Journal Article

Maxillary expansion in the mixed dentition: rapid or semi-rapid?

Sabri Ilhan Ramoglu and Zafer Sari

in The European Journal of Orthodontics

Published on behalf of European Orthodontics Society

Volume 32, issue 1, pages 11-18
Published in print February 2010 | ISSN: 0141-5387
Published online October 2009 | e-ISSN: 1460-2210 | DOI:
Maxillary expansion in the mixed dentition: rapid or semi-rapid?

More Like This

Show all results sharing this subject:

  • Restorative Dentistry and Orthodontics


Show Summary Details


The purpose of this study was to investigate the effects of rapid maxillary expansion (RME) and semi-rapid maxillary expansion (SRME) in the mixed dentition period. The SRME group consisted of 18 patients (11 girls and 7 boys) with a mean age of 8.63 ± 1.09 years and the RME group 17 patients (11 girls and 6 boys) with a mean age of 8.78 ± 1.21 years. A splint type tooth- and tissue-borne modified bonded RME appliance was used, with the patients activating the screw two-quarter turns per day for the first week, followed by one-quarter turn every other day in the SRME group and two-quarter turns per day throughout treatment in the RME group. The average treatment time was 57.16 ± 21.52 and 21.23 ± 8.36 days for the SRME and RME groups, respectively. A Wilcoxon signed rank test was used to evaluate the treatment effects [pre-(T0) − post-(T1) treatment changes] for both the SRME and RME groups and a Mann–Whitney U-test to determine the differences between the two groups (T0–T1 changes SRME versus T0–T1 changes RME).

For both groups, the maxillary base, nasal cavity width and upper intercanine and intermolar distances were increased, and the upper molars tipped buccally. The only statistically significant (P < 0.05) difference between two groups was in inferior movement of posterior nasal spine (PNS) relative to the SN plane (SN┴PNS). This measurement increased in both groups yet significantly more in the RME group. The results suggest that RME and SRME have similar effects on dentofacial structures both in the transverse, vertical, and sagittal planes.

Journal Article.  4139 words.  Illustrated.

Subjects: Restorative Dentistry and Orthodontics

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.