Background and Aims: Disc displacement is the most common temporomandibular joint disorder and MAGNETIC resonance imaging (MRI) is the gold standard in its diagnosis. This disorder can lead to changes in signal intensity of MAGNETIC resonance (MR). The purpose of this study was evaluation of correlation between relative signal intensity of MR images of retrodiscal tissue, superior and inferior head of lateral ptrygoid muscle with type of anterior disk displacement and condylar head flattening in patients with temporomandibular disorder (TMD).Materials and Methods: In this retrospective study, 31 MR images of patients who had anterior disc displacement were evaluated. After relative signal intensity measurement for retrodiscal tissue, superior and inferior head of lateral ptrygoid muscle, the correlation between relative signal intensity and type of anterior disc displacement was evaluated with repeated measure ANOVA test. In each of these 3 areas, t-test was used to compare the groups with and without condylar head flattening.Results: The correlation between relative signal intensity of MR images and type of anterior disc displacement in retrodiscal tissue, superior and inferior head of lateral ptrygoid muscle was not significant. There was also no statistically significant correlation between relative signal intensity of MR images and flattening of condylar head in retrodiscal tissue, superior and inferior head of lateral ptrygoid muscle (P>0.05).Conclusion: According to findings of this study, relative signal intensity of MR images in retrodiscal tissue, superior and inferior head of ptrygoid muscle is not a good predictor for type of anterior disc displacement and flattening of condylar head. It seems that this cannot be used as a diagnostic marker for TMD progression.

Background: Finishing and polishing are important stages of composite restorations. Failure to polish will cause recurrent caries, plaque accumulation, and inflammation of the periodontium. This study evaluated the influence of diamond polish-pastes on the polish RETENTION of the nanocomposites after pH-Cycling and tooth brushing. Materials and Methods: Forty cylindrical specimens including nanofilled composite (FiltekZ350) and nanohybrid composite (Aelite) were subjected to 4 polishing methods in 8 groups (n=5). A reference under Mylar strip (M), sequence of Sof-Lex discs(S), Sof-Lex discs and diamond polishing paste (TDV) (ST), and Sof-Lex discs and diamond polishing paste (Ultradent) (SU). After finishing and polishing, the Ra and Rz were determined by a profilometer for the first time. Specimens were subjected to a pH-cycling regimen and 10,000 brushing cycle. New readings of the Ra and Rz parameters were obtained. All sets of data were subjected to one-way ANOVA, Duncan multiple range test, and T-test. Results: In Z350 composite, the analysis of variance test showed a significant difference between Ra1 and Rz1 of the four investigated groups (P=0. 002, P=0. 003). After pH-cycling and brushing, Ra2 values showed significant differences among the four investigated groups (P=0. 009). The Rz2 values were not significantly different among the four groups (P=0. 353). In Aelite composite, the analysis of variance test showed a significant difference between Ra1 and Rz1 of the four investigated groups (P<0. 000, P=0. 004). After pH-cycling and brushing, Ra2 and Rz2 showed significant differences among the four investigated groups (P<0. 000, P<0. 000). Conclusion: Comparison of Rz and Ra in Z350 composite before and after pH-cycling and brushing indicated no significant difference. In other words, pH-cycling and brushing did not change the surface roughness. Aelite composite had higher Rz than Z350 composite before and after pH-cycling and brushing. Diamond polishing pastes had no effect on reducing surface roughness.

Introduction: Relatively high prevalence of facial deficiencies caused by trauma and the need for ablative surgeries in maxillofacial cancers, cause aesthetic and functional problems for patients which can be rehabilitated with surgery, prosthesis or both of them. Prosthetic reconstruction for these patients has many advantages such as controlling wound healing, aesthetic, easy  and non expensive treatment. In this article the process for nose prosthesis fabrication with silicon materials has been presented step by step.Results: A 49 year-old female patient with past medical history of diabetes mellitus that had rhino-cerebral mucormycosis following by diabetic coma and had under gone ablative surgery in hospital. The resected regions in this surgery included nasal septum, superior, Middle and inferior conchea, anterior wall of ethmoid sinus, middle wall of maxillary sinus and anterior wall of sphenoid sinus, in addition to parts of hardpalate (maxillary anterior alveolar segment). She said that after the surgery, she rarely showed up in the public and always covered the defect with a guaze. Her speech was completely hypernasal and she had difficulty in swallowing. For satisfying her functional and aesthetic needs, a nasal silicon prosthesis attached to obturator prosthesis in maxilla with magnet RETENTION was fabricated.Conclusion: Reconstruction of Midface deficiencies according to defect region, its extension and patient's age can be accompolished with surgery, prosthesis or a combination of both approaches. In this patient, a nasal prosthesis and maxillary obturator was fabricated. In this article nasal prosthesis fabrication step by step was explained.

