Changes in facial dimensions and relationships between the ages of 5 and 25 years.

The purpose of this study is to quantify the changes in facial dimensions and relationship as well as in standing height which occur between the age of 5 years and adulthood. The total change between the ages of 5 and 25.5 years was arbitrarily divided into three periods of growth: from 5 years to 10 years of age (GP I), from 10 to 15 years of age (GP II), and from 15 to 25.5 years of age (GP III). The subjects included twenty males and fifteen females for whom complete sets of data were available for the period of this study. All subjects had clinically acceptable occlusion and had undergone no previous orthodontic treatment. Descriptive statistics summarized the changes in standing height and the facial parameters for males and females at 5, 10, 15, and 25.5 years of age. The analysis of variance and Duncan's multiple-range test were used for posterior tests of significance in the comparisons between the three periods of growth for each of the parameters and for both males and females. The findings in this investigation indicated that (1) the timing and magnitude of change in the various facial parameters differ during the same growth period as well as between males and females; (2) in general, most of the changes in the various parameters in females occurred in GP I and GP II, whereas in males the changes were relatively distributed over the three periods of growth; (3) changes in GP III for some parameters were of clinically significant magnitude (for example, in females the ratio of anterior face heights decreased significantly in GP III whereas in males a significant increase occurred in Ar-Pog, SNB, and SNPog, while the maxillary and mandibular relationship, the ratio of anterior to posterior face heights, MP-SN angle, and the convexity of the soft-tissue profile continued to decrease significantly during GP III); (4) during GP III, with the exception of standing height and mandibular depth, there were no significant differences in the magnitude of change between 15 and 17 years of age and the change after 17 years of age; and (5) the data provided by this investigation are useful in describing mean trends, but not in predicting changes occurring in both the size and/or relationship of some facial parameters after 15 years of age; the magnitude of these late changes, at least in certain persons, could either beneficially or adversely influence the orthodontic and/or surgical treatment results.