A short linear glucan nanocomposite hydrogel formed by in situ self-assembly with highly elastic, fatigue-resistant and self-recovery.

Polyacrylamide (PAM) hydrogels are widely used in wide-ranging applications in biology, medicine, pharmaceuticals and environmental sectors. However, achieving the requisite mechanical properties, fatigue resistance, self-recovery, biocompatibility, and biodegradability remains a challenge. Herein, we present a facile method to construct a nanocomposite hydrogel by integrating short linear glucan (SLG), obtained by debranching waxy corn starch, into a PAM network through self-assembly. The resulting composite hydrogel with 10 % SLG content exhibited satisfactory stretchability (withstanding over 1200 % strain), along with maximum compressive and shear strengths of about 490 kPa and 39 kPa at 90 % deformation, respectively. The hydrogel demonstrated remarkable resilience and could endure repeated compression and stretching. Notably, the nanocomposite hydrogel with 10 % SLG content exhibited full stress recovery at 90 % compression deformation after 20 s, without requiring specific environmental conditions, achieving an energy dissipation recovery rate of 98 %. Meanwhile, these hydrogels exhibited strong adhesion to various soft and hard substrates, including skin, glasses and metals. Furthermore, they maintain solid integrity at both 37 °C and 50 °C after swelling equilibrium, unlike traditional PAM hydrogels, which exhibited softening under similar conditions. We hope that this PAM-SLG hydrogel will open up new avenues for the development of multifunctional electronic devices, offering enhanced performance and versatility.

A retrospective study evaluating the influence of Class III correction appliances on the sagittal pharyngeal airway dimension.

The aim of this study was to compare the effects of Class III correction appliances including the Facemask (FM), and the new non-compliance fixed functional appliances such as the Reversed Forsus Fatigue Resistant Device (FRD), as well as the CS-2000 (CS), on the sagittal pharyngeal airway dimension (SPAD). Pre-treatment and post-treatment lateral cephalograms of 45 patients who underwent Class III appliance treatment, using either FM, Reversed FRD, or CS were collected from the files of treated patients. SPAD changes were evaluated in each group, and comparisons were conducted between the three study groups. Additionally, sagittal and vertical skeletal measurements were conducted. The FM, the Reversed FRD, and the CS, were found to generate a significant increase in the SPAD, with the Reversed FRD contributing to the most significant change at the OPAA (116.80 ± 26.36 mm2). All three appliances elicited significant antero-posterior changes in the SNA°, SNB°, and ANB°, also with the greatest intermaxillary change documented with the employment of the Reversed FRD (ANB° = 3.33 ± 0.82°). As for the vertical dimension, the FM, the Reversed FRD, and the CS elicited significant FMA° increases, with the greatest change attributed to the FM (FMA° = 2.32 ± 0.97°). Therefore, the three tested Class III corrective appliances generated significant SPAD, antero-posterior, and vertical changes. However, the Revered FRD showed a superior impact in increasing the SPAD at the OPAA level and in eliciting significant intermaxillary changes.

Fatigue-Resistant Polymer Electrolyte Membranes for Fuel Cells.

In a hydrogen fuel cell, an electrolyte membrane conducts protons, but blocks electrons, hydrogen molecules, and oxygen molecules. The fuel cell often runs unsteadily, resulting in fluctuating water production, causing the membrane to swell and contract. The cyclic deformation can cause fatigue crack growth. This paper describes an approach to develop a fatigue-resistant polymer electrolyte membrane. The membrane is prepared by forming an interpenetrating network of a plastic electrolyte and a rubber. The former conducts protons, and the latter enhances fatigue resistance. The introduction of the rubber modestly reduces electrochemical performance, but significantly increases fatigue threshold and lifespan. Compared to pristine plastic electrolyte, Nafion, an interpenetrating network of Nafion and perfluoropolyether (PFPE) reduces the maximum power density by 20%, but increases the fatigue threshold by 175%. Under the wet/dry accelerated stress test, the fuel cell with the Nafion-PFPE membrane has a lifespan 1.7 times that of a fuel cell with the Nafion membrane.

