Time-lapse observation of rat periodontal ligament during function and tooth movement, using microcomputed tomography
| Autor: | Takashi Oikawa, Kenzo Kawasaki, Shinji Shimoda, Chihiro Arai, Yoshiki Nakamura, Yoshiaki Nomura, Koji Noda |
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| Rok vydání: | 2008 |
| Předmět: |
Molar
Time Factors X-ray microtomography Tooth Movement Techniques Periodontal Ligament Radiodensity Dentistry Orthodontics Imaging Three-Dimensional stomatognathic system Tongue Maxilla Maxillary first molar Animals Medicine Periodontal fiber Longitudinal Studies business.industry Adaptation Physiological Rats Incisor medicine.anatomical_structure Tooth movement Models Animal Orthodontic Appliances Functional Tomography X-Ray Computed business |
| Zdroj: | The European Journal of Orthodontics. 30:320-326 |
| ISSN: | 1460-2210 0141-5387 |
| Popis: | The aim of this study was to observe the time-lapse changes in the rat periodontal ligament (PDL) during function and tooth movement. Under Nembutal anaesthesia, time-lapse changes in the thickness of the PDL of the first molars were investigated in five 12-week-old adolescent rats with microcomputed tomography. Three-dimensional (3D) images were reconstructed from the data. Histological observation was also performed, using undecalcified frozen sections of the maxillary first molar area. The PDL appeared as a radiolucent furrow on the 3D images. A slight change in the thickness of the PDL was observed 1 hour after initiation of orthodontic force loading, which became significant after 6 hours, with the appearance of pressure-tension zones during the tooth movement. These changes were more significant 3 days after orthodontic loading. Histological observation of the lingual cervical PDL (pressure zone) in nine 12- to 13-week-old rats demonstrated that the periodontal space had become narrow and the cellular elements appeared to be densely packed in the narrowed PDL 6 hours after orthodontic loading. Degeneration of tissues appeared 3 days after loading. Observation of the buccal cervical PDL (tension zone) demonstrated that the PDL was extended 6 hours after orthodontic force loading, and the extension continued for up to 3 days. Alkaline phosphatase activity was distributed in the PDL, except for the degenerating tissues in the pressure zone 3 days after loading. The results suggest that the periodontal reaction was initiated within 6 hours after orthodontic force loading, which was related to the structural changes of the PDL. The changes probably induced an early response in individual cells of the PDL. |
| Databáze: | OpenAIRE |
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