Excessive Coverage Research Articles

Excessive coverage effect (over peening) in the blasting operation of aluminum alloy “AA 7475-T7351” with steel shot

ABSTRACT Aluminum and its alloys are widely used in the aeronautics industry due to its high lightness and ductility, and it can add other elements, thus changing its characteristics. Fatigue is the major cause of failure of metal materials due to the dynamic and oscillating stresses of the finished materials. The objective of this work is to evaluate the effect of Shot Peening with coverage percentages 1blasting, 3 blasting and 10 blasting in fatigue life of aluminum alloy AA 7475-T351. Shot Peening is a cold surface treatment used to increase fatigue life of the alloy by inducing residual stresses of compression on the surface of the part. In the Shot Peening process, spherical steel grids of type S230 were used, in which the specimens were subjected to 1blasting, 3 blasting and 10 blasting coverage in two stress levels (42 Ksi and 50 Ksi). The results presented in the fatigue tests and electron scanning (SEM) showed the increase in the mechanical properties of all the samples, and those exposed to 1 blasting and 3 blasting presented better results.

Analysis of the Influence of High Peening Coverage on Almen Intensity and Residual Compressive Stress

The effectiveness of shot peening is mainly determined by the peening coverage. The peening coverage is required to be 100% for current technical standards of shot peening. With the increase of material strength, higher peening coverage is required in shot peening process. However, the influence of high peening coverage on Almen intensity and residual compressive stress is unclear, the difficulty mainly lies in the lack of quantitative description of peening coverage in finite element analysis. To analyze the influence of high peening coverage on Almen intensity and residual compressive stress, firstly an approximate quantitative description of peening coverage based on dent size, the distance of shots and shot numbers is proposed in this study. Based on this quantitative description of peening coverage, the arc height and residual stress of the Almen test are simulated with the finite element method. The simulation results of arc height and saturation curve agree well with that of the Almen test, by which the effectiveness of the quantitative description and FE simulation are proved. The further study indicates that in shot peening processes, the excessive peening coverage doesn’t improve Almen intensity and residual compressive stress.

Opposite Association Between Radiographic Lateral Ankle Instability and Osteochondral Lesions of the Talus in Patients with Ankle Inversion Injuries

Category:AnkleIntroduction/Purpose:Insufficient bony coverage surrounding the talus could cause considerable mechanical ankle instability, whereas excessive bony coverage could cause bone contusion at the time of injury and subsequent osteochondral lesions of the talus (OLT). This study aimed to investigate the relationship between radiographic lateral ankle instability and OLT in patients that sustained ankle inversion injuries.Methods:One-hundred-ninety-five patients (113 men and 83 women; mean age, 38.7 years; standard deviation, 8.8 years) with a history of ankle inversion injuries were included. All patients underwent ankle magnetic resonance imaging (MRI) and stress X-ray (varus stress and anterior drawer) examination. The tibiotalar tilt angle on varus stress X-ray, anterior translation of the talus on anterior-drawer lateral X-rays, bimalleolar tilt angle, and fibular position were radiographically determined. The anatomical grade of the lateral ankle ligament injury and the presence of OLTs were determined from MRI findings.Results:A greater lateral ankle ligament grade tends to increase the tibiotalar tilt angle (p=0.074), significantly affecting the anterior translation of the talus (p=0.036). The presence of radiographic lateral ankle instability (tibiotalar tilt angle =10°) showed opposite associations with the presence of OLT in the chi-square test (p=0.003). OLT was a negative significant factor (p=0.011) affecting the tibiotalar tilt angle in the multiple regression analysis (Table 1) and was negatively affected by the tibiotalar tilt angle (p=0.016) in the binary logistic regression analysis.Conclusion:This study showed an opposite association between lateral ankle instability and the development of OLT following ankle inversion injury. The role of bony predisposition in the development of sports injuries in the ankle should be considered and investigated further.

