The quantitative analysis of facial soft tissues is of overwhelming importance
for orthodontic patients. To assess the normal age-related
variations in shape, soft tissue facial profiles were studied in 96
healthy male children 3 to 11 years of age and 16 young men (age 18).
Standardized left-side photographs were taken of each subject, and
facial profiles were traced between trichion and cervical point. The line
joining the 2 landmarks was set as the baseline, and each outline was
automatically digitized and mathematically reconstructed by a 30-
harmonic elliptic Fourier series expansion. The same soft tissue profile
was traced and digitized from the Bolton standards of comparable
age. All profiles were standardized to the same area, and shape modifications
were quantified by calculating the morphologic distance between
the Fourier reconstructions of each facial profile and of (1) the
18-year-old Bolton standard (MD-18) and (2) the age-related Bolton
standard. Descriptive statistics were computed for each age class. On
average, MD-18 was 7.23 at 3 years of age, increased between 6 and 9
years of age, and decreased hereafter, reaching 6.86 at 18 years of age.
Within-group variability peaked at 8 years of age, and was minimal at
6 and 18 years of age. The current soft tissue child profiles seemed different
from the profile obtained from the Bolton standards.