Cephalometric evaluation of patients with Class III malocclusion after face mask therapy in mixed dentition period

Among different treatment options for patients with Class III malocclusion, orthopedic protraction of maxilla can be a beneficial treatment procedure during the mixed dentition period. The aim of this study was to evaluate the cephalometric changes of Class III patients in the mixed dentition period following face mask therapy without any maxillary expansion. This study was conducted to compare the pre and post treatment conditions of 10 children in mixed dentition period that had class III malocclusion and maxillary deficiency according to the Steiner and Mc Namara's analyses. These patients were treated with protraction face mask without any maxillary expansion. The cephalometric changes of maxilla, mandible, soft tissue and dental relationships during treatment were recorded and analyzed using Paired sample T test. Significant changes were found in several variables [P < 0.05]. The mean improvement in overjet was 2.3 mm, the N.Sn.Pog angle decreased 3.5 degrees and the soft tissue profile was improved greatly. A Class I molar relationship was also achieved. The ISA and ItoNA distances increased 2.8 and 2.3 mm respectively, resulting from anterior movement of maxillary incisors. Face mask therapy without maxillary expansion is able to improve the horizontal position of maxilla in Class III malocclusion during the mixed dentition period

Problems in standardization of orthodontic shear bond strength tests: a brief review

Bonding brackets to the enamel surface has gained much popularity today. New adhesive systems have been introduced and marketed and a considerable increase in research regarding bond strength has been published. A considerable amount of these studies deal with shear bond strength of adhesives designed for orthodontic purpose. Previous studies have used variety of test designs. This diversity in test design is due to the fact that there is no standard method for evaluating shear bond strength in orthodontics. Therefore comparison of data obtained from different study is almost impossible. This article tries to briefly discuss the developments occurred in the process of shear bond strength measurement of orthodontic adhesives with an emphasis on the type of test set up and load application. Although the test designs for measuring shear bond strength in orthodontics are still far from ideal, attempts must be made to standardize these tests especially in order to make comparison of different data easier. It is recommended that test designs be set up in such a manner that better matches with the purpose of the study