3-dimensional Analysis Research Articles

Dental biomechanics of root-analog implants in different bone types

Statement of problemWhen implants are applied to restore oral function, the masticatory load on the crown will lead to stress development in all parts of the crown-abutment-implant-bone system. An optimal design of the whole system will be important for sustained function. PurposeThe purpose of this 3-dimensional (3D) finite element analysis (FEA) study was to evaluate the influence of the root-analog implant (RAI) design in molar rehabilitation and bone type. Material and methodsTwelve 3D models of single posterior implant-supported restorations were created according to the zirconia implant design (monotype, 2-piece, or RAI) and bone type (D1, D2, D3, and D4, according to the Misch classification). The models were composed of cortical bone, cancellous bone, implant, cement layers, and a monolithic ceramic crown. For the 2-piece zirconia implant model, the titanium base, prosthetic screw, and framework were also designed. All materials were assumed to behave elastically throughout the entire analysis. The bone was fixed, and an axial loading of 600 N was applied to the contacts on the occlusal surface of the crowns. Results for the crown and implant were obtained in maximum principal stress, as well as the von Mises stress for the model and bone microstrain. ResultsHigh stress concentration was observed at the intaglio surface of the crowns near the loading region. Regardless of the design, the stress trend in the implant was similar, increasing proportionally to the bone type (D1>D2>D3>D4). RAI showed a homogeneous stress field near the values calculated for the conventional designs, but with lower magnitudes. The 2-piece zirconia model showed the highest stress magnitude regardless of the bone type and, therefore, the highest failure risk. All models showed a higher strain in the cortical bone than in the cancellous bone, located predominantly in the cervical region. A strain analysis showed that both conventional implant models presented similar behavior for D1 and D2 bone types, with an increasing difference for D3 and D4. RAI showed the lowest strain regardless of the bone type. ConclusionsRoot-analog zirconia implants present a promising biomechanical behavior for dissipating the masticatory load in comparison with conventional screw-shaped implants.

Elastomeric seal stress analysis using photoelastic experimental hybrid method

Stress freezing is an important and powerful procedure in 3-dimensional experimental stress analysis using photoelasticity. The application of the stress freezing technique to extract stress components from loaded engineering structures has, however, declined over the years even though its principles are well established. This is attributed to huge costs arising from energy consumption during the process. In addition, significant time is needed to generate the desired information from isoclinic and isochromatic fringes. To overcome the limitations of stress freezing in photoelasticity and transform it into an economical device for stress analysis in an engineering environment, a new stress freezing cycle that lasts 5 h is proposed. The proposed technique is used in several applications of elastomeric seals with different cross-sectional profiles to assess their suitability. It was found that reducing the cycle time can lead to huge energy savings without compromising the quality of the fringes. Moreover, the use of isochromatic only to extract stress components leads to a shorter processing time to achieve desirable information since the process of obtaining isoclinic data is involving. In this paper, results of stress analysis from stress-frozen elastomeric seals with various cross-sections using the new stress freezing cycle are presented.

Computer Simulation to Determine LHP of 4 Different Types of Transient Industrial Quenched Molybdenum Steel Bars

Simulation of hardness distribution in quenched specimens has been investigated using three-dimensional finite-element (FE) analyses which reduced into a 2-dimensional axisymmetric analysis based on Ansys Software capable of predicting temperature history; evolution hardness of four different types of Molybdenum steel bars during thermal processing of materials in quenching process is presented. The Jominy test results are used to estimate specimen hardness. specimen points hardness used to be determined through conversion of evaluated characteristic cooling time for phase transformation t8/5 into hardness. The lowest hardness point (LHP) of each quenched Molybdenum steel bar has been determined to be in mid its length in the center. Experimentally, it is quite impossible to determine this hardness value, and earlier approaches could only assess surface hardness. Normally, this value of hardness at the surface is greater than (LHP), that, under certain conditions might lead to component failure and deformation. The model can be employed to establish a cooling method to attain the required microstructure as well as mechanical properties, which include hardness.

Volumetric Analysis of Progressive Remodeling of Isolated Mesenteric Artery Dissection Treated by Conservative Therapy

