Measurements of facial points during growth utilizing centroids

Abstract

The aim of the present study was to investigate the movement of facial cephalometric points during growth in a vertical and horizontal direction. A sample of 36 lateral skull radiographs were selected from a bigger sample. Half of the radiographs were taken at aged 9 years ± 2 months and the other 18 radiographs were taken at 16 years ± 2 months. The sample was traced and digitized. The computer was able to produce a line joining the centres of the skull, cranium and face CFC (Cranio Facial Centroid line). Fifteen (15) cephalometric points were located for each subject and measured to a horizontal and a vertical line, based on the centre of the cranium and oriented 45° to the CFC. Millimetric measurements were used to calculate ratios. The data were subjected to descriptive statistics and student t-test. The greatest percentage change for the pooled sample was 11.75% upward movement for Nasion (SD± 17.90) and 11.46% downward movement for Gonion (SD ± 3.25). Horizontally, the greatest forward movement was for point A, maxillary and mandibular central incisors, point B, pogonion, Menton, Gnathion and Gonion. There was significant difference between girls and boys in the vertical direction for point B, pogonion, Gnathion and Menton. While in the horizontal direction, significant differences were found for ANS, point A, Apex and tip upper and lower incisor, point B, pogonion, Gnathion, Menton and Condylion.