A new classification for pterygomaxillary implants and its related surgical implications: a retrospective cohort study.

BACKGROUND: To provide a novel classification for all implants in the maxillary retromolar region to simplify surgical design, reduce surgical risks, and guide clinicians in clinical decision-making. METHODS: A total of 180 patients with bilateral partial or completely edentulous atrophic posterior maxillae who had received or were scheduled to receive pterygomaxillary implants were included in this study. Cone-beam computed tomography was performed, and the sagittal and coronal images were acquired at 110 kV and 10 mA. The exposure volume was 120 mm in diameter and 80 mm in height. The pterygomaxillary implants were divided into three different types based on the anatomical structures the implants passed through. RESULTS: The average age of the 180 patients was 69 (range: 39-89) years; 99 were men and 81 were women. All the patients exhibited 360 pterygomaxillary implant sites. However, during mimic implantation, 14 implant sites were excluded due to severe resorption of the tuberosity, very small pterygoid plates, or variations in the descending palatal artery configuration. Of the 346 pterygomaxillary implant sites, 24.0% (83/346), 40.7% (141/346), 22.0% (76/346), and 13.3% (46/346) were classified as Types I, IIa, IIb, and III, respectively. CONCLUSIONS: Type II pterygomaxillary implants were the most commonly used in the novel classification. Different types of pterygomaxillary implants should follow specific designs and surgical strategies to achieve optimal outcomes.

The role of pressure and friction forces in automated insertion of cochlear implants.

Objectives: Despite the success of cochlear implant (CI) surgery for hearing restoration, reducing CI electrode insertion forces is an ongoing challenge with the goal to further reduce post-implantation hearing loss. While research in this field shows that both friction and quasistatic pressure forces occur during CI insertion, there is a lack of studies distinguishing between these origins. The present study was conducted to analyze the contribution of both force phenomena during automated CI insertion. Methods: Five MED-EL FLEX28 CI electrode arrays were inserted into both a regular and uncoiled version of the same average scala tympani (ST). Both ST models had a pressure release hole at the apical end, which was kept open or closed to quantify pressure forces. ST models were filled with different sodium dodecyl sulfate (SDS) lubricants (1, 5, and 10% SDS, water). The viscosity of lubricants was determined using a rheometer. Insertions were conducted with velocities ranging from v= 0.125 mm/s to 2.0 mm/s. Results: Viscosity of SDS lubricants at 20°C was 1.28, 1.96, and 2.51 mPas for 1, 5, and 10% SDS, respectively, which lies within the values reported for human perilymph. In the uncoiled ST model, forces remained within the noise floor (maximum: 0.049 × 10-3 N ± 1.5 × 10-3 N), indicating minimal contribution from quasistatic pressure. Conversely, forces using the regular, coiled ST model were at least an order of magnitude larger (minimum: Fmax = 28.95 × 10-3 N, v = 1 mm/s, 10% SDS), confirming that friction forces are the main contributor to total insertion forces. An N-way ANOVA revealed that both lubricant viscosity and insertion speed significantly reduce insertion forces (p < 0.001). Conclusion: For the first time, this study demonstrates that at realistic perilymph viscosities, quasistatic pressure forces minimally affect the total insertion force profile during insertion. Mixed friction is the main determinant, and significantly decreases with increaseing insertion speeds. This suggests that in clinical settings with similar ST geometries and surgical preparation, quasistatic pressure plays a subordinate role. Moreover, the findings indicate that managing the hydrodynamics of the cochlear environment, possibly through pre-surgical preparation or the use of specific lubricants, could effectively reduce insertion forces.

Acute and chronic mammary periprosthetic histological changes of the muscle.

