Objective:To investigate the amount of space closure by movement of canines into the extraction spaces using four brands of elastomeric power chains (EPCs) by intraoral application with pre-adjusted appliance for 6 weeks.Materials and Methods:The sample size calculation was based on the studies of Boester and Johnston and also with repeated measures analysis of variance (ANOVA) continuous data for force degradation, standard deviation of 24.9 g, and also from a pilot study, which totaled to around 17 patients with a mean age of 20 ± 2 years and receiving fixed orthodontic treatment that required retraction of canines into the premolar extraction spaces in all four dental arch quadrants. Four brands of EPCs, namely the Ormco, 3M Unitek, Rocky Mountain, and Highland, which were closed-link with five loops delivering less than or equal to 250 g were used. The rates of canine retraction were measured between the attachment points on the canine bracket hook and first molar hook using a Mitutoyo Digital Vernier Caliper at the time of first application, after 3 weeks of use, and at the end of 6 weeks of use, and were subjected to statistical calculations.Results:The distances recorded from canine retraction were similar with slight differences noticed in the four brands of EPCs. However, no statistically significant difference was observed in relation to the EPCs.Conclusion:Although all brands of the EPCs produced space closure of canines, it was observed that not much of a significant difference existed among the products tested.

Background:A thorough knowledge of the salient features of malocclusion helps the clinician in arriving at a proper diagnosis and treatment plan, and also to predict the prognosis, prior to the onset of treatment process. Among the four classes of Angle's classification of malocclusion, Class II division 2 occurs with the least frequency. There is still continuing debate in the literature whether the Class II division 2 patients ascribe the pathognomonic skeletal and dental features.Aim of the study:The aim of this study is to describe the unique features of Angle's Class II division 2 malocclusion to differentiate it from Angle's Class II division 1 malocclusion.Materials and Methods:A total of 582 pre-treatment records (study models and cephalograms), with the age of patients ranging from 15 to 22 years, were obtained from the hospital records of Vishnu Dental College, Bhimavaram and Geetam's Dental College, Visakhapatnam. Out of these, 11 pre-treatment records were excluded because of lack of clarity. In the rest of the sample, 283 were Class II division 1 and 288 were Class II division 2. The lateral cephalograms were analyzed by using digiceph and the arch width analysis was done based on the anatomical points described by Staley et al. and Sergl et al.Results:An intergroup evaluation was done by using unpaired Student's “t” test. The skeletal vertical parameters, dental parameters, and the maxillary arch width parameters revealed a statistically significant difference between the two groups of malocclusion.Conclusion:Angle's Class II division 2 malocclusion has a pronounced horizontal growth pattern with decreased lower anterior facial height, retroclined upper anteriors, and significantly increased maxillary arch width parameters.