Mechanically-Compliant Bioelectronic Interfaces through Fatigue-Resistant Conducting Polymer Hydrogel Coating.

Because of their distinct electrochemical and mechanical properties, conducting polymer hydrogels have been widely exploited as soft, wet, and conducting coatings for conventional metallic electrodes, providing mechanically compliant interfaces and mitigating foreign body responses. However, the long-term viability of these hydrogel coatings is hindered by concerns regarding fatigue crack propagation and/or delamination caused by repetitive volumetric expansion/shrinkage during long-term electrical interfacing. This study reports a general yet reliable approach to achieving a fatigue-resistant conducting polymer hydrogel coating on conventional metallic bioelectrodes by engineering nanocrystalline domains at the interface between the hydrogel and metallic substrates. It demonstrates the efficacy of this robust, biocompatible, and fatigue-resistant conducting hydrogel coating in cardiac pacing, showcasing its ability to effectively reduce the pacing threshold voltage and enhance the long-term reliability of electric stimulation. This study findings highlight the potential of its approach as a promising design and fabrication strategy for the next generation of seamless bioelectronic interfaces.

Bioinspired Multiscale Micro-/Nanofiber Network Design Enabling Extremely Compressible, Fatigue-Resistant, and Rapidly Shape-Recoverable Cryogels.

Cryogels with extreme mechanical properties such as ultrahigh compressibility, fatigue resistance, and rapid recovery are attractive in biomedical, environmental remediation, and energy storage applications, which, however, are difficult to achieve in man-made materials. Here, inspired by the multiscale macro-/microfiber network structure of spider web, we construct an ultraelastic chitosan cryogel with interconnected hybrid micro-/nanofibers (CMNF cryogels) via freeze-induced physicochemical cross-linking. Chitosan chains are directionally assembled into high-aspect-ratio microfibers and nanofibers under shear-flow induction, which are further assembled into an interconnected three-dimensional (3D) network structure with staggered microfibers and nanofibers. In this multiscale network, nanofibers connecting the microfibers improve the stability, while microfibers improve the elasticity of the CMNF cryogels through long-range interaction. The synergy of the two-scale fibers endows the CMNF cryogel with extraordinary mechanical properties in comparison to those assembled with single-scale fibers, including its ultrahigh ultimate strain (97% strain with 50 cycles), excellent fatigue resistance (3200 compressing-releasing cycles at 60% compression strain), and rapid water-triggered shape recovery (recovering in ∼1 s). Moreover, the fibrous CMNF cryogel shows excellent functionalization capability via the rapid assembly of nanoscale building blocks for flexible electronics and environmental remediation. Our work thereby demonstrates the potential of this bioinspired strategy for designing gel materials with extreme mechanical properties.

TrkB signaling is correlated with muscular fatigue resistance and less vulnerability to neurodegeneration.

At the neuromuscular junction (NMJ), motor neurons and myocytes maintain a bidirectional communication that guarantees adequate functionality. Thus, motor neurons' firing pattern, which is influenced by retrograde muscle-derived neurotrophic factors, modulates myocyte contractibility. Myocytes can be fast-twitch fibers and become easily fatigued or slow-twitch fibers and resistant to fatigue. Extraocular muscles (EOM) show mixed properties that guarantee fast contraction speed and resistance to fatigue and the degeneration caused by Amyotrophic lateral sclerosis (ALS) disease. The TrkB signaling is an activity-dependent pathway implicated in the NMJ well-functioning. Therefore, it could mediate the differences between fast and slow myocytes' resistance to fatigue. The present study elucidates a specific protein expression profile concerning the TrkB signaling that correlates with higher resistance to fatigue and better neuroprotective capacity through time. The results unveil that Extra-ocular muscles (EOM) express lower levels of NT-4 that extend TrkB signaling, differential PKC expression, and a higher abundance of phosphorylated synaptic proteins that correlate with continuous neurotransmission requirements. Furthermore, common molecular features between EOM and slow soleus muscles including higher neurotrophic consumption and classic and novel PKC isoforms balance correlate with better preservation of these two muscles in ALS. Altogether, higher resistance of Soleus and EOM to fatigue and ALS seems to be associated with specific protein levels concerning the TrkB neurotrophic signaling.