Background: Augmentation mammoplasty with subpectoral prosthesis implantation is a frequent performed procedure in plastic surgery for reconstructive and aesthetic purposes. Although prosthesis implantation in a pocket under the major pectoralis muscle has been related to volumetric and functional alterations, there is not much information about the associated short- and long-term histological changes. Therefore, the aim of our study was to describe the acute and chronic histological muscle alterations associated with subpectoral prosthesis implantation. Materials and Method: We collected samples from patients with breast tissue expander (<6 months after implantation) and prosthesis (>1 year after implantation) and from patients without implantation as a control group. The samples were processed for assessing their histological, histochemical and immunohistochemical properties. Results: In the control group, no relevant histological findings were identified. Additionally, in the patients with expander, we observed mild augmentation of the internalised nuclei, normal morphology, significant muscle atrophy and fibrosis, whereas in the patients with prosthesis considerable augmentation of internalised nuclei, significant muscle atrophy, fibrosis and alteration of normal muscle morphology were observed. Conclusion: Prosthesis implantation induces histological changes in the periprosthetic striated muscle. Chronic fibrosis and inflammation play key roles in this process, which should be characterised in more detail from the histological and molecular biological perspective.

Primary stability evaluation of different morse cone implants in low-density artificial bone blocks: A comparison between high-and low-speed drilling.

This study aimed to evaluate various biomechanical parameters associated with the primary stability of Maestro and Due Cone implants placed in low-density artificial bones, prepared using high-speed drilling with irrigation and low-speed drilling without irrigation. The insertion torque (IT), removal torque (RT), and implant stability quotient (ISQ) values were recorded for Maestro and Due Cone implants placed in low-density polyurethane blocks (10 and 20 pounds per cubic foot (PCF) with and without a cortical layer) prepared using high-speed and low-speed with or without irrigation using a saline solution, respectively. A three-way ANOVA model and Tukey's post-hoc test were conducted, presenting data as means and standard deviations. P-values equal to or less than 0.05 were considered statistically significant. No statistically significant differences in IT, RT, and ISQ between drilling speeds were observed. However, Maestro implants exhibited lower IT and RT values after high- and low-speed drilling across almost all polyurethane blocks, significantly evident in the 20 PCF density block for IT and in the 20 PCF density block with the cortical layer for the RT with low-speed drilling (IT: 47.33 ± 10.02 Ncm and 16.00 ± 12.49 Ncm for Due Cone and Maestro implants, respectively, with p < 0.01; RT: 44.67 ± 22.81 Ncm and 20.01 ± 4.36 Ncm for Due Cone and Maestro implants, respectively, with p < 0.05) and among the same implant types inserted in different bone densities. Additionally, the study found that for all bone densities and drilling speeds, both implants registered ISQ values exceeding 60, except for the lowest-density polyurethane block. Overall, it can be inferred that low-speed drilling without irrigation achieved biomechanical parameters similar to conventional drilling with both implant types, even with lower IT values in the case of Maestro implants. These findings suggest a promising potential use of low-speed drilling without irrigation in specific clinical scenarios, particularly when focusing on preparation depth or when ensuring proper irrigation is challenging.

Laminin 332 functionalized surface improve implant roughness and oral keratinocyte bioactivity.

Objective: The biological seal (BS) at the implant-tissue interface is essential for the success of dental implants (DIs), and the absence of a proper BS can lead to peri-implantitis. The basement membrane (BM) and junctional epithelium are critical for sealing the peri-implant mucosa, and laminin 332 is an important protein in binding the epithelium to the implant surface. The aim of this study was to evaluate the response of oral keratinocytes to titanium dental implant surfaces biofunctionalized with laminin 332. Design: The dental implant surface was treated with a piranha solution to create hydroxyl (OH) groups, facilitating biofunctionalization with laminin 332. The modified surface underwent scanning electron microscopy, surface roughness evaluation, and chemical composition analysis. Human keratinocytes from the Cal-27 line were then cultured on the modified implants for 24 and 48 h to assess viability, morphology, cytokine secretion, and mRNA expression of tissue repair-associated genes. Results: The results showed that laminin 332 biofunctionalization of the implant surface resulted in lower values of Ra, Rq and positive surface roughness parameters Rsk, Rku and Rv. The elemental composition showed an increase in nitrogen and carbon content corresponding to protein binding. The biofunctionalized surfaces did not affect cell viability and promoted cytokine secretion (IL-1a and IL-8) and a significant increase (p < 0.05) in MCP-1, EGF, FGF, TGF and VEGF gene expression compared to the control. Conclusion: In conclusion, laminin 332 coating Ti implants was shown to be effective in promoting keratinocyte adhesion, spreading, and viability. This approach could be an alternative way to improve biocompatibility.

