Growth pattern of the rabbit snout dorsum: a serial cephalometric radiographic study with radiopaque implants.

Two radiopaque implants were inserted into each (left and right) frontal bone in five female rabbits. Ventrodorsal cephalometric radiographs were then taken in a specially designed head holder at 6 and 16 weeks of age. From these radiographs separate tracings were made on matte acetate paper of the left and right snout including the radiopaque implants. Since the implants maintained the same relationship to each other in each frontal bone, they served as stable reference sites. The markers of the 16 weeks tracing were superposed on the markers of the 6 weeks tracing. The difference in the two established outlines of the snout represented the changes in size and shape in two dimensions that had occurred during the 10 weeks period. The mean increase was 17.91 mm at the distal (anterior) border, 4.95 mm at the lateral border, and 1.22 mm at the medial border. Thus, growth at the lateral border of the snout was about 3 1/2 times that of the lateral border.