Skeletal alterations associated with the use of bonded rapid maxillary expansion appliance

Abstract

Bonded maxillary expansion appliances have been suggested to control increases in the vertical dimension of the face after rapid maxillary expansion (RME). However, there is still no consensus in the literature about its real skeletal effects. The purpose of this prospective study was to evaluate, longitudinally, the vertical and sagittal cephalometric alterations after RME performed with bonded maxillary expansion appliance. The sample consisted of 26 children, with a mean age of 8.7 years (range: 6.9-10.9 years), with posterior skeletal crossbite and indication for RME. After maxillary expansion, the bonded appliance was used as a fixed retention for 3.4 months, being replaced by a removable retention subsequently. The cephalometric study was performed onto lateral radiographs, taken before treatment was started, and again 6.3 months after removing the bonded appliance. Intra-group comparison was made using paired t test. The results showed that there were no significant sagittal skeletal changes at the end of treatment. There was a small vertical skeletal increase in five of the eleven evaluated cephalometric measures. The maxilla displaced downward, but it did not modify the facial growth patterns or the direction of the mandible growth. Under the specific conditions of this research, it may be concluded that RME with acrylic bonded maxillary expansion appliance did promote signifciant vertical or sagittal cephalometric alterations. The vertical changes found with the use of the bonded appliance were small and probably transitory, similar to those occurred with the use of banded expansion appliances.

Does rapid maxillary expansion induce adverse effects in growing subjects?

“…Application of the inclusion and exclusion criteria and follow-up on the referred studies identified 30 relevant publications (Figure 1). [3][4][5][6][7][8][9][10][11][12][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34] Heterogeneity of the results of the investigations with similar technique of maxillary expansion was high (.85%). A meta-analysis was not performed for this reason.…”

“…Twenty-one studies 3,4,6,8,9,15,[18][19][20][22][23][24][25][26][28][29][30][31][32][33][34] were retrospective, five studies 7,11,12,16,17 were prospective, and four studies 5,10,21,27 were prospective and randomized. Six studies 10,18,[22][23][24]33 compared the results with a control group of the same age, and eight studies 4,6,10,12,22,[32][33][34] analyzed the long-term effects of RME. Only two studies 10,17 specified that the subjects of the study groups were selected consecutively.…”

“…Mean age at the start of orthopedic expansion in the evaluated samples ranged from 7 to 17 years. Overall, in 24 studies 3,[4][5][6][7][9][10][11][15][16][17][18][19]21,22,[24][25][26][27][30][31][32][33][34] the sample comprised teenagers; in six studies, 8,12,20,23,28,29 the sample was younger than 10 years (mean age, 8.6 years). The devices applied were bonded with acrylic coverage on the occlusal surface of posterior upper teeth or banded with the 2 or 4 anchored tooth (Hyrax or Haas type maxillary expanders).…”

“…The devices applied were bonded with acrylic coverage on the occlusal surface of posterior upper teeth or banded with the 2 or 4 anchored tooth (Hyrax or Haas type maxillary expanders). The methods used to detect the treatment effects were different: two studies 3,5 used the dental casts before and after treatment, 11 studies 9,11,12,21,23,[25][26][27][28][29]31 used bidimensional radiographic techniques, 10 studies 4,[6][7][8]10,[15][16][17][18]20 used tridimensional radiographic techniques, 5 studies 22,24,30,32,34 used histological evaluation, and 2 Rapid maxillary expansion 4.…”

“…2,3 Although RME has been recognized as a safe and reliable orthopedic procedure that allows correction of the maxillary transverse deficiency in growing patients, some investigations [4][5][6][7][8][9][10] have focused on the unwanted consequences of heavy forces on sutures, periodontal alveolar bone, and dental structures identified as ''Adverse Effects'' (AEs). Moreover, other authors 11,12 have reported that RME with conventional appliances promotes the anterior and inferior displacement of the maxilla with a consequent posterior-inferior rotation of the mandible.…”