Abstract
Objective
To evaluate and compare the skeletal, dentoalveolar and soft tissue effects of two different alternate rapid maxillary expansion (RMEs) and constriction (Alt-RAMEC) procedures.
Material and methods
Thirty-two consecutive patients presenting with a skeletal Class III malocclusion were placed into two comparative groups. Group 1 consisted of 16 patients (5 females and 11 males; mean age: 11.45 ± 1.87 years) who had an Alt-RAMEC procedure for five weeks and Group 2 consisted of 16 patients (6 females and 10 males; mean age: 11.52 ± 1.29 years) who had an Alt-RAMEC procedure for nine weeks. The parents of the patients were instructed to open the screw twice per day for one week and to close it twice per day for the following week (0.20 mm per turn). Nine angular and 20 linear cephalometric variables were measured.
Results
The groups were well matched in relation to patient gender distribution, chronological age and initial cephalometric values. Both Alt-RAMEC procedures showed similar effects with no statistically significant differences. The maxillae moved slightly forward and the mandible moved slightly downward, the changes of which caused an improvement in the maxillo-mandibular relationship in both groups. The overjet slightly increased and the overbite decreased in both groups. The upper lip moved slightly forward during the nine-week treatment Alt-RAMEC group.
Conclusion
Despite the favourable and similar effects of both procedures, neither seems to be sufficient for the complete correction of a skeletal Class III malocclusion.