Low Hysteresis and Fatigue-Resistant Polyvinyl Alcohol/Activated Charcoal Hydrogel Strain Sensor for Long-Term Stable Plant Growth Monitoring.

Flexible strain sensor as a measurement tool plays a significant role in agricultural development by long-term stable monitoring of the dynamic progress of plant growth. However, existing strain sensors still suffer from severe drawbacks, such as large hysteresis, insufficient fatigue resistance, and inferior stability, limiting their broad applications in the long-term monitoring of plant growth. Herein, we fabricate a novel conductive hydrogel strain sensor which is achieved through uniformly dispersing the conductive activated charcoal (AC) in high-viscosity polyvinyl alcohol (PVA) solution forming a continuous conductive network and simple preparation by freezing-thawing. The as-prepared strain sensor demonstrates low hysteresis (<1.5%), fatigue resistance (fatigue threshold of 40.87 J m−2), and long-term sensing stability upon mechanical cycling. We further exhibit the integration and application of PVA-AC strain sensor to monitor the growth of plants for 14 days. This work may offer an effective strategy for monitoring plant growth with conductive hydrogel strain sensor, facilitating the advancement of agriculture.

Flexible organohydrogel ionic skin with Ultra-Low temperature freezing resistance and Ultra-Durable moisture retention.

HYPOTHESIS: One prevailing method to construct excellent temperature tolerance/long-lasting moisture hydrogels is to couple the original hydrogel networks with freezing-tolerant/moisture retaining agents, including ionic liquids, inorganic salts, zwitterionic osmolytes, and polyhydric alcohols. Among them, organohydrogels have shed new light on the development of ionic skins with long-term usability and stable sensing performance at subzero temperatures due to their long-lasting water retention and anti-freezing capability. EXPERIMENTS: We report a dual network organohydrogel by doping conductive ZnSO4 into the double network hydrogel of polyvinyl alcohol-polyacrylamide (PVA-PAM) with subsequent immersing in a mixed solvent of ethylene glycol (EG) and H2O. The anti-freezing and moisture retaining abilities of the PVA/PAM/Zn/EG (PPZE) organohydrogel were studied and the sensing performances of the PPZE organohydrogel-based ionic skin were investigated. FINDINGS: The organohydrogel exhibits a high conductivity (0.44 S m-1), excellent fatigue resistance and exceptional moisture retaining ability with more than 99.3% of the initial weight retention after 31 days storage at ambient temperature. Importantly, the PPZE organohydrogel-based ionic skin shows an ultra-low temperature anti-freezing ability and remains flexibility and sensing capability with a high sensitivity (signal response time âˆ¼ 0.23 s) even at -50 °C. The PPZE organohydrogel demonstrates a tremendous potential in artificial skin and health monitoring.

Skeletal and dentoalveolar contributions during Class II correction with Forsus™ FRD appliances : Quantitative evaluation.

PURPOSE: Primary objective of the study is to quantify and evaluate the skeletal and dental contributions during sagittal Class II correction with the Forsus™ fatigue resistant device (FRD; 3M Unitek Corp., Monrovia, CA, USA). Secondary objective is to evaluate the overall vertical, soft tissue and chin-throat relation changes with the Forsus™ appliance. PATIENTS AND METHODS: A retrospective sample of 27 Class II patients treated with the Forsus™ FRD appliance was compared to 20 untreated control subjects who were matched according to age and craniofacial morphology. Pre-Forsus™ (T0) and Post-Forsus™ (T1) cephalograms were subjected to composite cephalometric analysis. Growth changes were subtracted from the treatment changes to obtain the treatment effects of the appliance. The data were analyzed using Student's t­test and independent t test. RESULTS: Significant differences were found between the treated and the control group in 16 of 29 measured variables. The overjet and molar relation improved by 4.23 mm and 4.49 mm, respectively. This was mainly achieved by backward movement of maxillary incisors (1.4 mm) and molars (1.22 mm) and forward movement of mandibular incisors (2.26 mm) and molars (2.70 mm). Overbite decreased by 2.24 mm with no changes in mandibular and nasal plane angles. CONCLUSION: The Forsus™ FRD was effective in correcting Class II malocclusion mainly at the dentoalveolar level. The net skeletal and dentoalveolar contributions towards both overjet and molar correction was 13% and 87%, respectively. The improvement in soft tissue profile and chin-throat configuration was statistically insignificant.

