Site Of Weakness Research Articles

Imaging of the Pediatric Knee.

During normal development, imaging findings in the immature knee joint may mimic pathology or indicate transient sites of weakness, prone to injury. This article reviews the development of the knee joint, age- and maturation-dependent imaging considerations, and various developmental variants that can be encountered, subdivided into those that involve the tibiofemoral and patellofemoral compartments, soft tissues, and osseous components. The tibiofemoral compartment section reviews the focal periphyseal edema zone (FOPE), ossification variants of the femoral condyles, distal femoral metaphyseal cortical irregularity from periosteal traction, and the metaphyseal subperiosteal stripe, which should be distinguished from pathologic mimickers such as endochondral ossification dysfunction, osteochondritis dissecans (OCD), fibroosseous lesion, periosteal and subcortical pathologies. The patellofemoral compartment section includes a review of partite patella, dorsolateral defect, variant trochlear morphology, and maturation-dependent sites of transient weakness that are prone to injury from repetitive overuse (Sinding-Larsen-Johansson syndrome and Osgood-Schlatter disease) and avulsion fractures (patellar sleeve and tibial tubercle avulsions). Finally, soft tissue (discoid lateral meniscus, meniscal flounce, anterior cruciate ligament variants) and osseous components (meniscal ossicle, fabella, and cyamella) are reviewed.

The Immature Pediatric Appendicular Skeleton.

Growth and maturation occur in a predictable pattern throughout the body and within each individual bone. In the appendicular skeleton, endochondral ossification predominates in long bones and growth plates. The ends of these long bones are sites of relative weakness in the immature skeleton and prone to injury from acute insult and overuse. We present the normal histoanatomy and physiology of the growth plate complex, highlighting the unique contribution of each component and shared similarities between primary and secondary complexes. Components of the growth plate complex include the physis proper, subjacent vascularity within the growth cartilage, and the ossification front. The second section describes imaging considerations and features of normal and abnormal growth. Finally, we review the Salter-Harris classification for acute fractures and offer examples of characteristic overuse injury patterns involving the epiphyseal (proximal humerus and distal radius), apophyseal (medial epicondyle and tibial tubercle), and secondary growth plate complexes (medial femoral condyle and capitellar osteochondritis dissecans). This article provides a foundation and basic framework to better understand and anticipate potential complications and growth disturbances and to ensure optimal follow-up and early intervention when treatment can be less invasive.

RUPTURED RETINAL ARTERIAL MACROANEURYSMS ASSOCIATED WITH HEMORRHAGIC BACILLARY LAYER DETACHMENTS.

Bacillary layer detachments (BALAD) are a recently recognized form of retinal detachment involving a splitting of photoreceptors at the inner segment myoid zone, with separation of the external limiting membrane and ellipsoid zone on optical coherence tomography (OCT). A growing number of disease processes are recognized to cause BALAD, and here we present three of the first cases of hemorrhagic retinal artery macroaneurysms that resulted in BALAD. A retrospective review of three patients who presented for acute, painless, monocular vision loss was performed. Multimodal imaging including fundus photography and OCT are included in this analysis. Three elderly female patients, all with a history of hypertension, presented with ruptured macroaneurysms involving the macula. All three patients had evidence of BALAD on OCT. Various management strategies were used. Hemorrhagic retinal arterial macroaneurysms can be associated with BALAD, observed best on OCT. This is most likely secondary to the rapid accumulation of intraretinal fluid during the hemorrhage, which leads to an avulsion at the inner segment myoid zone-a site of inherent structural weakness in the photoreceptors. Visual recovery may be improved in instances of hemorrhagic macroaneurysms associated with BALAD, similar to other disease entities where BALAD occurs, although further research is needed.

Comparison of Perioperative Complication Rates of Total Extraperitoneal and Transabdominal Preperitoneal Repairs in Primary Inguinal Hernia.

