The action of vitamin d upon the incisor teeth of rats consuming diets with a high or low ca:p ratio

Abstract

Vitamin D is one of the factors essential for the proper formation of teeth, and in its absence the same changes are seen that occur in lack of Ca and P. The constantly developing incisor tooth of the rat is a very convenient object for studying the effects of vitamin D upon both the teeth and the body generally, as any change in Ca or P metabolism is immediately reflected in the appearance of the dentin, Erdheim [1911] having aptly compared the rat's incisor with the drum of a kymograph.The effects of massive doses of the vitamin upon the normal rat's incisor have been described by Schour & Ham [1934] and after parathyroidectomy by Schour, Tweedy, Chandler & Engel [1937]. In both instances, the dentin showed a hypocalcified stripe followed by a reactive hypercalcified zone. Downs [1932] described the effects of vitamin D upon the teeth of rats on diets with various Ca: P ratios. The vitamin was incorporated into the diets and thus the effect was prophylactic. He came to the rather unexpected conclusion that the vitamin acted deleteriously with diets with a lowered P content, causing the histological changes to be more marked, but with diets with a lowered Ca content the vitamin acted beneficially.The reaction of the tooth to curative doses of vitamin D after the establishment of well-marked dietary rickets does not, however, appear to have been followed. In the present.paper the effects of the vitamin upon the teeth of rats with rickets caused by diets with abnormally high or low Ca: P ratios are described. Preliminary reports of some of the findings have already been published [Irving, 1941[Irving, , 1943. METHODS AnimalsAlbino rats of the Wistar Institute strain were kept in a special animal house at a temperature of 68-70°. Males and females were used indiscriminately, the results found being the same in both sexes. After weaning at 25 days, the

Early postnatal development of the mandibular permanent first molar in infants with isolated cleft palate

“…Malnutrition in the form of vitamin (e.g. vitamin D) deficiency has for many years been known to influence mineralization negatively 30,31 . Furthermore, studies investigating the influence of general malnutrition/undernourishment in childhood 32,33 have shown a significant relation between malnutrition/undernourishment and delay in skeletal as well as dental maturation/mineralization; however, the delay in dental maturation/mineralization caused by malnutrition/undernourishment is less than that observed for the somatic development.…”

Nuclear uptake of 1,25‐dihydroxyvitamin D3 in developing rodent teeth: An autoradiographic study

“…The role of vitamin D in tooth formation has not been elucidated, although indirect evidence for its importance has been reported. Animals fed vitamin-D-deficient diets developed enamel hypoplasia (Gottlieb, 1920;Mellanby, 1928;Blackberg and Berke, 1932;Howe et al, 1940;Boyle and Wessen, 19431, hypocalcified dentin or increased thickness of predentin (Becks and Ryder, 1931;Boyle and Wessen, 1943;Irving, 1944;Weinmann and Schour, 1945a;Engfeldt and Hammarlund-Essler, 1957;Ferguson and Hartles, 1965;Harrand and Hartles, 1970;Yoshiki et al, 19741, inflammation of pulp (Blackberg and Berke 19321, and delayed tooth eruption (Weinmann and Schour, 1945b). Deciduous teeth, exfoliated from children with vitamin-D-resistant rickets, displayed a defective dentin (Tracy et al, 1971), similar to the findings in rodents.…”

Development and Healing of Rickets in Intramembranous Bone

“…the resorptive side the calcification began in discrete areas which gradually spread along the edge until the whole bone was calcified in a strip along this side. After putting the animals on to the stock diet or adjusting the Ca:P ratio of the diet, this calcification was seen twelve to twenty-four hours later and two days after dosing with vitamin D. On comparing these findings with those from the bones examined with the "line test" and the incisor teeth, it was found, as has been reported already (Irving, 1944(Irving, , 1946, that the teeth reacted first, usually within a few hours of treatment. The "line test" was, in all cases but one, positive later than the reaction in the fundic bone, which is not surprising as it is a relatively crude test compared with histological examination.…”