ABSTRACT
Background: FEM is a mathematical method in which the shape of complex geometric objects and their physical properties are computer-constructed. Physical interactions of the various components of the model can then be calculated in terms of stress and strain, detailed information which is difficult to obtain by any other experimental or analytical means due to the interaction of anatomical structures with the surrounding tissue.. The aim is to Comparison of biomechanical differences by FEM between labial and lingual orthodontic mechanotherapy involved in canine retraction. Material & Methods: ANSYS software was preferred over others for the analysis. As ANSYS can import computer assisted designing (CAD) data and also enables to build geometry , In the current study, we have shown the simulated individual (sequential) canine retraction using the sliding(friction method) mechanics by an elastic component. Sliding mechanics was preferred over the closing loop mechanics (frictionless method). Results: Stress in the PDL and Alveolar bone were calculated and depicted. Conclusion: On retraction, the high stress was produced with the Labial system in the PDL and alveolar bone that gradually reduced on force degradation. On combined force application slight increase in stress was noticed.
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Introduction: Long term success of any composite resinrestorative materials mainly depends on their color stability.The aim of the investigation was to examine the color stabilityof three resin-based composite materials with a high contentof inorganic filling material (Spectrum, Filtrex Z350 andTetric N Ceram).Material and Methods: Changes in color of test sampleswere determined after complete immersion in test solutionsused primarily in Kashmiri population viz. Kashmiri tea,Saffron Kehwa and a turmeric solution. Color differenceswere measured by using a spectrophotometer and CIE L*a*b*color scale and the total amount of color difference wasrepresented as ∆E.Results: For all composite resins, Turmeric solution causedthe most severe cases of discoloration (∆E > 8.25). Kashmiritea and Saffron Kehwa caused invisible (∆E <1) or visible (∆E>1) discoloration. In some samples clinically unacceptable(∆E > 3.3) discoloration was noted.Conclusion: No significant difference was found amongthe composite resins or between color values of specimensimmersed in Kashmiri tea or Saffron kehwa. Immersingspecimens in turmeric solution caused greater color changein all types of composite resins tested. It is apparent from theresults that it is essential to improve the color stability of thecomposite resin materials used in esthetic zone
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Background: Gonial angle is important parameter in orthodontics for determining the growth pattern i.e, verticalgrowers or horizontal growers, estimating the age and surgical decision in class III skeletal patients.The purpose of this study was to ensure the reliability of gonial angle in various classes of saggital mal occlusion in orthopantomogram(OPG) verses lateral cephalogram. Materials and methods: A cross sectional study carried out in the Department of Orthodontics and dentofacial orthopaedics Govt dental college Srinagar. The study included the pretreatment records of the cases undergoing orthodontic treatment in the department with 90 subjects divided into three groups viz (Gr1-30 subjects of Class I,Gr 2, 30 subjects of ClassII and Gr 3, 30 subjects of Class III cases) in the age range of 12-30 years. Results: Reliability of gonial angle was assessed in orthopantomogram (OPG) in comparison with lateral cephalogram and was found highly correlated to each other and differences exhibiting statistically not significant. Conclusion: The study concluded that the gonial angle in orthopantomogram in classI, ClassII, and Class III cases could be as reliable as found in lateral cephalogram.
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Background: The maxillary canines are of great importance both aesthetically and functionally. Ectopic eruption of maxillary canines cause various complications among which root resorption of adjacent incisors is most common. Objective: The objectives of this study were to investigate the prevalence, extent of resorption, and predisposing risk factors for incisor root resorption associated with impacted maxillary canines. Methods: Unilaterally and bilaterally impacted canines (n=53) from 42 patients (27 female, 15 male) who visited Department of Orthodontics for treatment were evaluated. CBCT scans were taken with NewTom GiANO NNT Scanner keeping in mind the risks associated with ectopic eruption of maxillary canines and were analyzed with 3D visualization software. Results: Among the studied impactions, 79.2% were impacted palatally and 11.3% buccally. The lateral incisors were the teeth most affected by resorption. 18 incisors were resorbed, which included 16 lateral incisors (30.2 per cent) and 2 central incisors (3.8 per cent). Among lateral incisors, the resorption was slight in 11 cases (20.8 per cent), moderate in 3 cases (5.6 per cent), and severe in 2 cases (3.8 per cent) while among central incisors, the resorption was only slight in 2 cases (3.8 per cent). A correlation was found between the proximity/contact of the impacted canine to the incisors and their resorption. Follicle size did not play a major role in incisor resorption. Conclusion: Canine impaction poses a higher risk for root resorption of adjacent incisors. Physical proximity (<0.5 mm) between impacted canine and adjacent roots of incisors is the most important predictor for root resorption. The width and the shape of the dental follicle of the impacted canines do not correlate with root resorption of maxillary incisors.
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As people all over the world are putting greater emphasis on self-improvement, and with recent advances in orthodontic technology and aesthetic materials, more adults are seeking orthodontic treatment. As a result, orthodontists are faced with the challenge of bonding to porcelain restorations (crowns, veneers). This has presented quite a challenge in the past, but using the proper materials and following the necessary procedure can ensure a reliable bond. The following article gives an overview of the literature for various techniques used for bonding orthodontic brackets to the porcelain surfaces to know which method is more reliable for porcelain bonding.
ABSTRACT
Background: The maxillary permanent canines play a key role in smile design. Any morphological defect or eruption anomaly, affecting the maxillary permanent canine has a negative impact on the smile and facial esthetics of the person. The purpose of this study was to examine whether a clinically significant association exists between maxillary transverse dimension and palatally displaced canines (PDC). Methods: Twenty-four subjects (8 males and 16 females) with PDC were matched to twenty-four subjects (8 males and 16 females) without PDC (control) for age, sex and posterior occlusion. Prior to any orthodontic treatment, a CBCT scan was taken on all the patients. On axial and coronal sections of CBCT images, the maxillary basal bone widths and interdental widths at the maxillary first premolars, second premolars and first molars were measured. Results: The maxillary basal bone widths and interdental widths at the maxillary first premolars, second premolars and first molars between the subjects with palatally displaced canines and the control group showed no statistically significant differences in their means, thus indicating that there was no statistically significant difference in maxillary transverse dimensions between the affected subjects and the control subjects. Conclusion: Skeletal and dental maxillary transverse width was not related to the occurrence of palatally displaced canine. Thus, affected patients exhibit adequacy of maxillary dental arch width