Herbst appliance anchored to miniscrews with 2 types of ligation: Effectiveness in skeletal Class II treatment

Introduction: The aim of this study was to evaluate the effectiveness of the treatment of skeletal Class II malocclusions with an acrylic splint Herbst appliance anchored to miniscrews with 2 types of ligation. Methods: Sixty patients (mean age, 11.6 years; SD, 1.9) with a bilateral Angle Class II Division 1 malocclusion were retrospectively selected and divided into 3 homogeneous and balanced groups on the basis of the Herbst anchorage used: without anchorage, miniscrews with elastic chains, and miniscrews with metallic ligatures. A cephalometric sagittal occlusion analysis merged with mandibular incisor proclination and skeletal divergence was carried out before and after treatment. To compare the absolute variations within and among the groups, we performed the 1-sample t test for repeated measures and 1-way analysis of variance, respectively. Results: Overjet was reduced similarly in all groups (P < 0.05). The mandibular bone base length increased in the group with elastic chains only (P = 0.001). The change in the distance between Point A and pogonion showed the most reduction in the group with elastic chains (P < 0.05). Incisive flaring was more pronounced in the group with no anchorage than in the group with elastic chains (P < 0.001) and the group with metallic ligatures (P = 0.003). Conclusions: Anchorage to miniscrews with elastic chains increases the orthopedic effect of the acrylic splint Herbst appliance. It has been confirmed that skeletal anchorage reduces incisor flaring.