Soft-tissue changes after Class II malocclusion treatment using the Sander bite jumping appliance: a retrospective study

BACKGROUND: The soft tissue profile outcome after functional treatment of Class II malocclusion is important for a patient's aesthetic and psychosocial results. The soft tissue effects of the Sander bite-jumping appliance (BJA), which is the device that produces the greatest mandibular advancement according to a systematic review, have never been investigated. The aim of the present study was to assess the soft tissue effects of the BJA in comparison to matched untreated controls. METHODS: A total of 19 patients treated with BJA during puberty were retrospectively recruited, and 15 untreated controls were retrieved from a previous growth study to match the treated group. Lateral cephalograms were used to evaluate the pre- and post-treatment differences in the ANB angle, the inclination of the upper and lower incisors, facial convexity, the nasolabial angle and the sagittal position of the skeletal and soft tissue at points A and B. Independent t-tests or Mann-Whitney U tests were used to detect differences between the two groups. RESULTS: Statistically significant differences were found for the ANB angle, the inclination of the upper incisors and facial convexity. CONCLUSIONS: Functional treatment of Class II patients with the Sander BJA during puberty was effective at improving the profile and reducing the facial convexity angle in the short term.