Strong, tough, anti-freezing, non-drying and sensitive ionic sensor based on fully physical cross-linked double network hydrogel.

Ionic conductive double network (DN) sensors have attracted increasing attention in wearable electronic devices. However, their low mechanical and sensing properties as well as poor moisture retention and freezing resistance restrict severely their applications. Herein, we synthesized a fully physical cross-linked poly (N-hydroxymethyl acrylamide)/agar/ethylene glycol (PHA/Agar/EG) ionic conductive DN hydrogel exhibiting high strength and toughness, fast self-recovery, good fatigue resistance and good self-healing. Agar could form a physical network via reversible sol-gel transition, and interact with physical cross-linked poly (N-hydroxymethyl acrylamide) and sodium chloride (NaCl) via hydrogen bonds and salting-out effect, respectively. Meanwhile, ethylene glycol and NaCl improved the mechanical properties, long-lasting moisture retention and anti-freezing ability. The PHA/Agar/EG gel-based flexible sensor possessed excellent long-lasting and fatigue resistant sensing properties, and could monitor various human activities stably and sensitively. Therefore, this work would provide a simple and promising strategy to fabricate flexible sensors with integrated high performances for smart wearable devices.

Durable and Fatigue-Resistant Soft Peripheral Neuroprosthetics for In Vivo Bidirectional Signaling.

Soft neuroprosthetics that monitor signals from sensory neurons and deliver motor information can potentially replace damaged nerves. However, achieving long-term stability of devices interfacing peripheral nerves is challenging, since dynamic mechanical deformations in peripheral nerves cause material degradation in devices. Here, a durable and fatigue-resistant soft neuroprosthetic device is reported for bidirectional signaling on peripheral nerves. The neuroprosthetic device is made of a nanocomposite of gold nanoshell (AuNS)-coated silver (Ag) flakes dispersed in a tough, stretchable, and self-healing polymer (SHP). The dynamic self-healing property of the nanocomposite allows the percolation network of AuNS-coated flakes to rebuild after degradation. Therefore, its degraded electrical and mechanical performance by repetitive, irregular, and intense deformations at the device-nerve interface can be spontaneously self-recovered. When the device is implanted on a rat sciatic nerve, stable bidirectional signaling is obtained for over 5 weeks. Neural signals collected from a live walking rat using these neuroprosthetics are analyzed by a deep neural network to predict the joint position precisely. This result demonstrates that durable soft neuroprosthetics can facilitate collection and analysis of large-sized in vivo data for solving challenges in neurological disorders.

Is there any enhanced treatment effect on class II growing patients when Forsus Fatigue Resistant Device is reinforced by either miniplates or miniscrews? A systematic review and meta-analysis.

