Maxillary protraction using orthodontic miniplates in correction of Class III malocclusion during growth

Abstract

IntroductionThis study was carried out to investigate the effect of bone-anchored maxillary protraction in treatment of growing patients with Class III malocclusion. MethodsThe sample of this study consisted of 10 subjects (5 boys and 5 girls; 9–12 years old). Each treated patient had four miniplates (HUBIT, Seoul, Korea) that were inserted between the lower left and right lateral incisor and canine and on the left and right infrazygomatic crest of the maxillary buttress. Class III elastics were applied between the miniplates on each side 24/7. The initial force was 300 g per side increased to 350 after 1 month and increased to 450 g per side 2 months later. Lateral cephalograms of each patient were evaluated at the beginning of treatment (T1), at the end of active treatment (T2). The effect of treatment was compared to the effect of growth changes in a matched untreated control group of the same malocclusion. ResultsIn the anteroposterior plane, the sella nasion point A angle increased 2.80°, and the sella nasion point B angle decreased 0.20°. The A point, nasion, B point angle increased 3.40°, the nasion A-point–pogonion angle increased 4.70°. No significant changes were observed in the vertical parameters measured nasion A-point pogonion while the maxillary incisors proclined significantly. ConclusionsThe bone-anchored maxillary protraction approach induced a significant orthopedic maxillary advancement, and retarded the mandibular growth with improvement of facial profile. Maxillomandibular divergency was increased mainly due a counterclockwise rotation of the maxilla.