In the past 25 years, rising of the Caspian Sea level, part of a natural treat to the sea, has inundated and destroyed many buildings and arable lands and threatened many inhabitations in coastal areas. The main reason for these damages is that the law-setback has lost its efficiency and human activities have proceeded seaward. The goal of this study is to introduce a proper setback line for the southern coast of Caspian Sea on the basis of critical water elevation and the results of coastal vulnerability assessment to sea level rise. This setback contains vertical and horizontal buffers. The Coastal vulnerability index (CVI) method is used for coastal vulnerability assessment and is also used in the Geographic Information System. Five variables in two sub-indices were used in this method. The final map obtained from coastal vulnerability assessment divided the coastal zone into low, moderate, high and very high risk categories based on quartile ranges and visual inspection of data. A mean distance of very high risk category of vulnerability map from a second vertical buffer in each rural district was then proposed as a width of horizontal buffer in the same rural district.

Background and Aim: Surgery for mandibular prognathism produces changes in the skeletal and soft tissue components of the orofacial complex. In particular, studies have shown changes in positions of the tongue and the hyoid bone and consequent narrowing of the pharyngeal airway space. This study evaluated the change in the pharyngeal airway space associated with surgical mandibular set back.Methods & Materials: Lateral cephalograms of 25 adult patients taken preoperatively and 3 months after mandibular setback surgery were traced, and the width of pharyngeal airway space and pharyngeal airway space area were calculated and compared by Paired T-test.Results: The mean amount of mandibular Set back was 6.8:1:2mm. There was not significant change in width of nasopharyngeal airway. Mean reduction in distance from uvula to the posterior pharyngeal wall was 1.4±0.7mm, mean reduction in distance from vallecula to the posterior pharyngeal wall was 2±0.7 mm, mean reduction in the distance from the tongue base to the posterior pharyngeal wall was 2.5±0.8 mm and the mean reduction in pharyngeal airway space area was 1.5±0.5 cm2.The hyoid bone moved in an superoposterior direction.Conclusion: .Mandibular set back surgery caused decrease in pharyngeal airway dimension. In the patients, who have other risk factors, for example, over weight, short necks, or large tongues, a mandibular set back procedure could possibly predispose the development of sleep apnea syndrome.

The damage of structures due to earthquake is the cause of loss of life and property and hence it is necessary to study the vulnerability characteristics of structures subjected to such seismic excitations. In this paper a brief review of seismic performance evaluation of a G+10 Reinforced Cement Concrete (RCC) frame by Capacity Spectrum Method (CSM) is presented as per IS: 1893 (Part 1):2002. Further the vulnerability assessment of different RCC frames and the applicability of HAZUS drift ratio based damage state thresholds for building designed as per IS 456: 2000 code are also studied. Fragility curves were developed for frames with setbacks on different storeys indifferent bays for frames with and without infill walls. Infill is provided by “Diagonal Strut Method” and their damage probabilities are compared. Study of performance of shear wall placed in least stiffness direction as a remedial measure for setback frames was also carried out. It was concluded from this study that setback frames are more vulnerable compared to regular frames, however setback frames with provision of infill are found to perform as regular RC frames.

One of the primary goals of seismic design codes is to prevent structural collapse caused by large displacements resulting from severe earthquake ground motions. In general, using the force-based design method prescribed in seismic codes is a common practice for seismic design of structures. In design of structures using force-based methods applied in current seismic codes, to obtain the nonlinear displacements of structures under the design earthquake, the deflection amplification factor (Cd) is applied. In other words, the displacements obtained from elastic analyses under the reduced seismic forces are amplified by Cd to obtain the inelastic displacements under the design earthquake. Research studies showed that using a constant coefficient for estimating the inelastic displacements may lead to considerable overestimation or underestimation of the displacements in different stories of structures. The seismic behavior of a structure is under the influence of three important structural features, including stiffness, strength, and mass. Any change in these parameters would change the dynamic characteristics of the structure. The change is occasionally caused by a sudden change in the geometry of the structure along the height, such that the lateral dimension of the structure decreases significantly along its height at specific level(s). Such structures are named setback buildings. This architectural form enables the lower floors to gain sufficient sunlight when the adjacent structures are close together. A setback building has a sudden discontinuity in the frame geometry along the height. Generally, in regular structures, the inelastic maximum interstory drift ratio (IMIDR) occurs in lower stories. Investigating the seismic performance of structures with irregularity in their heights showed that the inelastic responses of these types of structures can differ significantly from the inelastic responses of regular structures. The present study investigates Cd for estimating IMIDR and inelastic maximum roof drift ratio (IMRDR) for steel special moment resisting frames (SMRFs) with setback, under the design earthquake. In addition, the variation of Cd with the variation of the location of the setback in the structural height and bays is studied. For this purpose, 24 steel SMRFs, including two groups of 5-and 9-story two-dimensional structures as low-and mid-rise structures, respectively, are investigated. Each group consists of one regular and 11 irregular setback structures. The structures are designed according to the Iranian Code of Practice for Seismic Resistant Design of Buildings (Standard No. 2800) and Specifications for Design and Construction of Steel Buildings (2022). The structures are designed using elastic modal response spectrum analysis. To perform nonlinear dynamic analyses, seven ground motion records that are matched to the design response spectrum are applied. To obtain Cd from the nonlinear analyses, the mean of IMIDR for each story is divided by the corresponding value obtained from the modal response spectrum analysis. Therefore, for each story of each structure, the Cd value is obtained. To calculate Cd for predicting real nonlinear roof displacement in the structures, the mean of the maximum of the roof displacement obtained from the nonlinear dynamic analyses is divided by the corresponding value obtained from the modal response spectrum analysis. The results show that for the 5-story setback structures (as low-rise setback structures), the recommended value of Cd = 5. 5 by Standard No. 2800 significantly underestimates the inelastic IMIDR values under design earthquake. Whereas, in the case of the 9-story setback structures (as mid-rise setback structures) the recommended value of the design code overestimates the inelastic IMIDR values in most of the cases. In addition, it is shown that the recommended value of Cd = 5. 5 by Standard No. 2800 can precisely predict the inelastic roof displacements of the setback structures under the design earthquake.

