights the continuous attempts to improve surgical techniques and integrate new technologies for improved patient care. It gives a general review of the historical evolution, contemporary approaches, and prospective future possibilities in mandibular reconstruction.

Abstract 4113301: A Rare Cause of Recurrent Heart Failure Exacerbations After Transcatheter Aortic Valve Replacement: Ventricular Septal Defect and Significant Paravalvular Leak

Introduction: Ventricular septal defects (VSD) have been reported in <1% of cases following transcatheter aortic valve replacement (TAVR). A retrospective record review of VSD cases occurring after all TAVRs performed between January 2012 and September 2020 at one urban US tertiary hospital showed 0.37% incidence of these complications, mostly with small and restrictive VSD. Case Description: An 80-year-old woman with history of hypertension, HFpEF, and TAVR 8 months prior for severe aortic stenosis (AS) at an outside hospital presented with worsening dyspnea and peripheral edema over the past month. Blood pressure was 148/53mmHg, heartrate 83bpm, oxygen saturation 98% and auscultation revealed a harsh holosystolic murmur 4/6 loudest at left sternal border and bibasilar rales. Chest X-ray showed pulmonary edema and bilateral pleural effusions. NT-proBNP was 17,000pg/ml and troponin-I was negative. Echocardiogram showed EF55-60%, a membranous VSD, severe pulmonary hypertension, and moderate paravalvular leak (PVL). Coronary angiogram showed non-obstructive disease. Right heart catheterization confirmed significant left to right shunting. Treatment/Outcomes: Cardiothoracic surgery was consulted for multidisciplinary evaluation, and joint recommendation was for surgical aortic valve replacement and VSD closure which was successfully performed. One month follow-up echocardiogram showed normal aortic valve gradient without PVL and normal right ventricular pressure. Discussion/Conclusion: Numerous potential risks such as severe and uneven calcification of the native valve, an elliptic aortic annulus, excessive valve sizing, or elevated valve placement can lead to VSD. A recurrent element in many of these instances involves direct trauma to the septum caused by the implanted valve, exacerbated by subsequent annulus dilation. The presence of PVL is common post-TAVR and is an established independent prognostic factor, while VSD post-TAVR is uncommon, but may be associated with low implantation position relative to the aortic annulus or post-implantation balloon dilatation. Rarely, worsening VSD may require operative management. In this case, the improvement of heart failure symptoms and echocardiogram parameters after transthoracic surgery confirmed successful repair.

Effect of magnetic resonance imaging protocol on decision-making for positioning of dental implants in edentulous cases.

This study aimed to assess the influence of magnetic resonance imaging (MRI) protocol on the decision-making for the positioning of dental implants in edentulous arches in comparison to planning based on cone beam computed tomography (CBCT). One phantom was scanned with CBCT and two MRI protocols (T1- and T2-weighted). Two calibrated examiners performed digital implant planning (coDiagnostiX, Dental Wings), considering a digital prosthetic planning and alveolar ridge surface scan. Four implants were planned for each patient dataset, and the angular deviation between the long axis of the implants and the prosthetic planning occlusal plane was measured. Each examiner planned 40 implants, 12 implants with CBCT and 28 implants with MRI (16 with T1 and 12 with T2 images). Significant differences in angle deviation were observed between CBCT, T1, and T2 in the anterior region for both examiners (p=0.009 for examiner 1 and p=0.042 for examiner 2). Implants planned with CBCT showed significantly lower angular deviation than those based on the T1 and T2 scans for both examiners (p=0.028 and p=0.046 for examiner 1 and p=0.028 and p=0.027 for examiner 2). No significant difference in angular deviation was found between T1 and T2 for both examiners (examiner 1: p=0.600, examiner 2: p=0.916). Compared to CBCT planning, the MRI protocol influenced decision-making for anterior dental implants, with angular deviations within acceptable clinical thresholds, but further studies are needed to validate these findings.