Influence of Crown Height and Width on Marginal Bone Loss and Long-Term Stability of Dental Implants: A Systematic Review.

Still, a major focus of research in implantology is how crown height and width affect marginal bone loss (MBL) and the long-term durability of dental implants. Maximizing the success of implants and lowering problems depends on an awareness of these elements. Following the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines, this systematic review searched pertinent studies across several databases using keywords unique to databases. Studies on MBL and long-term implant stability evaluated in the review included those on crown height and width, horizontal and vertical cantilevers, and prosthesis dimensions. In the chosen studies, we found that both implant success and crestal bone loss were greatly influenced by crown height and width. Particularly in the posterior sections, horizontal cantilevers were connected to both increasing MBL and mechanical problems. Vertical cantilevers also affected MBL; however, their impacts were more obvious in circumstances with greater crown heights. Greater prosthesis widths, especially in the mandibular molar area, were linked to higher MBL. Bone density and insertion torque (IT) were the main determinants of MBL, more than the primary implant stability quotient. Early MBL was influenced by abutment height, mucosal thickness, and implant insertion depth; bone levels stabilized six months later. Short implants allow single crowns to be supported, but in some cases, a higher failure rate was seen. The success and stability of dental implants were found to be mostly dependent on crown height, width, and cantilever design. MBL and long-term stability are greatly influenced by horizontal and vertical cantilevers, which calls for careful design and planning. With specific care for bone density, IT, and early MBL stabilization, both short and standard implants can produce equivalent results. These results highlight the need for customized treatment plans to maximize implant success and lifetime.

A Case of Cochlear Implantation in a Deaf Patient With Eosinophilic Otitis Media in Whom Post-implantation Hearing Threshold Improved After Introduction of Dupilumab.

Eosinophilic otitis media (EOM) is a rare, intractable, and chronic form of otitis media. The associated hearing loss often progresses to deafness, necessitating cochlear implantation (CI). EOM is associated with type 2 inflammatory conditions such as asthma and chronic rhinosinusitis with nasal polyps (CRSwNP). Dupilumab, a monoclonal antibody targeting the IL4Rα subunit, has shown efficacy in mitigating type 2 inflammatory diseases, including asthma and CRSwNP. Recent studies also suggest its effectiveness in treating EOM. We report a unique case of CI for EOM, in which the post-implant hearing threshold improved after the introduction of dupilumab. The patient was a 63-year-old man with a history of asthma and multiple nasal polypectomies. Eosinophils were detected in otorrhea samples from both ears, leading to an EOM diagnosis four years prior. Despite local corticosteroid therapy, his hearing gradually deteriorated. One month ago, he experienced sudden bilateral deafness and was referred to our hospital. The right tympanic membrane had a pinhole perforation but no otorrhea. CT showed a small amount of soft tissue density in the right middle ear, while the left side displayed cochlear osteolysis with soft tissue density. A right CI and myringoplasty were performed one and a half months after his visit. The cochleostomy revealed no perilymph leakage, confirming that the scala tympani was filled with granulation tissue. The electrode was inserted successfully despite the granulation, and all electrodes were placed correctly. Six months after CI, his hearing threshold with the cochlear implant remained poor at 67.5 dB. However, upon starting dupilumab therapy seven months postoperatively, his hearing threshold with the cochlear implant rapidly improved to 31.3 dB. Intraoperative findings suggested that the scala tympani was filled with granulation tissue, indicating significant cochlear inflammation due to EOM. The subsequent hearing improvement after introducing dupilumab may be attributed to the reduction or disappearance of granulation in the cochlea, allowing for effective electrical stimulation from the electrodes to the spiral ganglion. This case suggests the potential for improved postoperative hearing outcomes in CI for EOM when inflammation is effectively controlled with dupilumab.