Refined Bonferroni prediction bands for autoregressive models

Joint prediction bands are often constructed using Bonferroni’s inequality. The drawback of such bands may be their large width and excessive coverage probability. The paper proposes two refinements to the basic Bonferroni method of constructing bootstrap prediction bands. These are based on higher order inequalities and optimization of the width of the band. The procedures are applied to the problem of predicting univariate autoregressive processes. Their properties are studied by means of Monte Carlo experiments. It is shown that the proposed methods lead, in many scenarios, to obtaining relatively narrow prediction bands with desired coverage probabilities.

Carbon black/graphene-modified aluminum foil cathode current collectors for lithium ion batteries with enhanced electrochemical performances

Though aluminum foils are widely applied as cathode current collectors for lithium ion batteries, they still face many challenges, such as the limited contact area, weak adhesion with electrode materials and localized corrosion by electrolytes during long-term cycling, which will lead to the degradation of electrochemical performances. Here, graphene-modified aluminum foils and carbon black/graphene modified aluminum foils are prepared as the current collectors for lithium iron phosphate lithium ion batteries by a facile solution coating method. We find that the batteries fabricated with carbon black/graphene-modified aluminum foils exhibit largely improved electrochemical performances in rate capability, internal resistance and long-term cycling capacity retention, compared with the bare aluminum and graphene-modified aluminum foils. This work reveals the coatings of graphene nanosheets not only can increase the contact area and enhance the adhesion between electrode materials and current collectors, which is beneficial for their electrical contact and charge transport, but also can suppress the aluminum foil corrosion during long-term cycling. Meanwhile, the excessive coverage of graphene nanosheets will lower the battery performances due to the interlayer contact increment of graphene nanosheets. In addition, carbon black combines graphene to form a co-conductive network effectively compensating the low interlayer electrical conductivity of graphene nanosheets.

BiPAD: Binomial Point Process Based Energy-Aware Data Dissemination in Opportunistic D2D Networks

In opportunistic device-to-device (D2D) networks, the epidemic routing protocol can be used to optimize the message delivery ratio. However, it has the disadvantage that it causes excessive coverage overlaps and wastes energy in message transmissions because devices are more likely to receive duplicates from neighbors. We therefore propose an efficient data dissemination algorithm that can reduce undesired transmission overlap with little performance degradation in the message delivery ratio. The proposed algorithm allows devices further away than the k-th furthest distance from the source device to forward a message to their neighbors. These relay devices are determined by analysis based on a binomial point process (BPP). Using a set of intensive simulations, we present the resulting network performances with respect to the total number of received messages, the forwarding efficiency and the actual number of relays. In particular, we find the optimal number of relays to achieve almost the same message delivery ratio as the epidemic routing protocol for a given network deployment. Furthermore, the proposed algorithm can achieve almost the same message delivery ratio as the epidemic routing protocol while improving the forwarding efficiency by over 103% when k≥10.

Life imprisonment and predicting behavior. An analysis on crime against minors and penal policy in Colombia

From time to time, a crime involving sexual violence against a minor is given excessive news coverage producing a strong social rejection and generating proposals for reforms to enlarge the scope of the criminal law. These proposals usually include the establishment of life imprisonment for such a crimes underthe idea that those who commit them are dangerous offenders, incapables of being rehabilitated, and, therefore, subject to incapacitation as the only possible aim of punishment. Then, this work, through the dialectic method and empirical research, analyses the scientific foundations of such proposals and,consequently, its acceptance and use in penal policy, with special emphasis on the last of the constructions regarding that subject: the sexually violent predator. In this regard, it is concluded that future behaviour cannot be predicted and there is no such thing as incorrigible people. DOI: http://dx.doi.org/10.21017/Rev.Repub.2018.v25.a57

Periacetabular quadruple osteotomy of the pelvis in older children: computed tomography scan analysis of acetabular retroversion and anterior overcoverage of the hip, preventing femoral acetabular impingement.