Dynamic Navigation-Guided Robotic Placement of Zygomatic Implants.

To assess the feasibility and accuracy of a new prototype robotic implant system for the placement of zygomatic implants in edentulous maxillary models. The study was carried out on eight plastic models. Cone beam computed tomographs were captured for each model to plan the positions of zygomatic implants. The hand-eye calibration technique was used to register the dynamic navigation system to the robotic spaces. A total of 16 zygomatic implants were placed, equally distributed between the anterior and the posterior parts of the zygoma. The placement of the implants (ZYGAN®, Southern Implants) was carried out using an active six-jointed robotic arm (UR3e, Universal Robots) guided by the dynamic navigation coordinate transformation matrix. The accuracy of the implant placement was assessed using EvaluNav and GeoMagicDesignX® software based on pre- and post-operative CBCT superimposition. Descriptive statistics for the implant deviations and Pearson's correlation analysis of these deviations to force feedback recorded by the robotic arm were conducted. The 3D deviations at the entry and exit points were 1.80 ± 0.96 mm and 2.80 ± 0.95 mm, respectively. The angular deviation was 1.74 ± 0.92°. The overall registration time was 23.8 ± 7.0 minutes for each side of the model. Operative time excluding registration was 66.8 ± 8.8 minutes for each trajectory. The exit point and angular deviations of the implants were positively correlated with the drilling force perpendicular to the long axis of the handpiece and negatively correlated with the drilling force parallel to the long axis of the handpiece. The errors of the dynamic navigation-guided robotic placement of zygomatic implants were within the clinically acceptable limits. Further refinements are required to facilitate the clinical application of the tested integrated robotic-dynamic navigation system. Robotic placement of zygomatic implants has the potential to produce a highly predictable outcome irrespective of the operator's surgical experience or fatigue. The presented study paves the way for clinical applications.

Contemporary implantation protocols enable markedly lower pacemaker rate for selfexpandable TAVR

Abstract Background Even in a low-risk cohort, the Evolut low-risk trial has reported a still rather high pacemaker implantation rate over 20%. In the recent years, contemporary implantation protocols have been introduced aiming on a higher implantation position. Purpose Data on a reduction of pacemaker rate in contemporary implantation practice is still limited. Methods We retrospectively analyzed baseline-characteristics and pacemaker-implantation rates after TAVR in patients being treated with a Medtronic Evolut Prosthesis for aortic valve stenosis in our center in the years 2018 (conventional implantation in 3-cusp view) vs. 2023 (contemporary implantation in cusp overlap technique). Results 160 Patients were retrospectively included. We found out, that contemporary implantation lead to a marked reduction of pacemaker rate (8.7 vs. 20.9%, p=0.047; HR 0.36[IQR 0.14-0.96; p=0.041]). While most baseline-parameters including age (83.5 (79.2/87.3) vs. 82.8 (79.4/86.2), p=0.654), LVEF (55.0 (54.3/57.8) vs. 55.0 (51.0/59.0), p=0.992) and overall risk score (Euroscore II 3.5 (2.5/4.7) vs. 3.6 (2.3/5.7), p= 0.726) had no relevant impact on pacemaker rate, female patients were less prone to receive a pacemaker (8.6% vs. 21.3%, p=0.030). Of all conduction disturbances before procedure, a pre-existing RBBB was strongly associated with a relevantly higher pacemaker rate (50.0% vs. 11.3% (p<0.001), HR 7.88 (IQR 2.73/22.74; p<0.001)). Furthermore, more severe leaflet calcification (p=0.049), a deeper implantation depth (6.0 (5.0/6.5) vs. 5.0 (4.0/60.), p=0.042), larger annular dimensions (perimeter 79.7 (75.2/87.7) 76.8 (71.9/80.7), vs. p=0.047) and prostheses sizes (Evolut 34 vs. smaller sizes 28.1 vs. 12.5%, p=0.053), higher BNP (547 (314/1488) vs. 396 (208/856)), p=0.039 and body weight (78.0 (71.3/90.0) vs. 73.0 (63.5/84.5), p=0.030) were attributed to a higher pacemaker rate. Conclusions In our retrospective database we demonstrated that a contemporary implantation protocol enabling higher implantation position leads to a significant reduction in pacemaker rate, even in the high-risk collective of patients with pre-existing RBBB (58.3 vs. 15.2%, p=0.002 compared to 33.3 vs. 6.3%, p=0.081).

