The concentration of dietary casein required for normal mandibular growth in the rat.
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.
Bozzini
C
C
Department of Physiology, Faculty of Dentistry, University of Buenos Aires, República Argentina.
Barcelo
A C
AC
Alippi
R M
RM
Leal
T L
TL
Bozzini
C E
CE
D000818:Animals; D001835:Body Weight; D002364:Caseins / Q000008:administration & dosage*; D004044:Dietary Proteins / Q000008:administration & dosage*; D008297:Male; D008334:Mandible / Q000033:anatomy & histology / Q000254:growth & development*; D009929:Organ Size; D051381:Rats; D011919:Rats, Inbred Strains
D002364:Caseins; D004044:Dietary Proteins