A cone-beam computed tomography study of hyoid bone position and airway volume in subjects with obstructive and nonobstructive adenotonsillar hypertrophy.

Objectives: To investigate hyoid bone position and airway volume in subjects with adenoid hypertrophy, tonsillar hypertrophy, and adenotonsillar hypertrophy compared to subjects with nonobstructive adenoids or tonsils and to assess the correlation between hyoid bone and airway parameters.

Materials and methods: A total of 121 subjects were grouped based on adenoid or tonsillar hypertrophy into four groups, as follows: (1) control group (C-group), (2) adenoid hypertrophy group (AH-group), (3) adenotonsillar hypertrophy group (ATH-group), and (4) tonsillar hypertrophy group (TH-group). Hyoid bone position and airway volumes were measured. The Kruskal-Wallis test was used for intergroup comparison, followed by pairwise comparison using the Mann-Whitney U-test. Bivariate correlation was conducted using Spearman correlation coefficients. Multiple linear regression was performed to create a model for airway volume based on hyoid bone predictive variables.

Results: No significant difference was found between subjects with isolated adenoid or tonsillar hypertrophy compared to the C-group. However, the ATH-group exhibited a significantly decreased hyoid bone vertical distance (HV), total airway volume (TA volume), and retroglossal airway volume (RG volume) compared to the C-group. HV and age had a high potential in terms of explaining the RG volume, whereas the TA volume and retropalatal airway volume (RP volume) models were not as successful as the RG volume counterpart.

Conclusions: Subjects in ATH-group were characterized by an elevated hyoid bone position and constricted TA volume and RG volume compared to those in the C-group. HV and age were predictor variables that best explained retroglossal airway volume.