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Buccal Alveolar Bone changes and upper first molar displacement after maxillary expansion with RME, Ni-Ti leaf
M Maschio1, F Gaffuri1, A Ugolini2
1Department of Biomedical Surgical and Dental Sciences, University of Milan, Milan, Italy - Fondazione IRCCS Cà Granda, Ospedale Maggiore Policlinico, Milan, Italy.
Aim:
To evaluate the buccal alveolar bone changes and the upper first molar displacement in subjects treated with conventional rapid maxillary expansion (RME), Ni-Ti leaf springs expander (Leaf Expander) and Tooth-Bone-borne Expander (Hybrid Expander) using CBCT scans.
Methods:
The sample consisted of 52 children treated with RME (n=18), Leaf Expander (n= 17) and Hybrid Expander (n= 17). CBCTs were taken before and after maxillary expansion and the Horos software was used for the analysis. Descriptive statistics and paired t-test were used to assess changes between the pre-treatment and post-treatment measurements. ANOVA test and Tukey's post hoc test with Bonferroni correction was used for between groups comparison.
Conclusion:
The Hybrid Expander during preadolescence showed few advantages over the use of tooth-anchored expanders. An expansion approach with mini-screws is not preferable during early mixed dentition to a conventional approach. The differences in dental tipping values were clinically insignificant and the reduction in cortical bone thickness remained less than 1 mm. When possible, the use of second primary molars as anchorage should be preferred.
