The Study of Growth - An Invariant Approach to Statistical Analysis of Shapes - page 215

Figure 5.1 Traditional growth series based on longitudinal cephalometric radiographs
from the Bolton-Brush growth Series (Broadbent et al., 1975). Tracings of the x-rays
are superimposed on the landmark sella located in the middle of the pituitary fossa
and oriented on a line that stretches from sella to nasion. The result is an impression
of craniofacial growth as an onion skin-like expansion away from the center of the
skull marked by sella.
between sella and nasion. Common sense indicates that conditions like
these cannot be assumed in the study of growth and research has con-
firmed this (Moyers and Bookstein, 1979; Richtsmeier and Cheverud,
1986). When superimposition or deformation methods are used for
studying growth, the same difficulties that were discussed in the com-
parison of forms ( Chapter 4 ) are encountered. In this chapter we show
how the coordinate system-free method of EDMA can be extended to
the study of growth and the comparison of growth patterns.