Effects of Simultaneous Administration of Estrogen and Parathyroid Extract upon Teeth, Periodontium, and Long Bones of Growing Albino Mice

¹ Department of Oral Pathology, Indiana University School of Dentistry, Indianapolis, Indiana

Based upon the findings of a pilot study, this study employed 12 animals per group and was continued for 7 weeks. The estrogen-treated animals received weekly injections for 6 weeks while the parathyroid extract-treated animals were injected daily for 1 week.

It was concluded that estrogen and parathyroid extract, administered individually or in combination, could produce changes in the jaws, periodontium, and long bones, which may be noted and evaluated by histologic and radiographic techniques in the growing, male, albino mouse.

This study indicated that estrogen administration markedly affects the growth of the animals as evaluated by weight gain. However, any appreciable effect of parathyroid-extract administration upon weight gain was not discernible in this study.

Estrogen and parathyroid-extract administration did not produce any obvious histologic or radiographic changes in the periodontal membrane or teeth, except that the incisors of those animals receiving estrogen exhibited an increased radiodensity.

Estrogen produced endosteal bone proliferation in the marrow spaces of the jaws as well as in the long bones of these animals, and there was an associated decrease in the size of the marrow cavity. The proliferation of endosteal bone was accompanied by a fibrous replacement of the hemopoietic tissue, and this phenomenon appeared most prominently in those animals that also received parathyroid extract.

Estrogen administration alone or with parathyroid extract was associated with a marked change in the morphology of the epithelial interdental papillae and chronic gingivitis. This morphologic change was characterized by a flattening of the normal pointed papillae and a thickening of the spinous cell layer.

Parathyroid extract produced or was associated with an increased osteoclastic activity in both jaws and long bones, but this finding was definitely more pronounced in the estrogen-treated animals.