PurposeTo characterize remodeling of conservatively treated isolated mesenteric artery dissection (IMAD) using 3-dimensional (3D) volumetric analysis. Material and MethodsPatients with Type I/II (classification of Yun) treated by conservative therapy between January 2018 and January 2020 were prospectively included. Semiautomatic morphological analysis of the superior mesenteric artery (SMA) included volumetric measurements of the true lumen (TL), false lumen (FL), and overall lumen (OL) and 3D aortomesenteric angles from computed tomography angiography data at admission (T0), 1 month (T1), and 12 months (T12). The SMA morphology of patients with IMAD (n = 15, mean age 53 years ± 7; 87% men) was also compared with that of control individuals (n = 51, mean age 56 years ± 4; 94% men). ResultsA significant reduction in OL volume was observed (P <.001), whereas TL volume remained stable (P =.23). The TL/OL volume ratio significantly increased over time (P =.001) from 53% at T1 to 78% at T12. Aortomesenteric 3D angles at 2, 4, and 6 cm from the ostium showed a progressive decrease toward values observed in the control group (P =.013, P =.002, and P =.027, respectively). At T12, 5 patients (33%) had complete remodeling, and aneurysmal change was observed in 2 patients (<20 mm). Smoking and SMA angle at a distance of 6 cm from the ostium (T0) were the only factors affecting remodeling negatively at T12. ConclusionsOne-year remodeling in IMAD followed an overall decrease in OL volume related to a decrease in FL volume. Smokers and patients with larger SMA angles at baseline showed poorer remodeling. Spontaneous arterial remodeling in IMAD might favor conservative therapy.

A simple method for restoring the femoral head center in hip arthroplasty: a 3-dimensional analysis in the Chinese population

BackgroundVarious authors have successfully demonstrated that the distance from the greater trochanter to the femoral head center (GTFHC) and the distance from the lesser trochanter to the femoral head center (LTFHC) can be used as parameters to determine the recovery of the femoral head center (FHC) during hip arthroplasty. It is necessary to undertake an anatomical study concerning the correlations between the greater trochanter (GT), the lesser trochanter (LT), and the FHC using data obtained from the 3D-CT reconstruction method.MethodsThe study comprised 293 patients (151 males and 142 females), with an average age of 65.06 years. The femoral head diameter(FHD), the linear distance from FHC to GT (GTFHC), and the linear distance from FHC to LT(LTFHC) were all measured and recorded data. The correlation between FHD with LTFHC and GTFHC was assessed using Pearson correlation coefficients, and the ratio of LTFHC and GTFHC to FHD was calculated from this ratio. All measured parameters were compared between the left and right sides and the sexes of the participants.ResultsThe average ratios of GTFHC/FHD and LTFHC/FHD were 0.99 and 0.95, respectively .96% of the LTFHC had absolute lateral differences of < 4 mm . 92% of the GTFHC had absolute lateral differences of < 4 mm.ConclusionLTFHC and GTFHC are reliable reference parameters for preoperative planning and reconstruction of FHC of hip arthroplasty. The ratio displayed in this research may yield insight into a practical and straightforward method for orthopedic surgeons to perform hip arthroplasty in patients with femoral neck fractures. Ratios from studies based on the same race may be desirable for future work.

Numerical Study of Non-Newtonian Fluid in a Cavity with Corrugated Bottom Wall Using Buongiorno’s Mathematical Model

A 2-dimensional computational analysis is carried out for a time dependent double diffusive mixed convection flow using non-Newtonian nanofluid. A square-shaped cavity with a corrugated bottom wall is taken with higher temperature and concentration on the top wall. The physical model under consideration is represented by a set of governing equations and solved using the Galerkin weighted residual method based on Finite Element Analysis. Solutions are done for 4 controlling parameters such as Richardson number (Ri = 0.1 - 15), Lewis number (Le = 0.5 - 3), and thermophoresis parameter (Nt = 0.2 - 0.9), and Brownian motion parameter (Nb = 0.2 - 1.0) at different values of τ. For the aforementioned parameters, heat and mass transfer rates, temperature distributions, velocity distributions, and mass distributions in terms of isotherm, streamlines, and iso-concentration are graphically presented. It has been observed that for higher values of Ri, both Nuav and Shav increased while Le decreased for higher values of Nt at any fixed time. It is worth noting that the considered parameter exhibits consistent behavior after a while. HIGHLIGHTS The numerical analysis of non-Newtonian nanofluid with a corrugated bottom wall and a sliding upward wall is performed using Buongiorno's mathematical model The effect of the Richardson number, Lewis number, Brownian motion, and thermophoresis parameters on different dimensionless time periods is addressed The heat and mass transfer rate is increased as the Richardson number, Lewis number, Brownian motion, and thermophoresis parameters increase in value GRAPHICAL ABSTRACT

