Long‐term effects produced by early treatment of Class III malocclusion with rapid maxillary expansion and facemask followed by fixed appliances: A multicentre retro‐prospective controlled study.

Objective: To assess the short‐ and long‐term dentoskeletal effects of early Class III treatment with rapid maxillary expansion and facemask (RME/FM) followed by fixed appliances. Materials and Methods: A total of 44 patients (27 females, 17 males) treated consecutively with RME/FM were included from the archives of 3 centres. Three lateral cephalograms were available: T0 (before the start of RME/FM therapy, mean age 8.1 ± 1.8 years), T1 (immediately after RME/FM, mean age 9.8 ± 1.6 years), and T2 (long‐term observation, mean age 19.5 ± 1.6 years). A control group of 17 untreated Class III subjects (12 females and 5 males) also was selected. Between‐group statistical comparisons were performed with ANCOVA. Results: No statistically significant differences for any of the cephalometric variables were found at T0. In the short term, the treated group showed significant improvements in ANB (+2.9°), Wits appraisal (+2.7 mm), SNA (+1.8°) and SNB (−1.1°). A significant closure of CoGoMe angle (−1.3°) associated with smaller increments along Co‐Gn (−2.4 mm) also was found together with a significant increase in intermaxillary divergence (+1.3°). In the long‐term, significant improvements in ANB (+2.6°), Wits appraisal (+2.7 mm) and SNB (−1.7°) were recorded together with a significant closure of the CoGoMe angle (−2.9°). No significant long‐term changes in vertical skeletal relationships were found. Conclusions: RME/FM therapy was effective in improving Class III dentoskeletal relationships in the short term. These changes remained stable in the long‐term due mainly to favourable mandibular changes. [ABSTRACT FROM AUTHOR]