Prosthesis

The objective of the present retrospective multi-center study was to analyze the outcomes of bone-level (BL) implants and tissue-level (TL) implants in immediate-loading full-arch rehabilitations. Patients who were previously rehabilitated with full-arch immediate-loading rehabilitations with either BL or TL implants were considered. Data regarding implant survival rate, marginal bone loss (MBL), peri-implant probing depth (PPD), plaque index (PI), and bleeding on probing (BOP) were recorded, and the 1-year follow-up data were statistically analyzed between the two groups. In total, 38 patients were evaluated for a total implant number of 156 (n = 80 TL implants and n = 76 BL implants). An implant survival rate of 97.37% was recoded for the BL group while an implant survival rate of 100% was noted for the TL group. A total MBL of 1.324 ± 0.64 mm was recorded for BL implants, while a total MBL of 1.194 ± 0.30 mm was recorded for TL implants. A statistically significant difference was highlighted regarding MBL at the mesial aspect (p = 0.01552) of the implants, with BL implants presenting with higher MBL. Within the range of acceptable healthy values, a statistically significant difference was also highlighted regarding BOP (p < 0.00001), with TL implants presenting higher values. No statistically significant difference (p > 0.05) was recorded for any of the other variables analyzed. Within the limitations of the present retrospective study, both TL and BL implants seem to provide good clinical outcomes after a 12-month observational period when employed in immediate-loading full-arch rehabilitation. Full article

The evolution of anthropomorphic robotic hands (ARH) in recent years has been sizable, employing control techniques based on machine learning classifiers for myoelectric signal processing. This work introduces an innovative multi-channel bio-signal transformer (MuCBiT) for surface electromyography (EMG) signal recognition and classification. The proposed MuCBiT is an artificial neural network based on fully connected layers and transformer architecture. The MuCBiT recognizes and classifies EMG signals sensed from electrodes patched over the arm’s surface. The MuCBiT classifier was trained and validated using a collected dataset of four hand gestures across ten users. Despite the smaller size of the dataset, the MuCBiT achieved a prediction accuracy of 86.25%, outperforming traditional machine learning models and other transformer-based classifiers for EMG signal classification. This integrative transformer-based gesture recognition promises notable advancements for ARH development, underscoring prospective improvements in prosthetics and human–robot interaction. Full article

The number of performed total knee arthroplasty (TKA) operations is constantly growing. This study proposes an evaluation of a series of patients undergoing medial pivot (MP) TKA surgery from a subjective, clinical and biomechanical point of view. A consecutive series of 100 TKAs implanted in a single centre, by the same surgeon, with a medial parapatellar approach with the sacrifice of the posterior cruciate ligament and cemented components were evaluated. All patients underwent standardized radiographic and functional clinical evaluation, with standing antero-posterior, lateral and patellar axial views; pre-operatively and post-operatively at 1, 3, 6 and 12 months; and then annually. Results were evaluated using three different patient-related outcome measurement scores (PROMs): the Knee Osteoarthritis Outcome Score (KOOS), the new Knee Society Score (nKSS) and the Short Form Health Survey 36 (SF-36). Excellent results in all treated knees were documented using the PROMs: the mean nKSS was 199.8, the mean KOOS was good to excellent in every subscale, and the mean was SF-36 82%. There were no cases of septic or aseptic loosening, vascular damage, neurological damage, or revision surgery for any reason. According to the experience gained, MP implants demonstrated excellent results, being clinically functional in both objective and subjective terms as well as radiographic evaluations, thus resulting in a winning strategy for obtaining a TKA that makes the patient satisfied and able to perform their daily life activities. Full article