Simultaneous cochlear implantation with early endoscopic surgery in small acoustic neuroma.

Objectives: The exclusive endoscopic transcanal transpromontorial approach (EETTA) has recently been developed for the removal of small-sized acoustic neuromas in the labyrinth (intralabyrinthine schwannoma [ILS]) or internal auditory canal (IAC). Although small tumors that meet the indications for EETTA are also good candidates for cochlear implantation (CI), there are few reports on CI after schwannoma removal using EETTA. Here we present an outcome of patients who underwent simultaneous EETTA and CI. Methods: Five patients (two with IAC fundus tumors and three with ILS) who underwent simultaneous EETTA and CI between 2020 and 2022 were retrospectively enrolled. Their medical charts and test results were reviewed. Results: After at least 12 months of follow-up, there were no severe surgical complications such as meningitis, infection, or skin necrosis. Four of the five patients responded to auditory stimulation. Three out of four auditory-responsive patients scored >80% on sentence recognition. Conclusion: Simultaneous EETTA and CI are feasible for the treatment of ILS and IAC fundus tumors. Preservation of the cochlear nerve and modiolus is important for favorable CI outcomes. Therefore, ILS and IAC fundus tumors in patients with nonserviceable hearing should be surgically removed as early as possible to enable proper hearing rehabilitation with CI. Level of Evidence: Level 4.

Assessment of cranial reconstruction utilizing various implant materials: finite element study.

The human head can sometimes experience impact loads that result in skull fractures or other injuries, leading to the need for a craniectomy. Cranioplasty is a procedure that involves replacing the removed portion with either autologous bone or alloplastic material. While titanium has traditionally been the preferred material for cranial implants due to its excellent properties and biocompatibility, its limitations have prompted the search for alternative materials. This research aimed to explore alternative materials to titanium for cranial implants in order to address the limitations of titanium implants and improve the performance of the cranioplasty process. A 3D model of a defective skull was reconstructed with a cranial implant, and the implant was simulated using various stiff and soft materials (such as alumina, zirconia, hydroxyapatite, zirconia-reinforced PMMA, and PMMA) as alternatives to titanium under 2000N impact forces. Alumina and zirconia implants were found to reduce stresses and strains on the skull and brain compared to titanium implants. However, PMMA implants showed potential for causing skull damage under current loading conditions. Additionally, PMMA and hydroxyapatite implants were prone to fracture. Despite these findings, none of the implants exceeded the limits for tensile and compressive stresses and strains on the brain. Zirconia-reinforced PMMA implants were also shown to reduce stresses and strains on the skull and brain compared to PMMA implants. Alumina and zirconia show promise as alternatives to titanium for the production of cranial implants. The use of alternative implant materials to titanium has the potential to enhance the success of cranial reconstruction by overcoming the limitations associated with titanium implants.

Experimental glaucoma microstent implantation in two animal models and human donor eyes-an ex vivo micro-computed tomography-based evaluation of applicability.

Background: Minimally invasive glaucoma surgery (MIGS) has become an important treatment approach for primary open angle glaucoma. Restoration of aqueous humour drainage by means of alloplastic implants represents a promising treatment option and is itself subject of methodological development. An adequate positioning in the targeted tissue regions is essential is important for the performance of our in-house developed Rostock glaucoma microstent (RGM). The aim of this study was to evaluate the applicability of two animal models and human donor eyes regarding RGM placement. Methods: Eyes were obtained from rabbits, pigs, and human body donations. After orbital exenterations, RGMs were placed in the anterior chamber draining in the subconjunctival space. X-ray contrast was increased by incubation in aqueous iodine solution for subsequent detailed micro-computed tomography (micro-CT)-based visualization and analysis. Results: In contrast to the human and porcine eyes, the stent extended far to the posterior pole with a more pronounced curvature along the globe in the rabbit eyes due to their smaller size. However, dysfunctional deformations were not depicted. Adequate positioning of the stent's inflow area in the anterior chamber and the outflow area in the Tenon space was achieved in both the animal models and the human eye. Conclusions: Micro-CT has proven to be a valuable tool for postoperative ex vivo evaluation of glaucoma drainage devices in its entire complexity. With regard to morphology, the porcine eye is the ideal animal model to test implantation procedures of the RGM. Nevertheless, rabbit eye morphology facilitates successful implantation results and provides all prerequisites for preclinical animal studies.

