A Comparison of the Influence of Hormones, Vitamins, and Other Dietary Factors upon the Formation of Bone, Dentine, and Enamel

Abstract

It would appear that the reactions of bone and dentine are similar under nutritional and endocrine influences as regards changes affecting apposition of tissue. This is seen in avitaminosis A and hypervitaminosis A and during scurvy and rickets. Thyroidectomy and hypophysectomy also affect these tissues in a comparable manner as do also ACTH and cortisone. Both these tissues consist of a calcified collagen, and thus it is not unexpected that these resemblances occur. When changes affecting resorption are considered, however, no resemblance at all is seen because the teeth have no resorptive mechanism. Thus the action of vitamin D after rickets, that of hypervitaminosis D and that of parathyroid extract are quite different on these two tissues. It is possible that changes like those in dentine also occur in bone, but are overshadowed by the resorptive changes. The only way to investigate this would be to use the well-known ia rat, in which bone resorption does not occur in early life, or the manatee, but these animals are not normally available to research workers.