A cephalometric evaluation of the dental and facial-skeletal effects using the Bionator with stepwise protrusive activations.

A study was conducted to ascertain dental effects of step-wise mandibular advancement with Bionator therapy. A sample of 24 girls in the age group of 9 to 12 years having Class II Division 1 malocclusion was well matched for age, severity of malocclusion and craniofacial morphology. The sample was divided into three groups. Eight girls underwent step-wise mandibular advancement in three stages, while eight were treated with single step advancement. Eight girls acted as control who did not undergo any treatment. The total treatment/observation period was 9 months. The cephalometric analysis revealed that the progressive mandibular advancement enhances favorable facio-skeletal changes, more so in the mandible. The sagittal correction was predominantly of skeletal type with step-wise advancement, while with single step advancement it was due to both skeletal and dental changes.