成长期大鼠下颌侧方偏位对髁突及下颌骨形态的影响  

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

作　　者：刘畅[1] 王金蕊[2] 李青山[3] 

机构地区：[1]吉林大学口腔医院正畸科,吉林长春130041 [2]吉林大学口腔医院牙体牙髓病科,吉林长春130041 [3]吉林大学口腔医院放射线科,吉林长春130041

出　　处：《吉林大学学报（医学版）》2009年第5期888-892,共5页Journal of Jilin University：Medicine Edition

基　　金：吉林省卫生厅重点实验室科研基金资助课题(2008Z010)

摘　　要：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。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 metal crown was fitted to lower incisors. The rats were killed 2, 4, 8 or 12 weeks after appliance attachment. The mandible was dissected out and halved. The length and width of condylar head were measured with a caliper. Radiographic films of the mandibles were exposed, and selected measurements were made. Results The length of condylar cartilage on the ipsilateral side was significantly larger than contralateral side in experimental group （P〈0. 05）, while there was no significant difference between two sides for the width of condylar cartilage. The experimental rats developed an asymmetric mandible, significantly shorter in horizontal dimension but longer in the vertical dimension on the ipsilateral side （P〈0.05）. The growth direction of mandible was also affected in experimental group with a more forward and upward growth on ipsilateral side. Conclusion The different shape of condylar cartilage and growth direction of mandible induced by mandibular lateral displacement on bilateral sides can be ascribed to the asymmetry of mandibular bone on two sides.

关 键 词：髁突软骨 下颌骨 下颌侧方偏位 形态学 

分 类 号：R78[医药卫生—口腔医学] R332[医药卫生—临床医学]