咬合紊乱对颞下颌关节盘厚度的影响

The effect of occlusal disorder on the thickness of temporomandibular joint disc

目的 :探讨咬合紊乱对颞下颌关节盘厚度的影响。方法 :12具尸体的 2 3侧颞下颌关节 ,5具尸体有以下咬合紊乱特征之一设为咬合紊乱组 :后牙缺失久未修复造成的邻牙倾斜、对颌牙伸长 ;第三磨牙因无对牙合牙而伸长 ;个别后牙的反牙合或锁牙合。 7具尸体没有上述表现者设为对照组。TMJ石蜡切片 ,HE染色观察。动物实验 :18只新西兰大白兔 ,9只以固定矫治技术将第一前磨牙拉向其近中的自然间隙 ,形成渐进性咬合紊乱 ,另 9只作对照 ,3个月后TMJ切片观察。结果 :尸体解剖及动物实验均表明 ,咬合紊乱组关节盘明显厚于对照组 (P <0 .0 5 )。结论 :关节盘可随咬合紊乱而作厚度方面的改建。

Objectives: To investigate the effects of cent ra l disordered occlusion on the thickness of TMJ disc. Methods:The thickness of temporomandibular joint disc was measured in 5 cadavers with centr al disordered occlusion, including secondary malocclusion caused by loss of post erior tooth for a comparable long time with collapse of neighbor teeth and supra -eruption of its antagonized tooth, the supra-erupted third molar resulted fro m lack of antagonized tooth for a comparable long time and individual posterior tooth cross bite or reverse cross bite asymmetrically. Other 7 cadavers without central disordered occlusion served as controls. All samples were examined histo logically for the TMJ disc thickness. Out of 18 New Zealand rabbits, aged 5 mont hs, 9 were treated orthodontically to pull the first premolar move medially, occ luding with its opposite un-coincidently, central disordered occlusion was grad ually induced. The other 9 rabbits served as blank controls. The TMJs were sampl ed 3 months after beginning of the experiments, stained with HE and observed und er microscope. Results: In both cadavers and animals, the TMJ di sc was found much thicker in central disordered occlusion group than that in the control group (P<0.05). Conclusion: The disc can be reconst ructed by changing its thickness in response to central disordered occlusion.