BackgroundThe study aimed to evaluate and compare the stress distribution and 3-dimensional displacements along the craniofacial sutures in between the Rapid maxillary Expansion (RME) and Implant supported RME (I-RME).MethodsFinite element model of the skull and the implants were created using ANSYS software. The finite element model thus built composed of 537692 elements and 115694 nodes in RME model & 543078 elements and 117948 nodes with implants model. The forces were applied on the palatal surface of the posterior teeth to cause 5mm of transverse displacement on either side of the palatal halves, making it a total of 10mm. The stresses and the displacement values were obtained and interpreted.ResultsVarying pattern of stress and the displacements with both positive and negative values were seen. The maximum displacement was seen in the case of plain RME model and that too at Pterygomaxillary suture and Mid-palatal suture in descending order. In the case of I-RME maximum displacement was seen at Zygomaticomaxillary suture followed by Pterygomaxillary suture. The displacements produced in all the three planes of space for the plain RME model were greater in comparison to the Implant Supported RME model. And the stresses remained high for all the sutures in case of an I-RME.ConclusionsThere is a definite difference in the stress and the displacement pattern produced by RME and I-RME model and each can be used according to the need of the patient. The stresses generated in case of conventional RME were considerably less than that of the I-RME for all the sutures.

Background:To assess the prevalence of malocclusion and to determine the different occlusal characteristics in primary dentition of 4 to 6 years old children in India.Materials and Methods:The target population comprised 4 to 6 years old children attending different nursery, kindergarten and primary schools of Bagalkot city. Stratified cluster random sampling procedure was executed to collect the representative sample. Each subject was assessed for various occlusal characteristics.Results:Occlusal characteristic found were flush terminal plane (52.5%), class I canine relationship (84%), maxillary developmental spaces (35.4%), primate spaces in maxilla (47.6%), mandibular crowding (4.6%), mandibular midline shift (5.6%), anterior multiple tooth crossbite (1.3%), scissors bite (0.6%), anterior open bite (1%), over bite of 0-2 mm (81.6%) and overjet of 0-2 mm (84.5%). The age wise difference for the occlusal characteristics was statistically significant.Conclusions:The data revealed that most of the children had malocclusion. This highlights the importance of identifying children who are in need of orthodontic treatment for dental health or aesthetic reasons.

Aim:The aim of this in vitro study was to evaluate the influence of the Dental chair light on the bond strength of light cured composite resin.Materials and Methods:Sixty therapeutically extracted human premolar teeth were randomly allocated to two groups of 30 specimens each. In both groups light cured composite resin (Transbond XT) and MBT premolar metal brackets (3M Unitek) was used to bond brackets. In group I and II light curing was done using Light-emitting diode light curing units without and with the dental chair light respectively. After bonding, all samples were stored in distilled water at room temperature for 24 hours and subsequently tested for shear bond strength and Adhesive Remnant Index (ARI) scores. Data was subjected to Mann Whitney U statistical test.Results:Results indicated that there was significantly higher shear bond strength (7.71 ± 1.90) for the Group II (composite cured with LED and dental chair light) compared with Group I (composite cured with LED LCU only) (5.74 ± 1.13).the obtained difference was statistically significant. There was no statistical significant difference between ARI scores in between the groups.Conclusions:light cure bonding with dental chair light switched on will produce greater bond strength than the conventional bonding. However, the ARI score were similar to both the groups. It is advised that the inexperienced orthodontist should always switch off the dental chair light while bonding for enough working time during the bracket placement.

Objectives:The study was aimed to evaluate the pharyngeal airway linear measurements of untreated skeletal class II subjects with normal facial vertical pattern in prognathic maxilla with orthognathic mandible and orthognathic maxilla with retrognathic mandible.Materials and method:the sample comprised of lateral Cephalograms of two groups (30 each) of class II malocclusion variants. Group 1 comprised of class II malocclusion with prognathic maxilla and orthognathic mandible, whereas group 2 comprised of class II malocclusion with orthognathic maxilla and retrognathic mandible. Each group was traced for the linear measurements of the pharyngeal airway like the oropharynx, nasopharynx and soft palate. The obtained data was subjected to independent t test and the Mann Whitney test to check the difference between the two groups and within the groups respectively.Results:there was significant difference between all the linear measurements at the soft palate region and the distance between the tip of soft palate to its counter point on the pharyngeal wall in oropharynx region (p-ppm).Conclusion:the pharyngeal airway for class II malocclusion with various combination in an average growth pattern adult showed significant difference. The present results suggested, that the pharyngeal airway space might be the etiological factor for different sagittal growth pattern of the jaws and probable usage of different growth modification appliance can influence the pharyngeal airway.

Objective:The aim of the study is to detect gender-wise difference in the skeletal asymmetry in the esthetically pleasing faces.Materials and methods:a cross sectional study was conducted on 25 females and 25 males of age 18 -25 years using the posterior-anterior cephalograms. The selected part of grummon’s frontal analysis for analyzing the vertical skeletal asymmetries, mandibular morphology, transverse asymmetry and mandibular deviation was used. The obtained data was subjected to independent student’s‘t’ test for comparing the difference between males and females.Results:there was statistically significant difference between the males and females for the measurements like Gonion-Menton length for the mandibular morphology and for the transverse parameters like zygomatico frontal suture length, jular length and antegonial notch length. There was no significant difference for the sidedness of asymmetry for the males and females.Conclusion:frontal facial asymmetry showed sexual dimorphism with males showing greater asymmetric values than the females. The asymmetry showed right sided prominence for both the males and females. This knowledge can be utilized for planning facial reconstruction and remodeling surgeries.

OBJECTIVE: This article aims to analyze the difference in stresses generated in the bracket-cement-tooth system by means of a peel load in single and double-mesh bracket bases using a three-dimensional finite element computer model. MATERIAL AND METHODS:A three-dimensional finite element model of the bracket-cement-tooth system was constructed and consisted of 40,536 bonds and 49,201 finite elements using a commercial mesh generating programmer (ANSYS 7.0). Both single and double-mesh bracket bases were modified by varying the diameter from 100-400 µm progressively, and the spacing between the mesh wires was kept at 300 µm for each diameter of wire. A peel load was applied on the model to study the stresses generated in different layers. RESULTS: In case of double-mesh bracket base, there was reduction in stress generation at the enamel in comparison to single-mesh bracket base. There was no difference in stress generated at the bracket layer between single and double-mesh bracket bases. At the impregnated wire mesh (IWM), layer stresses increased as the wire diameter of the mesh increased. CONCLUSION: Results show that bracket design modification can improve bonding abilities and simultaneously reduce enamel damage while debonding. These facts may be used in bringing about the new innovative bracket designs for clinical use.

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