Analysis method for the design of long submarine cables

The recent push for renewable electrical energy sources has resulted in a significant increase in the installation of the offshore wind farms. These farms become much bigger than their earlier counterparts and the generated power is much larger. This puts additional performance requirements on the export cables. Long submarine export cables are not only subjected to changing laying conditions along the route, including depth and seabed material variations, but also the loading patterns vary significantly over time. Additionally, applied reactive power compensation measures and the time-dependent grid situation change the distribution of the current along the route. These unique features of long submarine power cables necessitate a new type of approach to their design and construction optimization. This paper introduces a new approach for ampacity calculations of long submarine power cables. As the ampacity calculations form a basis for the design of a cable route, it is of paramount importance that they are performed as accurately as possible. The approach can be applied to general-purpose circuit solvers, and this paper describes how to implement it using the ATP-EMTP software, which is extended to the consideration of concurrent electrical and thermal effects. The approach permits considering all the important local and time-dependent parameters of the analysis simultaneously. In particular, the approach allows simultaneous analysis of the varying laying conditions along the route including changes in the depth of burial and thermal resistivity of the soil together with the temporal variations of the cable loading. Additionally, current characteristics in long AC cable conductors are strongly affected by the reactive power flow, which in turn depends on the location of the reactive power compensation, the reactive power demand for grid operation, and the wind farm voltage reactive power control strategy. Such analysis cannot be performed with any existing analytical tool. Also, numerical tools cannot handle such problems because a 3-dimensional time-dependent analysis of a cable route which is 100 km long would encounter convergence problems as the size of such model would be prohibitive. Hence, at present, the proposed approach is the only one available to solve this complex electro-thermal problem. Several numerical examples illustrate an application of the proposed methodology.

Optimization of the dimension of computer numerical control–milled polyetheretherketone clasps: An in vitro evaluation of accuracy

Statement of problemThe accuracy and optimal dimensions of computer numerical control (CNC)-milled polyetheretherketone (PEEK) removable partial denture (RPD) clasps are unclear. PurposeThe purpose of this in vitro study was to investigate the trueness and precision of CNC-milled PEEK clasps with different thicknesses and lengths. Material and methodsLadder-shaped specimens of 2 thicknesses with 5 lengths of clasps were designed and milled with PEEK and commercially pure titanium (CP Ti) (n=6). All milled specimens were scanned and superimposed onto the design data. Three-dimensional and 2-dimensional deviation analyses were carried out to evaluate the trueness of milled PEEK clasps. The scanning data of each group were superimposed pairwise, and the 3-dimensional deviations were analyzed to evaluate the precision. Nonparametric tests, ANOVA, the Pearson correlation, and univariate linear regression were used for statistical analysis (α=.05). ResultsThe deviation of trueness of the PEEK clasps (0.047 to 0.164 mm) was higher than that of the CP Ti clasps (0.037 to 0.060 mm) (P<.001). Increasing the length of the clasps increased the deviations (P<.001). Deviation in the 2 thicknesses was not significantly different (P=.210). The correlation coefficients of 1.0-mm-thick and 1.5-mm-thick PEEK and CP Ti clasps were 0.843, 0.794, 0.638, and 0.405. The positive correlation coefficients of PEEK were higher than those of CP Ti and those of 1.0-mm-thick clasps was higher than those of 1.5-mm-thick clasps. The deviations were evenly distributed in the 9-mm length of the clasp for CP Ti and in the 6-mm length of the clasp for PEEK. Beyond these lengths, deviations increased with increased length. The increasing amplitude of CP Ti was smaller than that of the PEEK group, and that of the 1.5-mm-thick clasp was smaller than that of the1.0-mm-thick clasp. The measured range of precision of PEEK clasps was 0.079 to 0.152 mm, while that of CP Ti clasps was 0.036 to 0.096 mm. CP Ti clasps tended to have better precision than PEEK clasps, except for the 1.0-mm-thick clasps with a length greater than 9 mm and the 1.5-mm-thick clasp with a 12-mm length. The correlation of the clasp length with precision showed that the lengths of 1.0-mm-thick clasps strongly influenced precision (PEEK, P=.020; CP Ti, P<.001); this correlation decreased sharply when the thickness of clasps was 1.5 mm (PEEK, P=.199; CP Ti, P=.107). ConclusionsGreater elasticity increased the deviations of milled clasps. The increased thickness helped the clasp remain stable during the milling process. The 1.5-mm-thick PEEK clasps in the 3-mm and 6-mm lengths were the optimal design tested.

Comparable Recovery and Compensatory Strategies in Heel-Rise Performance After a Surgically Repaired Acute Achilles Tendon Rupture: An In Vivo Kinematic Analysis Comparing Early Functional Mobilization and Standard Treatment

