Exploring the relationship between posture-dependent airway assessment in orthodontics: insights from kinetic MRI, cephalometric data, and three-dimensional MRI analysis

Background Previous studies have assessed the upper airway using various examination methods, such as cephalometric imaging and magnetic resonance imaging (MRI). However, there is a significant gap in the research regarding the relationship between these different imaging modalities. This study compares airway assessments using kinetic MRI and cephalometric scans, examining their correlation with three dimensional (3D) MRI data.
Materials and methods Kinetic MRI, cephalometric scans, and 3D MRI of forty-seven participants were used in the present study. Airway areas and widths were measured at the retropalatal, retroglossal, and hypopharyngeal levels in both kinetic MRI and cephalometric scans. Airway volumes were calculated from 3D MRI data. Statistical analyses, including the Wilcoxon Signed Rank test, Spearman correlation, and multiple linear regression, were performed to evaluate the data and identify significant differences, correlations, and prediction models, respectively.
Results Significant differences were found between kinetic MRI and cephalometric scans. Cephalometric data showed larger airway areas and widths compared to kinetic MRI measurements. Although both cephalometric and kinetic MRI showed a correlation with 3D MRI, kinetic MRI demonstrated stronger correlations with 3D MRI airway volumes than cephalometric scans. According to our linear regression model equations, RPA-Max (maximum retropalatal airway area) and RPA (retropalatal airway area) can elucidate variations in RPV (retropalatal airway volume). RGA-Med (median retroglossal airway area) and RGA-Min (minimum retroglossal airway area) can explain variations in RGV (retroglossal airway volume). HPA (hypopharyngeal airway area) and ULHPAW-Max (maximum upper limit hypopharyngeal airway width) account for variations in HPV (hypopharyngeal airway volume). Additionally, TA-Max (maximum total airway area) can account for variations in TPV (total pharyngeal airway volume).ConclusionBoth cephalometric data and kinetic MRI data showed correlations with 3D MRI data. The shared posture of kinetic MRI and 3D MRI led to stronger correlations between these two modalities. Although cephalometric data had fewer correlations with 3D MRI and predictors for 3D airway volume, they were still significant. Our study highlights the complementary nature of kinetic MRI and cephalometric imaging, as both provide valuable information for airway assessment and exhibit significant correlations with 3D MRI data.