ObjectivesTo modify the patients of defect of dentition and edentulous jaws, we established a rat model of different bite force for the study, left maxillary molars of Wistar rats were extracted and the left mandibular molar area was used as the model of the bite force lost. We detected the model rats'many kinds of cytokines in the periodontal ligament cells, in order to imitate the conditions of pathological periodontal ligament. The objective was to approach the extent and mechanism of the periodontal lig...