A comparison of the sagittal and vertical dentofacial effects of maxillary expansion produced by a memory screw and a hyrax screw
Online veröffentlicht: 30. Juli 2021
Seitenbereich: 31 - 40
Eingereicht: 01. Mai 2015
Akzeptiert: 01. Jan. 2016
DOI: https://doi.org/10.21307/aoj-2020-110
© 2016 Koray Halicioğlu et al., published by Sciendo
This work is licensed under the Creative Commons Attribution 4.0 International License.
Aim
The aim of the present study was to investigate and compare the cephalometric effects of a conventional Hyrax expansion screw and a memory screw on the skeletal and dentoalveolar structures and soft tissues of the face.
Methods
Thirty-two patients with a maxillary transverse deficiency were divided into two groups. A memory-screw group included 17 patients (nine females and eight males), while a Hyrax-screw group was comprised of 15 patients (eight females and seven males). The mean ages of the subjects in the memory-screw and Hyrax-screw groups were 13.00 ± 1.29 and 12.58 ± 1.50 years, respectively. Lateral cephalograms were taken of the patients at the beginning of the treatment (T1), at the end of expansion (T2) and retention periods (T3). The mean expansion period was 7.76 ± 1.04 days in the memory-screw group and 35.46 ± 9.39 days in the Hyrax-screw group. The Shapiro-Wilk Normality test was used to determine whether the investigated parameters were homogeneous. To determine the treatment changes within the groups, a paired
Results
A results summary indicates that mid-palatal sutural opening and subsequent important skeletal and dental expansions were obtained in all patients. The maxilla moved anteriorly and inferiorly in both groups while the mandible rotated inferiorly and posteriorly but to a greater extent in the memory-screw group.
Conclusion
The newly-developed memory expansion screw takes advantage of rapid and slow maxillary expansion protocols. The suture is opened and the maxilla expanded with relatively lighter forces over a shorter time. The RME using the memory screw resulted in similar sagittal and vertical changes to those produced by the Hyrax screw.