Longitudinal stability of rapid and slow maxillary expansion

• Main Authors: Fábio Henrique de Sá Leitão Pinheiro, Daniela Gamba Garib, Guilherme Janson, Roberto Bombonatti, Marcos Roberto de Freitas
• Format: Article
• Language: English
• Published: Dental Press Editora 2014-12-01
• Series: Dental Press Journal of Orthodontics
• Subjects: Técnica de expansão palatina; Ortodontia; Resultado de tratamento
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S2176-94512014000600070&lng=en&tlng=en

OBJECTIVE: The aim of this retrospective study was to compare the longitudinal stability of two types of posterior crossbite correction: rapid maxillary expansion (RME) and slow maxillary expansion (SME).METHODS: Study casts of 90 adolescent patients were assessed for interdental width changes at three different periods: pretreatment (T1), post-treatment (T2) and at least, five years post-retention (T3). Three groups of 30 patients were established according to the treatment received to correct posterior crossbite: Group A (RME), group B (SME) and group C (control- Edgewise therapy only). After crossbite correction, all patients received fixed edgewise orthodontic appliances. Paired t-tests and one-way ANOVA were used to identify significant intra and intergroup changes, respectively (P < 0.05).RESULTS: Except for intercanine distance, all widths increased in groups A and B from T1 to T2. In the long-term, the amount of relapse was not different for groups A and B, except for 3-3 widths which showed greater decrease in group A. However, the percentage of clinically relapsed cases of posterior crossbite was similar for rapid and slow maxillary expansion.CONCLUSION: Rapid and slow maxillary expansion showed similar stability in the long-term.