A PROPORTIONAL ANALYSIS OF SOME FACIAL HEIGHT AND DEPTH VARIABLES IN 10-YEAR-OLD TO 16-YEAR-OLD CHILDREN

A method for analysing the horizontal and vertical proportions of the face is described, based on natural head orientation (NHO). It demonst rates how individual deviations from the mean proportions can be quant ified both horizontally and vertically. Correlation between facial dep th to height (index 1) and the mandibular plane angle was determined a nd found to be fairly strong and highly significant (r = 0.5, P < 0.00 1). Facial depth to height and lower facial height to total facial hei ght (index 2) relationships were found to be strongly correlated at ea ch age between 10 and 16 years, with only small mean differences. For this reason the norm values presented for 12-year-old children for ind ices 1 and 2 should be applicable to orthodontic patients within this age range. The relationship between mandible and maxilla (index 3) inc reases continually between 10 and 16 years in boys, and between 10 and 14 years in girls, about 0.3 units a year. It can provide supplementa ry information for individual case analysis. For boys the increase was 2.2 units per year between 14 and 16 years of age.