Introduction: In the orthogenetic surgery of the mandible and especially bilateral sagital spilt osteotomy (B.S.S.O), the most complication is some change in mandibular border movement, and as a result limitation of mandibular movement. The aim of this study was to evaluate the changes in maximum interincisal opening, left and right lateral excursion, and protrusive movements in all patients before and after operation in the period of three to six months and the effects of modern physiotherapical plans (CPM) on increasing these movements after surgery.Materials and Methods: This is a prospective clinical trial study. In this study 30 patient's (18 females & 12 males) who were 13-30 years old (average age 20.5), BSSO surgery was performed according to Epker procedure with surgical handpice and bur, rigid fixation were performed with 3 positional screw of 2mm diameter for all patients. MIO, LLE, RLE, PM were measured before and after operation in the period of three to six months. At the end the patients who still had mandibular movement limitations were divided into two groups of experiment and sample, then the effects of 20 physiotherapical sessions were studied after the 9th month.Results: After 3 months post-op, considerable reduction in all mandibular movements has occurred, but after 6 months post-op, 12 patients (40%) had significant limitation of mandibular movements, especially in MIO & PM. At the end of nine months post-op all patients in sample group, had limitation in mandibular mobility but in the experiment group all patients had normal mandibular border movement.Discussion: There are different reports about the effect of orthogenetic surgery on mandibular border movements. In this study BSSO for mandibular setback has led to considerable reduction in mandibular movement especially maximum interincisal opening & protrusive movements and the physiotherapical treatment have been considered as the solution of the mentioned problems but the major difference between our study and others are, using of Rigid fixation, not using MMF and two week usage of elastic Training.

Mandibular defects due to surgical resection of pathologies are common challenges for maxillofacial surgeons. In some clinical situations, alteration or combination of different surgical procedures is needed to reduce the size of bony defects and improve the success rate of bone grafts. In the current study, an 18-year-old female with a pathological lesion (ameloblastoma) in the mandible is presented. After tumor resection, bony defect reconstruction with autogenous bone graft was combined with a mandibular setback to facilitate the procedure. In this case, the simultaneous combination of orthognathic mandibular setback movement with tumor resection in a single surgical session helped to reduce the bony defect size. The adoption of this approach led to a decrease in the volume of graft harvesting and improved the success rate of the grafting procedure.

In the early years, the rising of the sea level, which is a part of natural treatment, destroyed many buildings, arable lands, residential and commercial areas. It seems that the main reason of these destructions is the diminishing of the legal setback efficiency and the proceeding of human activities. The aim of this study is to introduce the appropriate setback for southern coast of Caspian Sea (Gilan province) on the basis of critical levels of Caspian Sea and the results of coastal vulnerability regarding sea level rise. This setback is composed of two parts, vertical buffer and horizontal buffer. In this study, CVI method (coastal vulnerability index) was used for coastal vulnerability assessment. In this method, five variables were employed as in two sub-indexes, natural and human-induced subindexes. The final map is divided into four categories, from low to very high vulnerability. Finally the mean distance from the very high vulnerability category to vertical buffer boundary in every district is introduced as the horizontal buffer.

Many studies since 1977, in the southern coast of Caspian Sea revealed that the law-setback and low-lying coastal zone have been severely and increasingly impacted by rising sea-level. This rising continued until 1995. The rate of rising was nearly l3cm per year in this period (1977-1995). The general concept of setback determination is tended to introduce a buffer area between human activities (especially buildings) and a shoreline that is likely at the highest risk of sea-level rise and following damages. This study could help managers to solve many problems in the future, noticeably due to lack of criteria for determination of setback in this region. In this study a setback is introduced on the basis of critical levels of Caspian Sea and the results of coastal vulnerability assessment to sea-level rise in Mazandaran Province. This setback is composed of two parts called, vertical buffer and horizontal buffer. In this study, the CVI (Coastal Vulnerability Index) method is used for coastal vulnerability assessment to sea-level rise. The CVI includes 5 variables describing two dimensions, natural and anthropogenic. Final map is divided into 4 classes from low to very high vulnerable. Mean distance between very high vulnerable classes to the vertical buffer boundary is introduced as a horizontal buffer in each district.