Background: Deficits in calf muscle function and heel-rise performance are common after an Achilles tendon rupture (ATR) and are related to tendon elongation and calf muscle atrophy. Whether early functional mobilization (EFM) can improve calf muscle function compared with standard treatment (ST) with 2 weeks of immobilization and unloading in a plaster cast is unknown. Hypothesis: EFM would lead to superior recovery of heel-rise performance, as demonstrated by more symmetrical side-to-side ankle and knee joint kinematics, compared with ST. Study Design: Cohort study; Level of evidence, 2. Methods: In total, 47 patients with an ATR were prospectively included and treated with open surgical repair and randomized 2:1 postoperatively to either EFM or ST. Overall, 29 patients were treated with a dynamic orthosis (EFM), and 18 underwent ST. At 8 weeks and 6 months after ATR repair, 3-dimensional motion analysis of heel-rise performance was conducted. At 6 months, tendon length and muscle volume were assessed with ultrasound imaging, calf muscle function with the heel-rise test, and patient-reported outcomes with the Achilles tendon Total Rupture Score. Results: At 8 weeks and 6 months, there were no significant group differences between the EFM and ST groups in heel-rise performance, but significant side-to-side differences in ankle and knee kinematics were detected. At 8 weeks and 6 months, both the EFM and ST groups showed a significantly decreased peak ankle plantarflexion angle and increased knee flexion angle on the injured limb compared with the uninjured limb during bilateral heel raises. Linear regression demonstrated that greater atrophy of the medial gastrocnemius muscle (P = .008) and higher body weight (P < .001) were predictors of a decreased maximum peak ankle plantarflexion angle on the injured limb at 6 months. Conclusion: EFM after an ATR repair did not lead to superior recovery of calf muscle function, as assessed by heel-rise performance, compared with ST. Increased knee flexion seemed to be a compensatory strategy for decreased ankle plantarflexion. Medial gastrocnemius atrophy and increased body weight were additional factors associated with a decreased ankle plantarflexion angle. Registration: NCT02318472 (ClinicalTrials.gov identifier).

3-dimensional analysis of nasal soft tissue alterations following maxillary Lefort I advancement with and without impaction using 3D photogrammetry scanner.

This study was designed to investigate the changes in nasal soft tissue following maxillary Lefort I advancement with and without impaction in subjects presenting a skeletal class III malocclusion, using a 3D photogrammetry scanner. Patients with class III malocclusion undergoing Lefort I advancement with and without impaction and bilateral sagittal split osteotomy with the standard technique were included in this study. Patients were divided into two groups: maxillary Lefort I advancement alone (group 1) and combined with impaction (group 2). Facial soft tissue landmarks of the nose including nasal height (NH), nasal length (NL), nasal tip projection (NTP), alar width (AW), alar base width (ABW), subalar width (Sbal), nasolabial angle (NLA), nasofrontal angle (NFA), and columella inclination (CI) before and at least 4months after surgery were obtained by a 3D scanner. Twenty-one patients were included in this study (Group 1: 11 and Group 2: 10). NH, NTP, and NL decreased significantly in both groups following surgery. In addition, Sbal decreased only in group 2. On the other hand, NLA and CI increased significantly in group 2. The inter-group comparison revealed a statistically significant difference in the alterations in NH, NL, and CI between the two groups. Changes in the nose soft tissue occurred after both surgeries, but their type and extent were different. Actions taken to reduce unwanted changes need to be further investigated. To evaluate the changes, 3D photogrammetry scan is a feasible imaging technique that can be used, providing numerous benefits.

Intraoperative Noninvasive Left Ventricular Myocardial Work Indices in Patients Undergoing On-Pump Coronary Artery Bypass Surgery

Noninvasive echocardiographic analysis of left ventricular (LV) myocardial work (MW) enables insights into cardiac mechanics, contractility, and efficacy beyond ejection fraction (EF) and global longitudinal strain (GLS). However, there are limited perioperative data on patients undergoing coronary artery bypass graft (CABG) surgery. The authors aimed to describe the feasibility and the intraoperative course of this novel assessment tool of ventricular function in these patients, and compare it to conventional 2-dimensional (2D) and 3-dimensional (3D) echocardiographic parameters and strain analysis. A prospective observational study. At a single university hospital. Twenty-five patients with preoperative preserved LV and right ventricular function, sinus rhythm, without significant heart valve disease or pulmonary hypertension, and an uncomplicated intraoperative course scheduled for isolated on-pump CABG surgery. Transesophageal echocardiography (TEE) was performed intraoperatively after the induction of anesthesia (T1), after termination of cardiopulmonary bypass (T2), and after sternal closure (T3). All measurements were performed under stable hemodynamic conditions, in sinus rhythm or atrial pacing, and vasopressor support with norepinephrine ≤ 0.1 µg/kg/min. The EchoPAC v204 software (GE Vingmed Ultrasound AS, Norway) was used for analysis of 2D and 3D LVEF, LV GLS, LV global work index (GWI), LV global constructive work (GCW), LV global wasted work (GWW), and LV global work efficiency (GWE). The MW analysis was feasible in all patients. Although there was no significant difference in the values of 2D and 3D EF during the intraoperative interval, GLS deteriorated significantly after CABG compared to assessment after induction of anesthesia (T1 v T2, -13.3 ± 3.0% v -11.6 ± 3.1%; p=0.012). The GWI declined significantly after surgery (T1 v T2, 1,224 ± 312 mmHg% v 940 ± 267 mmHg%; p < 0.001), as well as GCW (T1 v T2, 1,460 ± 312 mmHg% v 1,244 ± 336 mmHg%; p=0.005). The GWW increased after CABG (T1 v T2, 143 mmHg% (IQR 99-183) v 251 mmHg% (IQR 179-361); p < 0.001), and GWE decreased (T1 v T2, 89% (IQR 85-92) v 80% (IQR 75-87); p < 0.001). There were no significant changes in the values of 2D and 3D EF, GLS, GWI, GCW, GWW, and GWE before and after sternal closure (T2 v T3). The intraoperative analysis of noninvasive echocardiographically-assessed LV MW indices is feasible. In the short-term period after uncomplicated on-pump CABG, GLS, as well as global and constructive MW, decreased, whereas wasted work increased, resulting in a less efficient left ventricle. None of these aspects was detected by conventional echocardiographic parameters. Therefore, strain and MW analysis might be more sensitive parameters in detecting myocardial dysfunction by TEE in the perioperative setting, adding information on perioperative cardiac energetics.

