Cephalometric changes in Angle Class II treatment.

The efficiency of Angle class II correction using functional orthopedic appliances is well accepted in the literature. However, there are controversial views as to whether dentoalveolar processes, growth alteration or jaw displacement predominates. This study was therefore designed to clarify the mode of action in class II treatment using Bimler's "GebiBformer". Cephalometric radiographs taken in 146 patients before and after treatment were analysed (mean age at beginning of treatment: 9.2 years). In these patients, Angle class II of one premolar width was successfully corrected during a mean 4.2 years of treatment. Matching data of 100 patients, who had undergone functional jaw orthopaedics because of class I malocclusion served as comparison group. According to cranio-facial growth type, the patients were subdivided in to three subgroups. Statistical analyses were performed using the t-test. The results indicate, that point A develops posteriorly relative to the nasion in the class II group and anteriorly in the class I group. The length of the maxilla develops equally in the groups compared. The sagittal discrepancy between upper and lower jaw deminishes significantly in treated class II patients. The B point comes only slightly more anteriorly in the class II group than in the control group. Shape and length of the mandible showes similar development in the two groups. In correcting class II with the "GebiBformer", changes in the craniofacial pattern take place. However, class II correction cannot be attributable to skeletal changes alone. It can only be explained by additional dentoalveolar changes.