A Vision-Guided Robotic System for Safe Dental Implant Surgery.

Background: Recent advancements in dental implantology have significantly improved outcomes, with success rates of 90-95% over a 10-year period. Key improvements include enhanced preplanning processes, such as precise implant positioning, model selection, and optimal insertion depth. However, challenges remain, particularly in achieving correct spatial positioning and alignment of implants for optimal occlusion. These challenges are pronounced in patients with reduced bone substance or complex anthropometric features, where even minor misalignments can result in complications or defects. Methods: This paper introduces a vision-guided robotic system designed to improve spatial positioning accuracy during dental implant surgery. The system incorporates advanced force-feedback control to regulate the pressure applied to bone, minimizing the risk of bone damage. A preoperative CBCT scan, combined with real-time images from a robot-mounted camera, guides implant positioning. A personalized marker holder guide, developed from the initial CBCT scan, is used for patient-robot calibration. The robot-mounted camera provides continuous visual feedback of the oral cavity during surgery, enabling precise registration of the patient with the robotic system. Results: Initial experiments were conducted on a 3D-printed mandible using a personalized marker holder. Following successful patient-robot registration, the robotic system autonomously performed implant drilling. To evaluate the accuracy of the robotic-assisted procedure, further tests were conducted on 40 identical molds, followed by measurements of implant positioning. The results demonstrated improved positioning accuracy compared to the manual procedure. Conclusions: The vision-guided robotic system significantly enhances the spatial accuracy of dental implants compared to traditional manual methods. By integrating advanced force-feedback control and real-time visual guidance, the system addresses key challenges in implant positioning, particularly for patients with complex anatomical structures. These findings suggest that robotic-assisted implant surgery could offer a safer and more precise alternative to manual procedures, reducing the risk of implant misalignment and associated complications.

Mechanical properties and damage mechanism of SMAHC laminates

Abstract The combination of smart materials and composite materials to achieve lightweight and intelligent structures has been an important research direction in recent years. In this paper, a three-dimensional woven hybrid shape memory alloy (SMA actuator) is modularly implanted into a composite laminate to prepare a SMA hybrid composite (SMAHC) laminate. The orthogonal test was designed with the three variables of SMA actuator modular implantation position, SMA pre-strain and SMA number. According to the orthogonal test results and finite element results, the influence of the three variables on the stiffness before heating, the stiffness change rate after heating and the strength of SMAHC laminates was studied. According to the test index, the influence of the three variables on the results was further evaluated. The results show that the implantation position has the greatest influence on the mechanical properties of SMAHC laminates, followed by SMA pre-strain, and the number of SMA has the least influence. The location and form of damage of SMAHC laminates are further summarized, and the bending damage mechanism of SMAHC laminates is analyzed.

Effect of acid-etching 3D printed Ti templates on mechanical properties and corrosion resistance of Mg alloy scaffolds with different pore geometries

Segmental bone defect repair currently remains a major challenge in orthopedic clinics. In this study, to match different implantation positions, different pore geometries (P, G and Do) of Mg alloy scaffolds were designed and prepared by infiltration casting with the acid-etching treated Ti scaffold as the templates. The results showed that the acid-etching treatment for Ti templates resulted in a smoother surface of the Mg alloy scaffolds with improving the mechanical properties and corrosion resistance. Both experiments and simulations showed that the P scaffold had the highest mechanical properties, with yield strength and elastic modulus up to 26.7±2.1 MPa and 327.1±16.2 MPa, respectively. And the P scaffold had the best corrosion resistance after cleaning the Ti template, with a degradation rate of 0.34±0.17 mm/y at 228 h. In vitro cellular experiments showed good cytocompatibility on the surface of all three scaffolds.

