Predictors of successful outcome of tubularized incised plate for primary distal hypospadias repair

Background Several preoperative factors affect the outcome of Tabularized Incised Plate (TIP) repair. Our aim was to collect and analyze all these factors to define what the most important predictive factors are. Methods Hundred patients (1–5 years old) with primary distal hypospadias were included. Exclusion criteria included previous penile operations and hormonal treatment or associated congenital anomalies. Anogenital distance (AGD), stretched penile length (SPL), meatal site, glanular shape, chordee and torsion degree, plate width and glans meatus shaft (GMS) score were assessed. TIP repair was done to all patients and followed up for one year. The outcome was correlated with the above parameters. Results Mean ± SD of age of patients was 3.5 ± 1.5 years, while weight was 14.1 ± 3.0 kg. Complication rate was 18% including urethrocutaneous fistula (UCF) and meatal stenosis 14%, repair breakdown 1% and urethral stricture 3%. Patients with chordee degree < 30° and distal penile meatal location were associated with increased risk for complications by 11.6 and 8.2 times; 95% CI was (1.46–91.75) and (1.02–66.52), respectively (p < 0.05 for each). Plate width ≥ 9 mm, AGD > 5 cm, GMS score ≤ 7 (p < 0.001 for each), age of patient ≤ 2 years old, and SPL > 3.5 cm (p < 0.01 for each) were associated with successful outcome of repair. Conclusion The proposed successful criteria of TIP repair were absent chordee, coronal/subcoronal penile meatal location, plate width ≥ 9 mm, AGD > 5 cm, age of patient ≤ 2 years old, GMS score ≤ 7, SPL > 3.5 cm and grooved glanular shape.

Investigation of Bursting Stress and Spalling Stress in Post-tensioned Anchorage Zones

Over the past decades, considerable efforts have been made to quantify the bursting forces in the post-tensioned anchorage zones based on the simplified model or fitting formulas, however reproducing the transverse stress distribution is still a challenging topic, which is also important to detail the reinforcing details in the anchorage zones, especially for cracking control. To address this issue, this paper is devoted to seeking an elasticity solution for transverse stresses in the anchorage zones, and providing a more rational equation for transverse distribution in anchorage zones. The sum function of normal stresses is employed to solve the stresses filed in the anchorage zones with concentric load and two eccentric loads. The bursting stresses in the concentric anchorage zones and spalling stresses in the eccentric anchorage zones are verified by the photoelastic tests. The transverse stresses along the symmetry axis of the eccentric anchorage zones can be handled as a concentric single anchorage zone with equivalent bearing plate width. Moreover, according to the concept of force stream tube, the profiles of isostatic line of compression (ILCs) are determined and validated, which confirms the existence of ILCs.

The Cone Beam Computed Tomography Evaluation of Cortical Bone Plate after Piezocision-Assisted Orthodontic Upper Arch Expansion: A Case Series

Background: The purpose of the study was to evaluate cone beam computed tomography (CBCT) after piezocision-assisted orthodontic maxillary arch expansion. Methods: Forty CBCT images of 20 patients taken before and after treatment were included in the study. The following radiographic parameters were measured: buccal/palatal bone plate thickness measured in three locations, 0.5 mm, 3.5 mm, and 5 mm from the margin of alveolar process; cemento-enamel junction-crest distance (CEJ-C) measured at buccal (CEJ-B) and palatal/lingual (CEJ-P) aspects. Results: After treatment there were insignificant changes in CEJ-C and thickness of buccal/palatal plates for all the dental groups except for incisors and premolars. CEJ-B increased by 1.43 mm on premolars and CEJ-P by 1.65 mm on incisors and by 0.31 mm on premolars. On the incisors, the buccal plate width increased significantly, by 0.2 mm and 0.44 mm at 3.5-mm and 5-mm measurement points. On premolars, the buccal plate width decreased in three measuring points by 0.27 mm, 0.37 mm, and 0.25 mm. Conclusions: Piezocision-assisted orthodontic maxillary arch expansion does not cause evident negative changes of cortical plates except for the premolar region. Therefore, premolars may be at greater risk of buccal plate loss than other teeth.

