Longitudinal study of cranio-facial growth (circular analysis)

Abstract

A longitudinal study of growth statistically was performed by superimposition on the tracings of 41 individuals, at 6, 9, 12 and 20 years of age from the sample of the Burlington Growth Centre, University of Toronto, Canadá. With a new approach in cefalometrics, named Circular Cephalogram. The Basion is it registration point and the centre of a circle that inscribes the face and the skull where lines like radii are joining the Basion to more external anatomic points. The Circular Cephalogram with origin in the basion point was proposed mainly because most classics cephalograms show by superimposition the cranial base displaced backwards and downwards which doesn't correspond to reality as the cranial base cannot grow against the cervical column that grows in the oposite direction that is upwards. The superimposition in the Basion point is assumed that shows better the actual direction of the face growth, as the unfolded growth of any part of the body goes in a radial way, where the inner part is always smaller than the external one. Angular measures were effected; in the angles created by the tines of junction of the anatomic or virtual points to the Basion in all cephalograms of the sample and averages obtained. The "t" test has been used for the comparison of the averages. It was not found any significant variation at the level of alpha=0.05 and 0.01. It was also found, by the Pearson's coeficient of the variation, that the averages represent the sample.