Evaluation of changes seen in tmj after mandibular advancement in treatment of class ii malocclusions, with functional appliances, a cbct study

Abstract

Introduction and Aim: Various functional appliances are developed to remodel the glenoid fossa and, thereby change the position of the mandible and correct Class II malocclusion. Many diagnostic aids have already been used to evaluate the changes,but Cone Beam computed tomography (CBCT), three-dimensional diagnostic tool is rarely used .So this study was conducted with an aim is to evaluate the changes seen in the temporomandibular joint (TMJ) after mandibular advancement in class II malocclusions with functional appliance therapy, using CBCT, and also to assess and compare the efficacy of Twin Block, Power Scope and Forsus Fatigue Device used for the correction of class II malocclusion. Materials and Methods: The retrospective study was performed using the 52 CBCT scans of 26 patients with class II malocclusion due to retrognathic mandible. The subjects were divided into three groups based on appliance (Twin Block, Power Scope and Forsus Fatigue Resistant Device) used for the treatment. The changes seen in TMJ after mandibular advancement and condylar response to functional therapy was evaluated using the six. Data obtained were subjected to one-way Anova analysis with Posthoc Tukey test. Software SPSS version 20 was used to analyse the data. The level of significance was set at p < 0.05. Results: In subjects treated with Twin Block, the condyle was displaced slightly downwards and anteriorly; and condylar height was reduced. The decrease in the anterior and superior joint spaces were also found. In subjects treated with PowerScope and Forsus Fatigue Resistant Device, there was an increase in condylar height and width with a decrease in anterior and superior joint space. Conclusion: All three appliances were found to bring about changes in TMJ structures, but amongst them the Twin block has proved to be more efficient.