OBJECTIVE: To investigate the treatment effects, on skeletal class II growing patients, when miniplate-anchored Forsus Fatigue Resistant Device (MP-FFRD) and miniscrew-anchored Forsus Fatigue Resistant Device (MS-FFRD) were separately compared with conventional Forsus Fatigue Resistant Device (C-FFRD). Thus, distinguishing the differences between direct and indirect anchorages. MATERIALS AND METHODS: Comprehensive electronic and hand searching, without restrictions, were performed in CENTRAL, Scopus, Web of science, EMBASE via OVID, PubMed and ClinicalTrials.gov. Only randomized controlled trials (RCTs) and controlled clinical trials (CCTs) with patients receiving orthodontic functional treatment with MP-FFRD or MS-FFRD were included. Risk of bias was assessed using Cochrane's tools (RoB 2 and ROBINS-I). For quantitative synthesis, inverse variance method and standardized mean differences with 95% confidence intervals were chosen. RESULTS: Four RCTs and three CCTs were included. All reviewed articles included 101 patients in the experimental group and 103 patients in the control group. Regarding MP-FFRD, the analysis included data from 78 subjects (39 MP-FFRD, 39 C-FFRD). The pooled estimates showed an increase in SNB (SMD=0.7; 95% CI (0.21, 1.19); P=0.005) and in mandibular length (Co-Gn) (SMD=1.69; 95% CI (1.11, 2.27); P<0.001) in MP-FFRD compared with C-FFRD. Additionally, a reduction in lower incisors' inclination was observed in MP-FFRD group (SMD=-3.13; 95%CI (-3.83, -2.43); P<0.001). Concerning MS-FFRD, the analysis included data from 94 subjects (46 MS-FFRD, 48 C-FFRD). No significant improvement was achieved in SNB (SMD=0.19; 95% CI (-0.22, 0.60); P=0.36), yet two studies out of three reported a better control in the lower incisors' inclination. CONCLUSIONS: According to the available evidence, the direct loading of FFRD on bilateral miniplates enhanced the skeletal and dental corrections in class II growing patients; however, the clinical significance of the statistical results is questionable. The treatment effects of the indirect loading of FFRD on miniscrews were mainly dentoalveolar, yet with better control of lower incisors' inclination.

Treatment outcome and long-term stability of class II correction with forsus fatigue resistant device in non-growing patients.

OBJECTIVES: Forsus™ Fatigue Resistant Device (FRD) is one of the commonly used semirigid fixed functional devices. Purpose of the present study was to investigate effects and long-term stability of Class II correction following use of Forsus FRD in a retrospective clinical study. SETTING AND SAMPLE POPULATION: Records of 20 patients (mean age 18.3 ± 2.5 years) with Class II malocclusion, who had undergone fixed functional treatment protocol with Forsus FRD, were collected from our clinical archive. MATERIALS AND METHODS: Lateral cephalometric radiographs at pre-treatment (T0), end of comprehensive treatment (T1) and post-retention period (T2, mean duration: 19 ± 3 months) were analysed and superimposed to assess skeletal and dental changes on the long-term. Repeated measurement one way ANOVA was used for the study of the significant differences among the mean values of cephalometric parameters at T0, T1, and T2. To analyse the nature of the bilateral significant differences between two different time points, Bonferroni test was used. RESULTS: Sagittal and vertical skeletal changes at T0-T1 were statistically insignificant while all dentoalveolar parameters exhibited highly significant changes. At T1-T2, all skeletal and dentoalveolar parameters were stable except the slight relapse in overjet (0.3 ± 0.5 mm; P < .05). At T0-T2 interval, no significant skeletal changes were recorded while the dentoalveolar changes remained significantly improved. CONCLUSION: Correction of Class II malocclusion achieved with Forsus FRD was dentoalveolar and treatment effects were stable in the 19 ± 3 months follow-up period.

Effects of the Forsus Fatigue-resistant Device on Skeletal Class II Malocclusion Correction.

AIM: To test the hypothesis that skeletal and dentoalveolar effects are both important in skeletal class II malocclusion corrected with the Forsus fatigue-resistant device (FRD). MATERIALS AND METHODS: A total of 35 patients (16 females and 19 males; age 12.0 ± 0.6 years) with skeletal class II malocclusion treated with the Forsus FRD were included. Lateral cephalometric radiographies before and after treatment were collected. Cephalometric analysis and superimpositions were applied. Pancherz's analysis was performed to discover the skeletal and dentoalveolar effects on all patients and 60% contribution was set as a milestone to classify. Statistical comparisons were performed by paired t testing (p < 0.05). RESULTS: The mean treatment period of the Forsus FRD was 6.4 ± 0.2 months. All patients (AG) have been corrected to class I molar relationship in three mechanisms: 15 patients in the skeletal group (SG), 10 patients in the dentoalveolar group (DG), and 10 patients in the skeletal and dentoalveolar group (SDG). Four groups showed a significant change in skeletal sagittal relationship improvement (p < 0.05). The AG, SG, and SDG showed a significant improvement in the growth of the mandible (Co-Go, Go-Pog, and Co-Gn, p < 0.05). The DG showed a significant improvement in the growth of the mandibular body (Go-Pog, p < 0.05). CONCLUSION: Three mechanisms were found in skeletal class II malocclusion corrected with the Forsus FRD. Skeletal and dentoalveolar effects are both important in skeletal class II malocclusion corrected with the Forsus FRD. And skeletal and dentoalveolar effects played differential roles in different cases. CLINICAL SIGNIFICANCE: The mechanism of skeletal class II correction with Forsus FRD may divide into mandibular growth, dentoalveolar effects, and both.