The association of dynamic spinal alignment on gait endurance of patients with adult spinal deformity: a cross-sectional study.

The purpose of this study was to evaluate the gait posture of patients with adult spinal deformity (ASD) using a 3-dimensional motion analysis system (3DMAS) and to investigate whether it affects gait endurance. Fifty-one patients with ASD aged 50years or older who were admitted to our hospital between March 2016 and March 2018 were included in the study. The subjects completed the 6-min walking test, which is an indicator of gait endurance. Static standing posture was assessed by whole-spine x-ray examination (coronal cobb angle, CCA; sagittal vertical axis, SVA; pelvic tilt, PT; and pelvic incidence minus lumbar lordosis, PI-LL). In addition, the gait posture was evaluated by a 3DMAS (dynamic trunk tilt angle, DTA; and dynamic pelvic tilt angle, DPA). The relationship between standing and gait postures and gait endurance was investigated by multivariable analysis. In univariable analysis, SVA, PI-LL, and DTA were associated with gait endurance. Furthermore, in the multivariable analysis, DTA showed the strongest association among the static and dynamic parameters (R2 = 0.61, β = - 0.35, P < 0.05). An association was found between gait posture and gait endurance in patients with ASD. These findings can be useful to health care providers treating patients with ASD. It is advisable to assess the gait posture of patients with ASD because they present postural abnormalities during gait.

Alterations in Sphenoid Anatomy in Craniosynostosis: Implications for Fronto-orbital Advancement

OBJECTIVE: Fronto orbital advancement (FOA) requires the removal of the fronto-orbital bandeau via an anatomically challenging osteotomy that passes from the anterior cranial fossa to the middle fossa. During the intracranial portion of the osteotomy, visualization of the saw blade is lost as it passes through the fronto-orbito-sphenoid junction, prior to entering the middle cranial fossa. This places the temporal lobe dura and parenchyma at risk of injury. The aim of this study is to provide a 3-dimensional analysis of the space surrounding this osteotomy, and determine differences amongst different types of craniosynostosis. METHOD: 18 head CT scans of patients from ages 2 to 24 months with craniosynostosis (6 Metopic, 6 nonsyndromic Bicoronal, and 6 Unicoronal) were reconstructed to 3D skulls using Mimics 24.0 (Materialise NV, Lueven, Belgium). Unicoronal skulls were mirrored as necessary to be right sided. These skulls were landmarked with 47 cephalometric points. Measurents and volumetric analysis was performed to determine differences in sphenoid anatomy between the 3 craniosynostoses. RESULTS: For the 3 craniosynostosis groups, metopic, bicoronal and unicoronal, the average distance from the lateral orbital rim to temporal lobe tip was significantly different (17.37mm, 10.15mm, 14.76mm, respectively (p<0.05)). The mean depth of the temporal lobe tip from the edge of the sphenoid was also significantly different (16.23mm, 27.5mm, 22.8 mm respectively, p<0.05). The thickness of the fronto-orbito-sphenoid junction at the level of the supraorbital rim was significantly different between the three groups as well (7.75mm, 3.60mm, 8.04mm; p=0.01). Distances from the cornea to the lateral orbital rim, anteroposterior depth of the lateral orbit, and overhang of the lesser sphenoid wing over the middle cranial fossa were not significant between groups. CONCLUSION: Sphenoid shape and the zone of the fronto-orbital-sphenoid junction differs between types of craniosynostosis. Bicoronal craniosynostosis has the most unfavorable anatomy in this area, with minimal distance between the orbit and the anterior portion of the temporal lobe, a vertically deep middle cranial fossa, and thin bone at the fronto-orbital sphenoid junction, all of which make retraction and protection of the temporal lobe more challenging. Careful understanding of the patient’s specific anatomy is necessary to perform this osteotomy safely.

