成长期大鼠下颌侧方偏位对髁突及下颌骨形态的影响

目的： 观察下颌侧方偏位对成长期大鼠髁突及下颌骨形态的影响，阐明下颌侧方偏位与下颌骨不对称畸形的关系。方法：选用健康雄性4周龄Wistar大鼠48 只,随机分为实验组24只和对照组24只。于实验组大鼠上颌切牙上黏固有侧方诱导斜面的超硬树脂冠，并于下颌切牙上黏固自制的金属冠，大鼠咬合时下颌被诱导向左侧约2 mm(偏位侧)。于实验开始2、4、8和12周后处死实验组及对照组大鼠，游离大鼠双侧下颌骨。用游标卡尺测量髁突的长度和宽度，通过软X线片定点进行下颌骨形态的测量。结果：实验组大鼠偏位侧髁突软骨长度明显大于对侧(P<0.05)，而髁突软骨宽度两侧无明显差别。实验组大鼠下颌骨不对称，偏位侧下颌骨长度明显小于非偏位侧，高度大于非偏位侧(P<0.05)。实验组大鼠下颌骨的生长方向也受到影响，偏位侧更向前上方生长。结论：下颌侧方偏位导致双侧髁突形状及生长方向的不同，进而导致下颌骨不对称畸形。

Effect of mandibular lateral displacement on morphology of condyle and mandible in growing rats

Objective To elucidate the relationship between mandibular lateral displacement and mandible asymmetry by observing the morphological changes of condylar head and mandible during mandibular lateral displacement in growing rats.Methods Forty-eight male Wistar rats at the age of four weeks were divided at random into experimental and control groups,with 24 rats in each group.A super-hard resin plate was cemented to upper incisors to displace rat mandibles 2 mm to the left during closure(Ipsilateral side).A me...