Effects of rapid maxillary expansion in cleft patients resulting from the use of two different expanders

Daniel Santos Fonseca Figueiredo, Lucas Cardinal, Flávia Uchôa Costa Bartolomeo, Juan Martin Palomo, Martinho Campolina Rebello Horta, Ildeu Andrade, Dauro Douglas Oliveira

The aim of this study was to evaluate the skeletal and dental effects of rapid maxillary expansion (RME) in cleft patients using two types of expanders. Twenty unilateral cleft lip and palate patients were randomly divided into two groups, according to the type of expander used: (I) modified Hyrax and (II) inverted Mini-Hyrax. A pretreatment cone-beam computed tomographic image (T0) was taken as part of the initial orthodontic records and three months after RME as need for bone graft planning (T1). In general, there was no significant difference among groups (p > 0.05). Both showed significant transverse maxillary expansion (p < 0.05) and non-significant forward and/or downward movement of the maxilla (p > 0.05). There was greater crown than apical expansion. Maxillary posterior expansion tended to be larger than anterior opening (p < 0.05). Cleft and non-cleft sides were symmetrically expanded and there was no difference in dental tipping between both sides (p > 0.05). The appliances tested are effective for transverse expansion of the maxilla. However, these appliances should be better indicated to cleft cases also presenting posterior transverse discrepancy, since there was greater expansion in the posterior maxillary region than in the anterior one.