Three-dimensional Analysis of Asymmetrical Maxillary Molar Distalization Using the Indirect Palatal Miniscrew Anchorage and Distalization Appliance

Introduction: The purpose of this clinical study was to evaluate the dentoalveolar changes due to unilateral maxillary molar distalization and to determine side effects using a 3-dimensional intraoral scanning method. Methods: The study group comprised 30 patients (mean age: 19.8 years) with a Class II molar relationship. All patients were treated with the iPANDA for unilateral and bilateral maxillary molar distalization. Three-dimensional models were obtained before and after distalizaion. Digital models were superimposed using surface-to-surface matching of the palatal area, which included the midpalatal screws of iPANDA and rugae as a reference area. Molar movement was measured on the superimposed maxillary arches before and after distalization. Results: A Class I molar relationship was obtained in an average 5 months, with a movement rate of 0.6 mm per month. In the sagittal plane, the first molars showed a mean linear movement of 1.2 ± 0.7 mm and the average molar inclination was 4.22 ± 3.41°. In the vertical plane, the first molars showed slightly intrusion, with a mean value of 0.7 mm ± 1.3 mm. In the transverse plane, rotation of the first molars was 1.70 ± 3°. Conclusions: Through support from midpalatal miniscrews, the maxillary first molars were effectively distalized without anchorage loss. Furthermore, movement was observed in all three dimensions. Keywords: Distalization, iPanda, miniscrew