Dento-Alveolar Changes after Maxillary Hybrid Expansion and Multi-Bracket Therapy: A Comparative Study at Three Different (Vertebral) Maturation Stages

Abstract

Background: Rapid maxillary expansion is a common therapy when a palatal transversal discrepancy occurs. Different anchorage solutions have been proposed to obtain an effective skeletal expansion, even for adult patients. The aim of the present research was to evaluate the dentoskeletal effects of a hybrid expander and multi-bracket therapy, considering three groups of patients with different cervical vertebral maturation (CVM) stages. Materials and Methods: The study evaluated 68 consecutively treated patients. The age of the patients varied from 7 to 27 years old (mean age 13.45). The sample was divided into the following three groups based on CVM stage at the start of treatment: Group 1 (CS1–CS2) included 21 patients (mean age 10.21, SD 1.34), Group 2 (CS3–CS4) included 28 patients (mean age 13.37, SD 1.37) and Group 3 (CS5–CS6) was composed of 19 patients (mean age 17.14, SD 3.48). Each patient underwent orthodontic therapy where the first step was a palatal expansion by means of a hybrid expander; afterwards, the therapy was completed with a multi-bracket appliance. Expansion and torque values were observed at the end of treatment on digital models. Results: Significant intragroup differences in transversal expansion were found over time for all parameters in all groups. No significant differences were found among groups for longitudinal changes. No significant differences were found among groups for longitudinal changes of torque. Conclusions: The tooth–bone-borne maxillary expander and multi-bracket produced a significant clinical expansion with negligible dental compensation. The effect of the maxillary expansion and multi-bracket therapy showed no differences among the maturation groups in regard to transversal diameter changes and torque values.

Keywords

• maxillary expansion
• hybrid expander
• transversal expansion