On the Solution to Pre- Buckling of a Thin Rectangular Plate Subjected to a Thick Strip in-plane Loading

The current paper deals with the problem of the simply supported thin rectangular plate subjected to the intermediate strip in-plane loading. Based on the strain energy method (Fourier ansatz), the critical (minimum value) of buckling stress occurrence was determined in a general form dependent only on the strip thickness, strip location, plate width and stress magnitude. Compatible with the classical columns Euler method it was found that the plate stability is decreased with the increasing of the plate width due to larger induced stresses. Also, strip location relative to the support region was found to influence the buckling (same analogy to the Euler buckling theory; consider the strip as a both sides pressed rod). Additionally, the strip width parameter increase is likely to cause larger buckling stress. Moreover, expressions that includes both axial and transverse loads for different extended cases configurations were also derived and examined based on the strain energy method alongside explanation for possible applications (thin aluminum plate welding). In a general view, it was found that the cases of combined axial and perpendicular loading action are less stabilized than cases where only one kind of loading configuration is participated. Finally, the buckling stress was found to agree qualitatively with the cited literature.

A multi-objective approach to optimize the weight and stress of the locking plates using finite element modeling

This paper aims to identify an optimum bone fracture stabilizer. For this purpose, three design variables including the ratio of the screw diameter to the plate width at three levels, the ratio of the plate thickness to the plate width at three levels, and the diameter of the bone at two levels were selected for analysis. Eighteen 3D verified finite element models were developed to examine the effects of these parameters on the weight, maximum displacement and maximum von Mises stress of the fixation structure. Considering the relations between the inputs and outputs using multivariate regression, a genetic algorithm was used to find the optimal choices. Results showed that the diameter of the bone and the amount of load applied on it did not have a significant effect on the normalized stresses on the structures. Furthermore, in all ratio of the plate thickness to the plate width, as the ratio of the screw diameter to the plate width increased, the amount of stress on the structure decreased. But, by further increasing the ratio of the screw diameter to the plate width, the amount of stress on the structure increased. On the other hand, by increasing the value of the ratio of the plate thickness to the plate width, the maximum amount of stress on the structure decreased. Finally, optimal solutions in terms of the weight and the maximum amount of stress on the structure were presented.

The effect of a plate installation upstream of an orifice on the pressurized flushing efficiency

The effect of a plate installation upstream of an orifice was investigated as a new method for improving the pressurized flushing efficiency. In this regard, a plate with three different widths (B_T) was installed at four different distances (L_T) upstream of the orifice. According to the results, the plate installation significantly increased the pressurized flushing efficiency due to the wake vortices formed upstream of the orifice. The flushing efficiency increased up to a maximum value of 11.5 times relative to what was calculated for the experiment without plate for the same conditions. For the best configuration of the plate width and its distance from the outlet (i.e., L_T/D_O =0.7 and B_T/D_O =0.5, D_O is the orifice diameter), the length, width, and depth of the flushing cone increased by about 160, 90, and 240% relative to the control experiment under the same conditions, respectively.

Scattering of Gravity Waves by a Rectangular Floating Flexible Porous Plate

Scattering of oblique surface gravity waves by a finite, floating porous-elastic plate is investigated, with assumptions of linear water wave theory and plate response. A boundary value problem is set up, wherein the thin plate equation together with a porosity parameter is used to formulate the condition on the floating plate. A matched eigenfunction approach is adopted for the solution of this problem, with roots of the dispersion relation being located with the aid of contour plots, and various hydrodynamic scattering quantities are computed. Energy dissipation due to plate porosity is seen to have a significant impact on both reflection and transmission of waves, while flexibility of plate only alters the extent of wave reflection by porous elastic plates. An oscillatory trend is shown by reflection coefficient for smaller values of relative plate width, and there is no variation in reflection or transmission coefficients when the plate width is increased beyond a certain cut-off value. Comparison of scattering properties of four different types of plates highlights the effects of porosity and flexibility and establishes the superiority of a flexible porous plate as a wave attenuating device, with moderate reflection, high energy dissipation and low transmission.

The Effect of Pre-Incision Urethral Plate Width and Glanular Width on the Outcome of Tubularized Incised Urethral Plate Repair Surgery in Distal Penile Hypospadias, A Prospective Study