Reviving XEN63 Gel Stent Patency in Uveitic Glaucoma: A Novel Approach Using 10-0 Nylon Probe.

Purpose: This case report describes the possibility of XEN63 lumen obstruction at the middle of the device and emphasizes the potential to restore its flow using an ab-externo revision technique involving a 10-0 nylon suture probe, before considering more aggressive surgical interventions. Methods: A 55-year-old female with uveitic glaucoma underwent XEN63 implantation but experienced elevated intraocular pressure (IOP) (35 mm Hg) 1 month after the operation, despite medical therapy. A flat bleb, lack of response to medication, yttrium aluminum garnet (YAG) laser treatment, and slit-lamp needling necessitated revision. Results: An ab-externo surgical procedure was performed using a 10-0 nylon probe to release the obstruction, followed by the application of mitomycin C and removal of fibrous tissue and subconjunctival Tenon's capsule. Intraoperatively, flow was observed only after probing with the 10-0 nylon. Postoperatively, the patient's IOP decreased immediately and remained well-controlled at 2 months (8 mm Hg) without requiring further medication. Conclusion: For patients experiencing increased inflammatory response, the XEN63 gel stent may develop deep lumen occlusion that is unresponsive to conventional treatments. This case report introduces a novel surgical technique applicable to various glaucoma devices, utilizing an ab-externo approach with a 10-0 nylon probe. The demonstrated success in reducing IOP suggests its potential as a less invasive alternative to consider before resorting to more aggressive surgical interventions. How to cite this article: Marchese V, Randazzo V, Badalamenti R, et al. Reviving XEN63 Gel Stent Patency in Uveitic Glaucoma: A Novel Approach Using 10-0 Nylon Probe. J Curr Glaucoma Pract 2024;18(2):74-78.

Cochlear-implant simulated spectral degradation attenuates emotional responses to environmental sounds.

OBJECTIVE: Cochlear implants (CI) provide users with a spectrally degraded acoustic signal that could impact their auditory emotional experiences. This study evaluated the effects of CI-simulated spectral degradation on emotional valence and arousal elicited by environmental sounds. DESIGN: Thirty emotionally evocative sounds were filtered through a noise-band vocoder. Participants rated the perceived valence and arousal elicited by each of the full-spectrum and vocoded stimuli. These ratings were compared across acoustic conditions (full-spectrum, vocoded) and as a function of stimulus type (unpleasant, neutral, pleasant). STUDY SAMPLE: Twenty-five young adults (age 19 to 34 years) with normal hearing. RESULTS: Emotional responses were less extreme for spectrally degraded (i.e., vocoded) sounds than for full-spectrum sounds. Specifically, spectrally degraded stimuli were perceived as more negative and less arousing than full-spectrum stimuli. CONCLUSION: By meticulously replicating CI spectral degradation while controlling for variables that are confounded within CI users, these findings indicate that CI spectral degradation can compress the range of sound-induced emotion independent of hearing loss and other idiosyncratic device- or person-level variables. Future work will characterize emotional reactions to sound in CI users via objective, psychoacoustic, and subjective measures.

Evaluating the long-term outcomes from cochlear implant surgery for children with single and multiple additional needs.

