[The temporal and spatial expression of CBFalpha1 in rabbit condylar cartilage during forward mandibular positioning].

Purpose: To identify the relationship between the expression of Core binding factor alpha1 (Cbfalpha1) in condylar cartilage and condylar growth modifications in growing rabbits following forward positioning mandibles with functional appliance.
Methods: Sixty rabbits with age of 8 weeks were randomly divided into the experimental group (n=36) and control group (n=24). Rabbits in the experimental groups were induced to forward their mandibles by a functional appliance. The animals in the two groups were killed after 3 days and 1, 2, 4, 8 and 12 weeks, respectively. The temporal and spatial expression of Cbfalpha1 in condylar cartilage was examined by immunohistochemical staining and measured with Image Computer Analysis Software. Date was statistically analyzed by Student's t test and one-way ANOVA.
Results: The expression of Cbfalpha1 was mainly found in the chondrocytes from the transitive zone and hypertrophic zone, and was also observed in the chondrocytes and osteoblasts of the mineralized zone. Compared with those of the age-matched controls, the positive signals for Cbfalpha1 of each zone in the experimental animals were significantly stronger (P<0.05), and the highest expression of transitive zone, hypertrophic zone and mineralized zone was detected after 4 weeks of treatment (71.00+/-1.52, 50.00+/-0.75, 82.00+/-0.39).
Conclusion: The pattern of Cbfalpha1 expression is concerned with the adaptive remodeling of the condylar cartilage after functional appliance.