A high-flexion design total knee prosthesis: a ten to twelve-year follow-up study

BackgroundThe purpose of this study was to investigate the clinical and radiographic outcomes and to determine the survivorship of a high-flexion design total knee arthroplasty (TKA) prosthesis, the LOSPA knee system, over a follow-up period of 10–12 years.MethodsThe study included 386 patients (503 TKAs) who were treated with TKA from 2011 to 2013 (follow-up period 10–12 years).The patients were assessed clinically using range of motion (ROM) of the knee, the Knee Society scoring system (KSS), and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). For radiographic analysis, the positions of femoral and tibial implants as α, β, γ, and δ angles, hip knee ankle (HKA) angle, and radiolucent lines were used. Kaplan–Meier survival analysis was performed.ResultsMean ROM improved significantly from the preoperative baseline of 117.3° to 126.5° at the final follow-up (p < 0.001). The mean KSS and WOMAC scores also both showed significant improvement after surgery (all p < 0.001). A non-progressive radiolucent line less than 2 mm was observed in 23 cases (4.7%). Nine patients underwent revision surgery on the knee during the follow-up period. Revision surgery was performed on four patients due to aseptic loosening, three patients due to infection, one patient due to ankylosis, and one patient due to instability. When the endpoint of survival was the entire surgical cases, the survival rate was 96.2%. The survival rate, with revision for any reason as the endpoint, was 97.2%, and 97.8% for aseptic causes.ConclusionsThe LOSPA knee system, a high-flexion design total knee prosthesis, showed excellent long-term survivorship and improvements in clinical outcomes at 10- to 12-year follow-up.

Wearable bio-adhesive metal detector array (BioMDA) for spinal implants

Dynamic tracking of spinal instrumentation could facilitate real-time evaluation of hardware integrity and in so doing alert patients/clinicians of potential failure(s). Critically, no method yet exists to continually monitor the integrity of spinal hardware and by proxy the process of spinal arthrodesis; as such hardware failures are often not appreciated until clinical symptoms manifest. Accordingly, herein, we report on the development and engineering of a bio-adhesive metal detector array (BioMDA), a potential wearable solution for real-time, non-invasive positional analyses of osseous implants within the spine. The electromagnetic coupling mechanism and intimate interfacial adhesion enable the precise sensing of the metallic implants position without the use of radiation. The customized decoupling models developed facilitate the precise determination of the horizontal and vertical positions of the implants with incredible levels of accuracy (e.g., <0.5 mm). These data support the potential use of BioMDA in real-time/dynamic postoperative monitoring of spinal implants.

Mode Conversion Trimming in Asymmetric Directional Couplers Enabled by Silicon Ion Implantation.

An on-chip asymmetric directional coupler (DC) can convert fundamental modes to higher-order modes and is one of the core components of mode-division multiplexing (MDM) technology. In this study, we propose that waveguides of the asymmetric DC can be trimmed by silicon ion implantation to tune the effective refractive index and facilitate mode conversion into higher-order modes. Through this method of tuning, transmission changes of up to 18 dB have been realized with one ion implantation step. In addition, adjusting the position of the ion implantation on the waveguide can provide a further degree of control over the transmission into the resulting mode. The results of this work present a promising new route for the development of high-efficiency, low-loss mode converters for integrated photonic platforms, and aim to facilitate the application of MDM technology in emerging photonic neuromorphic computing.

