Corrosion of orthodontic brackets: qualitative and quantitative surface analysis

ObjectivesTo determine and compare surface characteristics and presence of corrosion in new and used brackets with optical light microscopy (OLM) and scanning electron microscopy (SEM), and with elemental chemical analysis with energy-dispersive X-ray spectroscopy (EDS).Materials and MethodsOLM and SEM were used to analyze 24 new and 24 used conventional premolar brackets. EDS analysis was performed in six used brackets and four new brackets with corrosion-suspected spots.ResultsOLM and SEM images showed wear/abfraction signs, striations, pits/crevices, and adherent material. Used brackets showed more deterioration than new brackets. SEM images disclosed more morphological features than OLM images. EDS analysis revealed a significantly higher phosphorus (P = .001) and sodium (P < .005) weight fraction and significantly lower amounts of chromium (P < .001) in used brackets. The iron, chromium, and nickel weight fractions did not differ significantly between the clean and corrosion-suspected spots. Of the corrosion-suspected spots analyzed by combined SEM and EDS, 44.14% and 6.90% remained corrosion-suspected on used and new brackets, respectively.ConclusionsUsed brackets showed more signs of corrosion than new ones. Combined assessment of SEM and EDS indicates that the bracket surface is affected during orthodontic treatment as a result of corrosion.     

Laparoscopic Anterior Resection: New Anastomosis Technique in a Pig Model

Background and Objectives:

Bowel anastomosis after anterior resection is one of the most difficult tasks to perform during laparoscopic colorectal surgery. This study aims to evaluate a new feasible and safe intracorporeal anastomosis technique after laparoscopic left-sided colon or rectum resection in a pig model.

Methods:

The technique was evaluated in 5 pigs. The OrVil device (Covidien, Mansfield, Massachusetts) was inserted into the anus and advanced proximally to the rectum. A 0.5-cm incision was made in the sigmoid colon, and the 2 sutures attached to its delivery tube were cut. After the delivery tube was evacuated through the anus, the tip of the anvil was removed through the perforation. The sigmoid colon was transected just distal to the perforation with an endoscopic linear stapler. The rectosigmoid segment to be resected was removed through the anus with a grasper, and distal transection was performed. A 25-mm circular stapler was inserted and combined with the anvil, and end-to-side intracorporeal anastomosis was then performed.

Results:

We performed the technique in 5 pigs. Anastomosis required an average of 12 minutes. We observed that the proximal and distal donuts were completely removed in all pigs. No anastomotic air leakage was observed in any of the animals.

Conclusion:

This study shows the efficacy and safety of intracorporeal anastomosis with the OrVil device after laparoscopic anterior resection.     

Lower eyelid reconstruction in a paediatric face: a one-stage aesthetic approach using the versatile temporoparietal fascia flap

There are many different lower eyelid reconstruction techniques defined in the literature. Almost all of the published techniques have been described on elderly patients and use upper eyelid, periorbital or facial tissues as donor sites. However, in case of a paediatric patient or a young adult who has a crease-free and scarless face, camouflage of the facial donor-site scar is usually impossible. In order to avoid possible facial donor-site scars and upper eyelid deformities, a technique which uses the temporoparietal fascia (TPF) flap as the framework of a new eyelid was used for the reconstruction of an adolescent patient's postoncologic defect. The inner side of the flap was covered with nasal septal chondromucosal graft and the external side was covered with a retroauricular full-thickness skin graft. Eighteen months of unproblematic follow-up of this overlooked usage of the versatile TPF flap indicates that our technique has proved successful in terms of good functional and cosmetic outcome that is obtained at one stage.     

Value of Dual Energy Computed Tomography for detection of myocardial iron deposition in Thalassaemia patients: initial experience

Purpose

The aim of our study was to compare the value of cardiac DECT (cDECT) for detection of myocardial iron deposition to T2*w cardiac MRI (cMRI).