Total knee arthroplasty (TKA) is a successful and highly effective procedure in most patients with tricompartmental knee arthritis. Despite the innovations in surgical techniques due to planning software and technological innovations, patients’ dissatisfaction after TKA is still high, at up to 20%. Robotic-assisted surgery (RAS) could be considered as a future option for improving outcomes due to its higher accuracy, precision, and reliability. Robotic systems can be classified as fully active, semi-active, or passive depending on the surgeon’s involvement during the procedure, and as imageless or image-based according to the necessity of radiological exams for the pre-operative planning. Three of the most well-known robotic systems for knee surgery are MAKO^® (Stryker Ltd., Kalamazoo, MI, USA), NAVIO^® (Smith & Nephew, Andover, TX, USA), and ROSA^® (Zimmer Inc., Warsaw, IN, USA). These systems show differences in terms of surgeon involvement, the use of CT scans or X-rays for pre-operative planning, the possibility to perform both unicompartmental knee arthroplasty (UKA) and TKA (or even total hip arthroplasty THA), and in the different kinds of knee prosthesis that can be implanted. This article aims to describe the features of the most used robotic systems for knee arthroplasty, to examine their outcomes and analyze their cost-effectiveness, and to evaluate future perspectives. Full article

Despite recent advancements in prosthetic technology, lower-limb amputees often remain limited to passive prostheses, which leads to an asymmetric gait and increased energy expenditure. Developing active prostheses with effective control systems is important to improve mobility for these individuals. This study presents a machine-learning-based approach to classify five distinct locomotion tasks: ground-level walking (GWL), ramp ascent (RPA), ramp descent (RPD), stairs ascent (SSA), and stairs descent (SSD). The dataset comprises fused electromyographic (EMG) and inertial measurement unit (IMU) signals from twenty non-amputated and five transtibial amputated participants. EMG sensors were strategically positioned on the thigh muscles, while IMU sensors were placed on various leg segments. The performance of two classification algorithms, support vector machine (SVM) and long short-term memory (LSTM), were evaluated on segmented data. The results indicate that SVM models outperform LSTM models in accuracy, precision, and F1 score in the individual evaluation of amputee and non-amputee datasets for 80–20 and 50–50 data distributions. In the 80–20 distribution, an accuracy of 95.46% and 95.35% was obtained with SVM for non-amputees and amputees, respectively. An accuracy of 93.33% and 93.30% was obtained for non-amputees and amputees by using LSTM, respectively. LSTM models show more robustness and inter-population generalizability than SVM models when applying domain-adaptation techniques. Furthermore, the average classification latency for SVM and LSTM models was 19.84 ms and 37.07 ms, respectively, within acceptable limits for real-time applications. This study contributes to the field by comprehensively comparing SVM and LSTM classifiers for locomotion tasks, laying the foundation for the future development of real-time control systems for active transtibial prostheses. Full article

Nowadays there are various prosthetic arm designs in the literature, the market, and CAD design websites, with different shapes, sizes, and degrees of freedom. Only limited options are available for controlling such prostheses. Prosthetic arm users reported muscle fatigue and unreliability when using the market-dominated myoelectric sensors. This work presents the “Infinity Foot Controller” as a new approach to control a five-finger below-the-elbow prosthetic arm with wrist rotation and bending capabilities. This foot control system receives user input from a custom insole and a sensor-controller unit placed alongside the user’s shoe to perform various hand grips, gestures, and/or rotations. To demonstrate the new foot controller, a design of a 3D-printed below-the-elbow prosthetic arm, called the “Infinity Arm”, is presented. This arm is suitable for gripping relatively lightweight objects and making hand gestures. It includes a wrist actuation system that permits 120° wrist rotation and 70° wrist extension and flexion. It also includes a haptic feedback system that utilizes fingertip force sensors to relay a vibratory response in an armband placed on the user’s arm, giving the user a sense of touch. A proof-of-concept model was built to demonstrate the system and a testing procedure was proposed. Full article

The human hand is a complex and versatile organ that enables humans to interact with the environment, communicate, create, and use tools. The control of the hand by the brain is a crucial aspect of human cognition and behaviour, but also a challenging problem for both neuroscience and engineering. The aim of this study is to review the current state of the art in hand and grasp control from a neuroscientific perspective, focusing on the brain mechanisms that underlie sensory integration for hand control and the engineering implications for developing artificial hands that can mimic and interface with the human brain. The brain controls the hand by processing and integrating sensory information from vision, proprioception, and touch, using different neural pathways. The user’s intention can be obtained to control the artificial hand by using different interfaces, such as electromyography, electroneurography, and electroencephalography. This and other sensory information can be exploited by different learning mechanisms that can help the user adapt to changes in sensory inputs or outputs, such as reinforcement learning, motor adaptation, and internal models. This work summarizes the main findings and challenges of each aspect of hand and grasp control research and highlights the gaps and limitations of the current approaches. In the last part, some open questions and future directions for hand and grasp control research are suggested by emphasizing the need for a neuroscientific approach that can bridge the gap between the brain and the hand. Full article

