Comparison of the short-term effects of tooth-bone-borne and tooth-borne rapid maxillary expansion in older adolescents

Purpose To compare the short-term effects of tooth-bone-borne and tooth-borne rapid maxillary expansion (RME) devices on dentofacial structures in older adolescents. Methods The retrospective study reviewed pre- and posttreatment lateral and posteroanterior cephalometric images and orthodontic model records of patients who underwent maxillary expansion. Two groups were formed, in which the same upper jaw expansion protocol was applied with two different maxillary expansion devices: the first group consisted of 15 individuals treated with tooth-bone-borne (hybrid) RME (HRME; 9 girls and 6 boys; mean age, 16.9 +/- 0.42 years) and the second group consisted of 15 individuals treated with tooth-borne (conventional) RME (CRME; 8 girls and 7 boys; mean age, 16.74 +/- 0.54 years). Cephalometric and orthodontic model measurements were conducted on the records taken before and after treatment. Results Significant skeletal and dental expansions were observed in both groups (p < 0.05). However, the increase in nasal width measurements in the HRME group (2.24 +/- 0.61 mm) was significantly higher than the increase in the CRME group (1.12 +/- 0.25 mm; p < 0.01). Buccal tipping of the premolars was significantly less in the HRME group (0.46 +/- 0.35 degrees) than in the CRME group (2.46 +/- 0.63 degrees; p < 0.01). The amount of tipping of the molars was higher in the HRME group (4.76 +/- 0.88 degrees) compared to the CRME group (2.9 +/- 1.03 degrees; p < 0.01). Conclusion Although the HRME device increase the nasal width in older adolescents to a greater extent, more dental side effects were seen at the maxillary first molars.