Cephalometric and model evaluations after molar distalization using modified C-palatal plates in patients with severe arch length discrepancy

Abstract

This study aimed to evaluate the dentoskeletal and soft-tissue changes after molar distalization using modified C-palatal plates in patients with severe maxillomandibular arch length discrepancies. Twenty-four patients with Class I and II malocclusion (19.0 ± 7.3 years; 17 females and 8 males), who had severe maxillary crowding of>10 mm, and moderate mandibular crowding of>6 mm, underwent molar distalization using modified C-palatal plates and buccal miniscrews with approximately 300 g of force per side. Models were made, and cephalograms were taken before and after treatment. Cephalometric variables and arch dimensions were measured. Paired t test and Wilcoxon rank sum test were used for statistical analysis. In the maxillary dentition, an average of 12.4 mm of crowding was resolved by molar distalization of 4.4 mm, interproximal stripping of 0.7 mm, and arch expansion. In the mandibular dentition, crowding of 6.7 mm was alleviated by molar distalization of 2.4 mm, an interproximal of 1.5 mm, and additional arch expansion. The incisor positions were maintained (SN-U1, 101.3°; IMPA, 88.8°), and soft-tissue profiles were improved (LL/E-line -1.1 mm; P< 0.001) after treatment. Maxillary and mandibular tooth-size arch length discrepancy of 12.4 mm and 6.7 mm, respectively, were resolved by molar distalization, interproximal reduction, and arch expansion, whereas incisor positions were maintained, and soft-tissue profiles were improved. This could be a viable treatment option in patients with moderate-to-severe crowding.