Interrrelationships of varrious facial axes, anterior and posterior facial heights

Objective: This was a cephalometric study to determine if any association exists between various facial growth axes, chin position, anterior and posterior face heights in Angle Class II division 1 malocclusion. Methods: Cephalometric headfilms of 84 Class II division 1 pretreatment patients were selected with a mean age of 8.7 years and a SD of 1.9 years. Age cephalometric landmarks (Ba, S, N, M, Ans, Pg, Ar, Gn) and planes (facial, BaNM, FH], RIL, XY, NSGN and ConAxis were used. Landmarks to FH were projected at right angles to a plane perpendicular to FH for vertical relations. Coben's coordinate analysis was used. Angles, linear and proportional dimensions were determined with correlation coefficients and p values used to evaluate the data with significance determined only when the confidence level was less than p<0.05. Results: ConAxis, XY and RIL angles maintain a positive correlation to each other and a negative correlation to Y and NSGn angles. RIL and ConAxis demonstrate no significant correlation to facial depth while Y and NSGN indicate negative correlation. Height proportions as related to cranial depth (BaN) have a positive correlation with Y and NSGn correlation to NM and negative with the others The only correlation when relating to proportional posterior face height (SGo%BaN) was found with a negative correlation of the condylar axis, as proportional face height decreases the condylar axis becomes more acute. Conclusions: Condylar axis does not appear to have a significant relationship top facial depth, but maybe a better indicator of the vertical proportional components relative to cranial depth and maybe more closely related to the XY and RIL. NSGn and Y axes could be considered interchangeable.