Implant position accuracy using dynamic computer-assisted implant surgery (CAIS) combined with augmented reality: A randomized controlled clinical trial

Background/purposeComputer-assisted implant surgery (CAIS) is increasingly performed to reduce deviations in implant position. Dynamic CAIS or navigation systems provide instant display of implant drilling instruments and patient positions directly on the computer monitor. Augmented reality (AR) technology allows operators to visualize real-time information projected onto the lenses of AR glasses. Although AR is being used in medical applications, there are few clinical studies on applying AR glasses to dental implants. The purpose of this randomized clinical study was to compare the accuracy of implant position using the dynamic CAIS with and without AR glasses. Materials and methodsTwenty patients who needed a single dental implant were randomly divided into two groups: combined dynamic CAIS with AR glasses (AR glasses group, n = 10) and dynamic CAIS without AR glasses (non-AR glasses group, n = 10). Three-dimensional (3D) deviations of implant platform, apex and angular deviations were measured and analyzed using independent t-tests (P < 0.05). ResultsThe 3D angular deviations in the AR glasses and non-AR glasses groups were 1.47 ± 1.01° and 2.42 ± 0.76°, respectively. Mean 3D entry point and apical deviations were 0.75 ± 0.45 mm and 0.87 ± 0.45 mm in the AR glasses group, whereas the non-AR glasses group were 1.11 ± 0.44 mm and 1.18 ± 0.50 mm, respectively. There was no statistically significant difference between the two groups. ConclusionImplant position accuracy using dynamic CAIS with AR glasses was similar to dynamic CAIS without AR glasses during a single implant placement.

Does Preoperative Virtual Reality Experience Enhance Implant Positioning Accuracy in Total Hip Arthroplasty?

Purpose Total hip arthroplasty (THA) requires precise implant positioning to ensure long-term success. Herein, we evaluated the effect of virtual reality (VR) on the surgical precision of THA, particularly when used by experienced surgeons. Methods In this single-center, prospective, case-control study, 34 patients who underwent primary THA performed by a single experienced surgeon were divided into the control (without VR simulation) and VR (with VR simulation) groups. Preoperative planning involved the creation of three-dimensional models from computed tomography scans using ZedHip® software (Lexi, Tokyo, Japan). The primary outcomes assessed included the accuracy of implant placement, operative time, and intraoperative blood loss. The secondary outcomes included postoperative hospital stay and in-hospital complications. Results A significant improvement in radiographic inclination (RI) was observed in the VR group as compared to controls. Other surgical parameters, such as radiographic anteversion, operation time, blood loss, and postoperative hospital stay, showed no significant differences between the groups. Discrepancies in planned versus actual implant sizes were notedbut were not significantly different between groups. Conclusion VR application in preoperative planning improved the RI accuracy in acetabular cup placement for THA, demonstrating its potential to enhance surgical precision for experienced surgeons. This study highlights the evolving role of VR, from a training tool to an integral part of advanced surgical planning in orthopedics.

Comparing Between Different Impressions Materials and Techniques for the Accuracy of Implant Position Transfer

Comparing Between Different Impressions Materials and Techniques for the Accuracy of Implant Position Transfer

Comparing Between Different Impressions Materials and Techniques for the Accuracy of Implant Position Transfer

Comparing Between Different Impressions Materials and Techniques for the Accuracy of Implant Position Transfer

Stereo-Photogrammetry for Impression of Full-Arch Fixed Dental Prosthesis—An Update of the Reviews

Photogrammetry (PG) appeared as an alternative for multiple implant impressions. Stereo-photogrammetry is a more sophisticated alternative to PG, which estimates the 3D coordinates of the points of an object, making the process quicker and more precise. A search in PubMed MEDLINE, PMC, and Google Scholar was conducted to find systematic reviews published in the last 10 years. The PICdental® camera (IDITEC NORTH WEST, SL; Torrelodones, Spain) is a stereocamera that records implant positions in the mouth by means of photogrammetry with the objective of registering and obtaining a viable, reliable, and direct digital impression of the positions of the multiple implants. The use of photogrammetry via PiCdental® camera as an alternative to digital impression for multiple implants is an easy and trustworthy technique that permits an adequate fit without prosthetic complications.