Background and Objectives: Learning is essential for understanding mental disorders, normal behavior, and forgetfulness. In this regard, the hippocampus plays an important role in the learning process. It has been reported that gammaaminobutyric acid (GABA) receptors in the hippocampus are involved in learning and memory mechanisms and some diseases, such as epilepsy and Alzheimer's. This study aimed to investigate the effect of coumarin on RETENTION, tissue index, and GABA type A receptor gene expression in the hippocampus of male gonadectomy rats. Methods: The population of this study consisted of 40 Wistar rats, which were randomized into 5 groups (n=8 each). These groups included healthy without treatment, gonadectomized without treatment, gonadectomized receiving solvent or Dimethyl sulfoxide, and gonadectomized receiving coumarin at a dose of 3. 5 mg/kg. The treatment was administered intraperitoneally once daily in 2 weeks. A shuttle box was used to test the memory RETENTION of the rats. At the end of the research process, the rats were exterminated in accordance with research ethics. After removing the brains of rats, in each group, in four brains histology test was implemented with Niels staining, and in four other brains, the hippocampus was removed quickly. The hippocampi were placed inside the micro type and frozen with liquid nitrogen. Finally, a gene expression test was taken from the hippocampus using a real-time polymerase chain reaction. Results: Based on the findings, in the memory RETENTION test of initial latency to enter the dark room (step through latency), the gonadectomy group showed a reduction, compared to the healthy group. Moreover, a significant decrease was observed in the number of healthy hippocampal pyramidal neurons; however, GABAA gene expression showed no significant difference. In the gonadectomy groups receiving treatments with different doses of coumarin, the amount of STL (Step Through Latency) and number of healthy pyramidal neurons in the memory RETENTION test showed a significant decrease, compared to the gonadectomy group receiving solvent; nonetheless, a significant increase was revealed in the GABAA-α 2 gene expression. Conclusion: It can be concluded that Gonadectomy caused memory impairment and coumarin affects memory impairment by increasing the GABAA-α 2 gene expression and decreasing the number of healthy hippocampal neurons.

Background and Objective: Using 2 implants in edentulous lower jaw is a standard protocol treatment for improvement of prosthesis RETENTION. Different attachments have been produced in factories. One of these attachments is locator that is now a famous clinical option. In this in vitro study, the effect of inter implant distance on RETENTION in simulated function condition and on 2 brands including Dio and 3i is analyzed.Materials and Methods: In this study, 24 nylon inserts pairs were provided from dio and 3i system attachment. Then, 2 hollow blocks with parallel walls were constructed. Attachments splinted to analogue and assembly inserted in block with GC reline materials in 2 inter implant distances of 19 and 23 mm and parallelism has confirmed with jelenko surveyor. The samples were assembled in zwick jaws and every sample was loaded at 1440 cyclic loading from vertical. Data is measured at cycles of zero, 120, 360, 720, and 1440 with 34560 cyclic loading exerted. Data were analyzed with proper statistical tests.Results and Conclusion: The results were analyzed with one-way analysis of variance (ANOVA). It was found out that RETENTION value in 23 mm distance was greater than 19 mm until 720 cycles and difference was significant but at 1440 cycles, there was no significant difference.

This study was conducted to identify and to rank the factors affecting market RETENTION in fitness centers. 14 participants including the customers and managers of fitness centers participated in a semi-structured interview to collect the required data. Sixteen factors were extracted from the interviews and sixteen experts evaluate the relationships among these factors with pairwise comparisons. Based on Interpretive-Structural Modeling, the factors categorized in five levels, i. e. 1) customer relationship quality, customer experience quality, reputation, price, perceived value and satisfaction, 2) Overall servicequality, secondary services and ethical climate, 3) Training type and schedule, location and accessibility and social responsibility, 4) Interior design and equipment, 5) Manager communication and trainer’ s competencies. For the sake of customer RETENTION, fitness centers are required to align their decisions with their customer requirements. Ranking the effective factors in this study can provide the fitness centers’ managers with a better understanding of the factors affecting customers’ decisions.

The most important challenges of using minerals and fillers in the papermaking process are low RETENTION and sharp reduction in paper strength properties. In this research, MAGNETIC papers were produced using commercial kraft fibers and iron salts. Nano-iron oxide has the same performance as fillers, as a result, to prevent reducing strengths properties and RETENTION of material in the final paper, Chitosan was used as a strength agent and RETENTION aid at 10 and 15% levels. Characteristics of MAGNETIC papers were investigated by atomic force microscope, scanning electron microscope, X-ray diffraction and vibration sample magnetometer. Tensile index and tear index were also determined in MAGNETIC paper samples. The results of the microscopic examination showed that the magnetite nanoparticles were in the size range of 1 to 84 nm and the MAGNETIC materials completely covered the fibers surface. Also, increasing chitosan content, increased the degree of loading and MAGNETIC saturation of the samples. The MAGNETIC paper samples had super para MAGNETIC behavior. The results showed that adding chitosan at 10% increased tear and tensile strength but higher dosage at 15% chitosan the strengths properties of MAGNETIC paper.