The long-term efficacy of rapid maxillary expansion and facemask therapy in Class III malocclusion

Aim: The aim of the present study was to investigate the long-term efficacy of rapid maxillary expansion (RME) and facemask (FM) therapy in the treatment of Class III malocclusions by comparing Class III subjects treated by RME/FM mechanics with untreated Class III controls at the Western Australian public dental hospital. Materials and methods: The lateral cephalograms of 42 (26 males, 16 females) Class III patients treated by RME/FM therapy were analysed and compared with a control sample comprised of 23 (14 males, 9 females) untreated Class III patients. Evaluations were carried out prior to facemask therapy and at a long-term follow-up period of approximately eight to nine years post-treatment. Statistical comparisons were performed using t-tests for unpaired data. Results: At long-term follow-up, there were no statistically significant differences between the treated and control groups except in overjet, which was greater in the treated group (p < 0.05). Conclusions: These results suggest that the short-term effects on the maxilla in RME/FM therapy are not maintained in the long term. Success in treatment is largely dependent on the patient’s skeletal growth pattern.