Hernia may be defined as a protrusion of viscus through layers anatomically designed to contain that viscus. Most abdominal hernias occur at well-described sites of potential weakness. Repair of inguinal hernia is one of the most common operations in general surgery. Objectives: To compare the perioperative complication rates of total extraperitoneal (TEP) and transabdominal preperitoneal (TAPP) repairs of primary inguinal hernias. It is a randomised comparative study, conducted at the department of general surgery. A total of 50 patients were included and divided into two groups with 25 in each. Group A represents the laparoscopic TEP repair and group B represents the laparoscopic TAPP repair. Patients above 18 years with primary unilateral inguinal hernia were included. Patients having complicated inguinal hernia and history of previous abdominal surgery were excluded. We observed that hernia occurrence is more common in the 31-50 years of age group and right-sided hernia is more common. Scrotal oedema and conversion to open surgery chances are similar in both TEP and TAPP groups. The duration of surgery in TEP is significantly higher as compared to TAPP. Patients who underwent TEP experienced less pain as compared to TAPP as per visual analogue scale. Postoperative hospital stay and time taken to resume the routine activity were significantly less in case of TEP. TEP is preferred over TAPP for laparoscopic hernia repair because it preserves the peritoneal integrity and has lesser postoperative pain. The early recovery and return to the routine work were seen with the patient treated with the TEP and also showed better visual analogue score than the TAPP repair group.

Incomplete Crack Sealing Causes Localization of Fracturing in Hydrothermal Quartz Veins

AbstractCyclic microfracturing and epitaxial crystal growth have long been recognized in crack‐seal veins, but an understanding of a single crack‐seal cycle is still missing. Here we present a phase‐field model that includes both fracture mechanics of crack propagation, and epitaxial crystal growth on the fracture walls, repeating this cycle multiple times in a polycrystalline, microporous quartz rock. Our simulations have two end members: If a vein completely seals, it is stronger than the host rock, cracking is delocalized, forming many single‐seal microveins. Incomplete sealing makes the vein weaker than the host rock and localizes the new fracture inside the vein, leading to multi‐crack‐seal. We suggest that the sealing degree is a key parameter in hydrothermal systems and multi‐crack‐seal veins are long‐lived, microporous sites of mechanical weakness. We generalize the phase‐field approach to conduct probabilistic simulations in between these two types, and show how systems of microveins and multi‐crack‐seal veins emerge.

Wedge tectonics in South China: constraints from new seismic data

Collisional orogens form when tectonic forces amalgamte fragments of Earth’s continental lithosphere. The sutures between individual fragments, or terranes, are potential sites of weakness that facilitate subsequent continental breakup. Therefore, the lithospheric architecture of collisional orogens provides key information for evaluating the long-term evolution of the continental interior: for example, the South China Block (SCB), where the tectonic history is severely obscured by extensive surface deformation, magmatism, and metamorphism. Using new passive-source seismic models, we show a contrasting seismic architecture across the SCB, with three prominent crustal dipping structures across the Jiangnan Orogen. Combined with constraints from multi-disciplinary regional geophysical datasets, these pronounced dipping patterns are interpreted as relict wedge-like lithospheric deformation zones initiated in the fossil collisions that assembled the Yangtze Block and the SCB. The overall trend of these tectonic wedges implies successive crustal growth along paleo-continental margins and is indicative of northward subduction and docking of accretional terranes. In contrast, no such dipping structures are preserved in the Cathaysia Block, indicating a weak and reorganized lithosphere. The variations in the deformation responses across the SCB reflect the long-term modifications of the lithosphere caused by prolonged collision and extension events throughout the tectonic history of the SCB. Our results demonstrate the critical roles that suture zones played in the successive growth and evolution of the continental lithosphere.

The polyene antifungal candicidin is selectively packaged into membrane vesicles in Streptomyces S4

In recent years, much attention has been focused on the biogenesis, engineering and utilisation of outer membrane vesicles (OMVs) in Gram-negative bacteria in a range of environments and niches. While the precise mechanism of biogenesis is unknown, it is focused on the modification of the Gram-negative cell wall to facilitate blebbing at sites of weakness in and around the characteristically thin peptidoglycan layer within the periplasm. Here, we investigate the biogenesis of membrane vesicles (MVs) in the Gram-positive organism Streptomyces albus S4 (Seipke et al. J Bacteriol 193:4270–4271, 2011 and Fazal et al. Antonie Van Leeuwenhoek 113:511–520, 2020). The S. albus S4 strain is an antifungal (candicidin and antimycin) producing organism that was isolated from attine ants (Barke et al. BMC Biol 8:109, 2010). The biogenesis and characterisation of S. albus S4 MVs is demonstrated using the wild-type (WT) and mutant strains ΔantC (no antimycin production) ΔfscC (no candicidin production) and ΔantC ΔfscC (produces neither antimycin nor candicidin). Here, we have shown that the S. albus S4 strain produces MVs and that these are comprised of both specific protein profiles and secondary metabolites, with a clear demonstration of the ability to selectively package one antifungal (candicidin) but not the other (antimycin).