Worldwide, the number of revisions to total knee arthroplasty procedures is increasing. Revision surgery is a challenging procedure, required for the management of bone loss after removal of the first implant. Although further long-term follow-up studies are needed, the use of cones in revisions of total knee arthroplasty yields reliability in fixation and stability to restore joint lines, especially in challenging surgeries with poor bone stock. The introduction of 3D-printed cones in revision surgery seems to be advantageous for AORI type III bone defects, especially in reducing intraoperative complications and procedure times. The aim of this study is to review the currently available literature to analyse clinical outcomes, complications, and radiographical results with the use of metaphyseal tantalum cones and new 3D-printed cones for the management of bone defects in the revision of total knee arthroplasty. Full article

This case report focuses on applying a protocol for dental implant restoration in aesthetic zones, specifically the anterior sectors. The protocol aims to achieve optimal results with minimal complexity, reducing the number of sessions and impressions required for transferring clinical information to the laboratory. The historical development of dental implantology and the evolution of dental implant restoration workflows are discussed, highlighting the significance of osseointegration and advancements in materials, surgical techniques, and prosthetic components. The case report describes rehabilitating congenitally missing lateral incisors using fibre-reinforced composite Maryland bridges for provisional restoration and Osstem TSIII (Osstem^®, Seoul, South Korea) implants, zirconia abutments, and disilicate lithium crowns for definitive repair. The discussion covers essential aspects of aesthetic dental implant restoration, including materials, types of dental implants, surgical techniques for soft tissue enhancement, and prosthetic and impression techniques. The study emphasises the importance of selecting appropriate materials, employing advanced surgical procedures, and utilising accurate prosthetic and impression techniques to enhance the aesthetic outcomes of dental implant restorations. A multidisciplinary approach and patient-centred care are essential for successful aesthetic dental implant restorations. The methodology presented in this manuscript demonstrates its effectiveness in achieving optimal outcomes while minimising stress on soft tissues and improving patient comfort and satisfaction. This case report contributes to dental implant restoration, providing evidence-based techniques for achieving aesthetic and functional success. Full article

(1) Background: This systematic review intends to answer the following Patient–Intervention–Comparison–Outcome (PICO) question: Do digital impression systems generate significant errors during scanning in extensive implant restorative treatments? (2) Methods: Following the PRISMA protocol and according to predefined inclusion criteria, two trained investigators searched for relevant articles in the PubMed database and related sources using a standard keyword sequence. The investigators were responsible for selecting studies and performing quality analysis. (3) Results: From 78 titles, only 9 studies were selected. An analysis of registration distortion variations was conducted for each potential influencing factor in terms of accuracy: interimplant distance, implant angulation, scanner type, and scanning body type. The results showed repeatable differences in accuracy between types of scanning technologies and techniques, and a positive correlation between interimplant distance and the amplitude of deviations detected in comparative analysis, with the highest error levels in total edentulous arch recording. There was no consensus on the error level owing to implant angulation, and statistically significant differences were found between the types of scan bodies used. (4) Conclusions: Digital impression systems generate significant errors during scanning in extensive implant restorative treatments, influenced by scanning technology, interimplant distance, and scanning body type. Full article

(1) Background: Cleft lip and palate is the most common congenital malformation of the head and neck. After surgical closure, velopharyngeal dysfunction can arise, which has implications for phonation, sucking, swallowing, middle ear function, and interpersonal well-being. This case series aimed to present an adaptation of the conventional pharyngeal obturator design in order to allow its use with fixed orthodontic appliances. (2) Methods: A new custom-made pharyngeal obturator device was built in order to enable a correct function of the velopharyngeal valve. The fabrication of the plate was made by altering the conventional Hawley retainer, replacing the Adams hooks with 0.9 mm spherical hooks and removing the buccal arch. (3) Results: The new pharyngeal obturator design was used in six cleft patients with fixed orthodontic appliances. The appliance was well tolerated and there was a slight improvement in auditory-perceptive evaluations. (4) Conclusions: The new pharyngeal bulb design proved to have good retention during fixed orthodontic treatment. Moreover, despite the short-term follow-up, it also showed a reduction in the severity of the hypernasality sentences. Full article