Integrating GIS, deep learning, and environmental sensors for multicriteria evaluation of urban street walkability

The walkability of urban streets (WoUS) benefits public health and urban livability, but there is still no consensus on the quantitative and comprehensive evaluation of walkability. However, emerging deep-learning, sensor-network, and GIS technologies suggest the possibility of overcoming previous limitations. Therefore, this study explores a new approach for multicriteria evaluation of WoUS, including physical and perceived walkability. After capturing street-view images, traffic-flow data, and environmental-sensor data covering the streets to be analyzed, we automatically calculate physical walkability from four criteria (walkability index, street quality, traffic flow, and physical environment). We first integrate 2-dimensional analysis of walk score, noise, and light using GIS, then perform 3-dimensional composition calculations of greenery, enclosure, and relative walking width using semantic segmentation, vehicle density using multi-object tracking, and indicator weighting distributions using an analytic hierarchy process. Perceived walkability is evaluated by a hierarchy of walking needs model comprising feasibility, accessibility, safety, comfort, and pleasurability. As an empirical study, we conduct an experiment within Anonymous University for physical and perceived walkability evaluations. The results indicate that with perceived WoUS as a benchmark, the automated physical WoUS results reveal the strengths in data integration and processing that are feasible, reliable, and cost-effective. This was an initial attempt at constructing an integrated research methodology for WoUS from various walking-related variables. This framework could support designers as an assistive tool for generating both quantitative and qualitative judgments from various criteria and recommending walkable pedestrians paths to motivate people to walk further, longer, and more often, rather than providing the shortest paths based on a path-finding algorithm.

Plasma Rich in Growth Factors in the Treatment of Endodontic Periapical Lesions in Adult Patients: 3-Dimensional Analysis Using Cone-Beam Computed Tomography on the Outcomes of Non-Surgical Endodontic Treatment Using A-PRF+ and Calcium Hydroxide: A Retrospective Cohort Study.

The study presents results of periapical lesion healing after one-visit root canal treatment (RCT) with Advanced Platelet Rich Fibrin plus (A-PRF+) application compared to a two-visit RCT with an inter-appointment calcium hydroxide filling. The comparison was made based on CBCT-Periapical Index (PAI) lesion volume changes and the occurrence of post endodontic pain. The results of 3D radiographic healing assessments based on volume reduction criteria were different from the CBCT-PAI. Based on volume changes, the healing assessment criteria-9 cases from the Study Group and six cases in the Control Group were defined as healed. Based on the CBCT-PAI healing assessment criteria, 8 cases from the Study Group and 9 cases from the Control Group were categorized as healed. The volumes of apical radiolucency were, on average, reduced by 85.93% in the Study Group and by 72.31% in the Control Group. Post-endodontic pain occurred more frequently in the Control than in the Study Group. The highest score of pain in the Study Group was five (moderate pain, n = 1), while in the Control Group, the highest score was eight (severe pain, n = 2). In the 6-month follow-up, CBCT scans showed a better healing tendency for patients in the Study Group.

CFD analysis and environmental assessment on the heat transfer and flow of the pure water or water/silver Nano fluid coolants in a plate-fin heat sink applying two-phase mixture model

Environmental impacts are the consequences caused by the elementary flows on human health, plants, and animals (ecological health) or by the future availability of natural resources (resource depletion). The heat transfer characteristics of a plate-fin heatsink were investigated using a 3-dimensional numerical analysis based on the two-phase mixture model. The effect of using NF, fin spacing, and fin height on the performance of the system were studied considering the constant heat flux of 100 kW/m2 at the bottom of heatsink and NF inlet temperature of 300 K. The results showed that the increase in the secondary fin height (hsf) from 5 mm to 17.5 mm leads to increase in the pressure drop by 11.6%, 52%, to improve the heat convection coefficient (h) by 32.92%-23.84%, and consequently reduces the central processing unit (CPU) mean temperature by 4.31% and 2.34% for Re=500-2000. The maximum performance evaluation criterion (PEC) was obtained as 1.11-1.05 at Re numbers of 500-2000 for heatsink with hsf=12.5 mm. In addition, the optimum location for the secondary fin was determined to be at the mid-space of two primary fins (dsf=0.5 mm) which leads to improving h by 18%-5% at Re numbers of 500-2000 as compared to other fin spacing scenarios. Moreover, the intensification of nanoparticle concentration (ψ) leads to improve h by 15.71%-17.21% for Re=500-2000. Besides, the escalation of ψ decreases the pressure drop by 14.18% for all Re numbers. The PEC of the system with hsf=12.5 mm, ψ=1%, at Re=2000 was obtained as the highest PEC of 1.226 among the other studied cases. According to the design, the heat sink has an environmental impact of 0.5233.

