[Microvasculature of the dog's periodontal ligament and its immediate response to orthodontic forces].
The purpose of this study was to examine the microvascular architecture of dog's periodontal ligament (PDL) and its immediate response to horizontal orthodontic force. A force of 200 g was applied mesially to the mandibular premolar of a dog for 2 hours, the distal side served as the contrast side. Formalin ink was perfused into the carotid arteries bilaterally through the cannulas. After perfusion the mandible was decalcified, celloidin embedded, serially sectioned and stained with eosin. The sections were then observed by light microscope and analyzed by image analyzer. Vascular corrosion casts were prepared by the similar way with the formalin ink perfusion and examined by scanning electron microscope. The results showed: there were extensive interconnections among the PDL, dental pulp, gingiva, alveolus and the neighbour tooth PDL, which would benefit the maintenance of health and functions of the dental pulp and the periodontal tissues. Arterioles and venulae could be confirmed by the presence of characteristic differences of nuclear impressions in endothelial cell under the scanning electron microscope. The quantitative analysis showed that the tensioned PDL sites in the experimental group had a higher microvascular volume density than the corresponding sites in the contrast group, while the pressed PDL sites in the experimental group had a lower microvascular volume density than the corresponding sites in the contrast group. This should result from the hydraulic mechanism in the PDL.
He
T
T
Department of Orthodontics, Stomatology Hospital, China Medical University.
Deng
Y
Y
D000818:Animals; D001696:Biomechanical Phenomena; D004285:Dogs; D005260:Female; D008297:Male; D008833:Microcirculation / Q000502:physiology / Q000648:ultrastructure; D008963:Molar; D009970:Orthodontics; D010513:Periodontal Ligament / Q000098:blood supply*; D011897:Random Allocation