Material and methods

Nineteen patients with clinical history of Thalassaemia underwent T2*-weighted cardiac MRI (cMRI) with a 1.5 T MR scanner (MAGNETOM Symphony, Siemens Medical Solutions, Erlangen, Germany) and cardiac dual energy CT (cDECT) with a DSCT scanner (SOMATOM Definition, Siemens Medical Solutions, Erlangen, Germany) on the same day. HU values obtained from cDECT scans and T2*-values from cMRI were statistically correlated to calculate significance levels. Table times were measured for both cDECT and cMRI and compared. Patients were asked to grade their subjective comfort during the examination.

Results

In all patients cDECT scans were successfully acquired.HU values of septal muscle correlated strongly with T2*-values, whereas no correlation was found for paraspinal muscle.Table time was significantly shorter for cDECT compared to cMRI (mean: 3.7 min vs. 11.2 min) and subjective patient comfort was rated comfortable for cDECT and average to poor for cMRI. Mean radiation dose was 0.71 mSv.

Conclusion

cDECT scans seem to be possible for evaluation of myocardial iron load in pediatric Thalassaemia patients.     

Goat semen cryopreservation with rainbow trout seminal plasma supplemented lecithin-based extenders

The objective of this study was to determine the optimum concentrations of rainbow trout seminal plasma (RTS) supplemented extenders for goat semen quality at post-thaw and after incubation. Five sexually mature Saanen goat (Capra aegagrus hircus) were used for semen collection. Pooled semen was diluted with soybean lecithin-based extender without RTS (control) or supplemented with different concentrations of RTS (1%, 2%, 4% or 8%), at a final concentration of 150 × 10⁶ spermatozoon/ml. Sperm motility, plasma membrane functional integrity (HOST), damaged acrosome (PSA-FITC), mitochondrial activity (rhodamine123) and DNA integrity (TUNEL) were evaluated. Spermatological parameters were evaluated at post-thaw and after 6 hr incubation. RTS8 group preserved sperm motility, acrosomal integrity, plasma membrane functional integrity and mitochondrial function better than the control group (p < .05). The study demonstrated that RTS supplemented lecithin-based extenders have useful effects on goat spermatozoa. In addition, the results of the current study represented the positive effect of using 8% RTS supplemented extender.     

Early gallbladder carcinoma has a favorable outcome but Rokitansky–Aschoff sinus involvement is an adverse prognostic factor

The general impression about gallbladder carcinomas is that they are uniformly fatal; however, for the early forms, an entirely different picture indicating a very good prognosis is evolving from the high-incidence regions. We subjected 190 early gallbladder carcinomas (EGBC), defined as carcinomas confined to and above the tunica muscularis (AJCC's Tis, T1a, and T1b), and identified in cholecystectomy specimens sampled entirely according to an established protocol, to detailed analysis. Average patient age was 57.9 years (29–95). In more than half of the cases (114/190; 60 %), the tumor was inapparent by gross examination. In 81 cases (42.6 %), carcinomatous epithelium abutted the muscularis, whereas 57.4 % (n?=?109) were qualified as intramucosal with no overt contiguity with muscularis. Intraepithelial extension into Rokitansky–Aschoff sinuses (RAS) was found in 34 cases (17.8 %). At the time of data analysis, 171 patients (99 %) were alive. Overall actuarial survival was 92.3 % at 5 years and 90.4 % at 10 years. The 5- and 10-year actuarial survival rates of the intramucosal group (93.2 and 92.1 %, respectively) were not statistically different from that of the muscle-abutting group (89.7 % and 88.2 % ; p?=?0.334). Patients with RAS involvement had a significantly shorter survival than those without (p?<?0.001). Of the 33 patients with RAS involvement, 13 (39 %) died of disease, whereas only 6 of the 154 patients (4 %) without RAS involvement died of disease. Disease-related mortality in these cases occurred relatively late (median 48 months). EGBC has a very good prognosis with a 90 % 10-year survival rate. It is seen on average in patients almost a decade younger than those with advanced cancers. RAS involvement is an independent prognostic factor, and additional surgery may have to be considered for such cases. Occasional recurrences are encountered several years later, which suggests a field-effect phenomenon and warrants long-term follow-up.