Spine and lower body symmetry during treadmill walking in healthy individuals-In-vivo 3-dimensional kinematic analysis.

Although it is relevant to understand spine and lower body motions in healthy individuals for a variety of applications, such as clinical diagnosis, implant design, and the analysis of treatment outcomes, proper assessment and characterization of normative gait symmetry in healthy individuals remains unclear. The purpose of this study was to investigate the in vivo 3-dimensional (3D) spine and lower body gait symmetry kinematics during treadmill walking in healthy individuals. Sixty healthy young adults (30 males and 30 females) were evaluated during normal and fast treadmill walking using a motion capture system approach. Statistical parametric mapping and the normalized symmetry index approaches were used to determine spine, pelvis, and lower body asymmetries during treadmill walking. The spine and pelvis angular motions associated with the left and right lower limb motions, as well as the left and right lower extremity joint angles were compared for normal and fast treadmill walking. The lower lumbar left-right rotation (5.74±0.04°) and hip internal rotation (5.33±0.18°) presented the largest degrees of asymmetry during normal treadmill. Upper lumbar left-right lateral flexion (1.48±0.14°) and knee flexion (2.98±0.13°) indicated the largest asymmetries and during fast treadmill walking. Few asymmetry patterns were similar between normal and fast treadmill walking, whereas others appeared either only during normal or fast treadmill walking in this cohort of participants. These findings could provide insights into better understanding gait asymmetry in healthy individuals, and use them as reference indicators in diagnosing and evaluating abnormal gait function.

S2257 Cirrhosis, Varices, and Barrett’s Esophagus: WATS3D-only Surveillance and Band Ligation in the Management of Nondysplastic Barrett’s Esophagus Progressing to High Grade Dysplasia With Underlying Esophageal Varices

Introduction: Wide-area transepithelial sampling with 3-dimensional computer-assisted analysis (WATS3D) is an emerging technique used to collect esophageal samples via transepithelial brushing. WATS3D can be a safe and useful tool in Barrett’s esophagus (BE) management in patients with underlying small esophageal varices (EV) where traditional 4 quadrant cold forceps biopsies (CFB) would be contraindicated due to the risk of adverse events such as bleeding. We describe the utility of WATS3D-only surveillance combined with band ligation in the management and eradication of BE which progressed to high grade dysplasia (HGD) in a patient with underlying cirrhosis and EV. Case Description/Methods: We present a 66-year-old male with a history of nondysplastic (ND) BE (C0-M1), small Grade 1 EV and cirrhosis who presented for BE surveillance. Due to underlying EV and associated risk of bleeding, CFB was not performed and sampling with WATS3D-only was undertaken. WATS3D was first performed with surveillance esophagogastroduodenoscopy (EGD) in 2015 and demonstrated ND BE. On further EGD surveillance, BE histology remained ND until early 2021 where WATS3D revealed low grade dysplasia (LGD). Repeat EGD with WATS3D brushing was performed 4 months later, which demonstrated progression to HGD. Interval surveillance EGD with WATS3D brushing was, again, performed 4 months later and demonstrated LGD with rare foci of HGD. Of note, in both instances band ligation of the dysplastic segments was done. EGD with WATS3D 3 months later revealed endoscopic clearance of BE post-banding and pathology report revealed, ND, non-goblet cell metaplasia. The final interval surveillance EGD with WATS3D, 3 months later, showed complete eradication of BE with no evidence of intestinal metaplasia. Table 1 provides a thorough chronological description from first EGD to complete resolution of BE, 8 years later. Discussion: WATS3D has been increasingly shown to be an effective BE surveillance and screening tool. However, given the lack of data regarding appropriate surveillance windows for WATS3D-only BE surveillance, we performed sampling at shorter intervals than what would otherwise be recommended, to confirm the lack of dysplasia. This case presents a unique approach to WATS3D-only surveillance combined with band ligation therapy of dysplasia in the management of BE in a cirrhotic patient with underlying EV. Additionally, this case is unique in clearly documenting progression of a short segment of ND BE to HGD with WATS3D sampling alone. Table 1. - Summary of findings and intervention from first EGD to complete resolution of BE (8 year window) Date Variceal Grade Prague Score Number of BE Islands Sampling done by WATS3D Pathology Findings Banding therapy (# of bands) 04/09/14 2 C0-M1 3 No N/A 0 07/29/15 2 C0-M1 Scattered No N/A 0 12/2315 1 C0-M1 Scattered Yes No dysplasia 0 06/15/16 1 C0-M1 Scattered Yes No dysplasia 0 02/08/17 2 C0-M1 Scattered No N/A 4 01/22/18 1 C0-M1 1 No N/A 0 01/30/19 2 C0-M1 2 No N/A 0 01/29/20 1 C0-M1 2 No N/A 0 02/01/21 1 C0-M1 2 Yes Low-grade dysplasia 0 06/01/21 1 C0-M1 2 Yes High-grade dysplasia 3 10/25/21 1 C0-M1 2 Yes Low-grade with rare foci of high-grade dysplasia 2 01/25/22 1 N/A 3 Yes Non-goblet cell metaplasia, no dysplasia 0 04/25/22 1 N/A 0 Yes Squamocolumnar, no dysplasia or metaplasia 0

