Occlusal and Skeletal Changes induced by Protraction Facemask combined with Slow Maxillary Expansion

Abstract

The objective of this study was to investigate spontaneous changes in the mandibular intermolar widths concurrent with protraction facemask treatment combined with slow maxillary expansion in skeletal Class III children, and to evaluate whether slow expansion has favorable effects on maxillary protraction. Twenty-three patients were divided into expansion and non-expansion groups. The expansion group comprised 11 children (mean age, 6.9 ± 1.0 years) who underwent protraction facemask treatment combined with slow maxillary expansion. The non-expansion group consisted of 12 children (mean age, 7.8 ± 1.1 years) who underwent protraction only. Dental casts and lateral cephalograms obtained before and after protraction were used to analyze occlusal and skeletal changes during approximately 1 year of treatment. The expansion group showed significantly larger increments than the non-expansion group in all mandibular intermolar measures (P < .01). No significant differences in skeletal changes were seen for any cephalometric measures between groups. In conclusion, spontaneous increases in mandibular intermolar widths were found during maxillary protraction combined with slow expansion treatment. No favorable skeletal effects of slow expansion on protraction were confirmed.

Assessment of early dental arch growth modification with removable maxillary expansion by cone-beam computed tomography and lateral cephalometric radiographs: a retrospective study

“…As the expansion of the maxillary dental arch, the restriction on the transverse growth of the mandibular dental arch was removed, and a secondary increase in the mandibular dental arch width happened, which was an inspiring treatment effect in the clinic. The spontaneous increase in the mandibular intermolar width was consistent with the previous study on the slow maxillary expansion [ 32 ]. However, the expansion amount in the mandible was statistically smaller than in the maxilla, because of which a posterior deep overjet could often be observed in the clinic after the ERME treatment.…”