Rapid maxillary expansion. Is permanent it better in the mixed or in the dentition?

Sari Z., Uysal T., Üşümez S., Başçiftçi F. A.

ANGLE ORTHODONTIST, vol.73, no.6, pp.654-661, 2003 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 73 Issue: 6
  • Publication Date: 2003
  • Journal Name: ANGLE ORTHODONTIST
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.654-661
  • Keywords: rapid maxillary expansion, mixed dentition, early treatment, CROSS-BITE CORRECTION, PALATAL EXPANSION, MIDPALATAL SUTURE, DENTOFACIAL ORTHOPEDICS, POSTERIOR CROSSBITE, PRESCHOOL-CHILDREN, DENTAL CHANGES, SKELETAL
  • Akdeniz University Affiliated: No

Abstract

The aim of this study was to compare the dentoskeletal effects of a modified acrylic-bonded rapid maxillary expansion (RME) device when it is used in the mixed and permanent dentitions. The study group consisted of 51 patients in the mixed and permanent dentition (26 girls and 25 boys) who underwent RME treatment. Group I was composed of 34 subjects in the mixed dentition (19 girls and 15 boys; mean age, 9.2 +/- 1.3 years). Group 2 consisted of 17 subjects in the permanent dentition (seven girls and 10 boys; mean age 12.7 +/- 1.2 years). Lateral and frontal cephalograms and upper dental casts were collected before treatment (T1), after treatment (T2), and after retention (T3). Intragroup and intergroup changes were evaluated by paired t-test and Student's t-test, respectively. In both groups after RME, the maxilla moved forward; mandible rotated posteriorly; facial height increased; nasal, maxillary, and maxillary intercanine and first molar widths increased; and the upper molars tipped buccally. Almost all these significant changes were stable at follow-up (T3). When overall (T1 - T3) differences were considered, upper molars tipped more, and the ANB angle increased less in the mixed dentition group compared with the permanent dentition group (P < .01). Within the limits of this study, the results suggest that the orthopedic effects of RME are not as great as expected at early ages, and it might be a better alternative to delay RME to early permanent dentition.