Cochlear implant surgery is a cornerstone in the treatment of severe to profound hearing impairment. Despite comprising a significant proportion of the deaf population, children with additional needs have only been included for cochlear implant candidacy in recent years. This paper aims to evaluate the long-term progress of children with additional needs post-implantation compared to children without additional and assess how this trend changes over time. METHODS: This is a longitudinal cohort study comparing the outcomes between children with no additional needs, children with a single additional need, and children with multiple additional needs. The five outcome measures used assessed both auditory perception and expressive and receptive language. For each outcome measure, subjects were assessed pre implant and one-, three-, and five-years post-implant. RESULTS: The total cohort consisted of 334 subjects: 181 with no additional needs, 116 with a single additional need, and 37 with multiple additional needs. The results showed that children with additional needs performed significantly poorer in all outcome measures compared to those without additional needs, with a greater negative effect associated with multiple additional needs. In auditory perception, both additional needs groups increased in rate of progress over time, in contrast to language capabilities for which the rate plateaued at a significantly lower level than children without additional needs. Once again, both of these effects were greater for the multiple additional needs group. CONCLUSION: It is clear that there is reduced progress in children with additional needs compared to those without, and that the number of additional needs present is an important factor in this. Despite initial delays, it seems as though children with additional needs may catch up over time in auditory perception scores, however for language skills, this cohort may achieve limited scores even as time progresses. It is important to investigate this further to gauge the factors that are causing this discrepancy to see if any can be limited to maximise outcome.

The impact of hearing loss and cochlear implantation on the quality of life in children.

BACKGROUND: This study evaluates the Quality of Life (QoL) in children with moderate to profound hearing impairments using cochlear implants (CIs), compared to those with normal hearing. It explores the impacts of hearing loss and the effectiveness of CIs in pediatric populations. METHODS: Conducted at a tertiary care academic center, this cross-sectional study included children aged 13-18. Participants were divided into three groups: normal hearing, yet to be treated moderate or worse hearing loss (uHL), and CI users. Demographic data were collected, and the QoL was assessed using the Hearing Environments and Reflection of Quality of Life (HEAR-QL) questionnaire, with scores across various subdomains compared. RESULTS: Of the 79 children meeting the inclusion criteria, 38 % had normal hearing, 29 % had at least moderate HL, and 33 % were CI users. Statistically significant differences in HEAR-QL scores were found among the groups. The normal hearing group reported the highest scores. In the subdomain of hearing circumstances and academic performance, CI users showed no significant difference from the normal hearing group, unlike those with untreated uHL who scored lower. However, in social interaction and emotional well-being subdomains, CI users' scores were lower than those of the normal hearing group but similar to the uHL group. CONCLUSION: Children with CIs show comparable QoL in auditory capabilities to their normal hearing peers but experience significant challenges in psychosocial and emotional areas. This indicates that while CIs can improve hearing-related quality of life, they do not fully address the psychosocial impacts of hearing loss.

The Impact of Surgeon Volume on Unicompartmental Knee Arthroplasty Survivorship: A Michigan Arthroplasty Registry Collaborative Quality Initiative (MARCQI) Database Analysis.

BACKGROUND: The utilization of unicompartmental knee arthroplasty (UKA) has remained low when compared to total knee arthroplasty (TKA), possibly due to higher rates of revision and reoperation. This study aimed to quantify surgeon UKA case-volumes and measure the effect of surgeon volume on early revision. We hypothesized that surgeons who have high case volumes would have lower revision rates compared to medium- and low-volume surgeons. METHODS: Primary UKAs were performed between February 2012 and November 2021, and associated revisions were identified utilizing the Michigan Arthroplasty Registry Collaborative Quality Initiative (MARCQI). Surgeon information, including total cases and annual UKA volume, was collected. Case volume per year was stratified as High (≥ 35 cases per year), Medium (15 to 34 cases per year), and low (< 15 cases per year). RESULTS: There were a total of 15,542 UKAs performed. Of these, 701 (4.5%) were revised, and 412 (58.8%) revisions occurred within 2 years. Of the 287 surgeons who performed an UKA in the registry, 237 (82.6%) were low-volume surgeons, 36 (12.5%) were medium-volume, and 14 (4.9%) were high-volume. High-volume surgeons were more likely to operate on older patients (P < 0.01), Medicare patients (P < 0.01), and patients who had ASA (American Society of Anesthesiologists) scores of III and IV (P < 0.01). High-volume surgeons had significantly lower 5-year revision rates compared to medium and low-volume surgeons (high: 4.3% (95% CI [confidence interval]: 3.70 to 4.90), medium: 5.2% (4.44 to 6.12), low: 7.2% (6.37 to 8.02); P < 0.001). In comparison, the 5-year revision rate for TKA in Michigan was 3.0% (95% CI: 2.90 to 3.08). CONCLUSION: When UKAs were performed by high-volume surgeons in the state of Michigan, there was better survivorship when compared to low-volume and medium-volume surgeons. High-volume surgeons were more likely to perform UKA on older patients, Medicare patients, and patients who had ASA scores of III and IV. The revision rate for the high-volume surgeons still exceeded the 5-year revision rate for total knee arthroplasty in Michigan.