The need to modify removable partial dentures equipped with a metal framework in order to add other prosthetic teeth to replace natural teeth lost by the patient could lead to laboratory procedures so complex as to require the creation of new prostheses with a heavy economic burden. The creation of preformed metal pins to be welded using the economical TIG cold welding method could represent a valid alternative solution with the aim of modifying the prostheses using a reinforced resin capable of adequately resisting masticatory loads. This study evaluates and compares the mechanical robustness and the clinical reliability of these modified prostheses in cases of junctions of one or two contiguous prosthetic teeth. The 6-month follow-up demonstrated the total validity of the method via the absence of significant breakages or detachments in all of the patients analyzed; on the other hand, the prostheses modified using the traditional method and used as controls showed a high incidence of fractures. Full article

Obtaining a proper position for total hip arthroplasty components is a crucial aspect of implant performance and consequently of patient outcomes. Restoring the original hip center and maintaining the limb length are key factors in reaching the optimal implant positioning. The aim of this study was to assess the accuracy and safety of a computed dynamic analysis system that, through patient-specific guides, tries to improve implant positioning and functional orientation according to patients’ spinopelvic mobility and anatomy. A total of 100 consecutive patients were prospectively enrolled. All patients received an Optimized Positioning System dynamic hip preoperative planning schedule. A CT scan protocol follow-up analysis was performed 6 months after surgery. The mean deviations from the planned acetabular inclination and anteversion were 4.3° and 3.8°, respectively. In total, 98% of cases were within ± 10° of the Lewinnek safe zone, both for inclination and anteversion. The height of osteotomy deviated, on average, 1.6 mm. In total, 100% of cases were included within 4 mm of osteotomy. Patient-specific and laser-guided instrumentation was found to be safe and accurately reproduced dynamic planning in terms of the component orientation, osteotomy level, leg length and offset. Full article

Hip arthroplasty failures (either septic or aseptic) often require multiple revisions, thus leading to severe bone defects. The most common reconstruction methods do not allow the management of severe defects. For this reason, in recent years, techniques borrowed from surgical oncology have been applied in the field of revision surgery to deal with both acetabular and femoral bone losses. In this article, two cases of severe bone deficiency following multiple hip arthroplasty revisions that were treated with a custom-made hip prosthesis combined with a proximal femur megaprosthesis are presented. Both implants were silver coated. A review of the literature was conducted to analyze similar cases treated with either a custom-made prosthesis or a proximal femur megaprosthesis. At the 2-year follow-up, all prostheses were in site without clinical or radiographic signs of implant loosening. No postoperative complications occurred. At the last follow-up, both patients resumed their daily life activities with an MSTS score of 23 and 21, respectively. The combined approach of a proximal femur megaprosthesis with a custom-made partial pelvic replacement is a solution that allows severe bone deficiency cases to be tackled with good functional results. Additionally, silver coating may help prevent recurrence of infection. Full article

Reverse shoulder arthroplasty (RSA) has transformed the management of shoulder pathologies, including cuff tear arthropathy and osteoarthritis. The innovative design principles of RSA, such as the medialization and inferiorization of the joint center of rotation, distalization of the humerus, and a semi-constrained construct, enable effective deltoid compensation for rotator cuff deficiency. The Grammont-style RSA demonstrated excellent clinical outcomes. However, complications like instability and scapular notching prompted the exploration of lateralized designs. The radiographic evaluation of RSA is paramount for understanding the biomechanics of the implant and to foresee possible complications. Radiographic assessments encompass glenoid and humeral component positions, identifying features like scapular notching, radiolucent lines, heterotopic ossifications, bone adaptations, and humeral lengthening. Lateralized designs alter muscle moment arms and improve deltoid efficiency, influencing abduction and adduction mechanics. Despite the reduction in scapular notching, lateralized RSA introduces new challenges, such as increased risk of scapular spine and acromial fractures. Understanding the radiographic features and biomechanics of lateralized RSA is crucial for optimizing patient outcomes and mitigating potential complications. Full article

