Expression of EGFR on the rat gingival eqithelia during the experimental tooth movement

Lee, Sang Seon; Kim, Young Ho; Bae, Chang

Abstract

The purpose of this study id to investigate the change of the EGFR mRNA expression in the rat gingival epithelium by the experimental tooth movement. We applied reciprocal force between the upper anterior teeth using NiTi open coil spring and stainless steel wire for 1, 2 3, 7 days. For the detection of EGFR mRNA, in situ hybridization was done in the tissue samples which were taken from the pressure and tension sides of teeth. The results were as follows; 1. The expression of EGFR mRNA was increased application-time dependently. a Day 1: mild expression on the basal and spinous cell layers. b. Day 2: moderate expression on the whole layers. c. Day 3: severe expression on the basal and spinous cell layers. d. Day 7: severe expression on the whole layers 2. The expression level of EGFR mRNA in the pressure and tension sides were similar during the whole period of experiment except seven day application at which the cornified layer of the tension side showed moderate expression. 3. Removal of the appliance after 7-day force application lowered the level of EGRF mRNA expression. It was returned to the mild and control (rare) level at three and seven days after the removal, respectively. In conclusion, EFGR mRNA was increased by, the experimental tooth movement on the rat ginigval epithelium. Up-regulation of EGFR mRNA in the gingival epithelium can be regarded as responses to the possible changes caused byy the physical stersses to the oral environment to maintain the homeostatic conditions of the periodontium.