The effects of protein malnutrition, both in utero and prior to weaning, on formation of the first mandibular molars were evaluated by phase-contrast and electron microscopy in rats. The nourished group (GI) received a diet that included 20% casein, while the malnourished group (GII) received 5% casein. The first mandibular molars from GII exhibited low density of cells and odontoblasts, which lacked regular organization compared with molars from GI. In addition, a difference in collagen type was observed between the groups, with a prevalence of Type III collagen fibers detected in the dentin, periodontal ligament, and alveolar bone of GII, and a prevalence of Type I collagen fibers in GI. Finally, examination of surface area in molar sagittal sections indicated 30% less dentin in GII, compared with GI. Our results suggest that structural and ultra-structural features of the dentin-pulp complex and periodontal components of rat molars are affected by protein deficiency.

The effects of protein energy deprivation (PED) on trigeminal ganglion sectional area, neuronal density, number of neurons/section, neuronal body area and neuronal nucleus area were evaluated. The protein deprivation prenatally and for 21 days postnatally leads to reduce body weights (40% of control weights) and an increase in the number of neurons/section (35% more than control). Most neuron perikarya were within 400-600 m 2 (53,7%) in protein-deprived animals and 600-900 m 2 (48,2%) in the control group. Rows of neuronal bodies were separated by bundles of nerve and collagen fibers in both groups. Ganglionic neurons from both groups contained cytoplasmic Nissl's corpuscles and spherical nuclei with eccentric and large nucleoli. The elongated nuclei of the fibrocytes revealed the main axis oriented parallel to the bundles nerve fibers. By scanning electron microscopy, the structure of the ganglion from both groups was found to be similar.