Studies of dental caries,with special reference to internal secretions in their relation to the development and condition of dental enamel

Abstract

A. Do substances in the blood pass from dental pulp into dental enamel of living animals? Hattie L. Heft.

B. Is dental enamel permeable to substances in saliva? Elizabeth C. Franke.

C. Effects of parathyroidectomy and castration on dentition in albino rats. Edgar G. Miller, Jr.

D. Dental effects of feeding glandular tissues to albino rats. Edgar G. Miller, Jr.

E. A new glycoprotein: dentomucoid. Leila Noland.

Decay of teeth, except that arising from trauma, may be due, primarily, to local deficiency in the structure and quality of enamel, or it may result from local specific disintegrative attack on enamel, regardless of normality of the enamel, or it may be caused by both these types of influences. In this series of studies we are endeavoring to ascertain whether “influences from the inside,” such as those of a nutritional type and involving internal secretions, may be responsible factors in the incidence of dental caries.

Impairment of normal nutritive and endocrinic influences, by subtraction, has been induced by extirpation of various glands in albino rats. There were no effects on dentition after thymectomy, thyro-parathyroidectomy, and castration; deficient calcification of the teeth (incisors) followed parathyroidectomy.

Modification of normal nutritive and endocrinic influences, by addition, has been induced by feeding various glands to white rats. Dental calcification appeared to be (a) regularly decreased by oral administration of lymphatic, salivary, or thyroid, gland; (b) regularly increased by oral administration of testicle; and (c) wholly unaffected by oral administration of corpus luteum, parathyroid, pineal, pituitary, spleen, suprarenal, or thymus.

There were no effects on the general condition or dimensions of the teeth in any of the foregoing experiments.

Physiological variation in the composition of the teeth, in albino rats, is relatively slight and not great enough to account for any of the findings that were indecisive.