Background: To determine the outcomes of hypospadias repair according to the width of the urethral plate & glanular width. Materials and methods A prospective evaluation of patients operated for hypospadias. The urethral plate width (UPW) & glans width (GW) of the patients were measured preoperatively using standard calipers. The urethral plate width was correlated to the cosmetic outcome (using hypospadias objective penile evaluation [HOPE]) and functional outcome (using the urinary stream) of repair. All patients were managed via the same technique using Snodgrass tubularized incised plate repair (TIP). All intraoperative data were recorded. All patients were followed up for 1 year. Success was defined as slit shaped meatus at the tip of the glans without stenosis, fistula or diverticulum. Results: All 38 patients were evaluated at 6 months and 1 year follow up. The mean age at surgery was 4.5 ± 2.1 years. We categorized the patients into two groups:- (Group A) had a urethral plate width of less than 8 mm, they were 24 patients (63.15 %). (Group B) had a urethral plate width greater or equal to 8 mm. (group B) had a urethral plate width greater or equal to 8 mm, they are 14 patients (36.8 %) Overall, the mean ± of UPW was 10.92 ± 1.24 mm while the mean ± SD of GW was 9.52 ± 1.56 mm. Success was documented in 36/38 patients (94.7%). The documented complication was Fistula in two patient (5.2 %), glans dehiscensce in three patients (7.9%). Success rate was not statistically different in correlation of UPW and GW (p=0.5). The urinary stream was straight in 32 boys and sprayed in 6. Overall, mean ± SD HOPE score was 39.1 ± 8.83. The only statistically significant difference between all patients was a longer operative time in the patients with deficient urethral plate compared to others with adequate urethral plate (p= 0.005). A significant correlation found between the cosmetic outcome of the two groups and HOPE score (p = 0.06). Conclusions: The pre-incision urethral plate width and glanular width was not correlated with the TIP outcome. A better HOPE score is associated with wide urethral plate.

Previous Research Works on Reinforced Concrete Curved Beams

The current research work summarizes some previous research works on horizontally curved beams. Because of curvature, torsional effects in the analysis and design should be included. Diameter of ring beam, number of supports, beam width, compressive strength of the concrete, and bearing plate width. Which can be summarized from previous studies is that increasing diameter of ring by about 25-75% decreases the capacity load by about 14-36%, while increasing number of supports by about 33-100%, beam width by about 25-75%, compressive strength of concrete by about 24-76%, and bearing plate width by about 25-75% increases the capacity load by about 62-189%, 25-75%, 24-76%, and 5-16%, respectively due to the beam section increase and/or its properties. Frequently, reinforced concrete deep ring beams exhibit shear failure in a manner similar to straight beams. Strut and tie model (STM) and plastic analysis are useful tools for efficiently analyzing ring or curved deep beams. In addition, the nonlinear three-dimensional finite element modeling is typical for predicting the deep curved beams strength and behavior.

The effect of pre-incision urethral plate width and glanular width on the outcome of Tubularized Incised Urethral plate repair surgery in distal penile Hypospadias, A prospective study

Objective:To determine the cosmetic and functional outcomes of hypospadias repair in relation to the width of the urethral plate in addition to granular width and configuration.Materials and methodsThe study was a prospective evaluation of patients operated for hypospadias after approval of ethical committee a formal consent were taken from parents. The urethral plate width (UPW) and glans width (GW) of the patients were measured preoperatively using standard calipers. The width of the urethral plate was correlated to the cosmetic outcome (using hypospadias objective penile evaluation [HOPE]) and functional outcome (using the urinary stream) of hypospadias repair.All patients were managed via the same technique using Snodgrass tubularized incised plate repair (TIP). All operations were performed by a single surgeon. All intaoperative data were recorded. All patients were followed up for 1 year. Success was defined as slit shaped meatus at the tip of the glans with no stenosis, fistula or diverticulum.Results:All 38 patients were evaluated at 6 months and 1 year follow up. The mean age at surgery was 4.5 ± 2.1 years. Overall, the mean ± SD of UPW was 10.92 ± 1.24 mm. a 24 patients (61.5 %) (Group A) had a urethral plate width of less than 8 mm while 14 patients (35.9 %) (group B) had a urethral plate width greater or equal to 8 mm. the mean ± SD of GW was 9.52 ± 1.56 mm. Success was documented in 36/38 patients (94.3%).The only complication was Fistula in two patient (6.7 %), glans dehiscensce in three patients (10%). Success rate was not statistically different in correlation of UPW and GW (p=0.5).The only statistically significant difference between all patients was a longer operative time in the patients with deficient urethral plate compared to others with adequate urethral plate (p= 0.005). The urinary stream was straight in 32 boys and sprayed in 6. Overall, mean ± SD HOPE score was 39.1 ± 8.83. A significant correlation found between the cosmetic outcome of the two groups and HOPE score (p = 0.06).Conclusions:The pre-incision urethral plate width and glanular width was not correlated with the TIP outcome. A better HOPE score is associated with wide urethral plate.