幼年期小型猪髁突骨折后咀嚼肌的变化

EFFECT OF CHILDHOOD MINIATURE PIG FRACTURE OF MANDIBULAR CONDYLE ON MASTICATORY MUSCLE

目的：探讨髁突横断骨折对幼年小型猪咀嚼肌的影响。方法：应用幼年小型猪行髁突横断骨折，术后６个月应用磁共振显像（ＭＲＩ）观察，然后切取双侧咀嚼肌及翼外肌标本进行光镜及透射电镜检查。结果：ＭＲＩ可见双侧咀嚼肌、翼内肌及翼外肌呈中等强度信号，信号均匀，肌间隙层次清晰，双侧对称，无异常信号。光镜观察咀嚼肌和翼外肌横截面切片在不同时间均未显示任何破坏现象，透射电镜下髁突横断骨折后６个月组与正常对照组比较无明显变化，只显示线粒体数目减少、糖原颗粒较多、肌节各带清晰，无异常形态线粒体及脂肪变性。结论：幼年期小型猪髁突横断骨折后６个月咀嚼肌及翼外肌ＭＲＩ、光镜。

Objective:To evaluate the effect of childhood miniature pig transverse fracture of mandibular condyle on masticatory muscle.Methods:Transverse fracture of mandibular condyle was made in childhood miniature.The effect of fracture on masticatory muscle was observed by using MRI six months after the procedure,then both two sides of masticatory muscle were sectioned with light microscopic,transmission electron microscopic observation.Results:Six months after the childhood miniature pig transverse fracture of mandibular condyle,MRI medium sized signal in both two sides in symmetry,no muscle necrosis under light microscope,and decrease of mitochondria,more glycogen granulation,clear myotome were found and no abnormal mitochondria and fatty degeneration under transmission electron microscope were shown.Conclusion:Six months after the childhood miniature pig transverse fracture of mandibular condyle,no pathological change in masticatory muscle was found.