3-Dimensional Analysis of First Tarsometatarsal Joint after First Metatarsal Osteotomy with Weightbearing CT (WBCT)

Category: Midfoot/Forefoot; Bunion Introduction/Purpose: The pathology of the bunion deformity consists of deformities in the axial, coronal, and sagittal planes of the first metatarsal and its articular surface with the medial cuneiform. While weightbearing radiographs have been utilized for assessment of these deformities, such methods have limitations with regard to image magnification, patient position, and superimposition of bone alignments. With advances with weightbearing computed tomography (WBCT), evaluation of the 3- dimensional components of the first metatarsal along with its proximal articular surface can be assessed with greater precision. This study aims to observe the effect of the midshaft osteotomy on the alignment of the tarsometatarsal joint in three dimension Methods: Ten feet in 10 subjects underwent midshaft first metatarsal osteotomies. Weight-bearing (using a load equivalent to body weight) CT scans with .3mm cubic voxel size using an original loading device preoperatively and postoperatively were collected from each of the subjects in neutral standing position. Scans were segmented, and 3D renderings of the medial cuneiform, first metatarsal, and the first phalanx were also generated from the segmentations followed by definition of reference frames to evaluate changes in the metatarsal in relationship to the medial cuneiform. (Fig.1) Results: The measurements of the rotational parameters showed greater changes in the sagittal plane postoperatively with dorsiflexion of the first metatarsal relative to the medial cuneiform at the first tarsometatarsal joint (p&lt;0.05).(Fig.2) Post-operative changes in the coronal plane and axial plane with relationship of the first metatarsal to the medial cuneiform were noted. Distance mapping showed a significant increase in surface-to-surface distance at the dorsal tarsometatarsal joint post-operatively with a reduced distance at the inferior portion of the tarsometatarsal joint. (Fig.3). Conclusion: Based on the results of the study, midshaft osteotomies of first metatarsal can cause increased dorsiflexion in the sagittal plane, significant eversion in the coronal plane, and external rotation in the axial plane at the tarsometatarsal joint. Distance mapping analysis on WBCT images identified differences in surface-to-surface interaction of the first metatarsal and the medial cuneiform

The Knosp Criteria Revisited: 3-Dimensional Volumetric Analysis as a Predictive Tool for Extent of Resection in Complex Endoscopic Pituitary Surgery.

The Knosp criteria have been the historical standard for predicting cavernous sinus invasion, and therefore extent of surgical resection, of pituitary macroadenomas. Few studies have sought to reappraise the utility of this tool after recent advances in visualization and modeling of tumors in complex endoscopic surgery. To evaluate our proposed alternative method, using 3-dimensional (3D) volumetric imaging, and whether it can better predict extent of resection in nonfunctional pituitary adenomas. Patients who underwent endoscopic transsphenoidal resection of pituitary macroadenomas at our institution were reviewed. Information was collected on neurological, endocrine, and visual function. Volumetric segmentation was performed using 3D Slicer software. Relationship of tumor volume, clinical features, and Knosp grade on extent of resection was examined. One hundred forty patients were identified who had transsphenoidal resection of nonfunctional pituitary adenomas. Macroadenomas had a median volume of 6 cm 3 (IQR 3.4-8.7), and 17% had a unilateral Knosp grade of at least 3B. On multiple logistic regression, only smaller log-transformed preoperative tumor volume was independently associated with increased odds of gross total resection (GTR; odds ratio: 0.27, 95% CI: 0.07-0.89, P < .05) when controlling for tumor proliferative status, age, and sex (area under the curve 0.67). The Knosp criteria did not independently predict GTR in this cohort ( P > .05, area under the curve 0.46). Increasing use of volumetric 3D imaging may better anticipate extent of resection compared with the Knosp grade metric and may have a greater positive predictive value for GTR. More research is needed to validate these findings and implement them using automated methods.