Skeletal and Dental Response to Long-Term Herbst Appliance Treatment : A Cephalometric and CT scanning assessment

In orthodontics, one frequent problem is the correction of Class II malocclusion. This might be due to a mandible which is backward positioned compared to the face. One way to correct this malocclusion is the use of functional appliance which brings the mandible forward and then improves the profile and facial aesthetics. One of the most famous functional appliance used today is the Herbst appliance (bonded to the teeth) which works continuously. As the effects of the functional therapy are still controversial, we can notice that all studies using the Herbst appliance have been conducted over a short period of time between (6 to 8 months). As the length of the treatment might be one of the main parameter in the success or in the failure of such treatment, we decided to increase it to 20 months. The objectives in our studt are therefore to evaluate the skeletal and dental changes that occurred in the maxilla and the mandible after 20 months of treatment using cephalometrics radiographs and to assess any changes of the condyle to the glenoid fossa at the end of Herbst treatment using CT scans.