The Separate Effects of Protein and Calorie Malnutrition on the Development and Growth of Rat Bones and Teeth

Abstract
The effects of a specific protein malnutrition on the growth and development of rat teeth as well as bones were studied. The nutritional stress was imposed during the suckling period which is the time when first and second molars are actively mineralizing. Rat dams were fed a low protein (7%) diet so as to induce a protein-calorie deficiency in the suckling pups. Control rats were offered a diet containing 25% casein. Suckling pups from these groups were then given by intubation either distilled water or isocaloric supplements containing either nonprotein calories or protein. A specific protein deficiency was thus successfully imposed on the suckling pups during this critical period for tooth development. Protein deficiency limited the growth of incisors and molars and delayed eruption, but had no effect on tooth mineral composition. Such tooth changes are of great significance as teeth are not capable of repairing and compensating for these effects which, consequently, may be responsible for the increased caries susceptibility previously demonstrated under the same experimental conditions.