| 1298 Tissue Remodeling During Axial Movement of Teeth | ||
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T.G. DIEKWISCH, S. HOLLIDAY, M.T. GALANG, B. SCHNEIDER, and X. LUAN, University of Illinois - Chicago, USA Axial movement of teeth occurs during tooth eruption and can also be induced by orthodontic forces. Objectives: In order to understand the mechanisms and molecular factors involved in axial movement of teeth, we re-visited the classic model of the un-opposed rodent molar originally introduced by Harry Sicher and Joseph-Peter Weinmann at the University of Illinois. Methods: To generate an un-opposed molar situation, left maxillary mouse molar teeth were extracted under anesthesia. Mandibular molars were allowed to super-erupt for 1, 3, 6, 10, 12, and 30 days. To trace areas of tissue remodeling and to determine areas of new tissue formation, mice were injected with fluorescent dyes, tetracycline, alizarin red, calcein blue, and chlor-tetracycline. Subsequent to sacrifice, mandible tissue blocks were prepared for ultrathin ground sections and fluorescent microscopy. A second set of specimen was prepared for RNA extraction and microarray analysis. Results: Labeled tissue sections revealed significant differences in bone and cementum apposition between the experimental and the control side as measured in mid-sagittal cross-section (p<0.001) while periodontal ligament thickness did not change. Von Kossa staining and ground sections revealed mineralized layers of new cellular cementum at the root apex of un-opposed molars. Microarray and RT-PCR analysis demonstrated significant (more than 3-fold) increase in gene expression of proteoglycans, biglycan, brevican, and lumican as well as elastin and FGF9, as revealed by comparison between the experimental and the control group. Conclusion: In this study, the classic model of the un-opposed rodent molar proofed to be a useful model to study tissue dynamics during axial movement of teeth. Our data indicated new formation of bone and cementum in tandem with increased expression of extracellular matrix genes. This study was supported by NIDCR grant DE15425 to TGHD. | ||
| Seq #143 - Factors That Respond to or Influence Orthodontic Tooth Movement 2:00 PM-4:00 PM, Thursday, 10 March 2005 Baltimore Convention Center Exhibit Hall E-F | ||
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