pISSN 2234-7518
eISSN 2005-372X

Table. 2.

Definition of the cephalometric skeletodental and airway variables

Variable Definition
Skeletodental A-VRP (mm) Distance between point A (A) and vertical reference plane (VRP)
SNA (°) The angle between Sella-Nasion (SN) plane and Nasion-A plane
A-N perp (mm) The shortest linear distance between A and N-perpendicular line
PNS-HRP (mm) Distance between posterior nasal spine (PNS) and horizontal reference plane (HRP)
PNS-VRP (mm) Distance between PNS and VRP
SNB (°) The angle between SN plane and Nasion-B plane
B-N perp (mm) The shortest linear distance between point B and N-perpendicular line
SN-Pog (°) The angle between SN plane and Nasion-Pogonion (Pog) plane
Pog-N perp (mm) The shortest linear distance between Pog and N-perpendicular line
ANB (°) The angle between Nasion-A plane and Nasion-B plane
EMxL (mm) Distance between condylion (Co) and A
EMnL (mm) Distance between Co and Pog
PP-FH (°) The angle between palatal plane and Frankfort horizontal (FH) plane
MP-FH (°) The angle between FH plane and mandibular plane (MP)
LFH (°) The angle between anterior nasal spine (ANS)-geometric left of the ramus (Xi) plane and Xi-protuberance menti (Pm) plane
Overjet (mm) Horizontal distance between incisal edges of maxillary and mandibular incisors
U1-SN (°) The angle between the SN plane and the axis of upper central incisor
U1-FH (°) The angle between the FH plane and the axis of upper central incisor
L1-MP (°) The angle between MP and the axis of lower central incisor
Airway space Hyoid bone H-RGN (mm) Distance between hyoidale (H) and retrognathion (RGN)
MP-H (mm) Distance along perpendicular line from H to MP
H-PTV (mm) Distance along perpendicular line from H to pterygomandibular vertical plane (PTV) line
H-C3Me (mm) Distance along perpendicular line from H to the third vertebrae (C3)-Menton (Me) line
Tongue TGL (mm) Tongue length (distance between base of the epiglottic fold [Eb] and tongue tip [TT])
TGH (mm) Tongue height (maximum height of line perpendicular to Eb-TT line at tongue dorsum)
Td-PP (mm) Distance along perpendicular line from tongue dorsum (Td) to palatal plane
TT-PTV (mm) Distance along perpendicular line from TT to PTV line
Soft palate SPL (mm) Soft palate length (distance between PNS and tip of the soft palate [P])
SPT (mm) Soft palate thickness (maximum thickness of soft palate measured on line perpendicular to PNS-P)
SPA (mm) Soft palate angle (angle between P-PNS and palatal plane)
P-PTV (mm) Distance along perpendicular line from P to PTV line
Pharyngeal airway SPAS (mm) Superior posterior airway space (width of airway behind soft palate along line parallel to gonion [Go]-B plane)
MAS (mm) Middle airway space (width of airway along line parallel to Go-B line through P)
IAS (mm) Inferior airway space (width of airway along Go-B line)
VAL (mm) Vertical airway length (distance between PNS and Eb)
PNS-ad1 (mm) The distance between PNS and Ad1 (the point where PNS-Basion [Ba] line intersects the posterior pharyngeal wall)
PNS-ad2 (mm) The distance between PNS and Ad2 (the point where a line perpendicular to Sella [S]-Ba plane passing through PNS intersects the posterior pharyngeal wall)
Korean J Orthod 2020;50:238~248 https://doi.org/10.4041/kjod.2020.50.4.238
© Korean J Orthod