The periacetabular quadruple osteotomy of the pelvis (QOP), with the osteotomy of ischial spine to release the sacrospinal ligament, is reserved for older children with low potential of remodeling. Different parameters were studied with computed tomography (CT) scan before (pre-OH) and after surgery (post-OH) and for nonoperated hip (NOH). The study determined an optimal method to avoid retroversion and excessive anterior coverage. Fifteen QOP were performed in 13 patients, ranging in age from 10 to 15 years. The morphology of pelvis was analyzed with a CT scan before the surgery and 2 years after. Pathologies were Legg-Calve-Perthes (seven hips) and dysplasia (eight hips). The two-dimensional exam measured the acetabular index, the coverage, and the version of the acetabulum. The three-dimensional images measured the frontal lateral inclinations of the lips and the sagittal anterior acetabular inclination. The mean anterior acetabular index was 50.4° (NOH), 56° (pre-OH), and 58.7° (post-OH). The posterior acetabular index was 48.5° (NOH), 52.2° (pre-OH), and 40° (post-OH). The anterior coverage angle was 37.1° in (pre-OH), 27.6° (post-OH), and 30.1° (NOH). The posterior coverage was 20.4° (pre-OH), 17.2° (post-OH), and 12.4° (NOH). The acetabular version was 2.1° (pre-OH), 8.3° (post-OH), and 2.5° (NOH). The anterolateral lip inclination was 50.3° (pre-OH), 35.3° (post-OH), and 43.8° (NOH). The posterolateral lip inclination was 56.7° (pre-OH), 43.7° (post-OH), and 55.8° (NOH). The anterior acetabular inclination was 21.3° (pre-OH), 15.6° (post-OH), and 18° (NOH). The QOP enabled significant range of coverage of the hip in adolescents in whom the potential of remodeling is very low. External rotation related to figure-of-four should be omitted, whereas the maneuver to be applied, preventing the anterior impingement and decrease of the posterior coverage, should be performed by placing the acetabular fragment below the iliac bone, with a lateral inclination in the frontal plane similar to a steering wheel movement. This maneuver preserves comparable morphology of the OH with NOH and avoids retroversion with the excessive anterior coverage responsible for pain and early osteoarthritis.

Impingement-free Hip Range of Motion in Asymptomatic Young Adult Females

Background: Femoroacetabular impingement is a recognized cause of early hip osteoarthritis. This is attributed to either a cam impingement caused by a non-spherical head or a pincer impingement caused by excessive acetabular coverage. Although many surgical techniques aim to improve hip range of motion, little normative data exist on dynamic impingement-free hip range of motion (ROM) in asymptomatic individuals. Hip ultrasound can effectively …

Intermediate-Term Hip Survivorship and Patient-Reported Outcomes of Periacetabular Osteotomy: The Washington University Experience.