Optimization of polymer coating thickness and strut width in drug Eluting stents using Magnetic field.

The transport of drug/magnetic particle (MP) conjugates in the presence of a Magnetic Field (MF) in Drug Eluting Stents (DESs) is modeled numerically using the Finite Volume Method (FVM). The effects of physiological conditions corresponding to different degrees of calcification, drug particles sizes and hematocrit level, were analyzed by investigating the roles of the tissue permeability, its anisotropy and the plasma viscosity. It was found that both in the absence and presence of the MF, as the tissue permeability decreases or the plasma viscosity increases, the free-phase drug and Extracellular Matrix (ECM)-bound phase contents increase. Stronger tissue anisotropy leads to a decrease of the free-phase drug content and an increase of the ECM-bound phase content. Within the explored ranges, the Specific Receptor (SR)-bound phase of the drug was found to be insensitive to the tissue permeability and plasma viscosity, and to be larger in anisotropic tissues. The activation of the MF leads systematically to larger free-phase drug contents, with the increases most prominent at smaller tissue permeability, anisotropy and plasma viscosity. On the other hand, the effects on the ECM-bound phase content are found to be stronger at larger permeability, smaller plasma viscosity and lower tissue anisotropy. For an isotropic tissue, the MF induces a decrease of the ECM-bound phase content at early times, followed by an increase at later times. For the considered ranges of permeability and viscosity, the MF does not seem to have any noticeable effects on the SR-bound phase. However, this phase of the drug tends to increase with the activation of the MF in isotropic tissues and is unchanged in anisotropic ones. These reported effects of the MF hold promise for alleviating two factors contributing to In-Stent Restenosis, namely the polymer coating width and thickness. The study reveals that a narrower or thinner polymer layer, in combination with the MF, can mimic the drug release dynamics of a wider or thicker polymer layer in the absence of the MF. The corresponding width and thickness of the magnetized stents, that we referred to as the equivalent polymer width (EPW) and equivalent polymer thickness (EPT) were determined and their dependence on the tissue permeability, isotropy and the plasma viscosity, was investigated. The study shows that it is possible to achieve the same drug delivery with polymer coating of half the width or half the thickness of the non-magnetized stent when an electric intensity of 3A is used.

Designing and additive manufacturing of talus implant for post-traumatic talus avascular necrosis: a case study.

New technologies in additive manufacturing and patient-specific CT-based custom implant designs make it possible for previously unimaginable salvage and limb-sparing operations a practical reality. This study presents the design and fabrication of a lattice-structured implant for talus replacement surgery. Our primary case involved a young adult patient who had sustained severe damage to the talus, resulting in avascular necrosis and subsequent bone collapse. This condition caused persistent and debilitating pain, leading the medical team to consider amputation of the left foot at the ankle level as a last resort. Instead, we proposed a Ti6Al4V-based patient-specific implant with lattice structure specifically designed for pan-talar fusion. Finite element simulation is conducted to estimate its performance. To ensure its mechanical integrity, uniaxial compression experiments were conducted. The implant was produced using selective laser melting technology, which allowed for precise and accurate construction of the unique lattice structure. The patient underwent regular monitoring for a period of 24 months. At 2-years follow-up the patient successfully returned to activities without complication. The patient's functional status was improved, limb shortening was minimized.