The main aim of this case series was to report the clinical and radiographic outcomes of 22 one-piece zirconia dental implants positioned in 19 patients to restore single edentulisms and followed up for at least 2 years. The mean observation period was 58.18 months. At the last follow-up visit, no issues, such as foreign body sensation, discomfort or pain, were reported by the patients. No implant showed signs of infection with suppuration or implant mobility. Marginal bone levels (MBL) were assessed through standardized dental radiographs and a dedicated software. The mean distance between the implant head and the first detectable bone to implant contact was calculated at the mesial and distal aspect of each implant. The mean MBL at baseline was 1.82 ± 0.63 mm while the mean MBL at the last follow-up visit was 2.57 ± 0.72 mm. The results obtained in the present case series over a mean follow-up period of 58.18 months (range 27–96) showed that one-piece zirconia dental implants could be an alternative option to support single crowns in patients requiring metal-free restorations. Nevertheless, further better-controlled research featuring an adequate study design and longer follow-up is needed in order to clarify advantages and limitations which are related to this treatment modality. Full article

Removable functional appliances (RFA) have long been employed to address Class II malocclusion, particularly in cases involving a significant overjet, a deep bite, and molar class 2 issues. Notably divergent from RFA, myofunctional appliances (PMA) offer several distinct advantages, including applicability in noncompliant patients, adaptability in cases of dental element scarcity, suitability for allergic patients, impression-free utilization, and reduced costs. Within the array of clinical cases treated with PMA, we chose to present an intricate case involving an 8-year-old girl. Our aim was to showcase the immediate effects of PMA and to track the progress over a two-year span. Following one year of PMA treatment, substantial improvements were observed in a large overjet, a deep bite, and lip incompetence—factors often associated with elevated risks of dental trauma. These improvements not only positively impacted dental aesthetics but also engendered normalized nasal respiration and diminished palatal impingement, thereby enhancing the overall quality of life. Upon reaching the two-year mark, the clinical status pertaining to Class II malocclusion remained stable. Further treatment was advised in a subsequent phase to refine imperfections in the dental arch form. Nonetheless, comprehensive data from the prolonged follow-up of patients treated with these appliances are essential to establish robust scientific evidence concerning their long-term efficacy. Full article

The usage of monolithic zirconia has been increasing in daily practice in dentistry for the last 20 years. Monolithic zirconia is mainly used for posterior sector rehabilitation, as it lacks optical properties and has good technical properties; it does not chip and reduces antagonist wear compared to metal–ceramic prostheses. However, monolithic zirconia may present some issues, mainly low-temperature degradation (LTD), also known as “aging”, which must be considered and investigated in clinical studies with prolonged follow-up periods. The aim of this study was the aesthetic and functional evaluation of single monolithic zirconia crowns that were screwed onto implants for posterior dental rehabilitation using USPHS parameters and a long follow-up period of 7 years. The results showed that the USPHS scoring reduces year by year, passing from 100% excellence between the first and fourth years of observation, to 88% excellence and 12% success in the seventh year. Screw abutment loosening was the only technical adversity reported; no implant failure, crown fracture, or irreparable damage were additionally registered. Considering the emerging results and comparing them with the data available in the literature, the authors suggest that monolithic zirconia crowns could be considered as a valid alternative to classic metal–ceramic rehabilitations for the rehabilitation of posterior sectors. Full article

Since the end of the 19th and the beginning of the 20th centuries, technological equipment, implant designs (endoprosthesis) and the surgical technique of total hip replacement (THR) have been constantly improved and reached a high level of functionality and quality. Therefore, at present, THR is one of the most high-tech, reliable and popular surgical operations that allow a large number of people suffering from osteoarthritis and other serious diseases of the hip joint to return to an active lifestyle. At the same time, it is known that even operations at this level do not always guarantee the achievement of the desired result and can lead to various complications. The question arises: are there potential opportunities for creating an “ideal endoprosthesis” that allows one to perform an “ideal THR”? In this paper, based on a critical analysis of modern endoprosthesis designs for THR, technologies for their implantation and systemic postoperative complications, the most probable, according to the authors, ways of their development are formulated, which allow asymptotically approaching the “ideal”. Full article