The Bernese periacetabular osteotomy (PAO) is an alternative to arthroplasty for treating symptomatic acetabular dysplasia, but there have been few studies on the intermediate-term outcomes of this procedure. In the present study, we assessed intermediate-term hip survival and patient-reported outcomes of PAO used to treat symptomatic acetabular dysplasia. From July 1994 to August 2008, 238 hips (206 patients) were treated with PAO. Sixty-two had a diagnosis other than classic acetabular dysplasia, and 22 were lost to follow-up. The remaining 154 hips (129 patients) were evaluated at an average of 10.3 years postoperatively. Kaplan-Meier analysis was used to assess survivorship with an end point of total hip arthroplasty (THA). Hips were evaluated using the University of California at Los Angeles (UCLA) Activity Score, modified Harris hip score (mHHS), and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain subscale score. A WOMAC pain subscale score of ≥10 and/or an mHHS of ≤70 were considered to indicate a clinically symptomatic hip. Kaplan-Meier analysis revealed a hip survival rate of 92% (95% confidence interval [CI]: 82% to 97%) at 15 years postoperatively. Eight hips (5%) underwent THA at a mean (and standard deviation) of 6.8 ± 5.2 years. Twenty-four additional hips (16%) were considered symptomatic based on a WOMAC pain score of ≥10 and/or an mHHS of ≤70. One hundred and twenty-two hips (79%) did not undergo THA and did not meet the criteria for symptoms, and these hips had a mean mHHS of 92.4 ± 8.4, WOMAC pain subscale score of 1.2 ± 1.9, and UCLA Activity Score of 7.7 ± 2.0 at a mean of 10.1 years. A higher risk of failure was associated with fair or poor preoperative joint congruency (odds ratio [OR]: 8.65; 95% CI: 1.18 to 63.55; p = 0.034) and with a postoperative lateral center-edge angle of >38° (OR: 8.04; 95% CI: 2.01 to 32.22). A concurrent head-neck osteochondroplasty was associated with a decreased risk of failure (OR: 0.27; 95% CI: 0.09 to 0.78; p = 0.016). This study demonstrates the durability of the Bernese PAO. Fair or poor preoperative joint congruency and excessive postoperative femoral head coverage were found to be predictors of failure, while concurrent head-neck osteochondroplasty in patients with an inadequate range of motion after PAO was associated with a decreased risk of failure. Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Ablation of endothelial prolyl hydroxylase domain protein-2 promotes renal vascular remodelling and fibrosis in mice.

Accumulating evidence demonstrates that hypoxia‐inducible factor (HIF‐α) hydroxylase system has a critical role in vascular remodelling. Using an endothelial‐specific prolyl hydroxylase domain protein‐2 (PHD2) knockout (PHD2ECKO) mouse model, this study investigates the regulatory role of endothelial HIF‐α hydroxylase system in the development of renal fibrosis. Knockout of PHD2 in EC up‐regulated the expression of HIF‐1α and HIF‐2α, resulting in a significant decline of renal function as evidenced by elevated levels of serum creatinine. Deletion of PHD2 increased the expression of Notch3 and transforming growth factor (TGF‐β1) in EC, thus further causing glomerular arteriolar remodelling with an increased pericyte and pericyte coverage. This was accompanied by a significant elevation of renal resistive index (RI). Moreover, knockout of PHD2 in EC up‐regulated the expression of fibroblast‐specific protein‐1 (FSP‐1) and increased interstitial fibrosis in the kidney. These alterations were strongly associated with up‐regulation of Notch3 and TGF‐β1. We concluded that the expression of PHD2 in endothelial cells plays a critical role in renal fibrosis and vascular remodelling in adult mice. Furthermore, these changes were strongly associated with up‐regulation of Notch3/TGF‐β1 signalling and excessive pericyte coverage.

Are "normal hips" being labeled as femoroacetabular impingement due to EE angle?

Gluteal muscle contracture (GMC) is a clinical syndrome characterized by gait abnormality and limb dysfunction, as well as secondary deformities of pelvis and femur. Femoroacetabular impingement (FAI) typically could be diagnosed on the basis of computed tomography (CT) such as the equatorial-edge angle (EE angle), but it did not work well in GMC patients. In this study, we retrospected all image data and found small EE angles in GMCs, which meant retroverted acetabulum; however, none of them showed no symptoms and signs of FAI. Therefore, we had reasons to think that, some normal hips with unbalanced hip myodynamia as same as GMCs, may be incorrectly diagnosed as FAI through measuring EE angle only.In consequence, the paper was designed to assess the use of the EE angle in the assessment of FAI in the diagnosis, as described by Werner.Twenty-three patients (46 hips) were collected and calculated with the “equatorial-edge angle” (EE angle) by CT scans. All of them were excluded from FAI.Review of the hips showed a mean EE angle was 12.93°, with a minimum of -3.42° and a maximum of 24.08°. The mean value for males and females were 13.52° and 12.40°, respectively, without statistical significance, although the mean value of left hips and right sides reached 13.32° and 12.54° individually, not having statistical differences neither. There were not any symptoms or signs of FAI in all patients. Thus, the reduced EE angle could suggest the local excessive coverage of the femoral head by the anterior acetabular edge, but might not be a reasonably good predictor of FAI.GMC patient's acetabular deformity mainly manifests as increased retroversion, which may be the anatomical basis for FAI and lead to high risks of the acetabular impingement. However, all patients in this study showed no symptoms and signs of FAI, suggesting that the measurement of EE angle can only be applied to assessing those people with normal hip myodynamia, and the bone deformity and the muscular disorder should be both considered in the diagnosis of FAI.

