Table 1

Definitions of measurements on scan images

Measurement	Abbreviation	Definition
Parameters measured in post-coronal plane
Posterior nasal width	PNW	Maximum width of the posterior nasal cavity
Posterior midpalatal suture width	PMW	Distance between lower margins of medial limits of bilateral palatine processes
Posterior alveolar width	PAW	Distance between CRs of bilateral molars
Inter-molar width	IMW	Distance between central fossae of the bilateral molars
L/R molar angle	L/R_MA	Angle between the central fossa-CR line of the L/R molar and the horizontal plane
Parameters measured in the pre-coronal plane
Anterior nasal width	ANW	Maximum width of the anterior nasal cavity
Anterior midpalatal suture width	AMW	Distance between lower margins of medial limits of bilateral palatine processes
Anterior alveolar width	AAW	Distance between CRs of bilateral premolars
Inter-premolar width	IPW	Distance between central fossae of the bilateral premolars
L/R premolar angle	L/R_PA	Angle between the central fossa-CR line of the L/R premolar and the horizontal plane