Changes in soft tissue profile following treatment with the bionator.

The purpose of this study was to determine the changes in the soft tissue profile in patients treated in the mixed dentition with a bionator. Two groups of 30 individuals, between 9 and 12 years old and with Class II, Division 1, malocclusion were matched for age, sex, observation time, and dentofacial characteristics. Patients in the first group were treated with a bionator for an average of 18.7 months, resulting in a Class I molar relationship and reduction of overjet. The second group acted as a control and individuals did not receive any form of orthodontic treatment. Pretreatment and posttreatment cephalograms were analyzed and paired t-tests were used to compare the significance of changes between the two groups. Compared with the control group, the treated group demonstrated 1.97 degrees decrease in ANB, a 3.35 mm increase in anterior facial height, 2.22 degrees decrease in soft tissue profile convexity, and 17.4 degrees increase in mentolabial angle.