Virome Assembly and Annotation: A Surprise in the Namib Desert.

Sequencing, assembly, and annotation of environmental virome samples is challenging. Methodological biases and differences in species abundance result in fragmentary read coverage; sequence reconstruction is further complicated by the mosaic nature of viral genomes. In this paper, we focus on biocomputational aspects of virome analysis, emphasizing latent pitfalls in sequence annotation. Using simulated viromes that mimic environmental data challenges we assessed the performance of five assemblers (CLC-Workbench, IDBA-UD, SPAdes, RayMeta, ABySS). Individual analyses of relevant scaffold length fractions revealed shortcomings of some programs in reconstruction of viral genomes with excessive read coverage (IDBA-UD, RayMeta), and in accurate assembly of scaffolds ≥50 kb (SPAdes, RayMeta, ABySS). The CLC-Workbench assembler performed best in terms of genome recovery (including highly covered genomes) and correct reconstruction of large scaffolds; and was used to assemble a virome from a copper rich site in the Namib Desert. We found that scaffold network analysis and cluster-specific read reassembly improved reconstruction of sequences with excessive read coverage, and that strict data filtering for non-viral sequences prior to downstream analyses was essential. In this study we describe novel viral genomes identified in the Namib Desert copper site virome. Taxonomic affiliations of diverse proteins in the dataset and phylogenetic analyses of circovirus-like proteins indicated links to the marine habitat. Considering additional evidence from this dataset we hypothesize that viruses may have been carried from the Atlantic Ocean into the Namib Desert by fog and wind, highlighting the impact of the extended environment on an investigated niche in metagenome studies.

Cs and Cs/O adsorption mechanism on GaN nanowires photocathode

We have investigated the stability and electronic properties of GaN nanowires photocathode based on first-principle calculations. The most stable adsorption configuration of Cs adatoms on the (001) surface of [001]-oriented GaN nanowires changes accordingly as Cs coverage increases. The work function of Cs-only-covered surface falls off with increasing Cs coverage. For the nanowire surface covered with either excessive or minor Cs coverage, the work function surprisingly increases slightly after O activation; however, for Cs coverage of 0.5 (monolayer) ML and 0.75 ML, O activation process still works for the nanowires photocathode. A downward band bending region is formed after Cs adsorption and will further bend downward after O adsorption only for models with Cs coverage of 0.5 ML and 0.75 ML. The optimized atomic ratio of Cs/O is 3:1. The diversification of the band structures is mainly attributed to the orbital hybridization between Cs-5 s, Cs-5p, O-2p states and Ga-4 s, N-2p states.

Investigation into the Manufacture and Properties of Inhalable High-Dose Dry Powders Produced by Comilling API and Lactose with Magnesium Stearate.

