Effects of the sander bite jumping appliance in patients with class ii malocclusion before growth peak

Sander bite jumping appliance (BJA) is a functional appliance used to correct Class II malocclusion in growing patients. The aim of this study was to identify the dento-skeletal effects in patients treated with BJA before growth peak and to compare these effects with the ones obtained in a similar group treated with the Andresen activator (AA). Twenty subjects with class II relationship of the skeletal bases and cervical vertebrae maturation stage 1 or 2 were enrolled in the study and treated with BJA. This group were compared to 14 subjects treated with AA. Cephalometric analyses were carried out using landmarks derived from the analyses of Pancherz, Ricketts, Tweed and Steiner. After treatment with BJA Pg/OLp increase was 7.40±3.81 mm (P<0.001); Pg/OLp+Co/OLp significantly heightened from T0 to T1 (T0: 82.20±4.65 mm vs T1: 89.62±4.27, P<0.001). Overjet (is/OLp - ii/OLp) significantly decreased from T0 to T1 (T0: 7.40±2.31 mm vs T1: 3.05±1.34 mm, P<0.001). Molar relationship improved passing from 1.46±1.68 mm at T0 to -3.56±2.04 mm at T1 (P<0.001). No statistically significant differences were found between BJA and AA groups at T0 and T1. BJA treatment determined a Class II malocclusion correction in all patients. The correction of molar relationship was mainly due to the increase in mandibular length; the correction of the overjet was due to the increase in mandibular length, to the slight pro-inclination of the lower incisors and the mild retro-inclination of the upper incisors. No significant differences were found in effectiveness between BJA and AA.

Efficacy of the Andresen activator before peak growth in class II patients

Andresen activator (AA) is a functional appliance used to correct Class II malocclusion in growing patients. It corrects the malocclusion stimulating mandibular growth and determining a palatoversion of the upper incisors and a vestibularization of the lower incisors. The aim of this study was to analyze the treatment efficacy of class II malocclusion due to mandibular hypodevelopment before peak growth. Fourteen subjects with class II relationship of the skeletal bases and cervical vertebrae maturation stage 1 or 2 were enrolled in the study. Cephalometric analyses were carried out using landmarks derived from the analyses of Pancherz, Ricketts, Tweed and Steiner. A significant decrease (P less than 0.05) in ANB angle was found (-2.29±3.05°) after treatment, which was expression of an improvement in maxillo-mandibular sagittal skeletal relationships. There was also a significant reduction of OJ after treatment (-4.44±2.36 mm; P less than 0.001), indicating a vestibularization of the mandibular incisors and a palatoversion of the maxillary incisors, and a correction of the molar relationship. The favorable effects of the Andresen activator for the correction of the mandibular defect can be found even prior to peak growth; the achieved class I relationship maintains a correct mandible position in time, ensuring a proper skeletal growth. .