Effect of Maxillary Skeletal Expansion on Upper Airway Patency and Respiratory Function: A Narrative Review

Abstract

Rapid maxillary skeletal expansion (RME) has been proposed as a treatment for Obstructive Sleep Apnea (OSA), and numerous studies exist on the effectiveness. However, conclusive results have not been obtained. The aim of this narrative review was to identify suitable studies to assess the effectiveness of maxillary skeletal expansion on airway and respiratory function. Studies were identified with the following search strategy: [Palatial expansion technique] AND [Respiratory function test OR pharyngeal volume] through four databases PubMed, Scopus, Cochrane and Google scholar. Inclusion criteria for studies included human in vivo studies and quantitative analysis. In the selected 9 studies, 6 studies primarily assessed function change with RME, and 3 studies primarily assessed dimensional change in the airway, most commonly the transverse dimension of the nasal valve. Not all studies were able to be accessed full-text, and only 4 studies were able to be included in the analysis. The significant increase was noted in the transverse dimension and nasal volume, as well as a decrease in inspiration and expiration resistance during breathing. We could conclude based on the available evidence that there was a positive increase in the volume of the airway, especially when an obstruction was caused due to nasal valve constriction, and reduction in nasal airflow resistance.