Dentoalveolar effects of open-bite correction with the dual action vertical intra-arch technique: A finite element analysis.

Objective: To evaluate tooth displacement and periodontal stress generated by the dual action vertical intra-arch technique (DAVIT) for open-bite correction using three-dimensional finite element analysis. Methods: A three-dimensional model of the maxilla was created by modeling the cortical bone, cancellous bone, periodontal ligament, and teeth from the second molar to the central incisor of a hemiarch. All orthodontic devices were designed using specific software to reproduce their morpho-dimensional characteristics, and their physical properties were determined using Young's modulus and Poisson's coefficient of each material. A linear static simulation was performed to analyze the tooth displacements (mm) and maximum stresses (Mpa) induced in the periodontal ligament by the posterior intrusion and anterior extrusion forces generated by the DAVIT. Results: The first and second molars showed the greatest intrusion, whereas the canines and lateral incisors showed the greatest extrusion displacement. A neutral zone of displacement corresponding to the fulcrum of occlusal plane rotation was observed in the premolar region. Buccal tipping of the molars and lingual tipping of the anterior teeth occurred with intrusion and extrusion, respectively. Posterior intrusion generated compressive stress at the apex of the buccal roots and furcation of the molars, while anterior extrusion generated tensile stress at the apex and apical third of the palatal root surface of the incisors and canines. Conclusions: DAVIT mechanics produced a set of beneficial effects for open-bite correction, including molar intrusion, extrusion and palatal tipping of the anterior teeth, and occlusal plane rotation with posterior teeth uprighting.

Fabrication and Temporal Dependency Osteogenic Regulation of Dual-Scale Hierarchical Microstructures on Medical Metal Surface.

The structural characteristics at the interface of bone implants can guide biological regulation. In this study, a dual-scale hierarchical microstructure is proposed and customized using hybrid machining to achieve temporal dependency osteogenic regulation. It is observed that osteoblasts induced by dual-scale hierarchical structure exhibit adequate protrusion development and rapid cell attachment through the modulation of mechanical forces in the cell growth environment, and further promot the upregulation of the cell membrane receptor PDGFR-α, which is related to cell proliferation. Afterward, transcriptomic analysis reveals that during the differentiation stage, the DSH structure regulates cellular signaling cascades primarily through integrin adhesion mechanisms and then accelerates osteogenic differentiation by activating the TGF-ß pathway and cAMP signaling pathway. Furthermore, the calcium nodules are preferentially deposited within the lower honeycomb-like channels, thereby endowing the proposed dual-scale hierarchical structure with the potential to induce oriented deposition and improve the long-term stability of the implant.

Current status of pre- and retropectoral breast reconstructions worldwide: a narrative review.

Background and Objective: Advances in breast cancer research and technology contribute to conservative ablative surgical approach with emphasis on reconstruction. The introduction of biologic membranes in breast surgery facilitates a one-stage implant reconstruction while the importance of the pectoralis major muscle involvement in the procedure becomes debatable. A subsequent increase in prepectoral implant placement procedures seems to close a cycle of innovations in implant-based breast reconstructions. This sparks a debate that calls for a critical review of existing literature considering that new challenges tend to arise along with new perspectives. The authors seek to scope the present status of prepectoral and subpectoral implant reconstruction worldwide, and answer recurring questions, including the novelty of presented innovations in the context of existing literature. Methods: The article is based on a literature search in PubMed with the keywords "prepectoral" or "subpectoral" and "breast reconstruction", in addition to the authors' experience with a large number of patients. Key Content and Findings: Recent studies focus on the comparative safety of prepectoral vs. subpectoral placement debating the use of biologic vs. non-biologic sheets and implant texture. There seems to be more emphasis on early post-operative safety of the procedures, rather than any long-term prospects of their comparison, up to this point. Skin and nipple sparing mastectomy (SSM/NSM) together with biological membranes have played a key role in current practice and cannot be overlooked. Conclusions: After reading this paper, the reader should have a firm understanding of the key elements of implant-based breast reconstruction in historical context with emphasis on muscle planes and their pros and cons.