Skip to main content

Table 1 Explanation of the landmarks and measurements

From: Three-dimensional evaluation of hyoid bone position in nasal and mouth breathing subjects with skeletal Class I, and Class II

Measurement

Definition

Interpretation

H-Me

The distance between hyoid bone and Menton point

Hyoid bone position in relation to the mandible

H-EB

The distance between hyoid boneand Epiglottis point

Hyoid bone position in relation to the epiglottis

C3-H

The distance between the 3rd cervical vertebrae and hyoid bone

Hyoid bone position in relation to the 3rd cervical vertebrae

C3-Me

The distance between the 3rd cervical vertebrae and Menton point

This line forms the hyoid bone triangle combined with H-Me line, and C3-H line

H-C3Me

The perpendicular line from hyoid bone to the line connecting the 3rd cervical vertebrae and Menton point

The vertical height of the hyoid bone triangle. A positive value indicated a downward direction of the hyoid triangle, and a negative value indicated an upward direction of the hyoid triangle

H-PNS

The distance between hyoid bone and PNS point

Hyoid bone position in relation to the maxilla

H–H

The perpendicular distance running from hyoid bone to a vertical line extending from the Sella point

Horizontal position of hyoid bone

H-V

The perpendicular distance running from hyoid bone to a horizontal line extending from the Sella point

Vertical position of hyoid bone

  1. H, the most superior point of hyoid bone; Me, Menton; EB, epiglottis base; C3, the most supero-anterior point of the 3rd cervical vertebrae; PNS, posterior nasal spine; S, Sella