Craniofacial morphology and growth in the rat. Cephalometric analysis of the effects of a low calcium and vitamin D-deficient diet.

The influence of a low calcium and vitamin D-deficient diet on the growth and form of the skull of the growing rat was studied using a cephalometric radiographic technique. First, this technique was used to obtain an intra-individual cephalometric description of the normal growth and form of the skull at different ages during postnatal growth in the rat. It was shown that the methodological error and the biological variation between animals were significantly lower than the registered growth changes, thus demonstrating the suitability of the technique. In the animals fed the low calcium and vitamin D-deficient diet and impaired increase in body weight was found. This diet also caused changes in cranial dimensions, both when the deficient animals were compared with control animals of the same age and with control animals with the same weight. It was concluded that the vitamin D-free and low calcium diet caused a disturbed osteogenesis in growth sites determining the growth and form of the viscerocranium and its relation to the neurocranium.