Most of this chapter will be concerned with bones and teeth which share a common embryological origin. The Fels studies of these organs will be grouped as follows: (i) skeletal growth, (ii) growth of specific skeletal regions, (iii) skeletal variations, (iv) skeletal mass, and (v) teeth.

Skeletal growth

Studies of skeletal growth at Fels have attempted to determine the amounts of growth at specific locations and to examine changes in overall dimensions such as length and width. In an early attempt to establish a natural bone marker for use in studies of bone elongation, based on serial radiographs, Pyle (1939) observed the nutrient foramen of the radius. She found the groove leading to the foramen made it difficult to locate a fixed radiographic point, although the foramen could be recognized in about 90% of radiographs of children. Some difficulties were associated with the presence of multiple nutrient foramina in about 20% of radii and the changing location of points at the external end of the obliquely aligned nutrient canal as the cortex thickened. This interesting exploratory study did not establish the nutrient foramen as a suitable fixed point from which length measurements could be made.

Fels data have been analyzed to provide reference data derived for bone lengths and widths measured in serial radiographs. Garn et al. (197293) presented such data for the bones of the hand at annual intervals from 2 through 18 years. These workers defended the use of Fels data on the basis that these data were derived from a well-nourished contemporary population and, therefore, they should be applicable fairly generally to US whites.