Ultralight, Superelastic, and Fatigue-Resistant Graphene Aerogel Templated by Graphene Oxide Liquid Crystal Stabilized Air Bubbles.

Graphene aerogel (GA) has attracted great attention due to its unique properties, such as ultralow density, superelasticity, and multifunctionality. However, it is a great challenge to develop superelastic and fatigue-resistant GA (SFGA) with ultralow density because it is generally contradictory to improve the mechanical properties with reducing density of GA. Herein, we report a simple and efficient approach to prepare ultralight SFGA templated by graphene oxide liquid crystal (GOLC) stabilized air bubbles. The thus-prepared ultralight SFGA (∼2 mg cm-3) exhibits superelasticity (rapid recovery from >99% compression) and unprecedented fatigue-resistant performance (maintaining shape integrity after 106 compressive cycles at 70% strain and 5 Hz). The ultralow density and excellent dynamic mechanical properties of SFGA are mainly associated with the "volume exclusion effect" of the air bubbles as well as the highly ordered, closely packed, and uniform porous structure of the resultant GA, respectively. This study provides a green and facile strategy for preparing high-performance ultralight SFGA, which has great potential in various applications, including ultrafast dynamic pressure sensors, soft robot, and flexible devices.

Sagittal skeletal correction using symphyseal miniplate anchorage systems : Success rates and complications.

OBJECTIVES: Aim of this study is to evaluate success rates and complications related with symphyseal miniplate anchorage systems used for treatment of Class 2 and Class 3 deformities. METHODS: A total of 58 miniplates applied to 29 growing patients were evaluated. The first group comprised 24 symphyseal miniplates applied to 12 patients and Forsus Fatigue Resistant Devices were attached to the head of the miniplates for mandibular advancement. The second group consisted of 34 symphyseal miniplates applied to 17 patients and intermaxillary elastics were applied between acrylic appliances placed on the maxillary dental arch and the symphyseal miniplates for maxillary protraction. Success rate and complications of the symphyseal plate-screw anchorage system were evaluated. RESULTS: The overall success rate of symphseal miniplates was 87.9%. Six miniplates showed severe mobility and 2 miniplates broke during orthodontic treatment. Infection, miniplate mobility and mucosal hypertrophy were statistically different between the two groups. CONCLUSIONS: Symphyseal miniplates were generally used as successful anchorage units in most patients. Infection, mobility, and mucosal hypertrophy occurred more frequently in Class 2 deformity correction. However, the success rates regarding the two treatment modalities were comparable.

Treatment of class II malocclussion: A comparative study of the effects of twin-block and fatigue resistant device.