Rational Design of Pepsin for Enhanced Thermostability via Exploiting the Guide of Structural Weakness on Stability

Enzyme thermostability is an important parameter for estimating its industrial value. However, most naturally produced enzymes are incapable of meeting the industrial thermostability requirements. Software programs can be utilized to predict protein thermostability. Despite the fast-growing number of programs designed for this purpose; few provide reliable applicability because they do not account for thermodynamic weaknesses. Aspartic proteases are widely used in industrial processing; however, their thermostability is not able to meet the large-scale production requirements. In this study, through analyzing structural characteristics and modifying thermostability using prediction software programs, we improved the thermostability of pepsin, a representative aspartic protease. Based on the structural characteristics of pepsin and the experimental results of mutations predicted by several energy-based prediction software programs, it was found that the majority of pepsin’s thermodynamic weaknesses lie on its flexible regions on the surface. Using computational design, mutations were made based on the predicted sites of thermodynamic weakness. As a result, the half-lives of mutants D52N and S129A at 70°C were increased by 200.0 and 66.3%, respectively. Our work demonstrated that in the effort of improving protein thermostability, identification of structural weaknesses with the help of computational design, could efficiently improve the accuracy of protein rational design.

Retinal Pigment Epithelium Transplantation in a Non-human Primate Model for Degenerative Retinal Diseases

Retinal pigment epithelial (RPE) transplantation holds great promise for the treatment of inherited and acquired retinal degenerative diseases. These conditions include retinitis pigmentosa (RP) and advanced forms of age-related macular degeneration (AMD), such as geographic atrophy (GA). Together, these disorders represent a significant proportion of currently untreatable blindness globally. These unmet medical needs have generated heightened academic interest in developing methods of RPE replacement. Among the animal models commonly utilized for preclinical testing of therapeutics, the non-human primate (NHP) is the only animal model that has a macula. As it shares this anatomical similarity with the human eye, the NHP eye is an important and appropriate preclinical animal model for the development of advanced therapy medicinal products (ATMPs) such as RPE cell therapy. This manuscript describes a method for the submacular transplantation of an RPE monolayer, cultured on a polyethylene terephthalate (PET) cell carrier, underneath the macula onto a surgically created RPE wound in immunosuppressed NHPs. The fovea-the central avascular portion of the macula-is the site of the greatest mechanical weakness during the transplantation. Foveal trauma will occur if the initial subretinal fluid injection generates an excessive force on the retina. Hence, slow injection under perfluorocarbon liquid (PFCL) vitreous tamponade is recommended with a dual-bore subretinal injection cannula at low intraocular pressure (IOP) settings to create a retinal bleb. Pretreatment with an intravitreal plasminogen injection to release parafoveal RPE-photoreceptor adhesions is also advised. These combined strategies can reduce the likelihood of foveal tears when compared to conventional techniques. The NHP is a key animal model in the preclinical phase of RPE cell therapy development. This protocol addresses the technical challenges associated with the delivery of RPE cellular therapy in the NHP eye.

Retinal Pigment Epithelium Transplantation in a Non-human Primate Model for Degenerative Retinal Diseases.

Retinal pigment epithelial (RPE) transplantation holds great promise for the treatment of inherited and acquired retinal degenerative diseases. These conditions include retinitis pigmentosa (RP) and advanced forms of age-related macular degeneration (AMD), such as geographic atrophy (GA). Together, these disorders represent a significant proportion of currently untreatable blindness globally. These unmet medical needs have generated heightened academic interest in developing methods of RPE replacement. Among the animal models commonly utilized for preclinical testing of therapeutics, the non-human primate (NHP) is the only animal model that has a macula. As it shares this anatomical similarity with the human eye, the NHP eye is an important and appropriate preclinical animal model for the development of advanced therapy medicinal products (ATMPs) such as RPE cell therapy. This manuscript describes a method for the submacular transplantation of an RPE monolayer, cultured on a polyethylene terephthalate (PET) cell carrier, underneath the macula onto a surgically created RPE wound in immunosuppressed NHPs. The fovea-the central avascular portion of the macula-is the site of the greatest mechanical weakness during the transplantation. Foveal trauma will occur if the initial subretinal fluid injection generates an excessive force on the retina. Hence, slow injection under perfluorocarbon liquid (PFCL) vitreous tamponade is recommended with a dual-bore subretinal injection cannula at low intraocular pressure (IOP) settings to create a retinal bleb. Pretreatment with an intravitreal plasminogen injection to release parafoveal RPE-photoreceptor adhesions is also advised. These combined strategies can reduce the likelihood of foveal tears when compared to conventional techniques. The NHP is a key animal model in the preclinical phase of RPE cell therapy development. This protocol addresses the technical challenges associated with the delivery of RPE cellular therapy in the NHP eye.

