Background/Objectives: In our previous systematic review, we found no convincing evidence to support rapid maxillary expansion (RME) as a treatment for pediatric obstructive sleep apnea (OSA). Subsequent clinical guidelines and expert opinion have continued to recommend this orthodontic treatment. We aimed to update our search to determine whether new controlled prospective evidence alters this conclusion. Methods: We updated our previous systematic review, searching for controlled prospective studies on RME efficacy for pediatric OSA published up to 1st February 2026. Results: Three new randomized clinical trials (RCTs) were identified in addition to the five original studies. Critically, none of the new RCTs included a watchful waiting or supportive care control arm, leaving the sole available comparison against watchful waiting unchanged: a single RCT that found no significant difference in AHI change between RME and observation. Of the remaining new RCTs, two found marginal AHI improvement with RME and one found no significant AHI reduction. Conclusions: The observed AHI improvements in studies lacking an untreated comparator cannot be distinguished from the known potential for spontaneous improvement in growing children. Extreme caution is warranted before recommending RME as a treatment for pediatric OSA.
Fernández-Barriales et al. (Tue,) studied this question.