Can rapid maxillary expansion cause auditory improvement in children and adolescents with hearing loss? A systematic review.

OBJECTIVE: To evaluate whether the use of palatal expansion techniques can influence hearing loss in children and adolescents with previous hearing impairment. MATERIALS AND METHODS: Electronic searches in PubMed, Scopus, Web of Science, The Cochrane Library, Lilacs, OpenGrey, and Google Scholar were performed with a controlled vocabulary and free-text terms relating to palatal expansion and hearing loss. No language or time restrictions were imposed. Clinical trials that focused on human patients treated with rapid or semirapid maxillary expansion in children and teenagers with hearing loss were included. Data extraction was undertaken by two authors, with conflict resolution by a third author. Risk of bias assessment and data extraction were performed on the selected studies. RESULTS: Seventy-four citations were retrieved by the search. Initially, 12 studies were selected according to the eligibility criteria, but three studies were excluded because of the presence of adults, absence of hearing level evaluation, and oversampling, resulting in nine studies. The mean improvement in hearing levels varied from 2 to 19 dB among the studies. The risk of bias varied from low to moderate risk. CONCLUSIONS: The evidence indicated that there was a hearing improvement after maxillary expansion in patients with hearing loss in the evaluated studies, although more controlled and randomized studies are necessary to investigate this issue further.