HALT (Hernia Active Living Trial): protocol for a feasibility study of a randomised controlled trial of a physical activity intervention to improve quality of life in people with bowel stoma with a bulge/parastomal hernia

BackgroundParastomal hernia (PSH) can be repaired surgically, but results to date have been disappointing, with reported recurrence rates of 30 to 76%. Other types of intervention are therefore needed to improve the quality of life of people with PSH. One potential intervention is physical activity. We hypothesise that the intervention will increase core activation and control across the abdominal wall at a site of potential weakness and thus reduce the risk of PSH progression. Increases in physical activity will improve body image and quality of life (QoL).MethodsSubjects and sampleThere were approximately 20 adults with a bowel stoma and PSH. People with previous PSH repair will be excluded as well as people who already do core training.Study designThis is a feasibility study of a randomised controlled trial with 2 months follow-up, in 2 sites using mixed methods. Stage 1 involves intervention development and in stage 2, intervention and trial parameters will be assessed.InterventionA theoretically informed physical activity intervention was done, targeting people with PSH.Main outcome of feasibility studyThe main outcome is the decision by an independent Study Steering Committee whether to proceed to a full randomised controlled trial of the intervention.Other outcomesWe will evaluate 4 intervention parameters—fidelity, adherence, acceptability and safety and 3 trial parameters (eligible patients’ consent rate, acceptability of study design and data availability rates for following endpoints):Diagnosis and classification of PSHMuscle activationBody composition (BMI, waist circumference)Patient reported outcomes: QoL, body image and physical functioningPhysical activity;Psychological determinants of physical activityOther dataIncluded are other data such as interviews with all participants about the intervention and trial procedures.Data analysis and statistical powerAs this is a feasibility study, the quantitative data will be analysed using descriptive statistics. Audio-recorded qualitative data from interviews will be transcribed verbatim and analysed thematically.DiscussionThe feasibility and acceptability of key intervention and trial parameters will be used to decide whether to proceed to a full trial of the intervention, which aims to improve body image, quality of life and PSH progression.Trial registrationISRCTN15207595

Imaging of Acute Shoulder Trauma

Acute injuries to the shoulder girdle are common and frequently encountered by the practicing radiologist. The type of injury is highly dependent on the age of the patient and mechanism of trauma with injuries occurring at the site of greatest mechanical weakness. In this review, we discuss the main clinical features and key imaging findings for the most common shoulder injuries. For each injury, we also provide a section on the important features that the orthopedic surgeon needs to know in order to guide surgical versus nonsurgical management.

Leveling measurements of antifouling coatings using an optical profilometer: Effects of additives and solvent concentration and type

Ship hulls require smooth antifouling coating surfaces to decrease frictional drag and avoid sites of weakness for biofouling. Consequently, the leveling properties of antifouling coatings should be understood and optimized. In the present work, a novel approach to quantitatively measure leveling properties of coating films was developed. Using this approach, dynamic surface textures during leveling of selected model antifouling formulations were measured using a combination of a three-dimensional (3D) profilometer and a retrofitted automatic film application system. It was found that the leveling process is strongly coupled to the solvent evaporation rate and the associated development in coating viscosity. For low viscous coatings, three leveling stages were observed. High viscous coatings, on the other hand, only went through one leveling stage.Experimental data showed that an underlying tie-coat (relative to a flat acrylic panel) had negative effects on the smoothness of the top coat. In addition, using an anti-sagging agent enabled control of sagging, but resulted in negative effects on leveling. Nevertheless, it was still possible to obtain good leveling performance with anti-sagging agent in a formulation.The effects of minor amounts of three types of additives and two types of solvents on leveling of the model formulations during (and after) spraying application were found to be less significant than those seen from drawdown application. It is therefore important to take into account the application method when studying leveling phenomena.

