Randomized Controlled Clinical Trial to Evaluate Skeletal and Dental Treatment Effects of Rapid Maxillary Expansion in Children: Comparison Between Two-Band Expander and Bonded Palatal Expander

Abstract

Featured Application: This research paper aims to encourage specialists in orthodontics to customize their treatments of palatal expansion by choosing the appropriate device for the expected results. The rapid maxillary expander is one of the most widely used devices in orthodontics, and this study analyzes the skeletal and dental effects of a two-band rapid maxillary expander (RME) and a splint resin palatal expander (SRPE) in growing children with skeletal maxillary contraction. Seventy-four subjects with palatal skeletal contraction and unilateral or bilateral posterior crossbite were treated using maxillary expander devices. The sample was made up of two different randomly assigned groups: RME (21 females, 17 males; mean age ± SD 7.7 ± 1.1 years) and SRPE (24 females, 15 males; mean age ± SD 7.6 ± 1.0 years). The effects of these two different devices were evaluated based on lateral cephalograms and measurements of digital models before and after treatment (7.0 ± 1.0 months). Longitudinal changes in the different groups were evaluated statistically using Student’s t-test (p < 0.05). No significant differences in treatment effects were found for any vertical or sagittal skeletal variables in the groups. However, there was a significantly increased maxillary intercanine distance in the SRPE group (36 patients; mean ± SD = 6.0 ± 4.8 mm) compared to the RME group (38 patients; mean ± SD = 3.1 ± 2.9 mm). The results of this study showed an increase in vertical skeletal dimensions in more patients treated using SRPE than RME. Moreover, the SRPE device was shown to be better at increasing the intercanine distance, and it could therefore be preferred in children with anterior dental crowding. An evaluation of long-term treatment stability would be useful to confirm the study results.