The aim of the study was to understand the impact of different concentrations of the additive material, magnesium stearate (MGST), and the active pharmaceutical ingredient (API), respectively, on the physicochemical properties and aerosol performance of comilled formulations for high-dose delivery. Initially, blends of API/lactose with different concentrations of MGST (1-7.5% w/w) were prepared and comilled by the jet-mill apparatus. The optimal concentration of MGST in comilled formulations was investigated, specifically for agglomerate structure and strength, particle size, uniformity of content, surface coverage, and aerosol performance. Secondly, comilled formulations with different API (1-40% w/w) concentrations were prepared and similarly analyzed. Comilled 5% MGST (w/w) formulation resulted in a significant improvement in in vitro aerosol performance due to the reduction in agglomerate size and strength compared to the formulation comilled without MGST. Higher concentrations of MGST (7.5% w/w) led to reduction in aerosol performance likely due to excessive surface coverage of the micronized particles by MGST, which led to failure in uniformity of content and an increase in agglomerate strength and size. Generally, comilled formulations with higher concentrations of API increased the agglomerate strength and size, which subsequently caused a reduction in aerosol performance. High-dose delivery was achieved at API concentration of >20% (w/w). The study provided a platform for the investigation of aerosol performance and physicochemical properties of other API and additive materials in comilled formulations for the emerging field of high-dose delivery by dry powder inhalation.

Analysis of Japanese Articles about Suicides Involving Charcoal Burning or Hydrogen Sulfide Gas.

It is well known that certain types of media reports about suicide can result in imitative suicides. In the last two decades, Japan has experienced two suicide epidemics and the subsequent excessive media coverage of these events. However, the quality of the media suicide reports has yet to be evaluated in terms of the guidelines for media suicide coverage. Thus, the present study analyzed Japanese newspaper articles (n = 4007) on suicides by charcoal burning or hydrogen sulfide gas between 11 February 2003 and 13 March 2010. The suicide reports were evaluated in terms of the extent to which they conformed to the suicide reporting guidelines. The mean violation scores were 3.06 (±0.7) for all articles, 3.2 (±0.8) for articles about suicide by charcoal burning, and 2.9 (±0.7) for articles about suicide by hydrogen sulfide (p < 0.001). With the exception of not following several recommendations, newspaper articles about suicide have improved in quality, as defined by the recommendations for media suicide coverage. To prevent imitative suicides based on media suicide reports, individuals in the media should try not to report suicide methods and to make attempts to report the poor condition of suicide survivors.

Loss of prolyl hydroxylase domain protein 2 in vascular endothelium increases pericyte coverage and promotes pulmonary arterial remodeling.

Pulmonary arterial hypertension (PAH) is a leading cause of heart failure. Although pulmonary endothelial dysfunction plays a crucial role in the progression of the PAH, the underlying mechanisms are poorly understood. The HIF-α hydroxylase system is a key player in the regulation of vascular remodeling. Knockout of HIF-2α has been reported to cause pulmonary hypertension. The present study examined the role of endothelial cell specific prolyl hydroxylase-2 (PHD2) in the development of PAH and pulmonary vascular remodeling. The PHD2f/f mouse was crossbred with VE-Cadherin-Cre promoter mouse to generate an endothelial specific PHD2 knockout (Cdh5-Cre-PHD2ECKO) mouse. Pulmonary arterial pressure and the size of the right ventricle was significantly elevated in the PHD2ECKO mice relative to the PHD2f/f controls. Knockout of PHD2 in EC was associated with vascular remodeling, as evidenced by an increase in pulmonary arterial media to lumen ratio and number of muscularized arterioles. The pericyte coverage and vascular smooth muscle cells were also significantly increased in the PA. The increase in vascular pericytes was associated with elevated expression of fibroblast specific protein-1 (FSP-1). Moreover, perivascular interstitial fibrosis of pulmonary arteries was significantly increased in the PHD2ECKO mice. Mechanistically, knockout of PHD2 in EC increased the expression of Notch3 and transforming growth factor (TGF-β) in the lung tissue. We conclude that the expression of PHD2 in endothelial cells plays a critical role in preventing pulmonary arterial remodeling in mice. Increased Notch3/TGF-β signaling and excessive pericyte coverage may be contributing to the development of PAH following deletion of endothelial PHD2.

