Journal of Dental Research, Vol 68, 840-842, Copyright © 1989 by International & American Associations for Dental Research Online Journals
The concentration of dietary casein required for normal mandibular growth in the rat
C. Bozzini, A. C. Barcelo, R. M. Alippi, T. L. Leal and C. E. Bozzini
Department of Physiology, Faculty of Dentistry, University of Buenos Aires, Republica Argentina.
To determine a suitable casein concentration for normal, undeformed
mandibular growth, we placed weanling male rats on diets containing graded
levels of casein between 0% and 30% for 19 days. Some weanlings were killed
so that initial values could be established. Ten linear dimensions
corresponding to the six skeletal units of the mandible were evaluated so
that their growth rates at the end of the experimental period could be
established. Other dimensions were also evaluated for study of the growth
rate of the bone as a whole. The macroscopic growth of the mandible showed
a sigmoidal relationship with dietary casein concentration, most of the
measurements reaching a plateau at 20% casein. Within the skeletal units,
four dimensions corresponding to the alveolar and symphyseal regions did
not change with age and were not affected by the casein content of the
diet. The remaining six dimensions-corresponding to condylar, coronoid,
angular, and basal regions of the mandible-increased with age and were
related positively to dietary casein concentration. Their growth patterns
were not uniform, although all of them reached maximal values when the diet
contained 20% casein. Therefore, deformation of the mandible appears to
occur in rats fed diets with a casein concentration lower than 20%. It
appears that a dietary casein concentration of 20% is required for normal,
undeformed mandibular growth.