AIM: This is a retrospective cephalometric study aimed to compare the treatment effects of Twin-Block (TB) appliance with The Forsus Fatigue Resistant Device (FRD) appliance in class II division I patients in a composite of peak and post peak growth of period time. MATERIALS AND METHODS: The experimental sample consisted of the lateral cephalograms of 40 patients who were treated with either TB appliance (n = 15), FRD (n = 15) or the untreated control ones. In treatment groups lateral cephalograms taken before therapy as initial records (T1) and at the completion of functional therapy (T2) were used. The control group comprised 10 children with untreated skeletal Class II malocclusions. The normality of distribution of continuous variables was tested by Shaphiro wilk test. Oneway ANOVA and LSD test in parametric; Kruskall Wallis and all pairwaise multible comparison tests in non-parametric samples were used for comparing differences among 3 groups. RESULTS: Cephalometric analysis revealed that both TB and FRD appliances stimulated mandibular growth (P < 0.05) and no restriction was seen in maxilla in both groups (P > 0.05). The unwanted mandibular proclination was seen more in FRD group (P ≤ 0.001). Soft tissue didn't imitate the hard tissue (P > 0.05). CONCLUSION: FRD group produced skeletal effects as much as TB group in peak and post peak period of growth with still more mandibular incisor proclination.

Fatigue Resistant Bioinspired Composite from Synergistic Two-Dimensional Nanocomponents.

Portable and wearable electronics require much more flexible graphene-based electrode with high fatigue life, which could repeatedly bend, fold, or stretch without sacrificing its mechanical properties and electrical conductivity. Herein, a kind of ultrahigh fatigue resistant graphene-based nanocomposite via tungsten disulfide (WS2) nanosheets is synthesized by introducing a synergistic effect with covalently cross-linking inspired by the orderly layered structure and abundant interfacial interactions of nacre. The fatigue life of resultant graphene-based nanocomposites is more than one million times at the stress level of 270 MPa, and the electrical conductivity can be kept as high as 197.1 S/cm after 1.0 × 105 tensile testing cycles. These outstanding properties are attributed to the synergistic effect from lubrication of WS2 nanosheets for deflecting crack propagation, and covalent bonding between adjacent GO nanosheets for bridging crack, which is verified by the molecular dynamics (MD) simulations. The WS2 induced synergistic effect with covalent bonding offers a guidance for constructing graphene-based nanocomposites with high fatigue life, which have great potential for applications in flexible and wearable electronic devices, etc.

Three-dimensional effects of the mini-implant-anchored Forsus Fatigue Resistant Device: A randomized controlled trial.

OBJECTIVE: To detect three-dimensionally the effects of using mini-implant anchorage with the Forsus Fatigue Resistant Device (FFRD). MATERIALS AND METHODS: The sample comprised 43 skeletal Class II females with deficient mandibles. They were randomly allocated into three groups: 16 patients (13.25 ± 1.12 years) received FFRD alone (Forsus group), 15 subjects (13.07 ± 1.41 years) received FFRD and mini-implants (FMI group), and 12 subjects (12.71 ± 1.44 years) were in the untreated control group. Three-dimensional analyses of cone beam computed tomographic images were completed, and the data were statistically analyzed. RESULTS: Class I relationship and overjet correction were achieved in 88% of the cases. None of the two treatment groups showed significant mandibular skeletal effects. In the FMI group, significant headgear effect, decrease in maxillary width, and increase in the lower facial height were noted. In the FMI group, retroclination of maxillary incisors and distalization of maxillary molars were significantly higher. Proclination and intrusion of mandibular incisors were significantly greater in the Forsus group. CONCLUSIONS: FFRD resulted in Class II correction mainly through dentoalveolar effects and with minimal skeletal effects. Utilization of mini-implant anchorage effectively reduced the unfavorable proclination and intrusion of mandibular incisors but did not produce additional skeletal effects.

Management of Class II malocclusion with ectopic maxillary canines.

Correction of Class II relationship, deep bite and ectopically erupting canines is an orthodontic challenge for the clinician. A 13-year-old male patient presented with Class II malocclusion, ectopically erupting canines, and cross bite with maxillary left lateral incisor. He was treated with a combination of Headgear, Forsus™ fatigue resistant device [FFRD] with fixed mechanotherapy for the management of space deficiency and correction of Class II malocclusions. Headgear was used to distalize upper first molars and also to prevent further downward and forward growth of the maxilla. Then Forsus™ FFRD was used for the advancement of the mandible. The molar and canine relationship were corrected from a Class II to a Class I. The objectives were to establish good occlusion and enable eruption of unerupted canines. All these objectives were achieved and remained stable.