Effects of maxillary expansion on hearing outcomes in patients with cleft lip and palate: A systematic review

Otological management in patients with cleft lip and/or palate has focused on early interventions such as ventilation tube placement. Improving palatal width and nasal airflow by maxillary expansion may enhance Eustachian tube function. Thus, we aimed to determine whether maxillary expansion therapy had any effect on hearing outcomes in cleft palate patients.

Electronic searches employing defined keywords relevant to hearing impairment and maxillary expansion with no restriction on publication year or status, in adolescent nonsyndromic cleft patients were undertaken in PubMed, Scopus, Web of Science, Ovid MEDLINE, EBSCOhost, The Cochrane Library, LILACS, OpenGrey, and Google Scholar until January 15, 2025. Two authors on the Covidence software performed data extraction. The Methodological Index for Nonrandomized Studies and the Cochrane Risk of Bias tool were utilized to assess the risk of bias of the included studies.

The search retrieved 68 studies, of which four studies finally met the inclusion criteria that included 158 patients with cleft and 26 non-cleft participants. The improvement in hearing threshold varied from 3 to 21 decibels (dB) in the included final studies. Pure tone audiograms and tympanometry were largely used by studies with variations across the types of expanders employed for maxillary expansion. The risk of bias varied from moderate to high risk.

A preliminary analysis suggests that maxillary expansion may help improve hearing outcomes for patients with cleft palate, although the certainty of evidence by GRADE assessment was low to very low. More high-quality studies with randomized designs and extended follow-up are required to validate these conclusions and elucidate their clinical implications.