Related Experiment Video
Updated: Jun 16, 2026
Measuring Maxillary Posterior Tooth Movement: A Model Assessment using Palatal and Dental Superimposition
Published on: February 23, 2024
Influence of rapid palatal expansion on maxillary incisor alignment stability
Luiz Filiphe Gonçalves Canuto1, Marcos Roberto de Freitas, Guilherme Janson
1Department of Orthodontics, Bauru Dental School, University of São Paulo, Bauru, São Paulo, Brazil. luizfiliphecanuto@yahoo.com.br
Introduction:
The purpose of this retrospective study was to compare the long-term stability of maxillary incisor alignment in patients treated with and without rapid maxillary expansion (RME).
Methods:
The sample comprised 48 subjects with Class I and Class II malocclusions, treated without extractions with fixed edgewise appliances, divided into 2 groups according to the treatment protocol: group 1 comprised 25 patients (15 girls, 10 boys) at a mean initial age of 13.53 years (SD, 1.63), who had RME during orthodontic treatment. Group 2 comprised 23 patients (13 girls, 10 boys) at a mean initial age of 13.36 years (SD, 1.81 years), treated with fixed appliances without RME. Maxillary dental cast measurements were obtained at the pretreatment, posttreatment, and long-term posttreatment stages. Variables assessed were the irregularity index and maxillary arch dimensions. Intergroup comparisons were made with independent t tests.
Results:
Greater transverse increases were found during treatment in the group treated with RME. However, during the long-term posttreatment period, no significant difference was observed in the amount of incisor crowding relapse between the groups.
Conclusions:
RME did not influence long-term maxillary anterior alignment stability.