A manual synchronous low energy shock impedance as a predictor of successful defibrillation testing during subcutaneous ICD implantation.

Guidelines recommend defibrillation testing (DFT) during subcutaneous implantable cardioverter-defibrillator (S-ICD) implantation. Implant position, patient characteristics and device factors, such as shock impedance, influence defibrillation success. To evaluate the shock impedance, a manual synchronous 10J shock (low energy synchronous shock [LESS]) can be delivered, without the need to induce ventricular fibrillation (VF). To compare LESS and DFT impedance values and to evaluate the diagnostic accuracy of LESS impedance for predicting a successful DFT during S-ICD implantation. Consecutive S-ICD implantations were included. Shock impedances were compared by paired t-tests. Univariate analysis was performed to investigate factors associated with successful DFT. A prediction model of successful DFT based on LESS impedance was assessed by logistic regression. Receiver operating characteristic (ROC) curve, area under the ROC curve and the Hosmer-Lemeshow tests were used to evaluate the accuracy of LESS impedance. Sixty patients were included (52±14years; 69% male). LESS and DFT impedance values were highly correlated (r2=0.97, p<.01). Patients with a failed first shock had higher body mass index (BMI) (30±3vs. 25.7±4.3, p=.014), higher mean LESS (120±35Ω vs. 86.±23Ω, p=.0013) and DFT impedance (122±33Ω vs. 87±24Ω, p=.0013). ROC analysis showed that LESS impedance had a good diagnostic performance in predicting a successful conversion test (AUC 84% [95% CI: 0.72-0.92]) with a cutoff value of <94Ω to identify a successful DFT (sensitivity 71%, specificity 73%). LESS impedance values without the need to induce VF can intraoperatively predict a successful DFT.

Accuracy of Orthodontic Anchor Screw Placement Using a 3D-Printed Surgical Guide.

Background Although radiographs and computed tomography (CT) images are reviewed before temporary anchorage device (TAD) implantation, implantation of TADs exactly as planned is difficult. This study aimed to evaluate the accuracy of TAD implantation using an original surgical guide fabricated using cone-beam CT data and computer-aided design software. Methodology The studyparticipants included six experienced orthodontists who had implanted ≥20 TADs, and six inexperienced orthodontists who had never implanted a TAD. Maxillary dental typodont models with radiopaque tooth crowns and roots were used. A total of four TADs were implanted on the buccal sides: between the second bicuspid and first molars and between the first and second molars bilaterally. The accuracy of TAD implantation was examined in two groups: in 12 dental typodont models, TAD implantation was performed using a surgical guide (guide group), and in 12 dental typodont models, TAD implantation was performed without a surgical guide (freehand group). All dental typodont models implanted a total of 96 TADs.The TAD position was evaluated using the CT coordinate system and 3D image measurement software. Using the long axis of the TAD as a reference, the distance between the coronal and apical ends of the implanted TAD and those of the planned TAD, i.e., the ideal implantation position, was measured in both groups along the x, y, and z axes. The medians of the values were compared between the groups. Additionally, the presence of root contact was compared between the experienced and inexperienced orthodontists. Results On the x-axis, the linear deviations (median) of the coronal and apical ends of the TAD in the freehand group were 1.06 mm and 1.36 mm, respectively. In contrast, in the guide group, the deviations were 0.65 mm and 0.90 mm, respectively, and the difference was statistically significant (p = 0.002 and p = 0.005, respectively). On the y-axis, the deviations in the freehand group were 1.13 mm and 1.08 mm, respectively. In contrast, the deviations in the guide group were 0.71 mm and 0.79 mm, respectively, and only the coronal deviations were significantly different between the groups (p = 0.006). On the z-axis, the deviations in the freehand group were 1.44 mm and 1.86 mm, respectively. In contrast, the deviations in the guide group were 0.75 mm and 1.16 mm, respectively, and the difference was statistically significant (p = 0.006 and p = 0.002, respectively). Conclusions The use of a surgical guide allowed for more accurate TAD implantation. Additionally, TAD implantation using a guide prevented root damage.

