Comparison of carriere motion and herbst appliances used in class ii malocclusion treatment with 3 dimensional finite element method (3D fem)

Introduction and Aim: It is aimed to compare the effects of Carriere Motion and Herbst appliances used in the treatment of Class II malocclusion with the 3D finite element method (3D FEM). Materials and Methods: In our research, these two appliances were analysed by 3D FEM method. Since separate modelling was required for each appliance, 2 models were made. In the first model, the cast Herbst appliance was modelled. On the models obtained in the computer programme, chrome-cobalt cast splints were applied on the teeth to cover the posterior teeth of the upper jaw and the canines and all posterior teeth in the lower jaw. In the studies, it was found that when the mandible is positioned in front, the posterior part of the temporal muscle produces a force of 12 N at rest. We applied the force of the Herbst appliance as 12 N, taking reference from these studies. In the second model, the Carrier Motion appliance was used. The bar-shaped appliance made of stainless steel was attached to the upper canine and molar teeth. In the lower jaw, the tube is placed on the teeth numbered 7 and the essix appliance is applied. Intraoral force was applied with intraoral elastics from the upper canine to the lower molar tooth. In the studies, it was found that Henry Schein Orthodontics' force 2 elastic, which is the recommended intraoral elastic for the Carriere Motion appliance, exerts 540 g of force. Taking reference from these studies, we applied a force of 540 g in the Carriere Motion simulation. Results: According to the results of the analyses, the amount of tooth displacement was found to be higher in the Herbst simulation. Distalisation of the maxillary teeth and mesialisation of the mandibular teeth occurred in both appliances. The amount of stress on the condyle and disc was higher in the Herbst simulation than in the Carriere Motion simulation. The stress points in the maxillary bone were mostly in the dentoalveolar region in the Carriere Motion simulation, while the highest stress point in the Herbst simulation was in the zygomaticomaxillary suture region. Conclusion: According to the findings obtained in our study, the dental and skeletal effects of the Herbst appliance were found to be higher than the Carriere Motion appliance.