Clarification of pathogenic mechanism of PCR and development of the prevention method -a study with rat mandibular distraction model-

本研究采用大鼠下颌骨牵张实验模型，观察不同机械负荷对大鼠下颌骨髁状突形态的影响。10周龄雄性Wistar大鼠经5 d潜伏期后，单侧下颌骨牵张3.5 mm，持续10 d以上，观察牵张后1 d、1周、3周髁状突形态的变化。结果，确认髁突变形，软骨层破坏和骨吸收。这些结果表明，下颌骨髁状突过载是PCR的关键因素。

This study was undertaken to examine the effects of mechanical loadings on the morphology of mandibular condyle following distraction in rat experimental model.10-week-old male Wistar rats received 3.5 mm unilateral mandibular distraction over 10 days after5-day latency period, and the morphological changes of mandibular condyles were examined one day, one week and three weeks after distraction. As a result, the deformation of the condyle with a destruction of cartilage layer and a bone resorption was recognized. These findings indicate thatoverloading to the mandibular condyle is a key factor for PCR.