Examining switching power: Mark Zuckerberg as a novel networked media mogul

ABSTRACTThis paper explores Mark Zuckerberg's attempts at ‘network switching’ (Arsenault & Castells, 2008a. Switching power: Rupert Murdoch and the global business of media politics: A sociological analysis. International Sociology, 23(4), 488–513) in order to examine the nature of power in the network society in an age of social media dominance. Through a case study of Mark Zuckerberg and Facebook we illustrate how novel networked media moguls gain and retain power through the interconnection of multiple networks and attempts to reprogram common goals and resources. We thus further test Arsenault and Castells’ (2008a. Switching power: Rupert Murdoch and the global business of media politics: A sociological analysis. International Sociology, 23(4), 488–513) hypothesis through an analysis of Zuckerberg, and Facebook's, key operational strategies and their success in facilitating the interconnection of a multitude of networks. In disentangling the strategy, rhetoric and actions of Zuckerberg – notably in the Cambridge Analytica scandal and in his philanthropic efforts with the Chan Zuckerberg Initiative – we analyze how ‘switching’ power manifests within the context of an inextricable relationship between SNSs and a range of other networks including political, financial, philanthropic and scientific. Moreover, an examination of the multitude of networks Zuckerberg operates within highlights both the opportunities and pitfalls associated with the decentralization and dissemination of power within the network society. Accordingly, this paper offers two updates to the original hypothesis posed by Arsenault & Castells; (1) network switches act as both points for leveraging power and as potential sites of weakness and (2) growing technological interconnection and the visibility of social media require successful network switchers to increasingly operate ‘mega-switches’ in order to successfully compete against other power seekers.

The Profile of Amyotrophic Lateral Sclerosis in Natives of Western Himalayas: Hospital-Based Cohort Study.

Background:Despite the disabling nature of amyotrophic lateral sclerosis (ALS), there are no contemporary data on clinical characteristics available from rural hilly states from India. Thus, the present study aimed at reporting clinical profile in ALS patients from natives of Western Himalayas.Materials and Methods:A total of 32 patients of ALS were enrolled over a period of 1 year (2013–2014) in the present study. The demographic profile, clinical characteristics, and risk factors were systematically recorded, and these patients were followed for 1 year.Results:The mean age of ALS patients was 53 ± 15.88 (23–90 years). Maximum number of patients of both limb onset and bulbar onset were in the age group of 40–49 years [Figure 1]. Male to female ratio was 1.46. Limb-onset was seen in 23 (72%) and bulbar-onset in 9 (28%) of patients. Bulbar-onset was more common in females as compared to males. Mean duration of symptoms were 19.06 ± 24 months (range 4–120 months). None of the studied risk factor showed statistically significant association with outcome of the disease. No familial association was found. The most common site of weakness was upper limb distal weakness. Definite ALS was seen in 13 (40.6%) patients. Mean ALS functional rating scale (ALSFRS) at presentation is 35.7 ± 7.9. All patients were started on riluzole. Mean ALSFRS at 9-month follow-up was 32.9 ± 7.4. After 1 year of follow up, 5 out of 32 patients died and among them, 4 were of limb onset and 1 was of bulbar onset ALS. Mean age at death in males was 66 ± 16 years and in females was 56.33 ± 24.8 years; mean survival in these patients was 25 months.Conclusion:This present study highlights following findings: (1) Male preponderance is less common in our patients as compared to earlier reports from India. Bulbar onset is more common in elderly (age >60 years) females. (2) As per previous reports from India, when compared to Western population present study supports the fact of the younger age of onset and longer duration of symptoms and slow course of disease in Indian patients.

Initial experiences with a new design for a preattached intravenous port device.

All available conventional ports share a common design, including catheter, locking nut, and port body, and all share two sites of structural weakness. One site is the junction between the locking nut and the proximal end of the catheter. The other site is the catheter fixation site between the locking nut and the protruding stud of the connecting tube. To overcome these shortcomings, we designed a new type of intravenous port which combines the connecting tube into one piece. The aims of this study were to test the mechanical characteristics of the new design and assess its safety in animal study. The prototype of the preattached port was manufactured from biocompatible materials, including PEEK, silicone and polyurethane. All components were assembled with biocompatible glue and mechanical and safety tests were performed to determine the mechanical strength, and tissue reaction of surrounding soft tissue and entry vessels. The mechanical tests showed the new design would not lead to catheter fracture in the oscillation test. The traction test showed significant peak load (18.75 ± 3.29 vs. 26.61 ± 1.75 N; p = 0.036) because of the difference in catheter extension capacity (26.57 ± 4.28 vs. 47.93 ± 2.45 mm; p = 0.012). Significantly smaller endurable injection pressure was identified in the prototype. (90 ± 20 vs. 177.5± 9.48 psi; p = 0.01) The safety test showed good tolerance in beagle dogs and led to no intravascular thrombus and minimal reaction in surrounding tissues. The new prototype preattached port showed good mechanical strength and overcame two potential structural weakness points. The integrated fixation design not only reduced the dimensions of the port device but also provided a greater injection area compared to current designs. It did not cause intravascular thrombosis and produced minimal tissue reaction in surrounding soft tissue, as identified by autopsy. The new design of the fixation device could serve as the basis for the next generation of intravenous ports. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1017-1027, 2018.

