Correlation between the position of hyoid bone and subregions of the pharyngeal airway space in lateral cephalometry and cone beam computed tomography

Abstract

Objective: To correlate the pharyngeal airway subregions with the positioning of the hyoid bone.

Material and methods: The study examined 107 lateral cephalometric (LC) and cone beam computed tomography (CBCT) images. Linear and volumetric measurements of the pharyngeal subregions were made and correlated to linear measurements using hyoid triangle analysis on images of LC and multiplanar (MPR) and three-dimensional (3D) reconstructions of CBCT.

Results: There was significant correlation between linear measurements of the pharyngeal subregions and hyoid bone position in LC images and in MPR and 3D reconstructions of the CBCT. Correlations were more frequent in the oropharynx and hypopharynx, especially for LC images. No correlations were observed between LC images or CBCT reconstructions and the volumetric measurements of the pharyngeal subregions and the position of the hyoid bone.

Conclusion: The hyoid bone position showed more correlations with oropharynx and hypopharynx airway measurements. The hyoid triangle method was not applicable to 3D images, since it showed a smaller number of measures correlated to the hyoid bone position.

Keywords: Cone beam computed tomography; Hyoid bone; Pharynx; Radiography.

Figure 1.

Points: (A) Dental (B) S. (C) N. (D) 3D reference sagittal plane.

Figure 2.

1= Nasopharynx, 2= oropharynx, and 3= hypopharynx. (A) LC. (B) MPR. (C) 3D reconstruction of CBCT. (D) 3D segmentation for determination of volume.

Figure 3.

Hyoid triangle: (1) C3-RGn, (2) C3-H, (3) H-RGn, (4) H-H', (5) HP Angle, (6) AA-PNS, (7) dhoriz-H, (8) H, (9) HP-BaN, (10) HPPP. (A) LC. (B) MPR. Featured image: maximum intensity projection (MIP) for demarcation of the HP and dvert-H angles. (C) 3D reconstruction of CBCT.