Introduction: Correction of deep overbite and achieving a long-term stability are still major concerns for many orthodontists. There are three main ways for solving this problem: Bypass ARCH technique introduced by Ricketts, Segmented ARCH technique introduced by Burstone and using TADs. The aim of this study was to evaluate and compare the effects of Ricketts and Burstone techniques during correction of deep overbites.Materials and Methods: In this clinical trial, 18 female patients with Cl I and II occlusion and more than 4 mm of overbite were selected. The subjects were divided into two groups (n=9). The deep overbite in group A was treated with Ricketts technique and Burstone technique was used for correction of overbite in group B. Fifteen jaws were included in each group. Lateral cephalograms before and after intrusion were used to evaluate the results. Data were statistically analyzed with Student’s t-test and SPSS 18 (a=0.05).Results: There was a statistically significant difference in the means of true intrusion and extrusion between groups A and B (p value=0.014 and p value=0.47, respectively). However, overbite reduction was not significantly different between the two groups (p value=0.704). In addition, the differences in mean false intrusion (p value=0.02), changes in the axial inclination of posterior teeth (p value=0.047) and the angle between axial inclination of upper and lower anterior teeth (p value=0.002) were statistically significant between the two groups.Conclusion: Under the limitation of the present study, the results confirmed the superiority of Burstone technique in intruding incisors with less undesirable lateral movements.

Many nonlinear models have been developed based on the mean errors modeling. However, the non-linear models with Autoregressive conditional heteoscedasticity are based on variance modeling. These models are combined with linear models, partly to increase the accuracy of modeling and predictions. In this study, using data from the Urmia Lake water level data for the period 1973-2012, the models with autocorrelation moving average and Bilinear model and two combined models (Autoregressive conditional heteoscedasticity) and (Bilinear conditional heteoscedasticity) were evaluated. To select the ARMA family models, AICC test were used and regression coefficient (r) and root mean square error (RMSE) tests were used for validation models. The results of validation the ARMA, BL, ARMA-ARCH and BL-ARCH models showed the correlation coefficient of 0.707, 0.618, 0.792 and 0.704 and the mean square root equal 2.838, 4.309, 2.031 and 4.11 between observed and modeling data respectively. Also the results showed that model accuracy increased with combining both linear and nonlinear models, but with combining two nonlinear models is caused reduce the accuracy of the models. Overall the results showed that by combining ARMA and ARCH models, the model error decreased about 28 percentage and combining two non-linear models caused increased model error about 2 percentage.

Aortic rupture and pseudoaneurysm formation in the anterior ARCH of congenital double aortic ARCH anomaly associated with a coarctation is an exceedingly rare complication of aortic vascular ring. This is a case report of a double aortic ARCH with an anterior ARCH pseudoaneurysm, presenting with chest pain, respiratory distress, and hypotension. The patient underwent open-heart surgery with resection of the anterior ARCH pseudoaneurysm and bypassing of the coarctation with ascending aorta to descending aorta connection with a Dacron tube graft. Posterior aortic ARCH entering to pseudoaneurysm by a vertical artery also connected to the main Dacron tube by another small size of the Dacron tube. The postoperative course was complicated by chylothorax and respiratory distress that managed with prolonged preservation of chest tubes, chest physiotherapy, and low lipid content diet. One year follow-up with C_T angiography revealed the patency of both the Dacron tube and patient was in good condition.

A 4-year old boy with a history of poor feeding, dyspnea and irritability while feeding that started since infancy, was referred to our center. Long-term examination of the disorder was started by echocardiography since he was one-month old and was performed when he was 2 years old. Although in all those evaluations, right sided aortic ARCH (RSAA) and increased right ventricle (RV) and pulmonary artery (PA) pressures were noticed, the definite diagnosis was not reached at that occasion. The patient was referred to our radiographic center and preceeded to undergo CT angiography with multislice spiral thin section scans plus maximum intensity projection (MIP), multiplanar reconstruction (MPR) and volume rendering techniques. The computed tomography (CT) angiographic findings revealed type C aortic ARCH interruption with right sided aortic ARCH which is a very rare condition and only one similar case has been previously reported in the literature. Interestingly, almost all types of right sided aortic ARCH interruptions reported so far were of type B. The reason why our case is type C could be explained from an embryologic point of view. Explanation of this case could be helpful and attractive since echocardiographic and angiographic findings were not definitive enough for final diagnosis of this case. The symptoms intensified after repairing the patient’ s ventricular septal defect (VSD); however, definite diagnosis was obtained by CT angiography. What makes this case report more important is that the authors believe that diagnostic methods in developed countries are able to diagnose this congenital heart disease sooner in neonatal or even in prenatal periods, resulting in a lower incidence of presentation of similar cases in childhood.

The main purpose in this article has been to evaluate the exchange rate volatility in Iran using the family of the ARCH models. Doing so, the symmetric GARCH and asymmetric TARCH, EGARCH and APGARCH models are applied. The results have indicated that the volatility caused by the bad (negative) news is relatively larger than that caused by the good (positive) news.

In this paper, we investigate variations of gold coin price and also probe to model the fluctuations and conditional variance of coin market returns. The data consist of daily market prices of gold coin over the 1380 – 1386 period. Since volatility clustering is viewed in time series of returns, we employ ARCH (Autoregressive conditional heteroskedasticity) methodology in order to model the variance of returns. The results suggest that EGARCH is the best choice among other models of the ARCH family. The fluctuations are influenced by oil price and exchange rate.Exchange rate has the greater effect than oil price on conditional variance. Leverage effects were observed in gold coin market. It means that good news have greater influence rather than bad news with equivalent magnitude.

A 28- year- old woman was admitted because of uncontrolled hypertension following delivery. Aortography showed severe coarctation of the aortic ARCH, and a large- sized aneurysm that was located in the aortic ARCH distal to the left common carotid artery. The patient was scheduled for surgery. The coarctation was removed and the aortic ARCH was replaced with a 28-mm Dacron tube, and the left subclavian artery was reimplanted to the Dacron tube. The patient tolerated the procedure well and was discharged from hospital 15 days later.