Evaluation of Class II correction using the Xbow® appliance

The purpose of this study was to determine the magnitude of the skeletal and dental movements in subjects with different facial patterns following Class II correction using the Xbow® appliance. A retrospective sample of 134 subjects exhibiting Class II malocclusions was used. Subjects were categorized into three growth types according to pre-treatment cephalometric variables, which yielded 27 brachycephalic, 70 mesocephalic, and 37 dolichocephalic subjects. Dental changes induced by the Xbow® appliance included: proclination of the lower incisors (L1-MP 7.3-12.3°±1.0°), protrusion of the lower incisors (L1-APo 2.1-3.8mm±0.3mm), mesial movement of the mandibular first molar (5.5-6.9mm±0.7mm) and retrusion of the maxillary incisor (2.4-3.1mm±0.4mm). Retroclination of the maxillary incisor (U1-PP 0.2-0.8°±0.7°) and distal movement of the maxillary molar (0.4-0.7mm±0.3mm) were not significantly influenced by Xbow® treatment. Reduction of the skeletal Class II relationship was represented by a significant decrease of the Wits value (2.4-4.5mm±0.5mm) in all three groups. Skeletal correction must be validated by more than one cephalometric variable.