Long-term dentoskeletal effects and facial profile changes induced by bionator therapy.

OBJECTIVE To evaluate the long-term skeletal and soft tissue changes induced by the bionator in Class II subjects. MATERIALS AND METHODS The treatment sample consisted of 20 Class II patients (6 males and 14 females) treated consecutively with the bionator. The sample was evaluated at T1, start of treatment; T2, end of bionator therapy; and T3, long-term observation (including fixed appliances). Mean age at the start of treatment was 10 years 2 months (T1); at posttreatment, 12 years 4 months (T2); and at long-term follow-up, 18 years 11 months (CS 6). The control group consisted of 20 subjects (8 males and 12 females) with untreated Class II malocclusions. Lateral cephalograms were analyzed at the three time points for all groups. Student's t-tests were used for comparisons of starting forms, and of the T1-T2 and T1-T3 changes between groups. RESULTS The bionator group showed significant, favorable T1-T2 changes both at the skeletal and dentoalveolar levels. The vertical dimension was increased. Significant modifications were assessed for the soft tissues as well. The treated group showed a final improvement in soft tissue pogonion of about 2.5 mm. Significant mandibular changes were noted in the treated group, with a net average 3.3 mm long-term increase in mandibular length compared with untreated Class II controls. CONCLUSIONS This study suggests that bionator treatment of Class II malocclusion maintains favorable results over the long-term with a combination of skeletal, dentoalveolar, and soft tissue changes.