Long-term skeletal and soft tissue outcomes of Bionator therapy in Class II malocclusion subjects

AIM: The literature lacks long-term controlled data concerning the outcomes of functional jaw orthopaedics in Class II patients. The aim of this research was to evaluate the long-term skeletal and soft tissue changes induced by the bionator in Class II subjects at the completion of active growth. SUBJECTS AND METHOD: Twenty Class II patients (6 males, 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). Their mean age at T1 was approximately 10 years (T1), at T2 approximately 12 years and at T3 approximately 19 years (CS 6). The control group consisted of 20 subjects (8 males, 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 skeletal facial forms, and of the T1-T2 and T1-T3 changes between the groups. RESULTS: The bionator group showed significant favourable T1-T2 changes both at the skeletal and dentoalveolar levels. The vertical dimension was increased. Significant modifications were also found for the soft tissues. 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 in comparison with the untreated Class II controls. CONCLUSION: Bionator treatment of Class II malocclusions maintains favourable results over the long-term with a combination of skeletal, dentoalveolar, and soft tissue changes.