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.