The Once and Future King

On the cinema screen, boyhood has often been depicted as a period of freedom, rebellion, and energy, a pre-cursor to manhood in which young boys are able to negotiate their identity and place within the world. In 1990s Hollywood, however, a wave of films turn to depicting the death of young boys on screen. As a result, boyhood becomes a site of vulnerability and weakness. This article seeks to examine the implications of these deaths, framing them within the context of a wider negotiation of masculinity and fatherhood politics. In addition, it questions the extent to which the deaths of these young boys can be read queerly, subverting the drive towards the future inherent in the figure of the child.

Mantle plume–subduction zone interactions over the past 60 Ma

A variety of mantle plume types have been proposed and there is a wide range of ways that these plumes might interact with subduction zone arcs. This study looks at the frequency of interaction between previously catalogued plumes and subduction zones while also assessing the potential role of slab windows to either generate false plume signals or contribute to genuine examples of mantle plume–subduction zone interactions. Of the plumes included in several widely cited catalogues, 29% have moved within 1000km of a subduction zone and 17% have moved within 500km of a subduction zone over the past 60Ma, assuming that the plume life span extended over this period. Of the plumes that moved within 1000km of a subduction zone, 56% are rated as either a deep or mid-mantle plume by an author of at least one of the catalogues. The 44% of interacting plumes that are not rated as mid-mantle or deep by at least one author are the most likely to be related to “top-down” plate tectonic processes. This study shows that they were never coincident with a slab window, although they have often interacted within distances of 1000km. The manner of interaction between plumes and slab windows depends on the relative positions of the plume, ridge, and slab window. Of the plumes that interact over a 1000km circular “Zone of Potential Interaction” (ZPI), 28% are no longer interacting today, but have survived that process. While most plumes interact in the form of a ZPI moving over a trench from either behind or in front of the trench, several plumes do cross the trench, demonstrating that plumes can survive even that interaction. Plume–trench interaction occurs in clusters in the northeast and southwest Pacific with limited events in the northwest and southeast Pacific. The presence of clusters in the northeast and southwest Pacific may be caused by the closer proximity of mid-mantle and deep plumes to a subduction zone in these areas. Whereas some deeper plumes may be modified by slab related mantle flow, the coincidence of shallow plumes with changes in plate boundaries suggests an origin related to sites of weakness or extension in the oceanic crust.

Reasons for mini-implants failure: choosing installation site should be valued!

Mini-implant loss is often associated with physical and mechanical aspects that result from choosing an inappropriate placement site. It is worth highlighting that:a) Interdental alveolar bone crests are flexible and deformable. For this reason, they may not offer the ideal absolute anchorage. The more cervical the structures, the more delicate they are, thus offering less physical support for mini-implant placement; b) Alveolar bone crests of triangular shape are more deformable, whereas those of rectangular shape are more flexible; c) The bases of the alveolar processes of the maxilla and the mandible are not flexible, for this reason, they are more likely to receive mini-implants; d) The more cervical a mini-implant is placed, the higher the risk of loss; the more apical a mini-implant is placed, the better its prognosis will be; e) 3D evaluations play a major role in planning the use of mini-implants.Based on the aforementioned considerations, the hypotheses about mini-implant loss are as follows:1) Deflection of maxillary and mandibular alveolar processes when mini-implants are more cervically placed; 2) Mini-implants placed too near the periodontal ligament, with normal intra-alveolar tooth movement; 3) Low bone density, low thickness and low alveolar bone volume; 4) Low alveolar cortical bone thickness; 5) Excessive pressure inducing trabecular bone microfracture; 6) Sites of higher anatomical weakness in the mandible and the maxilla; 7) Thicker gingival tissue not considered when choosing the mini-implant.

Zoster paresis: Asymptomatic MRI lesions far beyond the site of rash and focal weakness

We describe a patient with zoster paresis and an MRI that revealed extensive spinal cord lesions from the upper cervical to the lower thoracic spinal cord. Importantly, the patient reported considerable spontaneous improvement in strength 2–3weeks after zoster. This report reveals a previously undescribed remarkable preponderance of MRI lesions far beyond the site of zoster rash and focal lower motor neuron weakness.