Assessment Accuracy of 2D vs. 3D Imaging for Custom-Made Acetabular Implants in Revision Hip Arthroplasty.

Revision total hip arthroplasty (rTHA) presents significant challenges, particularly in patients with severe acetabular bone defects. Traditional treatment options often fall short, leading to the emergence of custom-made 3D-printed acetabular implants. Accurate assessment of implant positioning is crucial for ensuring optimal postoperative outcomes and for providing feedback to the surgical team. This single-center, retrospective cohort study evaluates the accuracy of standard 2D radiographs versus 3D CT scans in assessing the positioning of these implants, aiming to determine if 2D imaging could serve as a viable alternative for the postoperative evaluation. We analyzed the implant positions of seven rTHA patients with severe acetabular defects (Paprosky ≥ Type IIIA) using an alignment technique that integrates postoperative 2D radiographs with preoperative CT plans. Two independent investigators, one inexperienced and one experienced, measured the positioning accuracy with both imaging modalities. Measurements included translational shifts from the preoperatively templated implant position in the craniocaudal (CC), lateromedial (LM), and ventrodorsal (VD) directions, as well as rotational differences in anteversion (AV) and inclination (INCL). The study demonstrated that 2D radiographs, when aligned with preoperative CT data, could accurately assess implant positions with precision nearly comparable to that of 3D CT scans. Observed deviations were 1.4 mm and 2.7 mm in CC and LM directions, respectively, and 3.6° in AV and 0.7° in INCL using 2D imaging, all within clinically acceptable ranges. For 3D CT assessments, mean interobserver variability was up to 0.9 mm for translational shifts and 1.4° for rotation, while for 2D alignment, observer differences were 1.4 mm and 3.2° for translation and rotation, respectively. Comparative analysis of mean results from both investigators, across all dimensions (CC, LM, AV, and INCL) for 2D and 3D matching, showed no significant differences. In conclusion, conventional anteroposterior 2D radiographs of the pelvis can sufficiently determine the positioning of custom-made acetabular implants in rTHA. This suggests that 2D radiography is a viable alternative to 3D CT scans, potentially enhancing the implementation and quality control of advanced implant technologies.

Intraindividual Comparison of Image Artifacts of Two Generations of Rotatable Cochlear Implant Magnets.

In cochlear implant recipients, the diagnostic value of magnetic resonance imaging (MRI) scans is reduced by image artifacts. The static magnetic field of a 3.0T scanner is associated with the risk of implant demagnetization. The development of rotatable implant magnets aimed to support the advancement of 3.0T MRI scanners and eliminate the risk of demagnetization of cochlear implant magnets. This study aimed to compare the image artifacts caused by first-t and second-generation rotatable cochlear implant magnets in 3.0T MRI. Three Tesla MRI T2W TSE sequences were performed on 3 subjects with first- and second-generation rotatable cochlear implant magnets. The cochlear implant was fixed to the head at the implantation position by a swim cap. The size of the image artifact was determined in the transverse plane. Intraindividual comparative analyses showed that within the margin of combined uncertainty of 5 mm at a resolution of 2 mm, the cochlear implant-induced image artifacts in all subjects showed for both (first- and second-generation rotatable cochlear implant magnets), the same maximum image artifact dimension of 125 mm. We could show that no difference in image artifact size was detected within the margin of error determined by resolution, localized induced shift of the scan, and reproducibility of the tilt angle of the head relative to the chest in a living subject. Assumed improved magnet attachment can be reached without compromising of the magnet artifact size.