Objective:

The aim of the present study was to evaluate the hard and soft tissue changes following rapid maxillary expansion (RME) and alternate rapid maxillary expansion and constriction (Alt-RAMEC) therapies.

Methods:

A total of 54 patients who needed maxillary expansion or Alt-RAMEC procedure were recruited and divided into two groups (27 subjects in the RME group and 27 subjects in the Alt-RAMEC group). Expansion screw was activated 0.5 mm/day (2 turns/day) in the RME group. Approximately 11 mm of expansion was achieved. In the Alt-RAMEC group, the screw was activated 1 mm/day (4 turns/day) during a period of 4 weeks. In the first and third weeks, the screw was opened; in the second and fourth weeks, the screw was closed. Cephalometric tracing and analyzing were done with the aid of digital software. Lateral cephalometric radiographs were obtained before (T0) and after (T1) RME and Alt-RAMEC applications.

Results:

In the RME group, the maxilla moved forward and downward. Upper incisor retrusion was observed according to the reference planes. In addition, the tip of the nose moved forward, and the upper lip moved downward. In the Alt-RAMEC group, the nasolabial angle became more obtuse, and the stomion superius moved backward and downward.

Conclusion:

RME therapy resulted in skeletal and dental changes in the maxilla and related structures, favoring a contribution to solving Class III problems. No remarkable changes were recorded in the Alt-RAMEC group.

Keywords: RME, Alt-RAMEC, Class III