Maxillary expansion with the memory screw: a preliminary investigation.
10.4041/kjod.2012.42.2.73
- Author:
Koray HALICIOGLU
1
;
Ali KIKI
;
Ibrahim YAVUZ
Author Information
1. Department of Orthodontics, Faculty of Dentistry, Abant Izzet Baysal University, Bolu, Turkey.
- Publication Type:Original Article
- Keywords:
Expansion;
Appliances;
Cephalometrics;
Retention and stability
- MeSH:
Aged;
Hand;
Humans;
Maxilla;
Memory;
Palatal Expansion Technique;
Parents;
Retention (Psychology);
Sutures
- From:The Korean Journal of Orthodontics
2012;42(2):73-79
- CountryRepublic of Korea
- Language:English
-
Abstract:
OBJECTIVE: The purpose of this study was to investigate the effects of a newly developed rapid maxillary expansion screw-the memory screw-over 6 months. METHODS: Five subjects, aged between 11.7 and 13.75 years, were enrolled in this study. All subjects underwent placement of a maxillary expansion appliance containing superelastic nickel-titanium open-coil springs in its screw bed. The parents of the patients and/or the patients themselves were instructed to activate the expansion screw by 2 quarter-turns 3 times a day (morning, midday, and evening; 6 quarter-turns a day). The mean expansion period was 7.52 +/- 1.04 days. Dentoskeletal effects of the procedure, including dentoalveolar inclination, were evaluated. Measurements of all the parameters were repeated after 6 months of retention in order to check for relapse. RESULTS: Sella-Nasion-A point (SNA) and Sella-Nasion/Gonion-Menton angles increased, and Sella-Nasion-B point (SNB) angle decreased in all the subjects during the expansion phase. However, they approximated to the initial values at the end of 6 months. On the other hand, the increments in maxillary apical base (Mxr-Mxl) and intermolar widths was quite stable. As expected, some amount of dentoalveolar tipping was observed. CONCLUSIONS: The newly developed memory expansion screw offers advantages of both rapid and slow expansion procedures. It widens the midpalatal suture and expands the maxilla with relatively lighter forces and within a short time. In addition, the resultant increments in the maxillary apical base and intermolar width remained quite stable even after 6 months of retention.
