Cephalometric growth analyses of the human upper face region during the last two trimesters of gestation This investigation was supported, in part, by research grant HD 00178 from the National Institute of Child Health and Human Development, National Institutes of Health, USPHS.

Abstract

This study was designed to demonstrate quantitative growth trends in the human upper face region before birth. Photographs of 68 sagittally sectioned fetal heads were measured using a series of linear and angular measurements for changing height, length and shape. Cross-sectional types of data were treated with a statistical model which tested for linearity of the data, correlation between growth changes and increasing fetal age, significance of the differences between rates of change in related upper face regions and the general significance of the trends shown in the study. Pooled data for the second and third trimesters suggested three distinct growth trends. Linear measurements of the cranial base, nasal area, and plate correlated significantly with increasing crown-rump length. Finally, a composite upper face profile for the sample suggested a relative migratio of the region downward and forward away from the anterior cranial base and the hypophyseal fossa. These three trends collectively demonstrated that the pattern of upper facial growth before birth involves progressive enlargement of a relatively static profile. It should be understood that this pattern is a group trend as shown by cross-sectional sampling of many individuals over a period of time with no individual being measured more than once. Conversely, variabilities in a specific individual's growth are most appropriately demonstrated by measuring that individual several times throughout some time span, i.e., by longitudinal sampling. Studies of the human fetus are restricted generally to the cross-sectional sampling technique. The close similarly of these prenatal trends with those reported for postnatal craniofacial growth suggests that certain patterns of facial growth in childhood can be seen as early as the beginning of the fetal period and emphasizes the continuum of human development.