Skeletal and Dentoalveolar Effects Using Three Types of Maxillary Protraction Protocols.

INTRODUCTION

The purpose of this study is to compare the skeletal and dentoalveolar effects of the three types of facemask protocols in children.

SUBJECTS AND

METHODS

Forty-eight subjects were grouped into three groups: bone-anchored facemasks (BAFMs) (BAFM group, n = 16, mean age 10.77 ± 1.00), facemask with miniscrew-assisted rapid palatal expanders (MARPEs) (MARPE/FM group, n = 16, mean age 10.47 ± 1.43) and facemask with rapid palatal expanders (RPEs) (RPE/FM group, n = 16, mean age 10.45 ± 1.04). Lateral cephalograms were taken at the initial observation (T0) and after maxillary protraction (T1). Cephalometric analysis was performed, and significance was assessed between the three groups. For statistical analysis, 1-way ANOVA or Kruskal-Wallis test was performed.

RESULTS

During maxillary protraction (T0-T1), greater maxilla advancement and greater intermaxillary relationship improvement were attained in BAFM (SNA: 2.28°, Mx. length: 3.13 mm, ANB: 3.41°, AB to MP: 5.31°) and MARPE/FM (SNA: 2.22°, Mx. length: 2.91 mm, ANB: 3.28°, AB to MP: 5.57°) groups than in the RPE/FM group (SNA: 1.09°, Mx. length: 1.46 mm, ANB: 2.08°, AB to MP: 2.77°) (p < 0.01). Protraction of the orbitale was greater in the BAFM (SNOr: 2.54°) group than in MARPE/FM (SNOr: 1.53°) and RPE/FM (SNOr: 1.28°) groups (p < 0.001). Also, the BAFM (PP to U6: 1.17 mm, U6 to VRmx: -1.18 mm) and MARPE/FM (PP to U6: 2.74 mm, U6 to VRmx: -2.80 mm) groups showed less maxillary first molar movement than the RPE/FM (PP to U6: 2.74 mm, U6 to VRmx: -2.80 mm) group. There was no significant difference in the mandibular variables and most of the vertical variables.

CONCLUSION

The orthopaedic effects of BAFM and MARPE/FM were greater with maxillary protraction and intermaxillary relationship improvement than RPE/FM after protraction. Midface traction effects with MARPE/FM were less than with BAFM. However, MARPE/FM was more effective in preventing mesial movement and extrusion of the maxillary first molars.