OBJECTIVE: To analyze the effect of protein restriction on histomorphometric parameters of bone remodeling in mandibular condyle process and its possible influence in facial development in growing rats. MATERIALS AND METHODS: Wistar rats weaned at the age of 21 days were assigned to one of the following groups: control (fed a regular hard diet ad libitum) and protein restricted (PR) (fed a hard diet lacking in protein ad libitum). The animals were euthanized on day 35 after the onset of the experiment. Mandibles were resected, fixed in 10% formalin, hemisected at the symphysis, and then radiographed in order to perform cephalometric studies of the condylar process length and the height of the lower alveolar process. Mandibles were then processed for light microscopy, and histomorphometric determinations were performed on histologic sections of the condylar process subchondral bone. RESULTS: The PR group showed a significantly lower body weight than control group at the end of the experiment. The length of the condylar process was lower in the PR group; however, the diet used in this study did not affect the height of the lower alveolar process. The histomorphometric analysis showed that the PR group exhibited a statistically significant decrease in bone formation and bone volume in condylar process subchondral bone. CONCLUSION: Protein restriction inhibits bone formation and longitudinal growth in the mandibular condylar process. This result suggest that protein restriction can alter normal facial development.
OBJECTIVE: To analyze the effect of protein restriction on histomorphometric parameters of bone remodeling in mandibular condyle process and its possible influence in facial development in growing rats. MATERIALS AND METHODS: Wistar rats weaned at the age of 21 days were assigned to one of the following groups: control (fed a regular hard diet ad libitum) and protein restricted (PR) (fed a hard diet lacking in protein ad libitum). The animals were euthanized on day 35 after the onset of the experiment. Mandibles were resected, fixed in 10% formalin, hemisected at the symphysis, and then radiographed in order to perform cephalometric studies of the condylar process length and the height of the lower alveolar process. Mandibles were then processed for light microscopy, and histomorphometric determinations were performed on histologic sections of the condylar process subchondral bone. RESULTS: The PR group showed a significantly lower body weight than control group at the end of the experiment. The length of the condylar process was lower in the PR group; however, the diet used in this study did not affect the height of the lower alveolar process. The histomorphometric analysis showed that the PR group exhibited a statistically significant decrease in bone formation and bone volume in condylar process subchondral bone. CONCLUSION: Protein restriction inhibits bone formation and longitudinal growth in the mandibular condylar process. This result suggest that protein restriction can alter normal facial development.