Amirhossein Mirhashemi; Sepideh Arab; Rashin Bahrami
Abstract
Background and Objective: Palatal expansion can be done with tooth-borne and bone-borne appliances; Bone maturity is one of the factors required placing a mini-screw in the palate for expansion. Expansion with bone-based appliance also has two dental and skeletal responses; Part of the skeletal response ...
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Background and Objective: Palatal expansion can be done with tooth-borne and bone-borne appliances; Bone maturity is one of the factors required placing a mini-screw in the palate for expansion. Expansion with bone-based appliance also has two dental and skeletal responses; Part of the skeletal response can be to increase the size of the airway. The present study evaluates the effect of Miniscrew-assisted palatal expansion on airway volume.Methods: Search was conducted for articles published between January 2010 to January 2021 in PubMed, Embase, Google Scholar, and Cochrane using the following inclusion criteria: 1) patients whose treatment with Miniscrew-assisted palatal expansion and who with transverse discrepancy 2) all languages, 3) Randomized clinical trials (RCTs) or non-randomized clinical trials (Non-RCTs) and retrospective studies were considered.Results: Of the 123 studies on miniscrew-assisted palatal expansion, only 7 studies clinically evaluated the effect of miniscrew-assisted palatal expansion on airway dimensions. The results of studies show that the miniscrew-assisted palatal expansion increasing airway dimensions; so that, increased nasal cavity volume and nasopharyngeal volume have been observed following this treatment. However, studies have shown that this approch does not effect on oropharyngeal, palatopharyngeal, glossopharyngeal and posterior areas.Conclusion: The results of the study demonstrated that Miniscrew-assisted palatal expansion is an effective and efficient treatment in increasing airway dimensions via its increasing nasal cavity and nasopharynx volume.
Mahsa Esfehani; Bahareh Mohammad Zahraiee; Sepideh Arab; Fatemeh Hajmanoochehri; Mohammadtaghi Vatandoust
Abstract
Objectives: This study was aimed to assess salivary sodium and potassium concentrations in patients with fixed orthodontic appliances.Methods: In this case-control study, saliva samples (5 cc) were collected from 13 patients with fixed orthodontic appliances before, and 1 week, 1 month and 3 months after ...
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Objectives: This study was aimed to assess salivary sodium and potassium concentrations in patients with fixed orthodontic appliances.Methods: In this case-control study, saliva samples (5 cc) were collected from 13 patients with fixed orthodontic appliances before, and 1 week, 1 month and 3 months after the beginning of the orthodontic treatment using the spitting method. Saliva samples were also collected from 10 healthy individuals as controls. The saliva samples were centrifuged at 3000 rpm for 10 minutes and the salivary sodium and potassium concentrations were measured by spectrophotometry. Data were analyzed using independent and paired t-tests. P-value < 0.05 was considered as significant. Results: The salivary sodium and potassium concentrations were almost the same in both groups at baseline (P > 0.05). A significant reduction in sodium and an increase in potassium levels were noted in the case group at 1 week compared with baseline (P < 0.001). At 1 week, the potassium concentration was significantly higher and the sodium concentration was significantly lower in the case group (P < 0.01). The salivary sodium significantly increased while the salivary potassium significantly decreased at 1 month compared with 1 week (P < 0.001). The differences with the control group were also significant (P < 0.05). No significant differences were noted between the two groups at 3 months (P > 0.05).Conclusions: Time has a significant effect on the release profile of sodium and potassium ions from orthodontic appliances. The salivary sodium and potassium concentrations returned to their normal pretreatment values within 3 months after the start of fixed orthodontic treatment.
Parham Pedram; Hannane Ghadirian; Sepideh Arab
Abstract
Background: Splinting anterior teeth is a way to fix them after orthodontics treatments. Occlusal trauma from functional or parafunctional forces can cause stress increase and movements of teeth especially while having bone loss.
Methods: Six anterior teeth with different bone levels were designed in ...
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Background: Splinting anterior teeth is a way to fix them after orthodontics treatments. Occlusal trauma from functional or parafunctional forces can cause stress increase and movements of teeth especially while having bone loss.
Methods: Six anterior teeth with different bone levels were designed in SolidWorks (2010), the models were then transferred to ANSYS Workbench 12.1. The models were loaded with 187 N force on the incisal edges of two incisors. Results: Stress on canine was 0.45 MPa in normal bone height and increased to 0.60 MPa in five millimeters of anterior teeth bone loss. Labial displacement was less in normal alveolar bone height while it was increased in all those teeth with five millimeter of bone loss.
Conclusions: Splinting distribute the forces between teeth and the stress production on canine increase while it splinted with low level bone incisors. Anterior teeth also showed tipping movements in reply to increased forces.
Sepideh Arab; Mina Hormozdiari Cham; Marzieh Morsaghian; Maryam Ghamari; Omid Mortezai
Abstract
Background: Stainless steel and Nickel Chromium alloys show special mechanical features, which has made them the most common materials for fabrication of orthodontic arch wires.
Objectives: The aim of this study was to evaluate the effect of length of immersion and type of arch wire on release of nickel ...
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Background: Stainless steel and Nickel Chromium alloys show special mechanical features, which has made them the most common materials for fabrication of orthodontic arch wires.
Objectives: The aim of this study was to evaluate the effect of length of immersion and type of arch wire on release of nickel and chromium ions from fixed orthodontic appliances.
Materials and Methods: 15 simulated half-arch maxillary fixed orthodontic appliances were divided into 3 groups according to the types of arch wires. Each sample was individually immersed in 50 ml of distilled water and incubated at 37ºC for 28 days. Afterwards, solutions were sent to laboratory for investigation of the released ions and the samples were incubated for another 28 days in new distilled water. After each 28-day time span, the concentrations of nickel and chromium were measured using an atomic absorption spectrophotometer. T-test was used for statistical analysis and P < 0.05 were considered statistically significant.
Results: Stainless steel arch wires released the greatest amount of nickel and chromium ions at both 28 days periods. The lowest amount of nickel and chromium in both time spans was released from NiTi and HANT arch wires, respectively Nickel ion release decreased overtime while the chromium release increased.
Conclusions: The amounts of released nickel and chromium ions from fixed orthodontic appliances from all three types of evaluated arch wires were below the daily dietary intake of these ions and do not bring about biological concerns.
Ahmad Sodagar; Sepideh Arab
Abstract
Aim: Accurate information about the normal dentofacial pattern of the patients' ethnic group is of critical importance for diagnosis and treatment planning. The aim of this study was to determine hard tissue cephalometric norms for Iranian adolescents.Materials and Methods: Cephalometric radiographs ...
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Aim: Accurate information about the normal dentofacial pattern of the patients' ethnic group is of critical importance for diagnosis and treatment planning. The aim of this study was to determine hard tissue cephalometric norms for Iranian adolescents.Materials and Methods: Cephalometric radiographs of 60 Iranian adolescents (38 girls and 22 boys) were analyzed regarding 4 common cephalometric analyses. Mean values and standard deviations were compared with those of original analyses.Results: Average Iranian adolescents revealed more protrusive maxillary and mandibular incisors, flatter mandibular plane with a tendency to deep bite and more acute gonial angle. SNA and SNB were less in Iranian sample. In addition, posterior to anterior facial height ratio was higher in Iranians.Conclusion: Some hard tissue cephalometric norms are specific for racial groups. More protrusive incisors in Iranians might indicate more possibility of non-extraction treatment planning for this population.