‘Stifled aspirations’: The 2014 General Election under restrictive laws

On 17 September 2014, eight years after the 5 December 2006 coup, Fiji held a General Election under repressive laws curtailing freedom of expression and the media, government accountability and the judiciary. A notable number of 248 candidates aspired for the 50 parliamentary seats under the 2013 Constitution and an Electoral Decree released a few months prior to elections. In an atmosphere of lavish campaign advertisements on billboards, public transport vehicles and the print and television news media by the post-coup Prime Minister Voreqe Bainimarama’s political party FijiFirst, recently activated political parties struggled to have their voices heard. Two daily media companies—the Fiji Broadcasting Corporation and the Fiji Sun—displayed bias towards the FijiFirst party by providing them with excessive and preferential coverage and portraying other parties in a negative light; other media organisations attempted to give fairer coverage. The debate heated up amid crackdowns by police on ‘trouble-makers’ vandalising FijiFirst posters. The country headed for the polls as celebrations marked the release of 45 Fijian soldiers held hostage by Al-Nusra in the Golan Heights. Amid complaints by five political parties, the election was declared ‘free and fair’ by the Electoral Commission. This article, through analysis of media materials, campaigning, polling and results calculations, contends that the elections only satisfied part of the international criteria for ‘free and fair elections’.

Morphology of Acetabulum and Femoral Head-Neck Junction in Hip Dysplasia Which Underwent Rotational Acetabular Osteotomy

The purpose of this study was to evaluate the preoperative radiographs with cases of developmental dysplasia of the hip (DDH) leading to rotational acetabular osteotomy (RAO) or curved peri-acetabular osteotomy (CPO), and examine the frequency of femoroacetabular impingement (FAI) related bone morphology in the acetabulum and femoral head-neck junction. Twenty-four hips with hip dyaplasia who underwent CPO or RAO were included in this study. Six hips had grade 0 and eighteen hips had grade 1 OA according to the Tonnis classification. We excluded patients with moderate and severe hip osteoarthritis and major femoral head deformities. Preoperative radiograph was evaluated on sharp angle, center-edge angle, alpha angle, crossover sign and posterior wall sign. Crossover signs were revealed in 7 hips (29.2%); posterior wall signs were revealed in 16 hips (66.7%); and cam-type deformities with an alpha angle of ≥50.5˚ were observed in 19 hips (79.2%) in preoperative evaluation. As determined using the Tonnis scale, no progression of osteoarthritis was found in 16 of the 24 hips; there was a one-grade progression in 8 hips. Among the 8 hips, either positive cross-over sign or posterior sign in acetabulum, and an alpha angle of ≥50.5˚ in femur were observed in six hips with progression of osteoarthritis. The presence of cam-type deformity and acetabular retroversion in patients who underwent RAO or CPO was relatively high in preoperative radiographs, and caution should be employed during surgery in patients with DDH. There is a possibility of secondary FAI due to excessive forward coverage of the bone fragments after RAO and CPO.

English

Introduction: Orthodontic treatment in-deep bite subjects has generally been focused on the correction of excessive vertical coverage (overbite); however, the impact on functional problems following treatment has not been well evaluated. This study aimed to investigate the differences in mandibular movements between deep bite and normal occlusion, and to compare the functional changes of mandible in the subjects with deep bite before and after treatment. Methods: This study included students from School of Dentistry, China Medical University (CMU), and employees from CMU Hospital. The participants were categorized into normal bite (n = 11) and deep bite (n = 16) groups. Considering the clinical practicability, convenience and affordability, Digi Gnatho software (Japan), was used to analyze mandibular movements recorded by digital video camera. Results: No significant difference was observed in the left side masticatory movements between two groups. Significant difference was only detected in the horizontal direction of right side mastication. All of the velocities and masticatory cycle duration of both sides showed no difference. In the mandibular border movements, protrusive movements in deep-bite group were distinct from normal occlusion group. Normal occlusion group had a larger range of mandibular movements compared to deep bite group. Conclusions: Different degrees of vertical coverage of the incisors not only presented differences in the ranges of masticatory movements and border movements, but also had an impact on the final occlusal phase of mastication.