功能性下颌偏斜对青春期大鼠下颌骨形态影响的初步研究

Effect of functional mandible shift on mandible morphology of pubertal rats

目的探讨功能性下颌偏斜对大鼠下颌骨生长发育的影响。方法选用4周龄雄性SD大鼠48只,随机分为实验组和对照组,每组24只。实验组大鼠上前牙粘结冠套模拟功能性下颌偏斜。分别在7、14、21及28d时各取6只大鼠处死,取左、右下颌骨进行X线摄片、定点,运用图像分析仪测量线距。结果实验第14d起,实验组大鼠下颌骨长度参数(Cd-Me、Co-Me、Go-Me)非偏斜侧明显大于偏斜侧(P<0.05),而下颌骨高度参数(CdH、CoH、MeH)非偏斜侧明显小于偏斜侧(P<0.05);实验组双侧下颌骨长度参数(Cd-Me、Co-Me、Go-Me)和高度参数(CdH、CoH、MeH)均小于对照组(P<0.05)。结论功能性下颌偏斜使下颌骨长度及高度发育不对称,影响下颌骨的正常生长发育,提示功能性下颌偏斜患者应尽早矫治。

Objective To study the effect of functional mandible shift on mandible development in pubertal rats.Methods Forty-eight male Sprague-Dawley rats at the age of 28 d were randomly divided into experimental group （n=24） and control group （n=24）.Maxillary occlusal splints were designed to simulate mandible shift in experimental group.Six rats in each group were killed after 7,14,21,and 28 days,respectively.Right and left mandibles were removed for X-ray radiography and localizing points.Distance between the points was measured with an image analyzer.Results Fourteen days from experiment,the length parameters of the non-shifted mandible（Cd-Me,Co-Me,Go-Me）were significantly higher than those of the shifted mandible length in rats of experimental group（P0.05）,the height parameters of the non-shifted mandible were lower than those of the shifted mandible height（P0.05）,and the length and height parameters of bilateral mandibles were lower in experimental group than in control group（P0.05）.Conclusion The length and height of functionally shifted mandibles in pubertal rats are asymmetry and influence their development,suggesting that patients with functional mandible shift should be treated as early as possible.